From 5aac662e859d10f42b541405fa0b8d14a1c1e2a8 Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@mutabah.net>
Date: Sun, 22 Mar 2015 09:28:56 +0800
Subject: Hack in UFCS <Type as Trait> syntax

---
 src/ast/expr.cpp        |  1 -
 src/ast/path.cpp        |  6 ++++++
 src/ast/path.hpp        |  5 +++++
 src/convert/resolve.cpp |  8 +-------
 src/parse/expr.cpp      | 24 ++++++++++++++++++++++--
 5 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/src/ast/expr.cpp b/src/ast/expr.cpp
index 3c1d3c66..97d951fc 100644
--- a/src/ast/expr.cpp
+++ b/src/ast/expr.cpp
@@ -75,7 +75,6 @@ SERIALISE_TYPE(Expr::, "Expr", {
     else _(ExprNode_Field)
     else _(ExprNode_Deref)
     else _(ExprNode_Cast)
-    else _(ExprNode_CallPath)
     else _(ExprNode_BinOp)
     else _(ExprNode_UniOp)
     else
diff --git a/src/ast/path.cpp b/src/ast/path.cpp
index 1f07d4b0..fae2642e 100644
--- a/src/ast/path.cpp
+++ b/src/ast/path.cpp
@@ -48,6 +48,12 @@ SERIALISE_TYPE(PathNode::, "PathNode", {
 })
 
 // --- AST::Path
+AST::Path::Path(TagUfcs, TypeRef type, TypeRef trait):
+    m_class(UFCS),
+    m_ufcs({::std::move(type), ::std::move(trait)} )
+{
+}
+
 template<typename T>
 typename ::std::vector<Item<T> >::const_iterator find_named(const ::std::vector<Item<T> >& vec, const ::std::string& name)
 {
diff --git a/src/ast/path.hpp b/src/ast/path.hpp
index 447ff0a0..4701b03a 100644
--- a/src/ast/path.hpp
+++ b/src/ast/path.hpp
@@ -80,6 +80,7 @@ private:
         RELATIVE,
         ABSOLUTE,
         LOCAL,
+        UFCS,
     };
     
     /// The crate defining the root of this path (used for path resolution)
@@ -89,7 +90,9 @@ private:
     /// - Absolute is "relative" to the crate root
     /// - Relative doesn't have a set crate (and can't be resolved)
     /// - Local is a special case to handle possible use of local varaibles
+    /// - UFCS is relative to a type
     Class   m_class;
+    ::std::vector<TypeRef>  m_ufcs;
     ::std::vector<PathNode> m_nodes;
     
     BindingType m_binding_type = UNBOUND;
@@ -114,6 +117,8 @@ public:
     Path(TagAbsolute):
         m_class(ABSOLUTE)
     {}
+    struct TagUfcs {};
+    Path(TagUfcs, TypeRef type, TypeRef trait);
     struct TagLocal {};
     Path(TagLocal, ::std::string name):
         m_class(LOCAL),
diff --git a/src/convert/resolve.cpp b/src/convert/resolve.cpp
index 95325da1..e519d485 100644
--- a/src/convert/resolve.cpp
+++ b/src/convert/resolve.cpp
@@ -435,13 +435,7 @@ void ResolvePaths_HandleModule_Use(const AST::Crate& crate, const AST::Path& mod
             case AST::Path::ENUM:
                 break;
             
-            case AST::Path::ALIAS:
-            case AST::Path::ENUM_VAR:
-            case AST::Path::STRUCT:
-            case AST::Path::STRUCT_METHOD:
-            case AST::Path::TRAIT:
-            case AST::Path::FUNCTION:
-            case AST::Path::STATIC:
+            default:
                 throw ParseError::Generic("Wildcard imports are only allowed on modules and enums");
             }
         }
diff --git a/src/parse/expr.cpp b/src/parse/expr.cpp
index d618a9af..222a6a3a 100644
--- a/src/parse/expr.cpp
+++ b/src/parse/expr.cpp
@@ -903,6 +903,7 @@ ExprNodeP Parse_ExprVal(TokenStream& lex)
     case TOK_BRACE_OPEN:
         lex.putback(tok);
         return Parse_ExprBlockNode(lex);
+    
     case TOK_RWORD_LOOP:
         return NEWNODE( AST::ExprNode_Loop, "", Parse_ExprBlockNode(lex) );
     case TOK_RWORD_WHILE:
@@ -919,9 +920,28 @@ ExprNodeP Parse_ExprVal(TokenStream& lex)
         return rv;
         }
     
-    case TOK_RWORD_SUPER:
+    // UFCS
+    case TOK_DOUBLE_LT:
+        lex.putback(tok);
+    case TOK_LT: {
+        TypeRef ty = Parse_Type(lex);
+        TypeRef trait;
+        if( GET_TOK(tok, lex) == TOK_RWORD_AS ) {
+            trait = Parse_Type(lex);
+        }
+        else
+            lex.putback(tok);
+        GET_CHECK_TOK(tok, lex, TOK_GT);
+        // TODO: Terminating the "path" here is sometimes valid
         GET_CHECK_TOK(tok, lex, TOK_DOUBLE_COLON);
-        path = Parse_PathFrom(lex, AST::Path(AST::Path::TagSuper()), PATH_GENERIC_EXPR);
+        path = Parse_PathFrom(lex, AST::Path(AST::Path::TagUfcs(), ty, trait), PATH_GENERIC_EXPR);
+        }
+        if(0)
+    case TOK_RWORD_SUPER:
+        {
+            GET_CHECK_TOK(tok, lex, TOK_DOUBLE_COLON);
+            path = Parse_PathFrom(lex, AST::Path(AST::Path::TagSuper()), PATH_GENERIC_EXPR);
+        }
         if(0)
     case TOK_IDENT:
         // Get path
-- 
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