MVP for higher order functions (#2849)

* MVP for higher order functions

* Add shader subgroup partitioned glsl intrinsics

* Implement parsing and checking for tuple types

Currently there is no way to do anything useful with them from the source language however

* neaten

* Correct precedence of function type parsing

* neaten

* higher order function tests

* function types of any arity

* Inference for higher order functions

* Add second test for unsynchronized params

* regenerate vs projects

* dx11 -> dx12 for saturated cooperations tests

* Disable saturated cooperation tests on vulkan

They fail on release builds in CI, not essential for the higher order function work however

* remove saturated-cooperation tests

* Remove unnecessary assert and clarify control flow in AddDeclRefOverloadCandidates

* Add Tuple type name mangling

* Use functype keyword to introduce function types

* Add more inference tests for hof

---------

Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 62 insertions, 11 deletions

diff --git a/source/slang/slang-parser.cpp b/source/slang/slang-parser.cpp
index 78433a96f..cce4b7e7b 100644
--- a/source/slang/slang-parser.cpp
+++ b/source/slang/slang-parser.cpp
@@ -2243,6 +2243,39 @@ namespace Slang
         return parseThisTypeExpr(parser);
     }
 
+    // (a,b,c) style tuples, curently unused
+#if 0
+    static Expr* parseTupleTypeExpr(Parser* parser)
+    {
+        parser->ReadToken(TokenType::LParent);
+        TupleTypeExpr* expr = parser->astBuilder->create<TupleTypeExpr>();
+        while(!AdvanceIfMatch(parser, MatchedTokenType::Parentheses))
+        {
+            expr->members.add(parser->ParseTypeExp());
+            if(AdvanceIf(parser, TokenType::RParent))
+                break;
+            parser->ReadToken(TokenType::Comma);
+        }
+        return expr;
+    }
+#endif
+
+    static Expr* parseFuncTypeExpr(Parser* parser)
+    {
+        parser->ReadToken(TokenType::LParent);
+        auto expr = parser->astBuilder->create<FuncTypeExpr>();
+        while(!AdvanceIfMatch(parser, MatchedTokenType::Parentheses))
+        {
+            expr->parameters.add(parser->ParseTypeExp());
+            if(AdvanceIf(parser, TokenType::RParent))
+                break;
+            parser->ReadToken(TokenType::Comma);
+        }
+        parser->ReadToken(TokenType::RightArrow);
+        expr->result = parser->ParseTypeExp();
+        return expr;
+    }
+
         /// Apply the given `modifiers` (if any) to the given `typeExpr`
     static Expr* _applyModifiersToTypeExpr(Parser* parser, Expr* typeExpr, Modifiers const& modifiers)
     {
@@ -2438,6 +2471,17 @@ namespace Slang
             typeSpec.expr = parseThisTypeExpr(parser);
             return typeSpec;
         }
+        // Uncomment should we decide to enable (a,b,c) tuple types
+        // else if(parser->LookAheadToken(TokenType::LParent))
+        // {
+        //     typeSpec.expr = parseTupleTypeExpr(parser);
+        //     return typeSpec;
+        // }
+        else if(AdvanceIf(parser, "functype"))
+        {
+            typeSpec.expr = parseFuncTypeExpr(parser);
+            return typeSpec;
+        }
 
         Token typeName = parser->ReadToken(TokenType::Identifier);
 
@@ -4820,6 +4864,8 @@ namespace Slang
         return parsePostfixTypeSuffix(parser, typeExpr);
     }
 
+    static Expr* _parseInfixTypeExpr(Parser* parser);
+
     static Expr* _parseInfixTypeExprSuffix(Parser* parser, Expr* leftExpr)
     {
         for(;;)
@@ -4829,16 +4875,20 @@ namespace Slang
             // a conjunction type expression.
 
             auto loc = peekToken(parser).loc;
-            if(!AdvanceIf(parser, TokenType::OpBitAnd))
-                break;
-
-            auto rightExpr = _parsePostfixTypeExpr(parser);
+            if(AdvanceIf(parser, TokenType::OpBitAnd))
+            {
+                auto rightExpr = _parsePostfixTypeExpr(parser);
 
-            auto andExpr = parser->astBuilder->create<AndTypeExpr>();
-            andExpr->loc = loc;
-            andExpr->left = TypeExp(leftExpr);
-            andExpr->right = TypeExp(rightExpr);
-            leftExpr = andExpr;
+                auto andExpr = parser->astBuilder->create<AndTypeExpr>();
+                andExpr->loc = loc;
+                andExpr->left = TypeExp(leftExpr);
+                andExpr->right = TypeExp(rightExpr);
+                leftExpr = andExpr;
+            }
+            else
+            {
+                break;
+            }
         }
 
         return leftExpr;
@@ -4846,8 +4896,9 @@ namespace Slang
 
         /// Parse an infix type expression.
         ///
-        /// Currently, the only infix type expression we support is the `&`
-        /// operator for forming interface conjunctions.
+        /// Currently, the only infix type expressions we support are the `&`
+        /// operator for forming interface conjunctions and the `->` operator
+        /// for functions.
         ///
     static Expr* _parseInfixTypeExpr(Parser* parser)
     {