Actually respect suffixes on numeric literals.

- Add logic to extract the value and suffix from a numeric literal
  - This duplicates some of the lexing logic, but this is hard to avoid without redundant runtime work

- Note that I'm not using and stdlib string-to-number code. This should be more robust once it is working, but it is obviously error prone in the near term. The main up-sides to this are:
  - We can handle binary integer literals
  - We can handle hexadecimal floating-point literals without stdlib support
  - We can hypothetically support digit separators, if we ever wanted

- The parser looks at the suffix characters sliced off by the lexer, and tries to pick a type to use for a literal
  - It uses `NULL` if there is no suffix, to avoid some nasty order dependencies where the stdlib might need to parse a number before it has seen the definition of `int`
  - Right now I only handle a few cases, so there may be bugs lurking here

- The emit logic needs to handle the fact that a literal node in the AST might have a non-default type attached.
  - Right now I just quickly check for the most likely types, and emit the literal with a matching suffix. This doesn't seem robust if any source language supports a suffix for a type where a target has no corresponding suffix. In the long term some amount of casting is probably required.

1 files changed, 4 insertions, 0 deletions

diff --git a/source/slang/syntax.h b/source/slang/syntax.h
index 7289719f4..81d6f8e01 100644
--- a/source/slang/syntax.h
+++ b/source/slang/syntax.h
@@ -375,6 +375,7 @@ namespace Slang
         UInt,
         UInt64,
         Float,
+        Double,
 #if 0
         Texture2D = 48,
         TextureCube = 49,
@@ -485,6 +486,7 @@ namespace Slang
 
         static ExpressionType* GetBool();
         static ExpressionType* GetFloat();
+        static ExpressionType* getDoubleType();
         static ExpressionType* GetInt();
         static ExpressionType* GetUInt();
         static ExpressionType* GetVoid();
@@ -1916,6 +1918,8 @@ namespace Slang
     class ConstantExpressionSyntaxNode : public ExpressionSyntaxNode
     {
     public:
+        Token token;
+
         enum class ConstantType
         {
             Int,