Fix everything if-refactor-related save reduced_ast

schala-lang/language/src/ast/visitor.rs

@@ -21,7 +21,7 @@ pub trait ASTVisitor: Sized {
   fn named_struct(&mut self, _name: &QualifiedName, _fields: &Vec<(Rc<String>, Expression)>) {}
   fn call(&mut self, _f: &Expression, _arguments: &Vec<InvocationArgument>) {}
   fn index(&mut self, _indexee: &Expression, _indexers: &Vec<Expression>) {}
-  fn if_expression(&mut self, _discrim: &Discriminator, _body: &IfExpressionBody) {}
+  fn if_expression(&mut self, _discrim: Option<&Expression>, _body: &IfExpressionBody) {}
   fn while_expression(&mut self, _condition: Option<&Expression>, _body: &Block) {}
   fn for_expression(&mut self, _enumerators: &Vec<Enumerator>, _body: &ForBody) {}
   fn lambda(&mut self, _params: &Vec<FormalParam>, _type_anno: Option<&TypeIdentifier>, _body: &Block) {}

schala-lang/language/src/ast/walker.rs

@@ -2,7 +2,7 @@
 use std::rc::Rc;
 use crate::ast::*;
 use crate::ast::visitor::ASTVisitor;
-use std::ops::Deref;
+use crate::util::deref_optional_box;
 
 pub fn ast<V: ASTVisitor>(v: &mut V, ast: &AST) {
   v.ast(ast);
@@ -143,8 +143,8 @@ fn expression_kind<V: ASTVisitor>(v: &mut V, expression_kind: &ExpressionKind) {
       v.index(indexee, indexers);
       index(v, indexee, indexers);
     },
-    IfExpression { discriminator, body } => v.if_expression(discriminator, body),
-    WhileExpression { condition, body } => v.while_expression(condition.as_ref().map(|b: &Box<Expression>| Deref::deref(b)), body),
+    IfExpression { discriminator, body } => v.if_expression(deref_optional_box(discriminator), body),
+    WhileExpression { condition, body } => v.while_expression(deref_optional_box(condition), body),
     ForExpression { enumerators, body } => v.for_expression(enumerators, body),
     Lambda { params , type_anno, body } => {
       v.lambda(params, type_anno.as_ref(), body);

schala-lang/language/src/parsing.rs

@@ -825,9 +825,9 @@ impl Parser {
   #[recursive_descent_method]
   fn if_expr_body(&mut self) -> ParseResult<IfExpressionBody> {
     match self.token_handler.peek_kind() {
-      Keyword(Kw::Then) => self.simple_conditional()?,
-      Keyword(Kw::Is) => self.simple_pattern_match()? ,
-      _ => self.cond_block()?
+      Keyword(Kw::Then) => self.simple_conditional(),
+      Keyword(Kw::Is) => self.simple_pattern_match(),
+      _ => self.cond_block(),
     }
   }
 

schala-lang/language/src/typechecking.rs

@@ -5,6 +5,7 @@ use ena::unify::{UnifyKey, InPlaceUnificationTable, UnificationTable, EqUnifyVal
 
 use crate::ast::*;
 use crate::util::ScopeStack;
+use crate::util::deref_optional_box;
 
 
 #[derive(Debug, Clone, PartialEq)]
@@ -318,7 +319,7 @@ impl<'a> TypeContext<'a> {
       StringLiteral(_) => ty!(StringT),
       PrefixExp(op, expr) => self.prefix(op, expr)?,
       BinExp(op, lhs, rhs) => self.binexp(op, lhs, rhs)?,
-      IfExpression { discriminator, body } => self.if_expr(&*discriminator, &**body)?,
+      IfExpression { discriminator, body } => self.if_expr(deref_optional_box(discriminator), &**body)?,
       Value(val) => self.handle_value(val)?,
       Call { box ref f, arguments } => self.call(f, arguments)?,
       Lambda { params, type_anno, body } => self.lambda(params, type_anno, body)?,

schala-lang/language/src/util.rs

@@ -1,6 +1,11 @@
 use std::collections::HashMap;
 use std::hash::Hash;
 use std::cmp::Eq;
+use std::ops::Deref;
+
+pub fn deref_optional_box<T>(x: &Option<Box<T>>) -> Option<&T> {
+  x.as_ref().map(|b: &Box<T>| Deref::deref(b))
+}
 
 #[derive(Default, Debug)]
 pub struct ScopeStack<'a, T: 'a, V: 'a>  where T: Hash + Eq {