Move stuff around

WIP

README.md

@@ -1,21 +1,21 @@
-
 # Schala - a programming language meta-interpreter
 
-Schala is a Rust framework written to make it easy to
+Schala is a Rust framework written to make it easy to create and experiment
-create and experiment with toy programming languages. It provides
+with toy programming languages. It provides a cross-language REPL and
-a common REPL, and a trait `ProgrammingLanguage` with provisions
+provisions for tokenizing text, parsing tokens, evaluating an abstract syntax
-for tokenizing text, parsing tokens, evaluating an abstract syntax tree,
+tree, and other tasks that are common to all programming languages.
-and other tasks that are common to all programming languages.
 
-Schala is implemented as a Rust library `schala_lib`, which provides a
+Schala is implemented as a Rust library `schala-repl`, which provides a
-`schala_main` function. This function serves as the main loop of the REPL, if run
+function `repl_main` meant to be used as the equivalent of main() for library
-interactively, or otherwise reads and interprets programming language source
+users. This function parses command-line arguments and either runs an interactive
-files. It expects as input a vector of `PLIGenerator`, which is a type representing
+REPL or interprets a program non-interactively.
-a closure that returns a boxed trait object that implements the `ProgrammingLanguage` trait,
-and stores any persistent state relevant to that programming language. The ability
-to share state between different programming languages is in the works.
 
-## About
+Individual programming language implementations are Rust types that implement
+the `ProgrammingLanguageInterface` trait and store whatever persistent state is
+relevant to that language. The ability to share state between different
+programming languages is in the works.
+
+## History
 
 Schala started out life as an experiment in writing a Javascript-like
 programming language that would never encounter any kind of runtime value
@@ -60,6 +60,7 @@ of learning how to write a programming language.
 https://skillsmatter.com/skillscasts/10868-inside-the-rust-compiler
 https://www.youtube.com/watch?v=il3gD7XMdmA
 http://dev.stephendiehl.com/fun/006_hindley_milner.html
+https://rust-lang-nursery.github.io/rustc-guide/type-inference.html
 
 ### Evaluation
 *Understanding Computation*, Tom Stuart, O'Reilly 2013
@@ -69,6 +70,7 @@ http://dev.stephendiehl.com/fun/006_hindley_milner.html
 ### Parsing
 http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/
 https://soc.github.io/languages/unified-condition-syntax
+http://www.lihaoyi.com/post/ZeroOverheadTreeProcessingwiththeVisitorPattern.html?a=1
 
 [Crafting Interpreters](http://www.craftinginterpreters.com/)
 
@@ -77,4 +79,5 @@ http://blog.ulysse.io/2016/07/03/llvm-getting-started.html
 
 ###Rust resources
 https://thefullsnack.com/en/rust-for-the-web.html
+
 https://rocket.rs/guide/getting-started/

TODO.md

@@ -1,6 +1,19 @@
 
 # TODO Items
 
+-Plan of attack:
+  -write a visitor pattern for AST
+  -convert AST type to including SourceMap'd wrappers (w/ .into())
+    -at the same time, amke sure the visitor pattern "skips over" the SourceMap'd stuff
+    so it can just care about AST structure
+
+- AST : maybe replace the Expression type with "Ascription(TypeName, Box<Expression>) nodes??
+- parser: add a "debug" field to the Parser struct for all debug-related things
+
+-scala-style html"dfasfsadf${}" string interpolations!
+
+-fuzz test schala
+
 
 *A neat idea for pattern matching optimization would be if you could match on one of several things in a list
 ex:
@@ -101,10 +114,7 @@ type enum {
 
 
 
-- AST : maybe replace the Expression type with "Ascription(TypeName, Box<Expression>) nodes??
-- parser: add a "debug" field to the Parser struct for all debug-related things
 
--scala-style html"dfasfsadf${}" string interpolations!
 
 *Compiler passes architecture
 

schala-lang/language/src/ast.rs

@@ -1,5 +1,7 @@
 use std::rc::Rc;
+use std::convert::From;
 
+use source_map::{SourceMap};
 use builtin::{BinOp, PrefixOp};
 
 #[derive(Debug, PartialEq)]
@@ -63,6 +65,12 @@ pub enum Variant {
 #[derive(Debug, PartialEq, Clone)]
 pub struct Expression(pub ExpressionType, pub Option<TypeIdentifier>);
 
+impl From<Expression> for SourceMap<Expression> {
+  fn from(node: Expression) -> Self {
+    SourceMap { node, data: None }
+  }
+}
+
 #[derive(Debug, PartialEq, Clone)]
 pub enum TypeIdentifier {
   Tuple(Vec<TypeIdentifier>),
@@ -111,10 +119,18 @@ pub enum ExpressionType {
   },
   Lambda {
     params: Vec<FormalParam>,
+    type_anno: Option<TypeIdentifier>,
     body: Block,
   },
   ListLiteral(Vec<Expression>),
 }
+
+impl From<ExpressionType> for SourceMap<ExpressionType> {
+  fn from(node: ExpressionType) -> Self {
+    SourceMap { node, data: None }
+  }
+}
+
 #[derive(Debug, PartialEq, Clone)]
 pub enum Discriminator {
   Simple(Expression),

schala-lang/language/src/ast_visitor.rs

@@ -0,0 +1,157 @@
+use std::rc::Rc;
+
+use builtin::{PrefixOp, BinOp};
+use ast::*;
+
+pub fn dispatch<V: ASTVisitor>(visitor: &mut V, ast: &AST) {
+  for statement in ast.0.iter() {
+    match statement {
+      Statement::ExpressionStatement(e) => {
+        dispatch_expression(visitor, e);
+        visitor.expression(e);
+      },
+      Statement::Declaration(decl) => {
+        dispatch_declaration(visitor, decl);
+        visitor.declaration(decl);
+      },
+    };
+    visitor.statement(statement);
+  }
+  visitor.ast(ast)
+}
+
+fn dispatch_expression<V: ASTVisitor>(visitor: &mut V, expression: &Expression) {
+  match expression {
+    Expression(expr, maybe_anno) => {
+      match expr {
+        ExpressionType::NatLiteral(n) => visitor.nat_literal(n),
+        ExpressionType::FloatLiteral(f) => visitor.float_literal(f),
+        ExpressionType::StringLiteral(s) => visitor.string_literal(s),
+        ExpressionType::BoolLiteral(b) => visitor.bool_literal(b),
+        ExpressionType::BinExp(binop, lhs, rhs) => visitor.binop(binop, lhs, rhs),
+        ExpressionType::PrefixExp(prefix, expr) => visitor.prefixop(prefix, expr),
+        ExpressionType::TupleLiteral(v) => visitor.tuple_literal(v),
+        ExpressionType::Value(v) => visitor.value(v),
+        ExpressionType::NamedStruct { name, fields } => visitor.named_struct(name, fields),
+        ExpressionType::Call { f, arguments } => visitor.call(f, arguments),
+        ExpressionType::Index { indexee, indexers } => visitor.index(indexee, indexers),
+        ExpressionType::IfExpression { discriminator, body } => visitor.if_expression(discriminator, body),
+        ExpressionType::WhileExpression { condition, body } => visitor.while_expresssion(condition, body),
+        ExpressionType::ForExpression { enumerators, body } => visitor.for_expression(enumerators, body),
+        ExpressionType::Lambda { params, type_anno, body } => visitor.lambda_expression(params, type_anno, body),
+        ExpressionType::ListLiteral(items) => visitor.list_literal(items),
+      }
+      visitor.anno_expr(maybe_anno);
+      visitor.expr_kind(expr);
+    }
+  }
+}
+
+fn dispatch_declaration<V: ASTVisitor>(visitor: &mut V, declaration: &Declaration) {
+  match declaration {
+    Declaration::FuncSig(sig) => visitor.func_signature(sig),
+    Declaration::FuncDecl(sig, block) => visitor.func_declaration(sig, block),
+    Declaration::TypeDecl { name, body, mutable } => visitor.type_declaration(name, body, mutable),
+    Declaration::TypeAlias(alias, name) => visitor.type_alias(alias, name),
+    Declaration::Binding { name, constant, expr} => visitor.binding(name, constant, expr),
+    Declaration::Impl { type_name, interface_name, block } => visitor.impl_block(type_name, interface_name, block),
+    Declaration::Interface { name, signatures } => visitor.interface(name, signatures),
+  }
+}
+
+pub trait ASTVisitor {
+  fn ast(&mut self, _ast: &AST) { }
+  fn statement(&mut self, _stmt: &Statement) { }
+  fn expression(&mut self, _expr: &Expression) { }
+  fn anno_expr(&mut self, &Option<TypeIdentifier>) { }
+  fn expr_kind(&mut self, _expr: &ExpressionType) { }
+
+  fn nat_literal(&mut self, _n: &u64) { }
+  fn float_literal(&mut self, _f: &f64) { }
+  fn string_literal(&mut self, _s: &Rc<String>) { }
+  fn bool_literal(&mut self, _bool: &bool) { }
+  fn binop(&mut self, _binop: &BinOp, _lhs: &Expression, _rhs: &Expression) { }
+  fn prefixop(&mut self, prefix: &PrefixOp, _expr: &Expression) { }
+  fn tuple_literal(&mut self, _v: &Vec<Expression>) { }
+  fn value(&mut self, _v: &Rc<String>) { }
+  fn named_struct(&mut self, _name: &Rc<String>, _values: &Vec<(Rc<String>, Expression)>) { }
+  fn call(&mut self, _f: &Box<Expression>, _arguments: &Vec<Expression>) { }
+  fn index(&mut self, _indexee: &Box<Expression>, _indexers: &Vec<Expression>) { }
+  fn if_expression(&mut self, _discriminator: &Discriminator, _body: &IfExpressionBody) { }
+  fn while_expresssion(&mut self, _condition: &Option<Box<Expression>>, body: &Block) { }
+  fn for_expression(&mut self, _enumerators: &Vec<Enumerator>, _body: &Box<ForBody>) { }
+  fn lambda_expression(&mut self, _params: &Vec<FormalParam>, type_anno: &Option<TypeIdentifier>, body: &Block) { }
+  fn list_literal(&mut self, _items: &Vec<Expression>) { }
+
+
+  fn declaration(&mut self, _decl: &Declaration) { }
+  fn func_signature(&mut self, _sig: &Signature) { }
+  fn func_declaration(&mut self, _sig: &Signature, _block: &Vec<Statement>) { }
+  fn type_declaration(&mut self, _name: &TypeSingletonName, _body: &TypeBody, _mutable: &bool) { }
+  fn type_alias(&mut self, _alias: &Rc<String>, _name: &Rc<String>) { }
+  fn binding(&mut self, _name: &Rc<String>, _constant: &bool, _expr: &Expression) { }
+  fn impl_block(&mut self, _type_name: &TypeIdentifier, _interface_name: &Option<InterfaceName>, _block: &Vec<Declaration>) { }
+  fn interface(&mut self, name: &Rc<String>, signatures: &Vec<Signature>) { }
+}
+
+#[derive(Clone)]
+struct SchalaPrinter { 
+  s: String
+}
+
+impl SchalaPrinter {
+  fn new() -> SchalaPrinter {
+    SchalaPrinter {
+      s: format!("Schala source code:\n"),
+    }
+  }
+
+  fn done(self) -> String {
+    self.s
+  }
+}
+
+impl ASTVisitor for SchalaPrinter {
+  fn statement(&mut self, _: &Statement) {
+    self.s.push_str("\n");
+  }
+
+  fn expression(&mut self, _: &Expression) {
+    self.s.push_str("some_expr");
+  }
+
+  fn binding(&mut self, name: &Rc<String>, constant: &bool, _expr: &Expression) {
+    self.s.push_str(&format!("let{} {} = {}",
+                            if *constant { "" } else { " mut" }, 
+                            name,
+                            "some_expr"));
+  }
+}
+
+
+#[cfg(test)]
+mod visitor_tests {
+  use ::tokenizing::{Token, tokenize};
+  use ::parsing::ParseResult;
+  use ::ast::AST;
+  use super::*;
+
+  fn parse(input: &str) -> ParseResult<AST> {
+    let tokens = tokenize(input);
+    let mut parser = ::parsing::Parser::new(tokens);
+    parser.parse()
+  }
+
+  #[test]
+  fn test() {
+    let ast = parse("let a = 1 + 2; let b = 2 + 44;foo()").unwrap();
+    let mut pp = SchalaPrinter::new();
+    dispatch(&mut pp, &ast);
+    let result = pp.done();
+    assert_eq!(result, r#"Schala source code:
+let a = 1 + 2
+let b = 2 + 44
+foo()
+"#);
+  }
+}

schala-lang/language/src/builtin.rs

@@ -2,7 +2,7 @@ use std::rc::Rc;
 use std::collections::HashMap;
 use std::fmt;
 
-use tokenizing::TokenType;
+use tokenizing::TokenKind;
 use self::BuiltinTypeSpecifier::*;
 use self::BuiltinTConst::*;
 
@@ -40,8 +40,8 @@ impl BinOp {
   pub fn sigil(&self) -> &Rc<String> {
     &self.sigil
   }
-  pub fn from_sigil_token(tok: &TokenType) -> Option<BinOp> {
+  pub fn from_sigil_token(tok: &TokenKind) -> Option<BinOp> {
-    use self::TokenType::*;
+    use self::TokenKind::*;
     let s = match tok {
       Operator(op) => op,
       Period => ".",
@@ -62,8 +62,8 @@ impl BinOp {
   pub fn min_precedence() -> i32 {
     i32::min_value()
   }
-  pub fn get_precedence_from_token(op: &TokenType) -> Option<i32> {
+  pub fn get_precedence_from_token(op: &TokenKind) -> Option<i32> {
-    use self::TokenType::*;
+    use self::TokenKind::*;
     let s = match op {
       Operator(op) => op,
       Period => ".",

schala-lang/language/src/eval.rs

@@ -7,7 +7,7 @@ use std::io;
 use itertools::Itertools;
 
 use util::ScopeStack;
-use reduced_ast::{ReducedAST, Stmt, Expr, Lit, Func, Alternative};
+use reduced_ast::{BoundVars, ReducedAST, Stmt, Expr, Lit, Func, Alternative, Subpattern};
 use symbol_table::{SymbolSpec, Symbol, SymbolTable};
 
 pub struct State<'a> {
@@ -21,7 +21,6 @@ macro_rules! builtin_binding {
   }
 }
 
-//TODO add a more concise way of getting a new frame
 impl<'a> State<'a> {
   pub fn new(symbol_table_handle: Rc<RefCell<SymbolTable>>) -> State<'a> {
     let mut values = ScopeStack::new(Some(format!("global")));
@@ -34,6 +33,19 @@ impl<'a> State<'a> {
   pub fn debug_print(&self) -> String {
     format!("Values: {:?}", self.values)
   }
+
+  fn new_frame(&'a self, items: &'a Vec<Node>, bound_vars: &BoundVars) -> State<'a> {
+    let mut inner_state = State {
+      values: self.values.new_scope(None),
+      symbol_table_handle: self.symbol_table_handle.clone(),
+    };
+    for (bound_var, val) in bound_vars.iter().zip(items.iter()) {
+      if let Some(bv) = bound_var.as_ref() {
+        inner_state.values.insert(bv.clone(), ValueEntry::Binding { constant: true, val: val.clone() });
+      }
+    }
+    inner_state
+  }
 }
 
 #[derive(Debug, Clone)]
@@ -72,6 +84,12 @@ impl Node {
       Node::PrimTuple { items } => format!("{}", paren_wrapped_vec(items.iter().map(|x| x.to_repl()))),
     }
   }
+  fn is_true(&self) -> bool {
+    match self {
+      Node::Expr(Expr::Lit(::reduced_ast::Lit::Bool(true))) => true,
+      _ => false,
+    }
+  }
 }
 
 #[derive(Debug)]
@@ -116,6 +134,23 @@ impl Expr {
       _ => format!("{:?}", self),
     }
   }
+
+  fn replace_conditional_target_sigil(self, replacement: &Expr) -> Expr {
+    use self::Expr::*;
+
+    match self {
+      ConditionalTargetSigilValue => replacement.clone(),
+      Unit | Lit(_) | Func(_) | Val(_) | Constructor { .. } |
+       CaseMatch { .. } | UnimplementedSigilValue => self,
+      Tuple(exprs) => Tuple(exprs.into_iter().map(|e| e.replace_conditional_target_sigil(replacement)).collect()),
+      Call { f, args } => {
+        let new_args = args.into_iter().map(|e| e.replace_conditional_target_sigil(replacement)).collect();
+        Call { f, args: new_args }
+      },
+      Conditional { .. } => panic!("Dunno if I need this, but if so implement"),
+      Assign { .. } => panic!("I'm pretty sure I don't need this"),
+    }
+  }
 }
 
 impl<'a> State<'a> {
@@ -194,7 +229,8 @@ impl<'a> State<'a> {
         Assign { box val, box expr } => self.assign_expression(val, expr),
         Unit => Ok(Node::Expr(Unit)),
         CaseMatch { box cond, alternatives } => self.case_match_expression(cond, alternatives),
-        UnimplementedSigilValue => Err(format!("Sigil value eval not implemented"))
+        ConditionalTargetSigilValue => Ok(Node::Expr(ConditionalTargetSigilValue)),
+        UnimplementedSigilValue => Err(format!("Sigil value eval not implemented")),
       }
     }
   }
@@ -351,52 +387,76 @@ impl<'a> State<'a> {
     Ok(Node::Expr(Expr::Unit))
   }
 
-fn case_match_expression(&mut self, cond: Expr, alternatives: Vec<Alternative>) -> EvalResult<Node> {
+  fn guard_passes(&mut self, guard: &Option<Expr>, cond: &Node) -> EvalResult<bool> {
-  match self.expression(Node::Expr(cond))? {
+    if let Some(ref guard_expr) = guard {
-    Node::PrimObject { tag, items, .. } => {
+      let guard_expr = match cond {
-      for alt in alternatives {
+        Node::Expr(ref e) => guard_expr.clone().replace_conditional_target_sigil(e),
-        if alt.tag.map(|t| t == tag).unwrap_or(true) {
+        _ => guard_expr.clone()
-          let mut inner_state = State {
+      };
-            values: self.values.new_scope(None),
+      Ok(self.expression(guard_expr.to_node())?.is_true())
-            symbol_table_handle: self.symbol_table_handle.clone(),
+    } else {
-          };
+      Ok(true)
-          for (bound_var, val) in alt.bound_vars.iter().zip(items.iter()) {
-            if let Some(bv) = bound_var.as_ref() {
-              inner_state.values.insert(bv.clone(), ValueEntry::Binding { constant: true, val: val.clone() });
-            }
-          }
-
-          if let Some(guard_expr) = alt.guard {
-            let evaled_guard = inner_state.expression(guard_expr.to_node());
-            println!("EVALED GUARD: {:?}", evaled_guard);
-            //continue
-          }
-
-          return inner_state.block(alt.item)
-        }
-      }
-      return Err(format!("PrimObject failed pattern match"));
-    },
-    Node::PrimTuple { .. } => Err(format!("Tuples not implemented")), //TODO make a distinction between not yet implemented and an actual runtime error
-    Node::Expr(_e) => {
-      for alt in alternatives {
-        match (alt.guard, alt.tag) {
-          (Some(ref guard_expr), None) => {
-            match self.expression(guard_expr.clone().to_node())? {
-              Node::Expr(Expr::Lit(::reduced_ast::Lit::Bool(true))) => 
-                return self.block(alt.item),
-              _ => continue,
-            }
-          },
-          (None, None) => return self.block(alt.item),
-          _ => return Err(format!("Shouldn't match an expr against a pattern"))
-        }
-      }
-      return Err(format!("Expr Failed pattern match"));
     }
-
   }
-}
+
+  fn case_match_expression(&mut self, cond: Expr, alternatives: Vec<Alternative>) -> EvalResult<Node> {
+
+    //TODO need to handle recursive subpatterns
+    let all_subpatterns_pass = |state: &mut State, subpatterns: &Vec<Option<Subpattern>>, items: &Vec<Node>| -> EvalResult<bool> {
+
+      if subpatterns.len() == 0 {
+        return Ok(true)
+      }
+
+      if items.len() != subpatterns.len() {
+        return Err(format!("Subpattern length isn't correct items {} subpatterns {}", items.len(), subpatterns.len()));
+      }
+
+      for (maybe_subp, cond) in subpatterns.iter().zip(items.iter()) {
+        if let Some(subp) = maybe_subp {
+          if !state.guard_passes(&subp.guard, &cond)? {
+            return Ok(false)
+          }
+        }
+      }
+      Ok(true)
+    };
+
+    let cond = self.expression(Node::Expr(cond))?;
+    for alt in alternatives {
+      // no matter what type of condition we have, ignore alternative if the guard evaluates false
+      if !self.guard_passes(&alt.guard, &cond)? {
+        continue;
+      }
+
+      match cond {
+        Node::PrimObject { ref tag, ref items, .. } => {
+          if alt.tag.map(|t| t == *tag).unwrap_or(true) {
+            let mut inner_state = self.new_frame(items, &alt.bound_vars);
+            if all_subpatterns_pass(&mut inner_state, &alt.subpatterns, items)? {
+              return inner_state.block(alt.item);
+            } else {
+              continue;
+            }
+          }
+        },
+        Node::PrimTuple { ref items } =>  {
+          let mut inner_state = self.new_frame(items, &alt.bound_vars);
+          if all_subpatterns_pass(&mut inner_state, &alt.subpatterns, items)? {
+            return inner_state.block(alt.item);
+          } else {
+            continue;
+          }
+        },
+        Node::Expr(ref _e) => {
+          if let None = alt.tag {
+            return self.block(alt.item)
+          }
+        }
+      }
+    }
+    Err(format!("{:?} failed pattern match", cond))
+  }
 
   fn value(&mut self, name: Rc<String>) -> EvalResult<Node> {
     use self::ValueEntry::*;
@@ -448,24 +508,20 @@ mod eval_tests {
     parser.parse()
   }
 
-  macro_rules! all_output {
+  fn evaluate_all_outputs(input: &str) -> Vec<Result<String, String>> {
-    ($string:expr) => {
+    let symbol_table = Rc::new(RefCell::new(SymbolTable::new()));
-      {
+    let mut state = State::new(symbol_table);
-        let symbol_table = Rc::new(RefCell::new(SymbolTable::new()));
+    let ast = parse(tokenize(input)).unwrap();
-        let mut state = State::new(symbol_table);
+    state.symbol_table_handle.borrow_mut().add_top_level_symbols(&ast).unwrap();
-        let ast = parse(tokenize($string)).unwrap();
+    let reduced = ast.reduce(&state.symbol_table_handle.borrow());
-        state.symbol_table_handle.borrow_mut().add_top_level_symbols(&ast).unwrap();
+    let all_output = state.evaluate(reduced, true);
-        let reduced = ast.reduce(&state.symbol_table_handle.borrow());
+    all_output
-        let all_output = state.evaluate(reduced, true);
-        all_output
-      }
-    }
   }
 
   macro_rules! test_in_fresh_env {
     ($string:expr, $correct:expr) => {
       {
-        let all_output = all_output!($string);
+        let all_output = evaluate_all_outputs($string);
         let ref output = all_output.last().unwrap();
         assert_eq!(**output, Ok($correct.to_string()));
       }
@@ -550,6 +606,15 @@ if a { is 15 -> "x", is 10 -> "y" }
   test_in_fresh_env!(source, "\"y\"");
   }
 
+  #[test]
+  fn string_pattern() {
+    let source = r#"
+let a = "foo"
+if a { is "foo" -> "x", is _ -> "y" }
+"#;
+    test_in_fresh_env!(source, "\"x\"");
+  }
+
   #[test]
   fn boolean_pattern() {
     let source = r#"
@@ -581,4 +646,102 @@ if Some(10) {
 "#;
     test_in_fresh_env!(source, "\"hella\"");
   }
+
+  #[test]
+  fn tuple_pattern() {
+    let source = r#"
+if (1, 2) {
+  is (1, x) -> x,
+  is _ -> 99
+}
+"#;
+    test_in_fresh_env!(source, 2);
+  }
+
+
+  #[test]
+  fn tuple_pattern_2() {
+    let source = r#"
+if (1, 2) {
+  is (10, x) -> x,
+  is (y, x) -> x + y
+}
+"#;
+    test_in_fresh_env!(source, 3);
+  }
+
+  #[test]
+  fn tuple_pattern_3() {
+    let source = r#"
+if (1, 5) {
+  is (10, x) -> x,
+  is (1, x) -> x
+}
+"#;
+    test_in_fresh_env!(source, 5);
+  }
+
+  #[test]
+  fn tuple_pattern_4() {
+    let source = r#"
+if (1, 5) {
+  is (10, x) -> x,
+  is (1, x) -> x,
+}
+"#;
+    test_in_fresh_env!(source, 5);
+  }
+
+  #[test]
+  fn  prim_obj_pattern() {
+    let source = r#"
+type Stuff = Mulch(Nat) | Jugs(Nat, String) | Mardok
+let a = Mulch(20)
+let b = Jugs(1, "haha")
+let c = Mardok
+
+let x = if a {
+  is Mulch(20) -> "x",
+  is _ -> "ERR"
+}
+
+let y = if b {
+  is Mulch(n) -> "ERR",
+  is Jugs(2, _) -> "ERR",
+  is Jugs(1, s) -> s,
+  is _ -> "ERR",
+}
+
+let z = if c {
+  is Jugs(_, _) -> "ERR",
+  is Mardok -> "NIGH",
+  is _ -> "ERR",
+}
+
+(x, y, z)
+"#;
+  test_in_fresh_env!(source, r#"("x", "haha", "NIGH")"#);
+  }
+
+  #[test]
+  fn basic_lambda_syntax() {
+    let source = r#"
+let q = \(x, y) { x * y }
+let x = q(5,2)
+let y = \(m, n, o) { m + n + o }(1,2,3)
+(x, y)
+  "#;
+  test_in_fresh_env!(source, r"(10, 6)");
+  }
+
+  #[test]
+  fn lambda_syntax_2() {
+    let source = r#"
+fn milta() {
+  \(x) { x + 33 }
+}
+milta()(10)
+  "#;
+    test_in_fresh_env!(source, "43");
+  }
 }

schala-lang/language/src/lib.rs

@@ -2,12 +2,16 @@
 #![feature(custom_attribute)]
 #![feature(unrestricted_attribute_tokens)]
 #![feature(slice_patterns, box_patterns, box_syntax)]
+
+//! `schala-lang` is where the Schala programming language is actually implemented. 
+//! It defines the `Schala` type, which contains the state for a Schala REPL, and implements
+//! `ProgrammingLanguageInterface` and the chain of compiler passes for it.
+
 extern crate itertools;
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]
 extern crate maplit;
-#[macro_use]
 extern crate schala_repl;
 #[macro_use]
 extern crate schala_repl_codegen;
@@ -25,9 +29,11 @@ macro_rules! bx {
 }
 
 mod util;
+mod source_map;
 mod builtin;
 mod tokenizing;
 mod ast;
+mod ast_visitor;
 mod parsing;
 mod symbol_table;
 mod typechecking;
@@ -41,9 +47,13 @@ mod eval;
 #[PipelineSteps(tokenizing, parsing(compact,expanded,trace), symbol_table, typechecking, ast_reducing, eval)]
 #[DocMethod = get_doc]
 #[HandleCustomInterpreterDirectives = handle_custom_interpreter_directives]
+/// All bits of state necessary to parse and execute a Schala program are stored in this struct
+/// `state` represents the execution state for the AST-walking interpreter, the other fields
+/// should be self-explanatory.
 pub struct Schala {
   state: eval::State<'static>,
   symbol_table: Rc<RefCell<symbol_table::SymbolTable>>,
+  type_context: typechecking::TypeContext<'static>,
   active_parser: Option<parsing::Parser>,
 }
 
@@ -58,21 +68,21 @@ impl Schala {
 }
 
 impl Schala {
+  /// Creates a new Schala environment *without* any prelude.
   fn new_blank_env() -> Schala {
     let symbols = Rc::new(RefCell::new(symbol_table::SymbolTable::new()));
     Schala {
       symbol_table: symbols.clone(),
       state: eval::State::new(symbols),
+      type_context: typechecking::TypeContext::new(),
       active_parser: None,
     }
   }
 
+  /// Creates a new Schala environment with the standard prelude, which is defined as ordinary
+  /// Schala code in the file `prelude.schala`
   pub fn new() -> Schala {
-    let prelude = r#"
+    let prelude = include_str!("prelude.schala");
-type Option<T> = Some(T) | None
-type Color = Red | Green | Blue
-type Ord = LT | EQ | GT
-    "#;
     let mut s = Schala::new_blank_env();
     s.execute_pipeline(prelude, &EvalOptions::default());
     s
@@ -82,7 +92,7 @@ type Ord = LT | EQ | GT
 fn tokenizing(_handle: &mut Schala, input: &str, comp: Option<&mut UnfinishedComputation>) -> Result<Vec<tokenizing::Token>, String> {
   let tokens = tokenizing::tokenize(input);
   comp.map(|comp| {
-    let token_string = tokens.iter().map(|t| format!("{:?}<L:{},C:{}>", t.token_type, t.offset.0, t.offset.1)).join(", ");
+    let token_string = tokens.iter().map(|t| format!("{:?}<L:{},C:{}>", t.kind, t.offset.0, t.offset.1)).join(", ");
     comp.add_artifact(TraceArtifact::new("tokens", token_string));
   });
 
@@ -131,7 +141,14 @@ fn symbol_table(handle: &mut Schala, input: ast::AST, comp: Option<&mut Unfinish
   }
 }
 
-fn typechecking(_handle: &mut Schala, input: ast::AST, _comp: Option<&mut UnfinishedComputation>) -> Result<ast::AST, String> {
+fn typechecking(handle: &mut Schala, input: ast::AST, comp: Option<&mut UnfinishedComputation>) -> Result<ast::AST, String> {
+  let result = handle.type_context.typecheck(&input);
+
+  comp.map(|comp| {
+    let artifact = TraceArtifact::new("type", format!("{:?}", result));
+    comp.add_artifact(artifact);
+  });
+
   Ok(input)
 }
 

schala-lang/language/src/parsing.rs

@@ -4,8 +4,9 @@ use std::vec::IntoIter;
 
 use tokenizing::*;
 use tokenizing::Kw::*;
-use tokenizing::TokenType::*;
+use tokenizing::TokenKind::*;
 
+use source_map::{SourceMap, SourceData};
 use ast::*;
 
 use builtin::{BinOp, PrefixOp};
@@ -35,7 +36,7 @@ pub struct ParseRecord {
 }
 
 pub struct Parser {
-  tokens: Peekable<IntoIter<Token>>,
+  token_handler: TokenHandler,
   parse_record: Vec<ParseRecord>,
   parse_level: u32,
   restrictions: ParserRestrictions,
@@ -45,26 +46,57 @@ struct ParserRestrictions {
   no_struct_literal: bool
 }
 
+struct TokenHandler {
+  tokens: Peekable<IntoIter<Token>>,
+}
+
+impl TokenHandler {
+  fn new(tokens: Vec<Token>) -> TokenHandler {
+    let tokens = tokens.into_iter().peekable();
+    TokenHandler { tokens }
+  }
+
+  fn peek(&mut self) -> TokenKind {
+    self.tokens.peek().map(|ref t| { t.kind.clone() }).unwrap_or(TokenKind::EOF)
+  }
+  fn peek_with_token_offset(&mut self) -> Token {
+    self.tokens.peek().map(|t: &Token| { t.clone()}).unwrap_or(Token { kind: TokenKind::EOF, offset: (0,0)})
+  }
+  fn next(&mut self) -> TokenKind {
+    self.tokens.next().map(|ref t| { t.kind.clone() }).unwrap_or(TokenKind::EOF)
+  }
+}
+
 impl Parser {
   pub fn new(initial_input: Vec<Token>) -> Parser {
     Parser {
-      tokens: initial_input.into_iter().peekable(),
+      token_handler: TokenHandler::new(initial_input),
       parse_record: vec![],
       parse_level: 0,
       restrictions: ParserRestrictions { no_struct_literal: false }
     }
   }
 
-  fn peek(&mut self) -> TokenType {
+  fn peek(&mut self) -> TokenKind {
-    self.tokens.peek().map(|ref t| { t.token_type.clone() }).unwrap_or(TokenType::EOF)
+    self.token_handler.peek()
   }
   fn peek_with_token_offset(&mut self) -> Token {
-    self.tokens.peek().map(|t: &Token| { t.clone()}).unwrap_or(Token { token_type: TokenType::EOF, offset: (0,0)})
+    self.token_handler.peek_with_token_offset()
   }
-  fn next(&mut self) -> TokenType {
+  fn next(&mut self) -> TokenKind {
-    self.tokens.next().map(|ref t| { t.token_type.clone() }).unwrap_or(TokenType::EOF)
+    self.token_handler.next()
   }
 
+  /*
+  fn next_mapped(&mut self) -> SourceMap<TokenKind> {
+    let tt = self.next();
+    SourceMap {
+      node: tt,
+      data: Some(SourceData { line_number: 420, char_idx: 69 })
+    }
+  }
+  */
+
   pub fn parse(&mut self) -> ParseResult<AST> {
     self.program()
   }
@@ -165,8 +197,9 @@ typed_identifier := IDENTIFIER type_anno
 /* Declaration - Functions */
 
 func_declaration := func_signature func_body
-func_body := ε | '{' (statement delimiter)* '}'
+func_body := ε | nonempty_func_body
-func_signature := 'fn' func_name formal_param_list func_body
+nonempty_func_body := '{' (statement delimiter)* '}'
+func_signature := 'fn' func_name formal_param_list type_anno+
 func_name := IDENTIFIER | operator
 formal_param_list := '(' (formal_param ',')* ')'
 formal_param := IDENTIFIER type_anno+
@@ -200,13 +233,13 @@ prefix_op := '+' | '-' | '!' | '~'
 call_expr := index_expr ( '(' expr_list ')' )*
 expr_list := expression (',' expression)* | ε
 index_expr := primary ( '[' (expression (',' (expression)* | ε) ']' )*
-primary := literal | paren_expr | if_expr | for_expr | while_expr | identifier_expr | curly_brace_expr | list_expr
+primary := literal | paren_expr | if_expr | for_expr | while_expr | identifier_expr | lambda_expr | anonymous_struct | list_expr
 
 /* Primary Expressions */
 
-curly_brace_expr := lambda_expr | anonymous_struct //TODO
 list_expr := '[' (expression, ',')* ']'
-lambda_expr := '{' '|' (formal_param ',')* '|' (type_anno)* (statement delimiter)* '}'
+lambda_expr := '\' lambda_param_list type_anno+ nonempty_func_body
+lambda_param_list := formal_param_list |  formal_param
 paren_expr := LParen paren_inner RParen
 paren_inner := (expression ',')*
 identifier_expr := named_struct | IDENTIFIER
@@ -368,7 +401,7 @@ impl Parser {
   fn func_declaration(&mut self) -> ParseResult<Declaration> {
     let signature = self.func_signature()?;
     if let LCurlyBrace = self.peek() {
-      let statements = delimited!(self, LCurlyBrace, statement, Newline | Semicolon, RCurlyBrace, nonstrict);
+      let statements = self.nonempty_func_body()?;
       Ok(Declaration::FuncDecl(signature, statements))
     } else {
       Ok(Declaration::FuncSig(signature))
@@ -386,7 +419,7 @@ impl Parser {
       },
       _ => (self.identifier()?, false)
     };
-    let params = delimited!(self, LParen, formal_param, Comma, RParen);
+    let params = self.formal_param_list()?;
     let type_anno = match self.peek() {
       Colon => Some(self.type_anno()?),
       _ => None,
@@ -394,6 +427,16 @@ impl Parser {
     Ok(Signature { name, operator, params, type_anno })
   }
 
+  #[recursive_descent_method]
+  fn nonempty_func_body(&mut self) -> ParseResult<Vec<Statement>> {
+    Ok(delimited!(self, LCurlyBrace, statement, Newline | Semicolon, RCurlyBrace, nonstrict))
+  }
+
+  #[recursive_descent_method]
+  fn formal_param_list(&mut self) -> ParseResult<Vec<FormalParam>> {
+    Ok(delimited!(self, LParen, formal_param, Comma, RParen))
+  }
+
   #[recursive_descent_method]
   fn formal_param(&mut self) -> ParseResult<FormalParam> {
     let name = self.identifier()?;
@@ -555,13 +598,13 @@ impl Parser {
 
   #[recursive_descent_method]
   fn call_expr(&mut self) -> ParseResult<Expression> {
-    let index  = self.index_expr()?;
+    let mut expr = self.index_expr()?;
-    Ok(if let LParen = self.peek() {
+    while let LParen = self.peek() {
       let arguments = delimited!(self, LParen, expression, Comma, RParen);
-      Expression(ExpressionType::Call { f: bx!(index), arguments }, None) //TODO fix this none
+      expr = Expression(ExpressionType::Call { f: bx!(expr), arguments }, None); //TODO none is incorrect
-    } else {
+    }
-      index
+
-    })
+    Ok(expr)
   }
 
   #[recursive_descent_method]
@@ -582,6 +625,7 @@ impl Parser {
   fn primary(&mut self) -> ParseResult<Expression> {
     match self.peek() {
       LCurlyBrace => self.curly_brace_expr(),
+      Backslash => self.lambda_expr(),
       LParen => self.paren_expr(),
       LSquareBracket => self.list_expr(),
       Keyword(Kw::If) => self.if_expr(),
@@ -600,26 +644,29 @@ impl Parser {
 
   #[recursive_descent_method]
   fn curly_brace_expr(&mut self) -> ParseResult<Expression> {
-    self.lambda_expr()
+    ParseError::new("Not implemented")
   }
 
   #[recursive_descent_method]
   fn lambda_expr(&mut self) -> ParseResult<Expression> {
-    expect!(self, LCurlyBrace);
+    expect!(self, Backslash);
-    let params = delimited!(self, Pipe, formal_param, Comma, Pipe);
+    let params = self.lambda_param_list()?;
-    let mut body = Vec::new();
+    let type_anno = match self.peek() {
-    loop {
+      Colon => Some(self.type_anno()?),
-      match self.peek() {
+      _ => None,
-        EOF | RCurlyBrace => break,
+    };
-        Newline | Semicolon => {
+    let body = self.nonempty_func_body()?;
-          self.next();
+    Ok(Expression(ExpressionType::Lambda { params, type_anno, body }, None)) //TODO need to handle types somehow
-          continue;
+  }
-        },
+
-        _ => body.push(self.statement()?),
+  #[recursive_descent_method]
-      }
+  fn lambda_param_list(&mut self) -> ParseResult<Vec<FormalParam>> {
+    if let LParen = self.peek() {
+      self.formal_param_list()
+    } else {
+      let single_param = self.formal_param()?;
+      Ok(vec![single_param])
     }
-    expect!(self, RCurlyBrace);
-    Ok(Expression(ExpressionType::Lambda { params, body }, None)) //TODO need to handle types somehow
   }
 
   #[recursive_descent_method]
@@ -728,19 +775,26 @@ impl Parser {
     //TODO - delimited! isn't sophisticated enough to do thisa
     //let guards = delimited!(self, LCurlyBrace, guard_arm, Comma, RCurlyBrace);
     expect!(self, LCurlyBrace);
+
     let mut guards = vec![];
     loop {
-      while let Newline = self.peek() {
-        self.next();
-      }
-      let guard_arm = self.guard_arm()?;
-      guards.push(guard_arm);
-      while let Newline = self.peek() {
-        self.next();
-      }
       match self.peek() {
-        Comma => {self.next(); continue },
+        RCurlyBrace | EOF => break,
-        _ => break
+        Semicolon | Newline => { self.next(); continue},
+        _ => {
+          let guard_arm = self.guard_arm()?;
+          guards.push(guard_arm);
+          loop {
+            match self.peek() {
+              Semicolon | Newline => { self.next(); continue; },
+              _ => break,
+            }
+          }
+          if let RCurlyBrace = self.peek() {
+            break;
+          }
+          expect!(self, Comma);
+        }
       }
     }
     expect!(self, RCurlyBrace);
@@ -991,7 +1045,7 @@ impl Parser {
   fn float_literal(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     let mut digits = self.digits()?;
-    if let TokenType::Period = self.peek() {
+    if let Period = self.peek() {
       self.next();
       digits.push_str(".");
       digits.push_str(&self.digits()?);
@@ -1071,7 +1125,8 @@ mod parse_tests {
   use super::Variant::*;
   use super::ForBody::*;
 
-  fn parse(tokens: Vec<::tokenizing::Token>) -> ParseResult<AST> {
+  fn parse(input: &str) -> ParseResult<AST> {
+    let tokens: Vec<::tokenizing::Token> = tokenize(input);
     let mut parser = super::Parser::new(tokens);
     parser.parse()
   }
@@ -1080,18 +1135,17 @@ mod parse_tests {
     ($string:tt) => { Rc::new(stringify!($string).to_string()) }
   }
   macro_rules! parse_test {
-    ($string:expr, $correct:expr) => { assert_eq!(parse(tokenize($string)).unwrap(), $correct) }
+    ($string:expr, $correct:expr) => { assert_eq!(parse($string).unwrap(), $correct) };
+  }
+  macro_rules! parse_test_wrap_ast {
+    ($string:expr, $correct:expr) => { parse_test!($string, AST(vec![$correct])) }
   }
   macro_rules! parse_error {
-    ($string:expr) => { assert!(parse(tokenize($string)).is_err()) }
+    ($string:expr) => { assert!(parse($string).is_err()) }
   }
   macro_rules! val {
     ($var:expr) => { Value(Rc::new($var.to_string())) }
   }
-  macro_rules! exprstatement {
-    ($expr_type:expr) => { Statement::ExpressionStatement(Expression($expr_type, None)) };
-    ($expr_type:expr, $type_anno:expr) => { Statement::ExpressionStatement(Expression($expr_type, Some($type_anno))) };
-  }
   macro_rules! ty {
     ($name:expr) => { Singleton(tys!($name)) }
   }
@@ -1099,16 +1153,17 @@ mod parse_tests {
     ($name:expr) => { TypeSingletonName { name: Rc::new($name.to_string()), params: vec![] } };
   }
 
-
-  /* new style of test macros */
-
-  macro_rules! single_expr {
-    ($exprtype:expr) => { AST(vec![Statement::ExpressionStatement(Expression($exprtype, None))]) };
-    ($exprtype:expr, $type:expr) => { AST(vec![Statement::ExpressionStatement(Expression($exprtype, $type))]) }
-  }
   macro_rules! ex {
-    ($expr_type:expr) => { Expression($expr_type, None) }
+    ($expr_type:expr) => { Expression($expr_type, None) };
+    (s $expr_text:expr) => {
+      {
+        let tokens: Vec<::tokenizing::Token> = tokenize($expr_text);
+        let mut parser = super::Parser::new(tokens);
+        parser.expression().unwrap()
+      }
+    };
   }
+
   macro_rules! binexp {
     ($op:expr, $lhs:expr, $rhs:expr) => { BinExp(BinOp::from_sigil($op), bx!(Expression($lhs, None)), bx!(Expression($rhs, None))) }
   }
@@ -1119,59 +1174,66 @@ mod parse_tests {
     ($expr_type:expr) => { Statement::ExpressionStatement(Expression($expr_type, None)) };
     ($expr_type:expr, $type_anno:expr) => { Statement::ExpressionStatement(Expression($expr_type, Some($type_anno))) };
     ($op:expr, $lhs:expr, $rhs:expr) => { Statement::ExpressionStatement(ex!(binexp!($op, $lhs, $rhs))) };
+    (s $statement_text:expr) => {
+      {
+        let tokens: Vec<::tokenizing::Token> = tokenize($statement_text);
+        let mut parser = super::Parser::new(tokens);
+        parser.statement().unwrap()
+      }
+    }
   }
 
   #[test]
   fn parsing_number_literals_and_binexps() {
-    parse_test! { ".2", single_expr!(FloatLiteral(0.2)) };
+    parse_test_wrap_ast! { ".2", exst!(FloatLiteral(0.2)) };
-    parse_test! { "8.1", single_expr!(FloatLiteral(8.1)) };
+    parse_test_wrap_ast! { "8.1", exst!(FloatLiteral(8.1)) };
 
-    parse_test! { "0b010", single_expr!(NatLiteral(2)) };
+    parse_test_wrap_ast! { "0b010", exst!(NatLiteral(2)) };
-    parse_test! { "0b0_1_0_", single_expr!(NatLiteral(2)) }
+    parse_test_wrap_ast! { "0b0_1_0_", exst!(NatLiteral(2)) }
 
-    parse_test! {"0xff", single_expr!(NatLiteral(255)) };
+    parse_test_wrap_ast! {"0xff", exst!(NatLiteral(255)) };
-    parse_test! {"0xf_f_", single_expr!(NatLiteral(255)) };
+    parse_test_wrap_ast! {"0xf_f_", exst!(NatLiteral(255)) };
 
-    parse_test!("0xf_f_+1", AST(vec![exprstatement!(binexp!("+", NatLiteral(255), NatLiteral(1)))]));
+    parse_test_wrap_ast! {"0xf_f_+1", exst!(binexp!("+", NatLiteral(255), NatLiteral(1))) };
 
     parse_test! {"3; 4; 4.3", AST(
-      vec![exprstatement!(NatLiteral(3)), exprstatement!(NatLiteral(4)),
+      vec![exst!(NatLiteral(3)), exst!(NatLiteral(4)),
-        exprstatement!(FloatLiteral(4.3))])
+        exst!(FloatLiteral(4.3))])
     };
 
     parse_test!("1 + 2 * 3", AST(vec!
       [
-        exprstatement!(binexp!("+", NatLiteral(1), binexp!("*", NatLiteral(2), NatLiteral(3))))
+        exst!(binexp!("+", NatLiteral(1), binexp!("*", NatLiteral(2), NatLiteral(3))))
       ]));
 
     parse_test!("1 * 2 + 3", AST(vec!
       [
-        exprstatement!(binexp!("+", binexp!("*", NatLiteral(1), NatLiteral(2)), NatLiteral(3)))
+        exst!(binexp!("+", binexp!("*", NatLiteral(1), NatLiteral(2)), NatLiteral(3)))
       ]));
 
-    parse_test!("1 && 2", AST(vec![exprstatement!(binexp!("&&", NatLiteral(1), NatLiteral(2)))]));
+    parse_test!("1 && 2", AST(vec![exst!(binexp!("&&", NatLiteral(1), NatLiteral(2)))]));
 
-    parse_test!("1 + 2 * 3 + 4", AST(vec![exprstatement!(
+    parse_test!("1 + 2 * 3 + 4", AST(vec![exst!(
       binexp!("+",
         binexp!("+", NatLiteral(1), binexp!("*", NatLiteral(2), NatLiteral(3))),
         NatLiteral(4)))]));
 
     parse_test!("(1 + 2) * 3", AST(vec!
-      [exprstatement!(binexp!("*", binexp!("+", NatLiteral(1), NatLiteral(2)), NatLiteral(3)))]));
+      [exst!(binexp!("*", binexp!("+", NatLiteral(1), NatLiteral(2)), NatLiteral(3)))]));
 
-    parse_test!(".1 + .2", AST(vec![exprstatement!(binexp!("+", FloatLiteral(0.1), FloatLiteral(0.2)))]));
+    parse_test!(".1 + .2", AST(vec![exst!(binexp!("+", FloatLiteral(0.1), FloatLiteral(0.2)))]));
-    parse_test!("1 / 2", AST(vec![exprstatement!(binexp!("/", NatLiteral(1), NatLiteral(2)))]));
+    parse_test!("1 / 2", AST(vec![exst!(binexp!("/", NatLiteral(1), NatLiteral(2)))]));
   }
 
   #[test]
   fn parsing_tuples() {
-    parse_test!("()", AST(vec![exprstatement!(TupleLiteral(vec![]))]));
+    parse_test!("()", AST(vec![exst!(TupleLiteral(vec![]))]));
-    parse_test!("(\"hella\", 34)", AST(vec![exprstatement!(
+    parse_test!("(\"hella\", 34)", AST(vec![exst!(
       TupleLiteral(
-        vec![ex!(StringLiteral(rc!(hella))), ex!(NatLiteral(34))]
+        vec![ex!(s r#""hella""#), ex!(s "34")]
       )
     )]));
-    parse_test!("((1+2), \"slough\")", AST(vec![exprstatement!(TupleLiteral(vec![
+    parse_test!("((1+2), \"slough\")", AST(vec![exst!(TupleLiteral(vec![
       ex!(binexp!("+", NatLiteral(1), NatLiteral(2))),
       ex!(StringLiteral(rc!(slough))),
     ]))]))
@@ -1179,41 +1241,42 @@ mod parse_tests {
 
   #[test]
   fn parsing_identifiers() {
-    parse_test!("a", AST(vec![exprstatement!(val!("a"))]));
+    parse_test!("a", AST(vec![exst!(val!("a"))]));
-    parse_test!("a + b", AST(vec![exprstatement!(binexp!("+", val!("a"), val!("b")))]));
+    parse_test!("some_value", AST(vec![exst!(val!("some_value"))]));
+    parse_test!("a + b", AST(vec![exst!(binexp!("+", val!("a"), val!("b")))]));
     //parse_test!("a[b]", AST(vec![Expression(
     //parse_test!("a[]", <- TODO THIS NEEDS TO FAIL
     //parse_test!(damn()[a] ,<- TODO needs to succeed
-    parse_test!("a[b,c]", AST(vec![exprstatement!(Index { indexee: bx!(ex!(val!("a"))), indexers: vec![ex!(val!("b")), ex!(val!("c"))]} )]));     
+    parse_test!("a[b,c]", AST(vec![exst!(Index { indexee: bx!(ex!(val!("a"))), indexers: vec![ex!(val!("b")), ex!(val!("c"))]} )]));     
 
-    parse_test!("None", AST(vec![exprstatement!(val!("None"))]));
+    parse_test!("None", AST(vec![exst!(val!("None"))]));
     parse_test!("Pandas {  a: x + y }", AST(vec![
-      exprstatement!(NamedStruct { name: rc!(Pandas), fields: vec![(rc!(a), ex!(binexp!("+", val!("x"), val!("y"))))]})
+      exst!(NamedStruct { name: rc!(Pandas), fields: vec![(rc!(a), ex!(binexp!("+", val!("x"), val!("y"))))]})
     ]));
   }
 
   #[test]
   fn parsing_complicated_operators() {
-    parse_test!("a <- b", AST(vec![exprstatement!(binexp!("<-", val!("a"), val!("b")))]));
+    parse_test!("a <- b", AST(vec![exst!(binexp!("<-", val!("a"), val!("b")))]));
-    parse_test!("a || b", AST(vec![exprstatement!(binexp!("||", val!("a"), val!("b")))]));
+    parse_test!("a || b", AST(vec![exst!(binexp!("||", val!("a"), val!("b")))]));
-    parse_test!("a<>b", AST(vec![exprstatement!(binexp!("<>", val!("a"), val!("b")))]));
+    parse_test!("a<>b", AST(vec![exst!(binexp!("<>", val!("a"), val!("b")))]));
-    parse_test!("a.b.c.d", AST(vec![exprstatement!(binexp!(".",
+    parse_test!("a.b.c.d", AST(vec![exst!(binexp!(".",
                                                 binexp!(".",
                                                   binexp!(".", val!("a"), val!("b")),
                                                 val!("c")),
                                                val!("d")))]));
-    parse_test!("-3", AST(vec![exprstatement!(prefexp!("-", NatLiteral(3)))]));
+    parse_test!("-3", AST(vec![exst!(prefexp!("-", NatLiteral(3)))]));
-    parse_test!("-0.2", AST(vec![exprstatement!(prefexp!("-", FloatLiteral(0.2)))]));
+    parse_test!("-0.2", AST(vec![exst!(prefexp!("-", FloatLiteral(0.2)))]));
-    parse_test!("!3", AST(vec![exprstatement!(prefexp!("!", NatLiteral(3)))]));
+    parse_test!("!3", AST(vec![exst!(prefexp!("!", NatLiteral(3)))]));
-    parse_test!("a <- -b", AST(vec![exprstatement!(binexp!("<-", val!("a"), prefexp!("-", val!("b"))))]));
+    parse_test!("a <- -b", AST(vec![exst!(binexp!("<-", val!("a"), prefexp!("-", val!("b"))))]));
-    parse_test!("a <--b", AST(vec![exprstatement!(binexp!("<--", val!("a"), val!("b")))]));
+    parse_test!("a <--b", AST(vec![exst!(binexp!("<--", val!("a"), val!("b")))]));
   }
 
   #[test]
   fn parsing_functions() {
     parse_test!("fn oi()",  AST(vec![Declaration(FuncSig(Signature { name: rc!(oi), operator: false, params: vec![], type_anno: None }))]));
-    parse_test!("oi()", AST(vec![exprstatement!(Call { f: bx!(ex!(val!("oi"))), arguments: vec![] })]));
+    parse_test!("oi()", AST(vec![exst!(Call { f: bx!(ex!(val!("oi"))), arguments: vec![] })]));
-    parse_test!("oi(a, 2 + 2)", AST(vec![exprstatement!(Call
+    parse_test!("oi(a, 2 + 2)", AST(vec![exst!(Call
     { f: bx!(ex!(val!("oi"))),
       arguments: vec![ex!(val!("a")), ex!(binexp!("+", NatLiteral(2), NatLiteral(2)))]
     })]));
@@ -1227,10 +1290,10 @@ mod parse_tests {
 
     parse_test!("fn a(x) { x() }", AST(vec![Declaration(
       FuncDecl(Signature { name: rc!(a), operator: false, params: vec![(rc!(x),None)], type_anno: None },
-        vec![exprstatement!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
+        vec![exst!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
     parse_test!("fn a(x) {\n x() }", AST(vec![Declaration(
       FuncDecl(Signature { name: rc!(a), operator: false, params: vec![(rc!(x),None)], type_anno: None },
-        vec![exprstatement!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
+        vec![exst!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
 
     let multiline = r#"
 fn a(x) {
@@ -1239,7 +1302,7 @@ fn a(x) {
 "#;
     parse_test!(multiline, AST(vec![Declaration(
       FuncDecl(Signature { name: rc!(a), operator: false, params: vec![(rc!(x),None)], type_anno: None },
-        vec![exprstatement!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
+        vec![exst!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
     let multiline2 = r#"
 fn a(x) {
 
@@ -1249,19 +1312,18 @@ fn a(x) {
 "#;
     parse_test!(multiline2, AST(vec![Declaration(
       FuncDecl(Signature { name: rc!(a), operator: false, params: vec![(rc!(x),None)], type_anno: None },
-        vec![exprstatement!(Call { f: bx!(ex!(val!("x"))), arguments: vec![] })]))]));
+        vec![exst!(s "x()")]))]));
-
   }
 
   #[test]
   fn parsing_bools() {
-    parse_test!("false", AST(vec![exprstatement!(BoolLiteral(false))]));
+    parse_test!("false", AST(vec![exst!(BoolLiteral(false))]));
-    parse_test!("true", AST(vec![exprstatement!(BoolLiteral(true))]));
+    parse_test!("true", AST(vec![exst!(BoolLiteral(true))]));
   }
 
   #[test]
   fn parsing_strings() {
-    parse_test!(r#""hello""#, AST(vec![exprstatement!(StringLiteral(rc!(hello)))]));
+    parse_test!(r#""hello""#, AST(vec![exst!(StringLiteral(rc!(hello)))]));
   }
 
   #[test]
@@ -1304,14 +1366,14 @@ fn a(x) {
   #[test]
   fn parsing_block_expressions() {
     parse_test! {
-      "if a() then { b(); c() }", AST(vec![exprstatement!(
+      "if a() then { b(); c() }", AST(vec![exst!(
         IfExpression {
           discriminator: bx! {
             Discriminator::Simple(ex!(Call { f: bx!(ex!(val!("a"))), arguments: vec![]}))
           },
           body: bx! {
             IfExpressionBody::SimpleConditional(
-              vec![exprstatement!(Call { f: bx!(ex!(val!("b"))), arguments: vec![]}), exprstatement!(Call { f: bx!(ex!(val!("c"))), arguments: vec![] })],
+              vec![exst!(Call { f: bx!(ex!(val!("b"))), arguments: vec![]}), exst!(Call { f: bx!(ex!(val!("c"))), arguments: vec![] })],
               None
             )
           }
@@ -1320,16 +1382,16 @@ fn a(x) {
     };
 
     parse_test! {
-      "if a() then { b(); c() } else { q }", AST(vec![exprstatement!(
+      "if a() then { b(); c() } else { q }", AST(vec![exst!(
         IfExpression {
           discriminator: bx! {
             Discriminator::Simple(ex!(Call { f: bx!(ex!(val!("a"))), arguments: vec![]}))
           },
           body: bx! {
             IfExpressionBody::SimpleConditional(
-              vec![exprstatement!(Call { f: bx!(ex!(val!("b"))), arguments: vec![]}), exprstatement!(Call { f: bx!(ex!(val!("c"))), arguments: vec![] })],
+              vec![exst!(Call { f: bx!(ex!(val!("b"))), arguments: vec![]}), exst!(Call { f: bx!(ex!(val!("c"))), arguments: vec![] })],
               Some(
-                vec![exprstatement!(val!("q"))],
+                vec![exst!(val!("q"))],
               )
             )
           }
@@ -1338,9 +1400,9 @@ fn a(x) {
     };
 
     /*
-    parse_test!("if a() then { b(); c() }", AST(vec![exprstatement!(
+    parse_test!("if a() then { b(); c() }", AST(vec![exst!(
         IfExpression(bx!(ex!(Call { f: bx!(ex!(val!("a"))), arguments: vec![]})),
-          vec![exprstatement!(Call { f: bx!(ex!(val!("b"))), arguments: vec![]}), exprstatement!(Call { f: bx!(ex!(val!("c"))), arguments: vec![] })],
+          vec![exst!(Call { f: bx!(ex!(val!("b"))), arguments: vec![]}), exst!(Call { f: bx!(ex!(val!("c"))), arguments: vec![] })],
           None)
         )]));
     parse_test!(r#"
@@ -1350,21 +1412,21 @@ fn a(x) {
     } else {
       c
     }"#,
-    AST(vec![exprstatement!(IfExpression(bx!(ex!(BoolLiteral(true))),
+    AST(vec![exst!(IfExpression(bx!(ex!(BoolLiteral(true))),
       vec![Declaration(Binding { name: rc!(a), constant: true, expr: ex!(NatLiteral(10)) }),
-           exprstatement!(val!(rc!(b)))],
+           exst!(val!(rc!(b)))],
-      Some(vec![exprstatement!(val!(rc!(c)))])))])
+      Some(vec![exst!(val!(rc!(c)))])))])
     );
 
-    parse_test!("if a { b } else { c }", AST(vec![exprstatement!(
+    parse_test!("if a { b } else { c }", AST(vec![exst!(
           IfExpression(bx!(ex!(val!("a"))),
-            vec![exprstatement!(val!("b"))],
+            vec![exst!(val!("b"))],
-            Some(vec![exprstatement!(val!("c"))])))]));
+            Some(vec![exst!(val!("c"))])))]));
 
-    parse_test!("if (A {a: 1}) { b } else { c }", AST(vec![exprstatement!(
+    parse_test!("if (A {a: 1}) { b } else { c }", AST(vec![exst!(
           IfExpression(bx!(ex!(NamedStruct { name: rc!(A), fields: vec![(rc!(a), ex!(NatLiteral(1)))]})),
-            vec![exprstatement!(val!("b"))],
+            vec![exst!(val!("b"))],
-            Some(vec![exprstatement!(val!("c"))])))]));
+            Some(vec![exst!(val!("c"))])))]));
 
     parse_error!("if A {a: 1} { b } else { c }");
     */
@@ -1418,21 +1480,21 @@ fn a(x) {
         Expression(val!("b"), Some(ty!("Int"))) })]));
 
     parse_test!("a : Int", AST(vec![
-      exprstatement!(val!("a"), ty!("Int"))
+      exst!(val!("a"), ty!("Int"))
     ]));
 
     parse_test!("a : Option<Int>", AST(vec![
-      exprstatement!(val!("a"), Singleton(TypeSingletonName { name: rc!(Option), params: vec![ty!("Int")] }))
+      exst!(val!("a"), Singleton(TypeSingletonName { name: rc!(Option), params: vec![ty!("Int")] }))
     ]));
 
     parse_test!("a : KoreanBBQSpecifier<Kimchi, Option<Bulgogi> >", AST(vec![
-      exprstatement!(val!("a"), Singleton(TypeSingletonName { name: rc!(KoreanBBQSpecifier), params: vec![
+      exst!(val!("a"), Singleton(TypeSingletonName { name: rc!(KoreanBBQSpecifier), params: vec![
         ty!("Kimchi"), Singleton(TypeSingletonName { name: rc!(Option), params: vec![ty!("Bulgogi")] })
       ] }))
     ]));
 
     parse_test!("a : (Int, Yolo<a>)", AST(vec![
-      exprstatement!(val!("a"), Tuple(
+      exst!(val!("a"), Tuple(
         vec![ty!("Int"), Singleton(TypeSingletonName {
           name: rc!(Yolo), params: vec![ty!("a")]
         })]))]));
@@ -1440,28 +1502,80 @@ fn a(x) {
 
   #[test]
   fn parsing_lambdas() {
-    parse_test! { "{|x| x + 1}", single_expr!(
+    parse_test_wrap_ast! { r#"\(x) { x + 1}"#, exst!(
-      Lambda { params: vec![(rc!(x), None)], body: vec![exst!("+", val!("x"), NatLiteral(1))] }
+        Lambda { params: vec![(rc!(x), None)], type_anno: None, body: vec![exst!(s "x + 1")] }
-    ) }
+      ) 
+    }
 
-    parse_test!("{      |x: Int, y| a;b;c;}", AST(vec![
+    parse_test!(r#"\  (x: Int, y) { a;b;c;}"#, AST(vec![
-      exprstatement!(Lambda {
+      exst!(Lambda {
         params: vec![(rc!(x), Some(ty!("Int"))), (rc!(y), None)],
-        body: vec![exst!(val!("a")), exst!(val!("b")), exst!(val!("c"))]
+        type_anno: None,
+        body: vec![exst!(s "a"), exst!(s "b"), exst!(s "c")]
       })
     ]));
 
-    parse_test!("{|x| y}(1)", AST(vec![
+    parse_test!(r#"\(x){y}(1)"#, AST(vec![
-      exprstatement!(Call { f: bx!(ex!(
+      exst!(Call { f: bx!(ex!(
-        Lambda { params: vec![(rc!(x), None)], body: vec![exprstatement!(val!("y"))] })),
+        Lambda { 
+          params: vec![(rc!(x), None)],
+          type_anno: None,
+          body: vec![exst!(s "y")] }
+        )),
         arguments: vec![ex!(NatLiteral(1))] })]));
+
+    parse_test_wrap_ast! {
+      r#"\(x: Int): String { "q" }"#,
+      exst!(Lambda {
+        params: vec![(rc!(x), Some(ty!("Int")))],
+        type_anno: Some(ty!("String")),
+        body: vec![exst!(s r#""q""#)]
+      })
+    }
+  }
+
+  #[test]
+  fn single_param_lambda() {
+    parse_test_wrap_ast! {
+      r"\x { x + 10 }", 
+      exst!(Lambda {
+        params: vec![(rc!(x), None)],
+        type_anno: None,
+        body: vec![exst!(s r"x + 10")]
+      })
+    }
+
+    parse_test_wrap_ast! {
+      r"\x: Nat { x + 10 }", 
+      exst!(Lambda {
+        params: vec![(rc!(x), Some(ty!("Nat")))],
+        type_anno: None,
+        body: vec![exst!(s r"x + 10")]
+      })
+    }
+  }
+
+  #[test]
+  fn more_advanced_lambdas() {
+    parse_test! {
+      r#"fn wahoo() { let a = 10; \(x) { x + a } };
+      wahoo()(3) "#,  AST(vec![
+        exst!(s r"fn wahoo() { let a = 10; \(x) { x + a } }"),
+        exst! {
+          Call {
+            f: bx!(ex!(Call { f: bx!(ex!(val!("wahoo"))), arguments: vec![] })),
+            arguments: vec![ex!(s "3")],
+          }
+        }
+      ])
+    }
   }
 
   #[test]
    fn list_literals() {
      parse_test! {
        "[1,2]", AST(vec![
-         exprstatement!(ListLiteral(vec![ex!(NatLiteral(1)), ex!(NatLiteral(2))]))])
+         exst!(ListLiteral(vec![ex!(NatLiteral(1)), ex!(NatLiteral(2))]))])
      };
    }
 
@@ -1469,12 +1583,12 @@ fn a(x) {
   fn while_expr() {
     parse_test! {
       "while { }", AST(vec![
-      exprstatement!(WhileExpression { condition: None, body: vec![] })])
+      exst!(WhileExpression { condition: None, body: vec![] })])
     }
 
     parse_test! {
       "while a == b { }", AST(vec![
-      exprstatement!(WhileExpression { condition: Some(bx![ex![binexp!("==", val!("a"), val!("b"))]]), body: vec![] })])
+      exst!(WhileExpression { condition: Some(bx![ex![binexp!("==", val!("a"), val!("b"))]]), body: vec![] })])
     }
   }
 
@@ -1482,120 +1596,110 @@ fn a(x) {
   fn for_expr() {
     parse_test! {
       "for { a <- maybeValue } return 1", AST(vec![
-      exprstatement!(ForExpression {
+      exst!(ForExpression {
         enumerators: vec![Enumerator { id: rc!(a), generator: ex!(val!("maybeValue")) }],
-        body: bx!(MonadicReturn(ex!(NatLiteral(1))))
+        body: bx!(MonadicReturn(ex!(s "1")))
       })])
     }
 
     parse_test! {
       "for n <- someRange { f(n); }", AST(vec![
-      exprstatement!(ForExpression { enumerators: vec![Enumerator { id: rc!(n), generator: ex!(val!("someRange"))}],
+      exst!(ForExpression { enumerators: vec![Enumerator { id: rc!(n), generator: ex!(val!("someRange"))}],
-        body: bx!(ForBody::StatementBlock(vec![exprstatement!(Call { f: bx![ex!(val!("f"))], arguments: vec![ex!(val!("n"))] })]))
+        body: bx!(ForBody::StatementBlock(vec![exst!(s "f(n)")]))
       })])
     }
   }
 
   #[test]
   fn patterns() {
-    parse_test! {
+    parse_test_wrap_ast! {
-      "if x is Some(a) then { 4 } else { 9 }", AST(vec![
+      "if x is Some(a) then { 4 } else { 9 }", exst!(
-        exprstatement!(
+        IfExpression {
-          IfExpression {
+          discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+          body: bx!(IfExpressionBody::SimplePatternMatch(Pattern::TupleStruct(rc!(Some), vec![Pattern::Literal(PatternLiteral::VarPattern(rc!(a)))]), vec![exst!(s "4")], Some(vec![exst!(s "9")]))) }
-            body: bx!(IfExpressionBody::SimplePatternMatch(Pattern::TupleStruct(rc!(Some), vec![Pattern::Literal(PatternLiteral::VarPattern(rc!(a)))]), vec![exprstatement!(NatLiteral(4))], Some(vec![exprstatement!(NatLiteral(9))]))) }
+        )
-          )
-      ])
     }
 
-    parse_test! {
+    parse_test_wrap_ast! {
-      "if x is Some(a) then 4 else 9", AST(vec![
+      "if x is Some(a) then 4 else 9", exst!(
-        exprstatement!(
+        IfExpression {
-          IfExpression {
+          discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+          body: bx!(IfExpressionBody::SimplePatternMatch(Pattern::TupleStruct(rc!(Some), vec![Pattern::Literal(PatternLiteral::VarPattern(rc!(a)))]), vec![exst!(s "4")], Some(vec![exst!(s "9")]))) }
-            body: bx!(IfExpressionBody::SimplePatternMatch(Pattern::TupleStruct(rc!(Some), vec![Pattern::Literal(PatternLiteral::VarPattern(rc!(a)))]), vec![exprstatement!(NatLiteral(4))], Some(vec![exprstatement!(NatLiteral(9))]))) }
+      )
-          )
-      ])
     }
 
-    parse_test! {
+    parse_test_wrap_ast! {
-      "if x is Something { a, b: x } then { 4 } else { 9 }", AST(vec![
+      "if x is Something { a, b: x } then { 4 } else { 9 }", exst!(
-        exprstatement!(
+        IfExpression {
-          IfExpression {
+          discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+          body: bx!(IfExpressionBody::SimplePatternMatch(
-            body: bx!(IfExpressionBody::SimplePatternMatch(
               Pattern::Record(rc!(Something), vec![
                 (rc!(a),Pattern::Literal(PatternLiteral::StringPattern(rc!(a)))),
                 (rc!(b),Pattern::Literal(PatternLiteral::VarPattern(rc!(x)))) 
               ]),
-              vec![exprstatement!(NatLiteral(4))], Some(vec![exprstatement!(NatLiteral(9))]))) 
+              vec![exst!(s "4")], Some(vec![exst!(s "9")]))) 
-            }
+        }
-          )
+      )
-      ])
     }
-
   }
 
   #[test]
   fn pattern_literals() {
-    parse_test! {
+    parse_test_wrap_ast! {
-      "if x is -1 then 1 else 2", AST(vec![
+      "if x is -1 then 1 else 2",
-        exprstatement!(
+      exst!(
-          IfExpression {
+        IfExpression {
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+          discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
-            body: bx!(IfExpressionBody::SimplePatternMatch(
+          body: bx!(IfExpressionBody::SimplePatternMatch(
-              Pattern::Literal(PatternLiteral::NumPattern { neg: true, num: NatLiteral(1) }),
+            Pattern::Literal(PatternLiteral::NumPattern { neg: true, num: NatLiteral(1) }),
-              vec![exprstatement!(NatLiteral(1))],
+            vec![exst!(NatLiteral(1))],
-              Some(vec![exprstatement!(NatLiteral(2))]),
+            Some(vec![exst!(NatLiteral(2))]),
-            ))
+          ))
-          }
+        }
-        )
+      )
-      ])
     }
 
-    parse_test! {
+    parse_test_wrap_ast! {
-      "if x is 1 then 1 else 2", AST(vec![
+      "if x is 1 then 1 else 2", 
-        exprstatement!(
+      exst!(
-          IfExpression {
+        IfExpression {
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+          discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
-            body: bx!(IfExpressionBody::SimplePatternMatch(
+          body: bx!(IfExpressionBody::SimplePatternMatch(
               Pattern::Literal(PatternLiteral::NumPattern { neg: false, num: NatLiteral(1) }),
-              vec![exprstatement!(NatLiteral(1))],
+              vec![exst!(s "1")],
-              Some(vec![exprstatement!(NatLiteral(2))]),
+              Some(vec![exst!(s "2")]),
-            ))
+              ))
-          }
+        }
-        )
+      )
-      ])
     }
 
     parse_test! {
       "if x is true then 1 else 2", AST(vec![
-        exprstatement!(
+        exst!(
           IfExpression {
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+            discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
             body: bx!(IfExpressionBody::SimplePatternMatch(
               Pattern::Literal(PatternLiteral::BoolPattern(true)),
-              vec![exprstatement!(NatLiteral(1))],
+              vec![exst!(NatLiteral(1))],
-              Some(vec![exprstatement!(NatLiteral(2))]),
+              Some(vec![exst!(NatLiteral(2))]),
             ))
           }
         )
       ])
     }
 
-    parse_test! {
+    parse_test_wrap_ast! {
-      "if x is \"gnosticism\" then 1 else 2", AST(vec![
+      "if x is \"gnosticism\" then 1 else 2",
-        exprstatement!(
+        exst!(
           IfExpression {
-            discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
+            discriminator: bx!(Discriminator::Simple(ex!(s "x"))),
             body: bx!(IfExpressionBody::SimplePatternMatch(
-              Pattern::Literal(PatternLiteral::StringPattern(rc!(gnosticism))),
+                Pattern::Literal(PatternLiteral::StringPattern(rc!(gnosticism))),
-              vec![exprstatement!(NatLiteral(1))],
+                vec![exst!(s "1")],
-              Some(vec![exprstatement!(NatLiteral(2))]),
+                Some(vec![exst!(s "2")]),
-            ))
+                ))
           }
         )
-      ])
     }
   }
 }

schala-lang/language/src/prelude.schala

@@ -0,0 +1,13 @@
+
+type Option<T> = Some(T) | None
+type Color = Red | Green | Blue
+type Ord = LT | EQ | GT
+
+
+fn map(input: Option<T>, func: Func): Option<T> {
+  if input {
+    is Some(x) -> Some(func(x)),
+    is None -> None,
+  }
+}
+  

schala-lang/language/src/reduced_ast.rs

@@ -1,6 +1,6 @@
 use std::rc::Rc;
 
-use ast::{AST, Statement, Expression, ExpressionType, Declaration, Discriminator, IfExpressionBody, Pattern, PatternLiteral, Guard, HalfExpr};
+use ast::*;
 use symbol_table::{Symbol, SymbolSpec, SymbolTable};
 use builtin::{BinOp, PrefixOp};
 
@@ -48,6 +48,7 @@ pub enum Expr {
     then_clause: Vec<Stmt>,
     else_clause: Vec<Stmt>,
   },
+  ConditionalTargetSigilValue,
   CaseMatch {
     cond: Box<Expr>,
     alternatives: Vec<Alternative>
@@ -55,19 +56,23 @@ pub enum Expr {
   UnimplementedSigilValue
 }
 
+pub type BoundVars = Vec<Option<Rc<String>>>; //remember that order matters here
+
 #[derive(Debug, Clone)]
 pub struct Alternative {
   pub tag: Option<usize>,
-  pub subpatterns: Vec<Alternative>,
+  pub subpatterns: Vec<Option<Subpattern>>,
   pub guard: Option<Expr>,
-  pub bound_vars: Vec<Option<Rc<String>>>, //remember that order matters here
+  pub bound_vars: BoundVars,
   pub item: Vec<Stmt>,
 }
 
-impl Alternative {
+#[derive(Debug, Clone)]
-  fn default(item: Vec<Stmt>) -> Alternative {
+pub struct Subpattern {
-    Alternative { tag: None, subpatterns: vec![], guard: None, bound_vars: vec![], item }
+  pub tag: Option<usize>,
-  }
+  pub subpatterns: Vec<Option<Subpattern>>,
+  pub bound_vars: BoundVars,
+  pub guard: Option<Expr>,
 }
 
 #[derive(Debug, Clone)]
@@ -135,11 +140,24 @@ impl Expression {
       },
       TupleLiteral(exprs) => Expr::Tuple(exprs.iter().map(|e| e.reduce(symbol_table)).collect()),
       IfExpression { discriminator, body } => reduce_if_expression(discriminator, body, symbol_table),
-      _ => Expr::UnimplementedSigilValue,
+      Lambda { params, body, .. } => reduce_lambda(params, body, symbol_table),
+      NamedStruct { .. } => Expr::UnimplementedSigilValue,
+      Index { .. } => Expr::UnimplementedSigilValue,
+      WhileExpression { .. } => Expr::UnimplementedSigilValue,
+      ForExpression { .. } => Expr::UnimplementedSigilValue,
+      ListLiteral { .. } => Expr::UnimplementedSigilValue,
     }
   }
 }
 
+fn reduce_lambda(params: &Vec<FormalParam>, body: &Block, symbol_table: &SymbolTable) -> Expr {
+  Expr::Func(Func::UserDefined {
+    name: None,
+    params: params.iter().map(|param| param.0.clone()).collect(),
+    body: body.iter().map(|stmt| stmt.reduce(symbol_table)).collect(),
+  })
+}
+
 fn reduce_if_expression(discriminator: &Discriminator, body: &IfExpressionBody, symbol_table: &SymbolTable) -> Expr {
   let cond = Box::new(match *discriminator {
     Discriminator::Simple(ref expr) => expr.reduce(symbol_table),
@@ -162,8 +180,14 @@ fn reduce_if_expression(discriminator: &Discriminator, body: &IfExpressionBody,
       };
 
       let alternatives = vec![
-        pat.to_alternative(&cond, then_clause, symbol_table),
+        pat.to_alternative(then_clause, symbol_table),
-        Alternative::default(else_clause),
+        Alternative {
+          tag: None,
+          subpatterns: vec![],
+          bound_vars: vec![],
+          guard: None,
+          item: else_clause
+        },
       ];
 
       Expr::CaseMatch {
@@ -177,7 +201,7 @@ fn reduce_if_expression(discriminator: &Discriminator, body: &IfExpressionBody,
         match arm.guard {
           Guard::Pat(ref p) =>  {
             let item = arm.body.iter().map(|expr| expr.reduce(symbol_table)).collect();
-            let alt = p.to_alternative(&cond, item, symbol_table);
+            let alt = p.to_alternative(item, symbol_table);
             alternatives.push(alt);
           },
           Guard::HalfExpr(HalfExpr { op: _, expr: _ }) => {
@@ -193,104 +217,134 @@ fn reduce_if_expression(discriminator: &Discriminator, body: &IfExpressionBody,
  * x is SomeBigOldEnum(_, x, Some(t))
  */
 
+fn handle_symbol(symbol: Option<&Symbol>, inner_patterns: &Vec<Pattern>, symbol_table: &SymbolTable) -> Subpattern {
+  use self::Pattern::*;
+  let tag = symbol.map(|symbol| match symbol.spec {
+    SymbolSpec::DataConstructor { index, .. } => index.clone(),
+    _ => panic!("Symbol is not a data constructor - this should've been caught in type-checking"),
+  });
+  let bound_vars = inner_patterns.iter().map(|p| match p {
+    Literal(PatternLiteral::VarPattern(var)) => Some(var.clone()),
+    _ => None,
+  }).collect();
+
+  let subpatterns = inner_patterns.iter().map(|p| match p {
+    Ignored => None,
+    Literal(PatternLiteral::VarPattern(_)) => None,
+    Literal(other) => Some(other.to_subpattern(symbol_table)),
+    tp @ TuplePattern(_) => Some(tp.to_subpattern(symbol_table)),
+    ts @ TupleStruct(_, _) => Some(ts.to_subpattern(symbol_table)),
+    Record(..) => unimplemented!(),
+  }).collect();
+
+  let guard = None;
+  /*
+     let guard_equality_exprs: Vec<Expr> = subpatterns.iter().map(|p| match p {
+     Literal(lit) => match lit {
+     _ => unimplemented!()
+     },
+     _ => unimplemented!()
+     }).collect();
+     */
+
+  Subpattern {
+    tag,
+    subpatterns,
+    guard,
+    bound_vars,
+  }
+}
 
 impl Pattern {
-  fn to_alternative(&self, cond: &Box<Expr>, item: Vec<Stmt>, symbol_table: &SymbolTable) -> Alternative {
+  fn to_alternative(&self, item: Vec<Stmt>, symbol_table: &SymbolTable) -> Alternative {
-    use self::Pattern::*;
+    let s = self.to_subpattern(symbol_table);
-
+    Alternative {
-    fn handle_symbol(symbol: &Symbol, subpatterns: &Vec<Pattern>, item: Vec<Stmt>) -> Alternative {
+      tag: s.tag,
-      let tag = match symbol.spec {
+      subpatterns: s.subpatterns,
-        SymbolSpec::DataConstructor { index, .. } => index.clone(),
+      bound_vars: s.bound_vars,
-        _ => panic!("Symbol is not a data constructor - this should've been caught in type-checking"),
+      guard: s.guard,
-      };
+      item
-      let bound_vars = subpatterns.iter().map(|p| match p {
-        Literal(PatternLiteral::VarPattern(var)) => Some(var.clone()),
-        _ => None,
-      }).collect();
-
-      /*
-      let guard_equality_exprs: Vec<Expr> = subpatterns.iter().map(|p| match p {
-        Literal(lit) => match lit {
-          _ => unimplemented!()
-        },
-        _ => unimplemented!()
-      }).collect();
-      */
-
-      let guard = None;
-      let subpatterns = vec![];
-
-      Alternative {
-        tag: Some(tag),
-        subpatterns,
-        guard,
-        bound_vars,
-        item,
-      }
     }
+  }
 
+  fn to_subpattern(&self, symbol_table: &SymbolTable) -> Subpattern {
+    use self::Pattern::*;
     match self {
-      TupleStruct(name, subpatterns) => {
+      TupleStruct(name, inner_patterns) => {
         let symbol = symbol_table.lookup_by_name(name).expect(&format!("Symbol {} not found", name));
-        handle_symbol(symbol, subpatterns, item)
+        handle_symbol(Some(symbol), inner_patterns, symbol_table)
-      },
-      TuplePattern(_items) => {
-        unimplemented!()
       },
+      TuplePattern(inner_patterns) => handle_symbol(None, inner_patterns, symbol_table),
       Record(_name, _pairs) => {
         unimplemented!()
       },
-      Ignored => Alternative::default(item),
+      Ignored => Subpattern { tag: None, subpatterns: vec![], guard: None, bound_vars: vec![] },
-      Literal(lit) => match lit {
+      Literal(lit) => lit.to_subpattern(symbol_table),
-        PatternLiteral::NumPattern { neg, num } => {
+    }
-          let comparison = Expr::Lit(match (neg, num) {
+  }
-            (false, ExpressionType::NatLiteral(n)) => Lit::Nat(*n),
+}
-            (false, ExpressionType::FloatLiteral(f)) => Lit::Float(*f),
+
-            (true, ExpressionType::NatLiteral(n)) => Lit::Int(-1*(*n as i64)),
+impl PatternLiteral {
-            (true, ExpressionType::FloatLiteral(f)) => Lit::Float(-1.0*f),
+  fn to_subpattern(&self, symbol_table: &SymbolTable) -> Subpattern {
-            _ => panic!("This should never happen")
+    use self::PatternLiteral::*;
-          });
+    match self {
-          let guard = Some(Expr::Call {
+      NumPattern { neg, num } => {
-            f: Box::new(Expr::Func(Func::BuiltIn(Rc::new("==".to_string())))),
+        let comparison = Expr::Lit(match (neg, num) {
-            args: vec![comparison, *cond.clone()]
+          (false, ExpressionType::NatLiteral(n)) => Lit::Nat(*n),
-          });
+          (false, ExpressionType::FloatLiteral(f)) => Lit::Float(*f),
-          Alternative {
+          (true, ExpressionType::NatLiteral(n)) => Lit::Int(-1*(*n as i64)),
-            tag: None,
+          (true, ExpressionType::FloatLiteral(f)) => Lit::Float(-1.0*f),
-            subpatterns: vec![],
+          _ => panic!("This should never happen")
-            guard,
+        });
-            bound_vars: vec![],
+        let guard = Some(Expr::Call {
-            item
+          f: Box::new(Expr::Func(Func::BuiltIn(Rc::new("==".to_string())))),
-          }
+          args: vec![comparison, Expr::ConditionalTargetSigilValue],
-        },
+        });
-        PatternLiteral::StringPattern(_s) => unimplemented!(),
+        Subpattern {
-        PatternLiteral::BoolPattern(b) =>  {
+          tag: None,
-          let guard = Some(if *b {
+          subpatterns: vec![],
-            *cond.clone()
+          guard,
-          } else {
+          bound_vars: vec![],
-            Expr::Call {
-              f: Box::new(Expr::Func(Func::BuiltIn(Rc::new("!".to_string())))),
-              args: vec![*cond.clone()]
-            }
-          });
-          Alternative {
-            tag: None,
-            subpatterns: vec![],
-            guard,
-            bound_vars: vec![],
-            item
-          }
-        },
-        PatternLiteral::VarPattern(var) => match symbol_table.lookup_by_name(var) {
-          Some(symbol) => handle_symbol(symbol, &vec![], item),
-          None => Alternative {
-            tag: None,
-            subpatterns: vec![],
-            guard: None,
-            bound_vars: vec![Some(var.clone())],
-            item
-          }
         }
       },
+      StringPattern(s) => {
+        let guard = Some(Expr::Call {
+          f: Box::new(Expr::Func(Func::BuiltIn(Rc::new("==".to_string())))),
+          args: vec![Expr::Lit(Lit::StringLit(s.clone())), Expr::ConditionalTargetSigilValue]
+        });
+
+        Subpattern {
+          tag: None,
+          subpatterns: vec![],
+          guard,
+          bound_vars: vec![],
+        }
+      },
+      BoolPattern(b) =>  {
+        let guard = Some(if *b {
+          Expr::ConditionalTargetSigilValue
+        } else {
+          Expr::Call {
+            f: Box::new(Expr::Func(Func::BuiltIn(Rc::new("!".to_string())))),
+            args: vec![Expr::ConditionalTargetSigilValue]
+          }
+        });
+        Subpattern {
+          tag: None,
+          subpatterns: vec![],
+          guard,
+          bound_vars: vec![],
+        }
+      },
+      VarPattern(var) => match symbol_table.lookup_by_name(var) {
+        Some(symbol) => handle_symbol(Some(symbol), &vec![], symbol_table),
+        None => Subpattern {
+          tag: None,
+          subpatterns: vec![],
+          guard: None,
+          bound_vars: vec![Some(var.clone())],
+        }
+      }
     }
   }
 }

schala-lang/language/src/source_map.rs

@@ -0,0 +1,27 @@
+
+#[derive(Debug, Clone)]
+pub struct SourceMap<T> {
+  pub node: T,
+  pub data: Option<SourceData>
+}
+
+impl<T> SourceMap<T> {
+  pub fn get(&self) -> &T {
+    &self.node
+  }
+
+  /*
+  pub fn get_source_data(&self) -> Option<SourceData> {
+    self.data.clone()
+  }
+  */
+}
+
+#[derive(Debug, Clone)]
+pub struct SourceData {
+  pub line_number: usize,
+  pub char_idx: usize
+}
+
+
+

schala-lang/language/src/tokenizing.rs

@@ -5,14 +5,14 @@ use std::iter::{Iterator, Peekable};
 use std::fmt;
 
 #[derive(Debug, PartialEq, Clone)]
-pub enum TokenType {
+pub enum TokenKind {
   Newline, Semicolon,
 
   LParen, RParen,
   LSquareBracket, RSquareBracket,
   LAngleBracket, RAngleBracket,
   LCurlyBrace, RCurlyBrace,
-  Pipe,
+  Pipe, Backslash,
 
   Comma, Period, Colon, Underscore,
   Slash,
@@ -27,9 +27,9 @@ pub enum TokenType {
 
   Error(String),
 }
-use self::TokenType::*;
+use self::TokenKind::*;
 
-impl fmt::Display for TokenType {
+impl fmt::Display for TokenKind {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
     match self {
       &Operator(ref s) => write!(f, "Operator({})", **s),
@@ -87,19 +87,28 @@ lazy_static! {
 
 #[derive(Debug, Clone)]
 pub struct Token {
-  pub token_type: TokenType,
+  pub kind: TokenKind,
   pub offset: (usize, usize),
 }
 
+#[derive(Debug, Clone)]
+pub struct TokenMetadata {
+  pub offset: (usize, usize)
+}
+
 impl Token {
   pub fn get_error(&self) -> Option<String> {
-    match self.token_type {
+    match self.kind {
-      TokenType::Error(ref s) => Some(s.clone()),
+      TokenKind::Error(ref s) => Some(s.clone()),
       _ => None,
     }
   }
   pub fn to_string_with_metadata(&self) -> String {
-    format!("{}(L:{},c:{})", self.token_type, self.offset.0, self.offset.1)
+    format!("{}(L:{},c:{})", self.kind, self.offset.0, self.offset.1)
+  }
+
+  pub fn get_kind(&self) -> TokenKind {
+    self.kind.clone()
   }
 }
 
@@ -121,7 +130,7 @@ pub fn tokenize(input: &str) -> Vec<Token> {
       .peekable();
 
   while let Some((line_idx, ch_idx, c)) = input.next() {
-    let cur_tok_type = match c {
+    let cur_tok_kind = match c {
       '/' => match input.peek().map(|t| t.2) {
         Some('/') => {
           while let Some((_, _, c)) = input.next() {
@@ -157,17 +166,18 @@ pub fn tokenize(input: &str) -> Vec<Token> {
       '{' => LCurlyBrace, '}' => RCurlyBrace,
       '[' => LSquareBracket, ']' => RSquareBracket,
       '"' => handle_quote(&mut input),
+      '\\' => Backslash,
       c if c.is_digit(10) => handle_digit(c, &mut input),
       c if c.is_alphabetic() || c == '_' => handle_alphabetic(c, &mut input), //TODO I'll probably have to rewrite this if I care about types being uppercase, also type parameterization
       c if is_operator(&c) => handle_operator(c, &mut input),
       unknown => Error(format!("Unexpected character: {}", unknown)),
     };
-    tokens.push(Token { token_type: cur_tok_type, offset: (line_idx, ch_idx) });
+    tokens.push(Token { kind: cur_tok_kind, offset: (line_idx, ch_idx) });
   }
   tokens
 }
 
-fn handle_digit(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenType {
+fn handle_digit(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenKind {
   if c == '0' && input.peek().map_or(false, |&(_, _, c)| { c == 'x' }) {
     input.next();
     let rest: String = input.peeking_take_while(|&(_, _, ref c)| c.is_digit(16) || *c == '_').map(|(_, _, c)| { c }).collect();
@@ -182,7 +192,7 @@ fn handle_digit(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) ->
   }
 }
 
-fn handle_quote(input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenType {
+fn handle_quote(input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenKind {
   let mut buf = String::new();
   loop {
     match input.next().map(|(_, _, c)| { c }) {
@@ -201,22 +211,22 @@ fn handle_quote(input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenType
         }
       },
       Some(c) => buf.push(c),
-      None => return TokenType::Error(format!("Unclosed string")),
+      None => return TokenKind::Error(format!("Unclosed string")),
     }
   }
-  TokenType::StrLiteral(Rc::new(buf))
+  TokenKind::StrLiteral(Rc::new(buf))
 }
 
-fn handle_alphabetic(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenType {
+fn handle_alphabetic(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenKind {
   let mut buf = String::new();
   buf.push(c);
   if c == '_' && input.peek().map(|&(_, _, c)| { !c.is_alphabetic() }).unwrap_or(true) {
-    return TokenType::Underscore
+    return TokenKind::Underscore
   }
 
   loop {
     match input.peek().map(|&(_, _, c)| { c }) {
-      Some(c) if c.is_alphanumeric() => {
+      Some(c) if c.is_alphanumeric() || c == '_' => {
         input.next();
         buf.push(c);
       },
@@ -225,12 +235,12 @@ fn handle_alphabetic(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>
   }
 
   match KEYWORDS.get(buf.as_str()) {
-    Some(kw) => TokenType::Keyword(*kw),
+    Some(kw) => TokenKind::Keyword(*kw),
-    None => TokenType::Identifier(Rc::new(buf)),
+    None => TokenKind::Identifier(Rc::new(buf)),
   }
 }
 
-fn handle_operator(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenType {
+fn handle_operator(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>) -> TokenKind {
   match c {
     '<' | '>' | '|' | '.' => {
       let ref next = input.peek().map(|&(_, _, c)| { c });
@@ -275,7 +285,7 @@ fn handle_operator(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>)
       }
     }
   }
-  TokenType::Operator(Rc::new(buf))
+  TokenKind::Operator(Rc::new(buf))
 }
 
 #[cfg(test)]
@@ -290,26 +300,29 @@ mod schala_tokenizer_tests {
   #[test]
   fn tokens() {
     let a = tokenize("let a: A<B> = c ++ d");
-    let token_types: Vec<TokenType> = a.into_iter().map(move |t| t.token_type).collect();
+    let token_kinds: Vec<TokenKind> = a.into_iter().map(move |t| t.kind).collect();
-    assert_eq!(token_types, vec![Keyword(Let), ident!("a"), Colon, ident!("A"),
+    assert_eq!(token_kinds, vec![Keyword(Let), ident!("a"), Colon, ident!("A"),
       LAngleBracket, ident!("B"), RAngleBracket, op!("="), ident!("c"), op!("++"), ident!("d")]);
   }
 
   #[test]
   fn underscores() {
-    let token_types: Vec<TokenType> = tokenize("4_8").into_iter().map(move |t| t.token_type).collect();
+    let token_kinds: Vec<TokenKind> = tokenize("4_8").into_iter().map(move |t| t.kind).collect();
-    assert_eq!(token_types, vec![digit!("4"), Underscore, digit!("8")]);
+    assert_eq!(token_kinds, vec![digit!("4"), Underscore, digit!("8")]);
+
+    let token_kinds2: Vec<TokenKind> = tokenize("aba_yo").into_iter().map(move |t| t.kind).collect();
+    assert_eq!(token_kinds2, vec![ident!("aba_yo")]);
   }
 
   #[test]
   fn comments() {
-    let token_types: Vec<TokenType> = tokenize("1  + /* hella /* bro */ */ 2").into_iter().map(move |t| t.token_type).collect();
+    let token_kinds: Vec<TokenKind> = tokenize("1  + /* hella /* bro */ */ 2").into_iter().map(move |t| t.kind).collect();
-    assert_eq!(token_types, vec![digit!("1"), op!("+"), digit!("2")]);
+    assert_eq!(token_kinds, vec![digit!("1"), op!("+"), digit!("2")]);
   }
 
   #[test]
   fn backtick_operators() {
-    let token_types: Vec<TokenType> = tokenize("1 `plus` 2").into_iter().map(move |t| t.token_type).collect();
+    let token_kinds: Vec<TokenKind> = tokenize("1 `plus` 2").into_iter().map(move |t| t.kind).collect();
-    assert_eq!(token_types, vec![digit!("1"), op!("plus"), digit!("2")]);
+    assert_eq!(token_kinds, vec![digit!("1"), op!("plus"), digit!("2")]);
   }
 }

schala-lang/language/src/typechecking.rs

@@ -1,3 +1,254 @@
 use std::rc::Rc;
 
+use ast::*;
+use util::ScopeStack;
+
 pub type TypeName = Rc<String>;
+
+pub struct TypeContext<'a> {
+  variable_map: ScopeStack<'a, Rc<String>, Type<TVar>>,
+  evar_count: u32
+}
+
+/// `InferResult` is the monad in which type inference takes place.
+type InferResult<T> = Result<T, TypeError>;
+
+#[derive(Debug, Clone)]
+struct TypeError { msg: String }
+
+impl TypeError {
+  fn new<A>(msg: &str) -> InferResult<A> {
+    Err(TypeError { msg: msg.to_string() })
+  }
+}
+
+/// `Type` is parameterized by whether the type variables can be just universal, or universal or
+/// existential.
+#[derive(Debug, Clone)]
+enum Type<A> {
+  Var(A),
+  Const(TConst),
+  Arrow(Box<Type<A>>, Box<Type<A>>),
+}
+
+#[derive(Debug, Clone)]
+enum TVar {
+  Univ(UVar),
+  Exist(ExistentialVar)
+}
+
+#[derive(Debug, Clone)]
+struct UVar(Rc<String>);
+
+#[derive(Debug, Clone)]
+struct ExistentialVar(u32);
+
+impl Type<UVar> {
+  fn to_tvar(&self) -> Type<TVar> {
+    match self {
+      Type::Var(UVar(name)) => Type::Var(TVar::Univ(UVar(name.clone()))),
+      Type::Const(ref c) => Type::Const(c.clone()),
+      Type::Arrow(a, b) => Type::Arrow(
+        Box::new(a.to_tvar()),
+        Box::new(b.to_tvar())
+      )
+    }
+  }
+}
+
+impl Type<TVar> {
+  fn skolemize(&self) -> Type<UVar> {
+    match self {
+      Type::Var(TVar::Univ(uvar)) => Type::Var(uvar.clone()),
+      Type::Var(TVar::Exist(_)) => Type::Var(UVar(Rc::new(format!("sk")))),
+      Type::Const(ref c) => Type::Const(c.clone()),
+      Type::Arrow(a, b) => Type::Arrow(
+        Box::new(a.skolemize()),
+        Box::new(b.skolemize())
+      )
+    }
+  }
+}
+
+impl TypeIdentifier {
+  fn to_monotype(&self) -> Type<UVar> {
+    match self {
+      TypeIdentifier::Tuple(_) => Type::Const(TConst::Nat),
+      TypeIdentifier::Singleton(TypeSingletonName { name, .. }) => {
+        match &name[..] {
+          "Nat" => Type::Const(TConst::Nat),
+          "Int" => Type::Const(TConst::Int),
+          "Float" => Type::Const(TConst::Float),
+          "Bool" => Type::Const(TConst::Bool),
+          "String" => Type::Const(TConst::StringT),
+          _ => Type::Const(TConst::Nat),
+        }
+      }
+    }
+  }
+}
+
+#[derive(Debug, Clone)]
+enum TConst {
+  User(Rc<String>),
+  Unit,
+  Nat,
+  Int,
+  Float,
+  StringT,
+  Bool,
+}
+
+impl TConst {
+  fn user(name: &str) -> TConst {
+    TConst::User(Rc::new(name.to_string()))
+  }
+}
+
+impl<'a> TypeContext<'a> {
+  pub fn new() -> TypeContext<'a> {
+    TypeContext { 
+      variable_map: ScopeStack::new(None),
+      evar_count: 0
+    }
+  }
+
+  pub fn typecheck(&mut self, ast: &AST) -> Result<String, String> {
+    match self.infer_ast(ast) {
+      Ok(t) => Ok(format!("{:?}", t)),
+      Err(err) => Err(format!("Type error: {:?}", err))
+    }
+  }
+}
+
+impl<'a> TypeContext<'a> {
+  fn infer_ast(&mut self, ast: &AST) -> InferResult<Type<UVar>> {
+    self.infer_block(&ast.0)
+  }
+
+  fn infer_statement(&mut self, stmt: &Statement) -> InferResult<Type<UVar>> {
+    match stmt {
+      Statement::ExpressionStatement(ref expr) => self.infer_expr(expr),
+      Statement::Declaration(ref decl) => self.infer_decl(decl),
+    }
+  }
+
+  fn infer_expr(&mut self, expr: &Expression) -> InferResult<Type<UVar>> {
+    match expr {
+      Expression(expr_type, Some(type_anno)) => {
+        let tx = self.infer_expr_type(expr_type)?;
+        let ty = type_anno.to_monotype();
+        self.unify(&ty.to_tvar(), &tx.to_tvar()).map(|x| x.skolemize())
+      },
+      Expression(expr_type, None) => self.infer_expr_type(expr_type)
+    }
+  }
+
+  fn infer_decl(&mut self, _decl: &Declaration) -> InferResult<Type<UVar>> {
+    Ok(Type::Const(TConst::user("unimplemented")))
+  }
+
+  fn infer_expr_type(&mut self, expr_type: &ExpressionType) -> InferResult<Type<UVar>> {
+    use self::ExpressionType::*;
+    Ok(match expr_type {
+      NatLiteral(_) => Type::Const(TConst::Nat),
+      FloatLiteral(_) => Type::Const(TConst::Float),
+      StringLiteral(_) => Type::Const(TConst::StringT),
+      BoolLiteral(_) => Type::Const(TConst::Bool),
+      Value(name) => {
+        //TODO handle the distinction between 0-arg constructors and variables at some point
+        // need symbol table for that
+        match self.variable_map.lookup(name) {
+          Some(ty) => ty.clone().skolemize(),
+          None => return TypeError::new(&format!("Variable {} not found", name))
+        }
+      },
+      IfExpression { discriminator, body } => self.infer_if_expr(discriminator, body)?,
+      Call { f, arguments } => {
+        let tf = self.infer_expr(f)?; //has to be an Arrow Type
+        let targ = self.infer_expr(&arguments[0])?; // TODO make this work with functions with more than one arg
+        match tf {
+          Type::Arrow(t1, t2) => {
+            self.unify(&t1.to_tvar(), &targ.to_tvar())?;
+            *t2.clone()
+          },
+          _ => return TypeError::new("not a function")
+        }
+      },
+
+      Lambda { params, .. } => {
+
+        let _arg_type = match &params[0] {
+          (_, Some(type_anno)) => type_anno.to_monotype().to_tvar(),
+          (_, None) => self.allocate_existential(),
+        };
+        //let _result_type = unimplemented!();
+        return TypeError::new("Unimplemented");
+
+        //Type::Arrow(Box::new(arg_type), Box::new(result_type))
+      }
+      _ => Type::Const(TConst::user("unimplemented"))
+    })
+  }
+
+  fn infer_if_expr(&mut self, discriminator: &Discriminator, body: &IfExpressionBody) -> InferResult<Type<UVar>> {
+    let _test = match discriminator {
+      Discriminator::Simple(expr) => expr,
+      _ => return TypeError::new("Dame desu")
+    };
+
+    let (_then_clause, _maybe_else_clause) = match body {
+      IfExpressionBody::SimpleConditional(a, b) => (a, b),
+      _ => return TypeError::new("Dont work")
+    };
+
+    TypeError::new("Not implemented")
+  }
+
+  fn infer_block(&mut self, block: &Block) -> InferResult<Type<UVar>> {
+    let mut output = Type::Const(TConst::Unit);
+    for statement in block.iter() {
+      output = self.infer_statement(statement)?;
+    }
+    Ok(output)
+  }
+
+  fn unify(&mut self, _t1: &Type<TVar>, _t2: &Type<TVar>) -> InferResult<Type<TVar>> {
+    TypeError::new("not implemented")
+  }
+
+  fn allocate_existential(&mut self) -> Type<TVar> {
+    let n = self.evar_count;
+    self.evar_count += 1;
+    Type::Var(TVar::Exist(ExistentialVar(n)))
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  fn parse(input: &str) -> AST {
+    let tokens: Vec<::tokenizing::Token> = ::tokenizing::tokenize(input);
+    let mut parser = ::parsing::Parser::new(tokens);
+    parser.parse().unwrap()
+  }
+
+  macro_rules! type_test {
+    ($input:expr, $correct:expr) => {
+      {
+      let mut tc = TypeContext::new();
+      let ast = parse($input);
+      tc.add_symbols(&ast);
+      assert_eq!($correct, tc.type_check(&ast).unwrap())
+      }
+    }
+  }
+
+
+
+  #[test]
+  fn basic_inference() {
+
+  }
+}

schala-repl-codegen/src/lib.rs

@@ -1,4 +1,5 @@
 #![feature(trace_macros)]
+#![recursion_limit="128"]
 extern crate proc_macro;
 extern crate proc_macro2;
 #[macro_use]
@@ -66,6 +67,65 @@ fn get_attribute_identifier(attr_name: &str, attrs: &Vec<Attribute>) -> Option<p
   })
 }
 
+/* a pass_chain function signature looks like:
+ * fn(&mut ProgrammingLanguageInterface, A, Option<&mut DebugHandler>) -> Result<B, String>
+ *
+ * TODO use some kind of failure-handling library to make this better
+ */
+fn generate_pass_chain(idents: Vec<Ident>) -> proc_macro2::TokenStream {
+  let final_return = quote! {
+    {
+      let final_output: FinishedComputation = unfinished_computation.finish(Ok(input_to_next_stage));
+      final_output
+    }
+  };
+
+  let nested_passes = idents.iter()
+    .rev()
+    .fold(final_return, |later_fragment, pass_name| {
+      quote! {
+        {
+          let pass_name = stringify!(#pass_name);
+          let (output, duration) = {
+            let ref debug_map = eval_options.debug_passes;
+            let debug_handle = match debug_map.get(pass_name) {
+              Some(PassDebugOptionsDescriptor { opts }) => {
+                let ptr = &mut unfinished_computation;
+                ptr.cur_debug_options = opts.clone();
+                Some(ptr)
+              }
+              _ => None
+            };
+            let start = time::Instant::now();
+            let pass_output = #pass_name(self, input_to_next_stage, debug_handle);
+            let elapsed = start.elapsed();
+            (pass_output, elapsed)
+          };
+          if eval_options.debug_timing {
+            unfinished_computation.durations.push(duration);
+          }
+          match output {
+            Ok(input_to_next_stage) => #later_fragment,
+            //TODO this error type needs to be guaranteed to provide a useable string
+            Err(err) => return unfinished_computation.output(Err(format!("Pass {} failed:\n{}", pass_name, err))),
+          }
+        }
+      }
+    });
+
+  quote! {
+    {
+      use std::time;
+      use schala_repl::PassDebugOptionsDescriptor;
+
+      let eval_options = options;
+      let input_to_next_stage = input;
+      let mut unfinished_computation = UnfinishedComputation::default();
+      #nested_passes
+    }
+  }
+}
+
 #[proc_macro_derive(ProgrammingLanguageInterface,
   attributes(LanguageName, SourceFileExtension, PipelineSteps, DocMethod, HandleCustomInterpreterDirectives))]
 pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream {
@@ -112,6 +172,8 @@ pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream
     }
   });
 
+  let pass_chain = generate_pass_chain(pass_idents.collect());
+
   let tokens = quote! {
     use schala_repl::PassDescriptor;
     impl ProgrammingLanguageInterface for #name {
@@ -122,8 +184,7 @@ pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream
         #file_ext.to_string()
       }
       fn execute_pipeline(&mut self, input: &str, options: &EvalOptions) -> FinishedComputation {
-        let mut chain = pass_chain![self, options; #(#pass_idents),* ];
+        #pass_chain
-        chain(input)
       }
       fn get_passes(&self) -> Vec<PassDescriptor> {
         vec![ #(#pass_descriptors),* ]

schala-repl/src/language.rs

@@ -173,61 +173,3 @@ pub trait ProgrammingLanguageInterface {
     None
   }
 }
-
-/* a pass_chain function signature looks like: 
- * fn(&mut ProgrammingLanguageInterface, A, Option<&mut DebugHandler>) -> Result<B, String>
- *
- * TODO use some kind of failure-handling library to make this better
- */
-
-#[macro_export]
-macro_rules! pass_chain {
-  ($state:expr, $eval_options:expr; $($pass:path), *) => {
-    |text_input| {
-      let mut comp = UnfinishedComputation::default();
-      pass_chain_helper! { ($state, comp, $eval_options); text_input $(, $pass)* }
-    }
-  };
-}
-
-#[macro_export]
-macro_rules! pass_chain_helper {
-  (($state:expr, $comp:expr, $eval_options:expr); $input:expr, $pass:path $(, $rest:path)*) => {
-    {
-      use std::time;
-      use schala_repl::PassDebugOptionsDescriptor;
-      let pass_name = stringify!($pass);
-      let (output, duration) = {
-        let ref debug_map = $eval_options.debug_passes;
-        let debug_handle = match debug_map.get(pass_name) {
-          Some(PassDebugOptionsDescriptor { opts }) => {
-            let ptr = &mut $comp;
-            ptr.cur_debug_options = opts.clone();
-            Some(ptr)
-          }
-          _ => None
-        };
-        let start = time::Instant::now();
-        let pass_output = $pass($state, $input, debug_handle);
-        let elapsed = start.elapsed();
-        (pass_output, elapsed)
-      };
-      if $eval_options.debug_timing {
-        $comp.durations.push(duration);
-      }
-      match output {
-        Ok(result) => pass_chain_helper! { ($state, $comp, $eval_options); result $(, $rest)* },
-        Err(err) => { //TODO this error type needs to be guaranteed to provide a useable string
-          $comp.output(Err(format!("Pass {} failed:\n{}", pass_name, err)))
-        }
-      }
-    }
-  };
-  // Done
-  (($state:expr, $comp:expr, $eval_options:expr); $final_output:expr) => {
-    {
-      let final_output: FinishedComputation = $comp.finish(Ok($final_output));
-      final_output
-    }
-  };
-}