Continuing work on reduced ir

schala-lang/language/src/reduced_ir/mod.rs

@@ -15,7 +15,7 @@ pub fn reduce(ast: &ast::AST, symbol_table: &SymbolTable) -> ReducedIR {
 
 struct Reducer<'a> {
     symbol_table: &'a SymbolTable,
-    functions: HashMap<DefId, Callable>,
+    functions: HashMap<DefId, FunctionDefinition>,
 }
 
 impl<'a> Reducer<'a> {
@@ -98,10 +98,10 @@ impl<'a> Reducer<'a> {
     fn insert_function_definition(&mut self, item_id: &ast::ItemId, statements: &ast::Block) {
         let symbol = self.symbol_table.lookup_symbol(item_id).unwrap();
         let def_id = symbol.def_id.clone();
-        let callable = Callable::UserDefined {
+        let function_def = FunctionDefinition {
             body: self.function(statements)
         };
-        self.functions.insert(def_id, callable);
+        self.functions.insert(def_id, function_def);
     }
 
     fn expression(&mut self, expr: &ast::Expression) -> Expression {
@@ -140,7 +140,7 @@ impl<'a> Reducer<'a> {
         match builtin {
             Some(op) => {
                 Expression::Call {
-                    f: Function::Builtin(op),
+                    f: Box::new(Expression::Callable(Function::Builtin(op))),
                     args: vec![self.expression(arg)],
                 }
             }
@@ -174,7 +174,7 @@ impl<'a> Reducer<'a> {
             },
             Some(op) => {
                 Expression::Call {
-                    f: Function::Builtin(op),
+                    f: Box::new(Expression::Callable(Function::Builtin(op))),
                     args: vec![self.expression(lhs), self.expression(rhs)],
                 }
             }
@@ -186,12 +186,27 @@ impl<'a> Reducer<'a> {
     }
 
     fn value(&mut self, qualified_name: &ast::QualifiedName) -> Expression {
-        let ast::QualifiedName { id, components, .. } = qualified_name;
+        use SymbolSpec::*;
-        println!("Qualified name: {:?}", qualified_name);
-        let maybe_symbol = self.symbol_table.lookup_symbol(&qualified_name.id);
-        println!("Symbol? {:?}", maybe_symbol);
 
-        Expression::Unimplemented
+        let ast::QualifiedName { id, components, .. } = qualified_name;
+
+        let symbol = match self.symbol_table.lookup_symbol(&qualified_name.id) {
+            Some(s) => s,
+            None => return Expression::ReductionError(format!("No symbol found for name: {:?}", qualified_name))
+        };
+        let Symbol { def_id, spec, .. } = symbol;
+        match spec {
+            Func(_) => Expression::Lookup { id: def_id.clone(), kind: Lookup::Function },
+            GlobalBinding => Expression::Lookup { id: def_id.clone(), kind: Lookup::GlobalVar },
+            LocalVariable => Expression::Lookup { id: def_id.clone(), kind: Lookup::LocalVar },
+            FunctionParam(_) => Expression::Lookup { id: def_id.clone(), kind: Lookup::Param },
+            DataConstructor { index, arity, .. } => {
+                Expression::Unimplemented
+            },
+            RecordConstructor { .. } => {
+                Expression::ReductionError(format!("The symbol for value {:?} is unexpectdly a RecordConstructor", qualified_name))
+            },
+        }
     }
 }
 
@@ -200,7 +215,7 @@ impl<'a> Reducer<'a> {
 /// statements, in an executable context will likely just be a pointer to the main() function.
 #[derive(Debug)]
 pub struct ReducedIR {
-    functions: HashMap<DefId, Callable>,
+    pub functions: HashMap<DefId, FunctionDefinition>,
     pub entrypoint: Vec<Statement>,
 }
 
@@ -223,14 +238,6 @@ impl ReducedIR {
     }
 }
 
-#[derive(Debug)]
-pub enum Callable {
-    Builtin(Builtin),
-    UserDefined {
-        body: Vec<Statement>
-    }
-}
-
 #[derive(Debug)]
 pub enum Statement {
     Expression(Expression),
@@ -245,12 +252,17 @@ pub enum Statement {
 pub enum Expression {
     Literal(Literal),
     Tuple(Vec<Expression>),
+    Lookup {
+        id: DefId, //TODO eventually not everything that can be looked up will have a DefId
+        kind: Lookup,
+    },
     Assign {
         lval: DefId,
         rval: Box<Expression>,
     },
+    Callable(Function),
     Call {
-        f: Function,
+        f: Box<Expression>,
         args: Vec<Expression>
     },
     Unimplemented,
@@ -258,11 +270,23 @@ pub enum Expression {
 }
 
 #[derive(Debug)]
-pub enum Function {
+pub struct FunctionDefinition {
-    Builtin(Builtin),
+    body: Vec<Statement>
-    Defined(DefId),
 }
 
+#[derive(Debug)]
+pub enum Function {
+    Builtin(Builtin),
+    UserDefined(DefId)
+}
+
+#[derive(Debug)]
+pub enum Lookup {
+    LocalVar,
+    GlobalVar,
+    Function,
+    Param,
+}
 
 #[derive(Debug)]
 pub enum Literal {

schala-lang/language/src/symbol_table/mod.rs

@@ -23,6 +23,12 @@ pub struct DefId {
   idx: u32,
 }
 
+impl DefId {
+  pub fn as_u32(&self) -> u32 {
+      self.idx
+  }
+}
+
 impl fmt::Display for DefId {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
     write!(f, "DefId:{}", self.idx)
@@ -221,6 +227,9 @@ impl fmt::Display for Symbol {
 //It would be good if individual functions could in parallel look up their own
 //local vars without interfering with other lookups. Also some type definitions
 //should be scoped in a similar way.
+//
+//Also it makes sense that non-globals should not use DefId's, particularly not
+//function parameters (even though they are currently assigned).
 #[derive(Debug, Clone)]
 pub enum SymbolSpec {
     Func(Vec<TypeName>),

schala-lang/language/src/symbol_table/resolver.rs

@@ -74,7 +74,6 @@ impl<'a> ScopeResolver<'a> {
         if components.len() == 1 {
             let local_name: Rc<String> = components[0].clone();
             let name_type = self.lexical_scopes.lookup(&local_name);
-            println!("resolver.rs lookup_name_in_scope: {:?} with name_type {:?}", name, name_type);
             match name_type {
                 Some(NameType::Import(fqsn)) => {
                     let symbol = self.symbol_table.fqsn_to_symbol.get(&fqsn);
@@ -92,7 +91,14 @@ impl<'a> ScopeResolver<'a> {
                     let fqsn = Fqsn { scopes: vec![Scope::Name(local_name.clone())] };
                     self.symbol_table.add_symbol(id, fqsn, spec);
                 },
-                None => (),
+                None => {
+                    //TODO see if I can reduce this duplicate code
+                    let fqsn = Fqsn { scopes: vec![Scope::Name(local_name.clone())] };
+                    let symbol = self.symbol_table.fqsn_to_symbol.get(&fqsn);
+                    if let Some(symbol) = symbol {
+                        self.symbol_table.id_to_symbol.insert(id.clone(), symbol.clone());
+                    }
+                }
             }
         } else {
             let fqsn = Fqsn { scopes: components.iter().map(|name| Scope::Name(name.clone())).collect() };

schala-lang/language/src/tree_walk_eval/mod.rs

@@ -1,4 +1,4 @@
-use crate::reduced_ir::{ReducedIR, Expression, Function, Statement, Literal};
+use crate::reduced_ir::{ReducedIR, Expression, Lookup, Function, FunctionDefinition, Statement, Literal};
 use crate::symbol_table::{DefId};
 use crate::util::ScopeStack;
 
@@ -9,7 +9,20 @@ type EvalResult<T> = Result<T, String>;
 
 #[derive(Debug)]
 pub struct State<'a> {
-  environments: ScopeStack<'a, DefId, RuntimeValue>,
+  environments: ScopeStack<'a, Memory, RuntimeValue>,
+}
+
+//TODO - eh, I dunno, maybe it doesn't matter exactly how memory works in the tree-walking
+//evaluator
+#[derive(Debug, PartialEq, Eq, Hash, Clone)]
+enum Memory {
+    Index(u32)
+}
+
+impl From<&DefId> for Memory {
+    fn from(id: &DefId) -> Self {
+        Self::Index(id.as_u32())
+    }
 }
 
 #[derive(Debug)]
@@ -47,6 +60,7 @@ fn paren_wrapped(terms: impl Iterator<Item=String>) -> String {
 #[derive(Debug)]
 enum RuntimeValue {
     Expression(Expression),
+    Function(FunctionDefinition),
 }
 
 impl From<Expression> for RuntimeValue {
@@ -76,7 +90,8 @@ fn expr_to_repl(expr: &Expression) -> String {
 impl RuntimeValue {
     fn to_repl(&self) -> String {
         match self {
-            RuntimeValue::Expression(ref expr) => expr_to_repl(expr)
+            RuntimeValue::Expression(ref expr) => expr_to_repl(expr),
+            RuntimeValue::Function(ref expr) => "<function>".to_string(),
         }
     }
 }
@@ -91,6 +106,11 @@ impl<'a> State<'a> {
     pub fn evaluate(&mut self, reduced: ReducedIR, repl: bool) -> Vec<Result<String, String>> {
         let mut acc = vec![];
 
+        for (def_id, function) in reduced.functions.into_iter() {
+            let mem = (&def_id).into();
+            self.environments.insert(mem, RuntimeValue::Function(function));
+        }
+
         for statement in reduced.entrypoint.into_iter() {
             match self.statement(statement) {
                 Ok(Some(output)) if repl => {
@@ -108,10 +128,10 @@ impl<'a> State<'a> {
 
     fn statement(&mut self, stmt: Statement) -> EvalResult<Option<RuntimeValue>> {
         match stmt {
-            Statement::Binding { id, expr, constant } => {
+            Statement::Binding { ref id, expr, constant } => {
                 println!("eval() binding id: {}", id);
                 let evaluated = self.expression(expr)?;
-                self.environments.insert(id, evaluated.into());
+                self.environments.insert(id.into(), evaluated.into());
                 Ok(None)
             },
             Statement::Expression(expr) => {
@@ -126,18 +146,38 @@ impl<'a> State<'a> {
       Ok(match expression {
           lit @ Expression::Literal(_) => lit,
           Expression::Tuple(items) => Expression::Tuple(items.into_iter().map(|expr| self.expression(expr)).collect::<EvalResult<Vec<Expression>>>()?),
-          Expression::Assign { lval, box rval } => {
+          Expression::Lookup { ref id, kind } => {
-              let mut env = self.environments.lookup(&lval);
+              let mem = id.into();
+              match kind {
+                  Lookup::Function => {
+                      if self.environments.lookup(&mem).is_some() {
+                          Expression::Callable(Function::UserDefined(id.clone()))
+                      } else {
+                          return Err(format!("Function not found for id: {}", id));
+                      }
+                  },
+                  kind @ Lookup::LocalVar | kind @ Lookup::GlobalVar | kind @ Lookup::Param => {
+                      match self.environments.lookup(&mem) {
+                          //Some(RuntimeValue::Expression(expr)) => (*expr).clone(),
+                          Some(RuntimeValue::Expression(expr)) => Unimplemented,
+                          _ => return Err(format!("Nothing found for variable lookup {} of kind {:?}", id, kind)),
+                      }
+                  },
+              }
+          },
+          Expression::Assign { ref lval, box rval } => {
+              let mem = lval.into();
+              let mut env = self.environments.lookup(&mem);
               Unimplemented
           },
-          Expression::Call { f, args } => self.call_expression(f, args)?,
+          Expression::Call { box f, args } => self.call_expression(f, args)?,
           Unimplemented => Unimplemented,
           Expression::ReductionError(e) => return Err(e.into()),
-          _ => Expression::Literal(Literal::Nat(69420)),
+          e => return Err(format!("Can't yet handle {:?}", e)),
       })
   }
 
-  fn call_expression(&mut self, f: Function, args: Vec<Expression>) -> EvalResult<Expression> {
+  fn call_expression(&mut self, f: Expression, args: Vec<Expression>) -> EvalResult<Expression> {
       Err("Call expression not implemented".to_string().into())
   }
 }