From fc9a04403eb5b694d37f77baa0de2f8e363f46f1 Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@mutabah.net>
Date: Sun, 22 Mar 2015 14:46:48 +0800
Subject: Parsing "Composite" DSTs (Trait + Trait2 + Trait3)

---
 src/parse/root.cpp  |  2 ++
 src/parse/types.cpp | 28 +++++++++++++++++++++++-----
 src/types.hpp       |  8 ++++++++
 3 files changed, 33 insertions(+), 5 deletions(-)

(limited to 'src')

diff --git a/src/parse/root.cpp b/src/parse/root.cpp
index c88b51a5..759c65ac 100644
--- a/src/parse/root.cpp
+++ b/src/parse/root.cpp
@@ -666,6 +666,8 @@ AST::Impl Parse_Impl(TokenStream& lex, bool is_unsafe/*=false*/)
         lex.putback(tok);
         
         impl_type = Parse_Type(lex);
+        // TODO: Handle the "impl Any + Send" syntax here
+        
         if( GET_TOK(tok, lex) == TOK_RWORD_FOR )
         {
             // Implementing a trait for another type, get the target type
diff --git a/src/parse/types.cpp b/src/parse/types.cpp
index aa29af64..57c1bad8 100644
--- a/src/parse/types.cpp
+++ b/src/parse/types.cpp
@@ -65,6 +65,7 @@ TypeRef Parse_Type(TokenStream& lex)
     // '<' - An associated type cast
     case TOK_LT: {
         DEBUG("Associated type");
+        // TODO: This should instead use the path code, not a special case in typing
         // <Type as Trait>::Inner
         TypeRef base = Parse_Type(lex);
         GET_CHECK_TOK(tok, lex, TOK_RWORD_AS);
@@ -86,12 +87,29 @@ TypeRef Parse_Type(TokenStream& lex)
             if( tok.str() == CORETYPES[i].name )
                 return TypeRef(TypeRef::TagPrimitive(), CORETYPES[i].type);
         }
-        lex.putback(tok);
-        return TypeRef(TypeRef::TagPath(), Parse_Path(lex, false, PATH_GENERIC_TYPE)); // relative path
+        // - Fall through to path handling
     // '::' - Absolute path
-    case TOK_DOUBLE_COLON:
-        // Path with generics
-        return TypeRef(TypeRef::TagPath(), Parse_Path(lex, true, PATH_GENERIC_TYPE));
+    case TOK_DOUBLE_COLON: {
+        lex.putback(tok);
+        ::std::vector<AST::Path>    traits;
+        ::std::vector< ::std::string>   lifetimes;
+        do {
+            if( LOOK_AHEAD(lex) == TOK_LIFETIME ) {
+                GET_TOK(tok, lex);
+                lifetimes.push_back( tok.str() );
+            }
+            else
+                traits.push_back( Parse_Path(lex, PATH_GENERIC_TYPE) );
+        } while( GET_TOK(tok, lex) == TOK_PLUS );
+        lex.putback(tok);
+        if( traits.size() > 1 || lifetimes.size() > 0 ) {
+            if( lifetimes.size() )
+                DEBUG("TODO: Lifetime bounds on trait objects");
+            return TypeRef(::std::move(traits));
+        }
+        else 
+            return TypeRef(TypeRef::TagPath(), traits.at(0));
+        }
     // 'super' - Parent relative path
     case TOK_RWORD_SUPER:
         GET_CHECK_TOK(tok, lex, TOK_DOUBLE_COLON);
diff --git a/src/types.hpp b/src/types.hpp
index 9505f2cd..86733ad1 100644
--- a/src/types.hpp
+++ b/src/types.hpp
@@ -55,6 +55,7 @@ class TypeRef:
         ARRAY,
         GENERIC,
         PATH,
+        MULTIDST,   // Multi-trait DST (e.g. Trait + Send + Sync)
         ASSOCIATED,
     };
     
@@ -147,6 +148,13 @@ public:
         TypeRef(TagPath(), ::std::move(path))
     {}
    
+    TypeRef( ::std::vector<AST::Path> traits ):
+        m_class(MULTIDST)
+    {
+        for( auto& t : traits )
+            m_inner_types.push_back( TypeRef(::std::move(t)) );
+    }
+    
     struct TagAssoc {};
     TypeRef(TagAssoc, TypeRef base, TypeRef trait, ::std::string assoc_name):
         TypeRef(::std::move(base), ::std::move(trait), ::std::move(assoc_name))
-- 
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