From 231d8b76970ec79405455ef47edfafcd5ddf8177 Mon Sep 17 00:00:00 2001
From: "Michael D. Lowis" <mike.lowis@gentex.com>
Date: Thu, 30 Jan 2020 15:01:07 -0500
Subject: [PATCH] added nillable types

---
 compile.rb  | 10 +++++++++-
 example.src |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/compile.rb b/compile.rb
index 2cbbd44..dc048bb 100755
--- a/compile.rb
+++ b/compile.rb
@@ -11,6 +11,7 @@ module Type
   Ptr = Struct.new(:type)
   Int = Struct.new(:min, :max)
   Float = Struct.new(:bits)
+  Nilable = Struct.new(:type)
 end
 
 module Ast
@@ -59,7 +60,7 @@ class Lexer
   SPACE = /([ \t\v\n\r]+|#.*\n)/
   IDENT = /[_a-zA-Z][_a-zA-Z0-9]*/
   BRACES = /[\(\)\[\]\{\}\.]/
-  OPERATORS = /[*\/=+-:\$]/
+  OPERATORS = /[*\/=+-:\$?]/
   INTEGER = /[0-9]+/
   STRING = /"(\\"|[^"])*"/
   ID_TYPES = {
@@ -207,6 +208,8 @@ class Parser
       struct_type()
     elsif matches("*")
       pointer_type()
+    elsif matches("?")
+      nilable_type()
 #    elsif matches(:func)
 #      func_type()
     else
@@ -242,6 +245,11 @@ class Parser
     Type::Ptr.new(type_specifier())
   end
 
+  def nilable_type()
+    expect("?")
+    Type::Nilable.new(type_specifier())
+  end
+
   #######################################
   # Variable Definitions
   #######################################
diff --git a/example.src b/example.src
index a0024b4..f8a72d1 100644
--- a/example.src
+++ b/example.src
@@ -1,7 +1,7 @@
 module Main
 imports (X11, XSel, Posix)
 
-#cmd : [String] = true
+cmd : ?[String] = true
 
 fetchsel(sel : String)
 {
-- 
2.49.0