Refactoring variable definition parsing

parser/src/ast.rs

@@ -3,7 +3,10 @@ use std::collections::HashMap;
 use serde::Serialize;
 
 #[derive(Debug, Clone, Serialize)]
-pub struct ParamList(pub HashMap<String, (bool, TypeExpr)>);
+pub struct FieldList(pub HashMap<String, (bool, TypeExpr)>);
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ParamList(pub Vec<VarDecl>);
 
 #[derive(Debug, Clone, Serialize)]
 pub struct Block(pub Vec<Statement>);
@@ -34,7 +37,7 @@ pub enum TopLevel {
     StructDecl {
         export: bool,
         name: String,
-        fields: ParamList,
+        fields: FieldList,
     },
     FunctionDecl {
         export: bool,
@@ -71,13 +74,18 @@ pub enum Statement {
 }
 
 #[derive(Debug, Clone, Serialize)]
-pub struct VarDeclStmt {
+pub struct VarDecl {
     pub mutable: bool,
     pub name: String,
-    pub init: Option<Expression>,
     pub type_: Option<TypeExpr>,
 }
 
+#[derive(Debug, Clone, Serialize)]
+pub struct VarDeclStmt {
+    pub decl: VarDecl,
+    pub init: Option<Expression>,
+}
+
 #[derive(Debug, Clone, Serialize)]
 pub struct VarAssignStmt {
     pub target: Expression,

parser/src/lib.rs

@@ -1,5 +1,3 @@
-use std::collections::HashMap;
-
 use pest::Parser;
 use pest_derive::Parser;
 
@@ -17,8 +15,6 @@ pub type ParseError = pest::error::Error<Rule>;
 pub fn parse(source: &str) -> Result<Vec<TopLevel>, ParseError> {
     let mut pairs = MistParser::parse(Rule::program, source)?;
 
-    println!("{pairs:#?}");
-
     let mut statements = vec![];
 
     for pair in pairs.next().unwrap().into_inner() {
@@ -49,14 +45,13 @@ impl TryFrom<pest::iterators::Pair<'_, Rule>> for TypeExpr {
     }
 }
 
-impl From<(bool, pest::iterators::Pair<'_, Rule>)> for ParamList {
+impl From<pest::iterators::Pair<'_, Rule>> for FieldList {
-    fn from((export_allowed, pair): (bool, pest::iterators::Pair<Rule>)) -> Self {
+    fn from(pair: pest::iterators::Pair<Rule>) -> Self {
         let params = pair
             .into_inner()
             .map(|p| {
                 let mut param_inner = p.into_inner();
-                let export =
+                let export = if param_inner.peek().unwrap().as_rule() == Rule::export {
-                    if export_allowed && param_inner.peek().unwrap().as_rule() == Rule::export {
                     param_inner.next().unwrap();
                     true
                 } else {
@@ -68,6 +63,14 @@ impl From<(bool, pest::iterators::Pair<'_, Rule>)> for ParamList {
             })
             .collect();
 
+        FieldList(params)
+    }
+}
+
+impl From<pest::iterators::Pair<'_, Rule>> for ParamList {
+    fn from(pair: pest::iterators::Pair<Rule>) -> Self {
+        let params = pair.into_inner().map(VarDecl::from).collect();
+
         ParamList(params)
     }
 }
@@ -106,9 +109,9 @@ impl TryFrom<pest::iterators::Pair<'_, Rule>> for TopLevel {
 
                 let name = inner.next().unwrap().as_str().to_string();
                 let params = if inner.peek().unwrap().as_rule() == Rule::param_list {
-                    ParamList::from((false, inner.next().unwrap()))
+                    ParamList::from(inner.next().unwrap())
                 } else {
-                    ParamList(HashMap::new())
+                    ParamList(Vec::new())
                 };
 
                 let body = Block::from(inner.next().unwrap());
@@ -136,7 +139,7 @@ impl TryFrom<pest::iterators::Pair<'_, Rule>> for TopLevel {
                 };
                 let name = inner.next().unwrap().as_str().to_string();
                 let fields_pair = inner.next().unwrap();
-                let fields = ParamList::from((true, fields_pair));
+                let fields = FieldList::from(fields_pair);
 
                 Ok(TopLevel::StructDecl {
                     export,
@@ -182,28 +185,7 @@ impl From<pest::iterators::Pair<'_, Rule>> for Statement {
 
             Rule::block => Statement::Block(Block::from(pair.into_inner().next().unwrap())),
 
-            Rule::var_decl_statement => {
+            Rule::var_decl_statement => Statement::VarDecl(VarDeclStmt::from(pair)),
-                let mut inner = pair.into_inner();
-
-                let mut var_decl = inner.next().unwrap().into_inner();
-
-                let type_ = var_decl.next().map(TypeExpr::try_from).unwrap().ok();
-                let mutable = if var_decl.peek().unwrap().as_rule() == Rule::mutable {
-                    var_decl.next();
-                    true
-                } else {
-                    false
-                };
-                let name = var_decl.next().unwrap().as_str().to_string();
-                let init = inner.next().map(Expression::from);
-
-                Statement::VarDecl(VarDeclStmt {
-                    mutable,
-                    name: name.as_str().to_string(),
-                    init,
-                    type_,
-                })
-            }
 
             Rule::return_stmt => {
                 let mut inner = pair.into_inner();
@@ -348,3 +330,48 @@ impl From<pest::iterators::Pair<'_, Rule>> for Postfix {
         }
     }
 }
+
+impl From<pest::iterators::Pair<'_, Rule>> for VarDeclStmt {
+    fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
+        match pair.as_rule() {
+            Rule::var_decl_statement => {
+                let mut inner = pair.into_inner();
+
+                let decl = VarDecl::from(inner.next().unwrap());
+
+                let init = inner.next().map(Expression::from);
+
+                VarDeclStmt { decl, init }
+            }
+
+            _ => unimplemented!(),
+        }
+    }
+}
+
+impl From<pest::iterators::Pair<'_, Rule>> for VarDecl {
+    fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
+        match pair.as_rule() {
+            Rule::var_decl => {
+                let mut inner = pair.into_inner();
+
+                let type_ = inner.next().map(TypeExpr::try_from).unwrap().ok();
+                let mutable = if inner.peek().unwrap().as_rule() == Rule::mutable {
+                    inner.next();
+                    true
+                } else {
+                    false
+                };
+                let name = inner.next().unwrap().as_str().to_string();
+
+                VarDecl {
+                    mutable,
+                    name: name.as_str().to_string(),
+                    type_,
+                }
+            }
+
+            _ => unimplemented!("{:?}", pair.as_rule()),
+        }
+    }
+}

src/codegen.rs

@@ -78,7 +78,15 @@ impl RustCodegen {
                 let params_str = params
                     .0
                     .iter()
-                    .map(|(n, (_, t))| format!("{}: {}", n, self.translate_type(t)))
+                    .map(|v| {
+                        format!(
+                            "{name}{}",
+                            v.type_
+                                .as_ref()
+                                .map(|t| format!(": {}", self.translate_type(t)))
+                                .unwrap_or_default()
+                        )
+                    })
                     .collect::<Vec<_>>()
                     .join(", ");
 
@@ -131,15 +139,11 @@ impl RustCodegen {
                 self.add_indentedln("}");
             }
 
-            Statement::VarDecl(VarDeclStmt {
+            Statement::VarDecl(VarDeclStmt { decl, init }) => {
-                mutable,
+                let mutability = if decl.mutable { "mut " } else { "" };
-                name,
-                init,
-                type_,
-            }) => {
-                let mutability = if *mutable { "mut " } else { "" };
 
-                let ty = type_
+                let ty = decl
+                    .type_
                     .as_ref()
                     .map(|t| format!(": {}", self.translate_type(t)))
                     .unwrap_or_default();
@@ -149,7 +153,7 @@ impl RustCodegen {
                     .map(|e| format!(" = {}", self.generate_expression(e)))
                     .unwrap_or_default();
 
-                self.add_indentedln(&format!("let {}{}{}{};", mutability, name, ty, init));
+                self.add_indentedln(&format!("let {}{}{}{};", mutability, decl.name, ty, init));
             }
 
             Statement::VarAssign(VarAssignStmt { target, value }) => {

test/src/main.mist

@@ -1,3 +1,3 @@
-int test() {
+int test(int mut b) {
     int mut a = 10;
 }