Move everything symbol-table-related into a separate module

schala-lang/src/eval.rs

@@ -7,11 +7,11 @@ use itertools::Itertools;
 
 use util::StateStack;
 use ast_reducing::{ReducedAST, Stmt, Expr, Lit, Func};
-use typechecking::{TypeContext, SymbolSpec, Symbol};
+use symbol_table::{SymbolSpec, Symbol, SymbolTable};
 
 pub struct State<'a> {
   values: StateStack<'a, Rc<String>, ValueEntry>,
-  type_context_handle: Rc<RefCell<TypeContext>>,
+  symbol_table_handle: Rc<RefCell<SymbolTable>>,
 }
 
 macro_rules! builtin_binding {
@@ -21,12 +21,12 @@ macro_rules! builtin_binding {
 }
 
 impl<'a> State<'a> {
-  pub fn new(type_context_handle: Rc<RefCell<TypeContext>>) -> State<'a> {
+  pub fn new(symbol_table_handle: Rc<RefCell<SymbolTable>>) -> State<'a> {
     let mut values = StateStack::new(Some(format!("global")));
     builtin_binding!("print", values);
     builtin_binding!("println", values);
     builtin_binding!("getline", values);
-    State { values, type_context_handle }
+    State { values, symbol_table_handle }
   }
 
   pub fn debug_print(&self) -> String {
@@ -181,7 +181,7 @@ impl<'a> State<'a> {
         }
         let mut func_state = State {
           values: self.values.new_frame(name.map(|n| format!("{}", n))),
-          type_context_handle: self.type_context_handle.clone(),
+          symbol_table_handle: self.symbol_table_handle.clone(),
         };
         for (param, val) in params.into_iter().zip(args.into_iter()) {
           let val = func_state.expression(val)?;
@@ -264,8 +264,8 @@ impl<'a> State<'a> {
     //TODO add a layer of indirection here to talk to the symbol table first, and only then look up
     //in the values table
 
-    let type_context = self.type_context_handle.borrow();
-    Ok(match type_context.symbol_table.values.get(&name) {
+    let symbol_table = self.symbol_table_handle.borrow();
+    Ok(match symbol_table.values.get(&name) {
       Some(Symbol { name, spec }) => match spec {
         SymbolSpec::Custom(_typename) => {
           Expr::Lit(Lit::Custom(name.clone()))
@@ -290,15 +290,15 @@ impl<'a> State<'a> {
 mod eval_tests {
   use std::cell::RefCell;
   use std::rc::Rc;
-  use typechecking::TypeContext;
+  use symbol_table::SymbolTable;
   use tokenizing::tokenize;
   use parsing::parse;
   use eval::State;
 
   macro_rules! fresh_env {
     ($string:expr, $correct:expr) => {
-      let type_context = Rc::new(RefCell::new(TypeContext::new()));
-      let mut state = State::new(type_context);
+      let symbol_table = Rc::new(RefCell::new(SymbolTable::new()));
+      let mut state = State::new(symbol_table);
       let all_output = state.evaluate(parse(tokenize($string)).0.unwrap().reduce(), true);
       let ref output = all_output.last().unwrap();
       assert_eq!(**output, Ok($correct.to_string()));

schala-lang/src/lib.rs

@@ -24,6 +24,7 @@ mod util;
 mod builtin;
 mod tokenizing;
 mod parsing;
+mod symbol_table;
 mod typechecking;
 mod ast_reducing;
 mod eval;
@@ -34,15 +35,16 @@ mod eval;
 #[PipelineSteps(tokenizing, parsing, symbol_table, typechecking, ast_reducing, eval)]
 pub struct Schala {
   state: eval::State<'static>,
-  type_context: Rc<RefCell<typechecking::TypeContext>>,
+  symbol_table: Rc<RefCell<symbol_table::SymbolTable>>,
+  //type_context
 }
 
 impl Schala {
   pub fn new() -> Schala {
-    let type_context = Rc::new(RefCell::new(typechecking::TypeContext::new()));
+    let symbols = Rc::new(RefCell::new(symbol_table::SymbolTable::new()));
     Schala {
-      type_context: type_context.clone(),
-      state: eval::State::new(type_context),
+      symbol_table: symbols.clone(),
+      state: eval::State::new(symbols),
     }
   }
 }
@@ -74,10 +76,10 @@ fn parsing(_handle: &mut Schala, input: Vec<tokenizing::Token>, comp: Option<&mu
 }
 
 fn symbol_table(handle: &mut Schala, input: parsing::AST, comp: Option<&mut UnfinishedComputation>) -> Result<parsing::AST, String> {
-  let add = handle.type_context.borrow_mut().add_top_level_types(&input);
+  let add = handle.symbol_table.borrow_mut().add_top_level_symbols(&input);
   match add {
     Ok(()) => {
-      let artifact = TraceArtifact::new("symbol_table", handle.type_context.borrow().debug_symbol_table());
+      let artifact = TraceArtifact::new("symbol_table", handle.symbol_table.borrow().debug_symbol_table());
       comp.map(|comp| comp.add_artifact(artifact));
       Ok(input)
     },
@@ -86,6 +88,7 @@ fn symbol_table(handle: &mut Schala, input: parsing::AST, comp: Option<&mut Unfi
 }
 
 fn typechecking(handle: &mut Schala, input: parsing::AST, comp: Option<&mut UnfinishedComputation>) -> Result<parsing::AST, String> {
+  /*
   match handle.type_context.borrow_mut().type_check_ast(&input) {
     Ok(ty) => {
       comp.map(|comp| comp.add_artifact(TraceArtifact::new("type_check", format!("{:?}", ty))));
@@ -96,6 +99,8 @@ fn typechecking(handle: &mut Schala, input: parsing::AST, comp: Option<&mut Unfi
       Ok(input)
     }
   }
+  */
+  Ok(input)
 }
 
 fn ast_reducing(_handle: &mut Schala, input: parsing::AST, comp: Option<&mut UnfinishedComputation>) -> Result<ast_reducing::ReducedAST, String> {

schala-lang/src/symbol_table.rs

@@ -0,0 +1,70 @@
+use std::collections::HashMap;
+use std::rc::Rc;
+use std::fmt;
+use std::fmt::Write;
+
+use parsing;
+
+//cf. p. 150 or so of Language Implementation Patterns
+pub struct SymbolTable {
+  pub values: HashMap<Rc<String>, Symbol> //TODO this will eventually have real type information
+}
+
+impl SymbolTable {
+  pub fn new() -> SymbolTable {
+    SymbolTable { values: HashMap::new() }
+  }
+}
+
+#[derive(Debug)]
+pub struct Symbol {
+  pub name: Rc<String>,
+  pub spec: SymbolSpec,
+}
+
+#[derive(Debug)]
+pub enum SymbolSpec {
+  Func, Custom(String)
+}
+
+impl SymbolTable {
+  /* note: this adds names for *forward reference* but doesn't actually create any types. solve that problem
+   * later */
+  pub fn add_top_level_symbols(&mut self, ast: &parsing::AST) -> Result<(), String> {
+    use self::parsing::{Statement, TypeName, Variant, TypeSingletonName, TypeBody};
+    use self::parsing::Declaration::*;
+    for statement in ast.0.iter() {
+      if let Statement::Declaration(decl) = statement {
+        match decl {
+          FuncSig(signature) | FuncDecl(signature, _) => {
+            self.values.insert(
+              signature.name.clone(),
+              Symbol { name: signature.name.clone(), spec: SymbolSpec::Func }
+              );
+          },
+          TypeDecl(TypeSingletonName { name, ..}, TypeBody(variants)) => {
+            for var in variants {
+              match var {
+                Variant::UnitStruct(variant_name) => {
+                  //TODO will have to make this a function to this type eventually
+                  let spec = SymbolSpec::Custom(format!("{}", name));
+                  self.values.insert(variant_name.clone(), Symbol { name: variant_name.clone(), spec });
+                },
+                e => return Err(format!("{:?} not supported in typing yet", e)),
+              }
+            }
+          },
+          _ => ()
+        }
+      }
+    }
+    Ok(())
+  }
+  pub fn debug_symbol_table(&self) -> String {
+    let mut output = format!("Symbol table\n");
+    for (sym, ty) in &self.values {
+      write!(output, "{} -> {:?}\n", sym, ty).unwrap();
+    }
+    output
+  }
+}

schala-lang/src/typechecking.rs

@@ -8,7 +8,6 @@ use std::fmt::Write;
 
 use itertools::Itertools;
 
-
 /* GIANT TODO - use the rust im crate, unless I make this code way less haskell-ish after it's done
   */
 
@@ -16,32 +15,8 @@ use parsing;
 
 pub struct TypeContext {
   environment: TypeEnvironment,
-  pub symbol_table: SymbolTable
 }
 
-//cf. p. 150 or so of Language Implementation Patterns
-pub struct SymbolTable {
-  pub values: HashMap<Rc<String>, Symbol> //TODO this will eventually have real type information
-}
-
-impl SymbolTable {
-  fn new() -> SymbolTable {
-    SymbolTable { values: HashMap::new() }
-  }
-}
-
-#[derive(Debug)]
-pub struct Symbol {
-  pub name: Rc<String>,
-  pub spec: SymbolSpec,
-}
-
-#[derive(Debug)]
-pub enum SymbolSpec {
-  Func, Custom(String)
-}
-
-
 /* real meat of type stuff here */
 
 #[derive(Debug, PartialEq, Clone)]
@@ -214,53 +189,9 @@ pub type TypeResult<T> = Result<T, String>;
 
 impl TypeContext {
   pub fn new() -> TypeContext {
-    TypeContext { environment: TypeEnvironment::default(), /*type_var_count: 0*/ symbol_table: SymbolTable::new() }
+    TypeContext { environment: TypeEnvironment::default(), /*type_var_count: 0*/ }
   }
 
-  /* note: this adds names for *forward reference* but doesn't actually create any types. solve that problem
-   * later */
-  pub fn add_top_level_types(&mut self, ast: &parsing::AST) -> TypeResult<()> {
-    use self::parsing::{Statement, TypeName, Variant, TypeSingletonName, TypeBody};
-    use self::parsing::Declaration::*;
-    use self::Type::*;
-    for statement in ast.0.iter() {
-      if let Statement::Declaration(decl) = statement {
-        match decl {
-          FuncSig(signature) | FuncDecl(signature, _) => {
-            self.symbol_table.values.insert(
-              signature.name.clone(),
-              Symbol { name: signature.name.clone(), spec: SymbolSpec::Func }
-            );
-          },
-          TypeDecl(TypeSingletonName { name, ..}, TypeBody(variants)) => {
-            for var in variants {
-              match var {
-                Variant::UnitStruct(variant_name) => {
-                  //TODO will have to make this a function to this type eventually
-                  let spec = SymbolSpec::Custom(format!("{}", name));
-                  self.symbol_table.values.insert(variant_name.clone(), Symbol { name: variant_name.clone(), spec });
-                },
-                e => return Err(format!("{:?} not supported in typing yet", e)),
-              }
-            }
-          },
-          _ => ()
-        }
-      }
-    }
-    Ok(())
-  }
-  pub fn debug_symbol_table(&self) -> String {
-    let mut output = format!("Symbol table\n");
-    for (sym, ty) in &self.symbol_table.values {
-      write!(output, "{} -> {:?}\n", sym, ty).unwrap();
-    }
-    write!(output, "\nType Env\n").unwrap();
-    for (sym, ty) in &self.environment.map {
-      write!(output, "{} : {:?}\n", sym, ty).unwrap();
-    }
-    output
-  }
 
   pub fn type_check_ast(&mut self, ast: &parsing::AST) -> TypeResult<String> {
     let ref block = ast.0;