From 9827345213328dff034515565c39953e2ad5d7f5 Mon Sep 17 00:00:00 2001
From: Jonathan Turner <probata@hotmail.com>
Date: Wed, 14 Oct 2009 13:51:35 +0000
Subject: [PATCH] Fix Id Literals so that they are keyed off an Id search. 
 This allows us to add operator overloading on the parse side.

---
 .../chaiscript/language/chaiscript_parser.hpp | 91 ++++++++-----------
 unittests/operator_overload.chai              |  8 ++
 unittests/operator_overload.txt               |  1 +
 3 files changed, 48 insertions(+), 52 deletions(-)
 create mode 100644 unittests/operator_overload.chai
 create mode 100644 unittests/operator_overload.txt

diff --git a/include/chaiscript/language/chaiscript_parser.hpp b/include/chaiscript/language/chaiscript_parser.hpp
index 25d73f7..49ba2ee 100644
--- a/include/chaiscript/language/chaiscript_parser.hpp
+++ b/include/chaiscript/language/chaiscript_parser.hpp
@@ -278,7 +278,32 @@ namespace chaiscript
                     ++col;
                 }
             }
+            else if ((input_pos != input_end) && (*input_pos == '`')) {
+                retval = true;
+                ++col;
+                ++input_pos;
+                std::string::iterator start = input_pos;
+                
+                while ((input_pos != input_end) && (*input_pos != '`')) {
+                    if (Eol()) {
+                        throw Eval_Error("Carriage return in identifier literal", File_Position(line, col), filename);
+                    }
+                    else {
+                        ++input_pos;
+                        ++col;
+                    }
+                }
 
+                if (start == input_pos) {
+                    throw Eval_Error("Missing contents of identifier literal", File_Position(line, col), filename);
+                }
+                else if (input_pos == input_end) {
+                    throw Eval_Error("Incomplete identifier literal", File_Position(line, col), filename);
+                }
+
+                ++col;
+                ++input_pos;
+            }
             return retval;
         }
 
@@ -296,10 +321,19 @@ namespace chaiscript
                 int prev_col = col;
                 int prev_line = line;
                 if (Id_()) {
-                    std::string match(start, input_pos);
-                    TokenPtr t(new Token(match, Token_Type::Id, filename, prev_line, prev_col, line, col));
-                    match_stack.push_back(t);
-                    return true;
+                    if (*start == '`') {
+                        //Id Literal
+                        std::string match(start+1, input_pos-1);
+                        TokenPtr t(new Token(match, Token_Type::Id, filename, prev_line, prev_col, line, col));
+                        match_stack.push_back(t);
+                        return true;
+                    }
+                    else {
+                        std::string match(start, input_pos);
+                        TokenPtr t(new Token(match, Token_Type::Id, filename, prev_line, prev_col, line, col));
+                        match_stack.push_back(t);
+                        return true;
+                    }
                 }
                 else {
                     return false;
@@ -1263,7 +1297,7 @@ namespace chaiscript
             std::string::iterator prev_pos = input_pos;
 
             unsigned int prev_stack_top = match_stack.size();
-            if (Id(true) || Id_Literal()) {
+            if (Id(true)) {
                 retval = true;
                 bool has_more = true;
 
@@ -1383,53 +1417,6 @@ namespace chaiscript
             return retval;
         }
 
-        /**
-         * Reads an identifier literal of the special form `<name>` from input
-         */
-        bool Id_Literal() {
-            bool retval = false;
-
-            SkipWS();
-
-            if ((input_pos != input_end) && (*input_pos == '`')) {
-                retval = true;
-
-                int prev_col = col;
-                int prev_line = line;
-
-                ++col;
-                ++input_pos;
-
-                std::string::iterator start = input_pos;
-
-                while ((input_pos != input_end) && (*input_pos != '`')) {
-                    if (Eol()) {
-                        throw Eval_Error("Carriage return in identifier literal", File_Position(line, col), filename);
-                    }
-                    else {
-                        ++input_pos;
-                        ++col;
-                    }
-                }
-
-                if (start == input_pos) {
-                    throw Eval_Error("Missing contents of identifier literal", File_Position(line, col), filename);
-                }
-                else if (input_pos == input_end) {
-                    throw Eval_Error("Incomplete identifier literal", File_Position(line, col), filename);
-                }
-
-                ++col;
-                std::string match(start, input_pos);
-                TokenPtr t(new Token(match, Token_Type::Id, filename, prev_line, prev_col, line, col));
-                match_stack.push_back(t);
-                ++input_pos;
-
-            }
-
-            return retval;
-        }
-
         /**
          * Reads a unary prefixed expression from input
          */
diff --git a/unittests/operator_overload.chai b/unittests/operator_overload.chai
new file mode 100644
index 0000000..1f3f8cb
--- /dev/null
+++ b/unittests/operator_overload.chai
@@ -0,0 +1,8 @@
+def Bob::`+`(y) { this.x + y.x }
+def Bob::Bob() { }
+attr Bob::x
+var b = Bob()
+var c = Bob()
+b.x = 4
+c.x = 5
+print(b+c)
diff --git a/unittests/operator_overload.txt b/unittests/operator_overload.txt
new file mode 100644
index 0000000..ec63514
--- /dev/null
+++ b/unittests/operator_overload.txt
@@ -0,0 +1 @@
+9