Add support for defaults to bytecode, compiler and VM

parser/src/ast.rs

@@ -95,12 +95,12 @@ pub enum Statement {
     ClassDef {
         name: String,
         body: Vec<LocatedStatement>,
-        args: Vec<String>,
+        args: Vec<(String, Option<Expression>)>,
         // TODO: docstring: String,
     },
     FunctionDef {
         name: String,
-        args: Vec<String>,
+        args: Vec<(String, Option<Expression>)>,
         // docstring: String,
         body: Vec<LocatedStatement>,
     },
@@ -161,7 +161,7 @@ pub enum Expression {
         name: String,
     },
     Lambda {
-        args: Vec<String>,
+        args: Vec<(String, Option<Expression>)>,
         body: Box<Expression>,
     },
     True,

parser/src/python.lalrpop

@@ -308,12 +308,16 @@ FuncDef: ast::LocatedStatement = {
   },
 };
 
-Parameters: Vec<String> = {
+Parameters: Vec<(String, Option<ast::Expression>)> = {
   "(" <a: TypedArgsList> ")" => a,
 };
 
-TypedArgsList: Vec<String> = {
-  <a: Comma<Identifier>> => a,
+// parameters are (String, None), kwargs are (String, Some(Test)) where Test is
+// the default
+TypedArgsList: Vec<(String, Option<ast::Expression>)> = {
+  <a: Comma<Identifier>> => {
+      a.iter().map(|param| (param.clone(), None)).collect()
+  },
 };
 
 ClassDef: ast::LocatedStatement = {