Basic parsing of FnDefs

Author: nathanwhit

chalk-parse/src/ast.rs

@@ -21,6 +21,7 @@ pub struct Program {
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum Item {
     StructDefn(StructDefn),
+    FnDefn(FnDefn),
     TraitDefn(TraitDefn),
     OpaqueTyDefn(OpaqueTyDefn),
     Impl(Impl),
@@ -42,6 +43,19 @@ pub struct StructFlags {
     pub fundamental: bool,
 }
 
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FnDefn {
+    pub name: Identifier,
+    pub variable_kinds: Vec<VariableKind>,
+    pub where_clauses: Vec<QuantifiedWhereClause>,
+    pub argument_types: Vec<Ty>,
+    pub return_type: Ty,
+    pub flags: FnDefFlags,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FnDefFlags {}
+
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct TraitDefn {
     pub name: Identifier,

chalk-parse/src/parser.lalrpop

@@ -14,6 +14,7 @@ Items: Vec<Item> = {
 Item: Option<Item> = {
     Comment => None,
     StructDefn => Some(Item::StructDefn(<>)),
+    FnDefn => Some(Item::FnDefn(<>)),
     TraitDefn => Some(Item::TraitDefn(<>)),
     OpaqueTyDefn => Some(Item::OpaqueTyDefn(<>)),
     Impl => Some(Item::Impl(<>)),
@@ -67,6 +68,32 @@ StructDefn: StructDefn = {
     }
 };
 
+FnReturn: Ty = {
+    "->" <ty:Ty> => ty,
+};
+
+FnDefn: FnDefn = {
+    "fn" <n:Id> <p:Angle<VariableKind>>"(" <args:FnArgs> ")" 
+        <ret_ty:FnReturn?> <w:QuantifiedWhereClauses> ";" => FnDefn
+    {
+        name: n,
+        variable_kinds: p,
+        where_clauses: w,
+        argument_types: args,
+        return_type: ret_ty.unwrap_or_else(|| Ty::Tuple { types: Vec::new() }),
+        flags: FnDefFlags {
+        },
+    }
+};
+
+FnArg: Ty = {
+    Id ":" <arg_ty: Ty> => arg_ty
+};
+
+FnArgs: Vec<Ty> = {
+    <Comma<FnArg>>
+};
+
 TraitDefn: TraitDefn = {
     <auto:AutoKeyword?> <marker:MarkerKeyword?> <upstream:UpstreamKeyword?> <fundamental:FundamentalKeyword?> <non_enumerable:NonEnumerableKeyword?> <coinductive:CoinductiveKeyword?> <object_safe:ObjectSafeKeyword?> <well_known:WellKnownTrait?> "trait" <n:Id><p:Angle<VariableKind>>
         <w:QuantifiedWhereClauses> "{" <a:AssocTyDefn*> "}" => TraitDefn