Bam! Variable substitution works!

src/document.cpp

 #include <cstdio>
 #include "document.hpp"
+#include <iostream>
 
 namespace Sass {
   using namespace Prelexer;
+  using std::cout; using std::endl;
 
   Document::Document(char* _path, char* _source) {
     path = _path;
@@ -42,13 +44,24 @@ namespace Sass {
     if (try_munching<block_comment>()) {
       return Node(Node::comment, top);
     }
+    else if (try_munching<variable>()) {
+      return parse_var_def();
+    }
     else return parse_ruleset();
   }
   
+  Node Document::parse_var_def() {
+    const Token key = top;
+    try_munching<exactly<':'> >();
+    environment[string(key)] = parse_values();
+    try_munching<exactly<';'> >();
+    return Node(Node::null);
+  }
+  
   Node Document::parse_ruleset() {
     Node ruleset(Node::ruleset);
     ruleset.push_child(parse_selector());
-    ruleset.push_child(parse_declarations());
+    ruleset.push_child(parse_clauses());
     return ruleset;
   }
   
@@ -57,14 +70,18 @@ namespace Sass {
     return Node(Node::selector, top);
   }
   
-  Node Document::parse_declarations() {
+  Node Document::parse_clauses() {
     try_munching<exactly<'{'> >();
-    Node decls(Node::declarations);
+    Node decls(Node::clauses);
     while(!try_munching<exactly<'}'> >()) {
       if (try_munching<block_comment>()) {
         decls.push_child(Node(Node::comment, top));
         continue;
       }
+      else if (try_munching<variable>()) {
+        decls.push_child(parse_var_def());
+        continue;
+      }
       try_munching<identifier>();
       Token id = top;
       if (try_munching<exactly<':'> >()) {
@@ -77,7 +94,7 @@ namespace Sass {
       else {
         Node ruleset(Node::ruleset);
         ruleset.push_child(Node(Node::selector, id));
-        ruleset.push_child(parse_declarations());
+        ruleset.push_child(parse_clauses());
         decls.push_opt_child(ruleset);
       }
     }
@@ -87,7 +104,15 @@ namespace Sass {
   Node Document::parse_values() {
     Node values(Node::values);
     while(try_munching<identifier>() || try_munching<dimension>()  ||
-          try_munching<percentage>() || try_munching<number>()) {
+          try_munching<percentage>() || try_munching<number>() ||
+          try_munching<hex>()        || try_munching<variable>()) {
+      if (top.begin[0] == '$') {
+        Node stuff(environment[string(top)]);
+        for (int i = 0; i < stuff.children.size(); ++i) {
+          values.push_child(stuff.children[i]);
+        }
+      }
+      else
         values.push_child(Node(Node::value, top));
     }
     return values;      

src/document.hpp

+#include <map>
 #include "node.hpp"
 
 namespace Sass {
   using std::vector;
+  using std::map;
   using namespace Prelexer;
 
   struct Document {
@@ -9,6 +11,10 @@ namespace Sass {
     char* source;
     char* position;
     unsigned int line_number;
+    
+    // TO DO: move the environment up into the context class when it's ready
+    map<string, Node> environment;
+    
     vector<Node> statements;
     Token top;
     bool last_munch_succeeded;
@@ -57,9 +63,10 @@ namespace Sass {
     
     void parse_scss();
     Node parse_statement();
+    Node parse_var_def();
     Node parse_ruleset();
     Node parse_selector();
-    Node parse_declarations();
+    Node parse_clauses();
     Node parse_values();
       
   };

src/node.cpp

@@ -48,7 +48,7 @@ namespace Sass {
       children[1].dump(depth);
       cout << ";" << endl;
       break;
-    case declarations:
+    case clauses:
       cout << " {" << endl;
       for (int i = 0; i < children.size(); ++i) {
         children[i].dump(depth + 1);
@@ -92,7 +92,7 @@ namespace Sass {
       children[1].emit_expanded_css(buf, prefix);
       buf << ";" << endl;
       break;
-    case declarations:
+    case clauses:
       buf << " {" << endl;
       for (int i = 0; i < children.size(); ++i)
         children[i].emit_expanded_css(buf, prefix);

src/node.hpp

@@ -9,7 +9,7 @@ namespace Sass {
       null,
       comment,
       ruleset,
-      declarations,
+      clauses,
       selector_group,
       selector,
       simple_selector_sequence,

src/test.scss

+$blah: bloo;
+
 /* top level comment -- should preserved */
 div {
   /* another comment that should be preserved */
   color: red;
   background: blue;
+  $blux: hux;
   span {
     font-weight: bold;
     a {
       text-decoration: none;
       color: green;
+      border: 1px $blah red;
     }
     /* yet another comment that should be preserved */
     display: inline-block;
   }
   p {
     padding: 10px 8%;
+    -webkit-box-sizing: $blux;
   }
   margin: 10px 5px;
 }

src/token.hpp

@@ -16,6 +16,11 @@ namespace Sass {
           unsigned int _line_number);
     Token(const Token& t);
     inline bool is_null() { return begin == 0 || end == 0; }
-    inline operator string() { return string(begin, end - begin); }
+    inline operator string() const { return string(begin, end - begin); }
+    inline bool operator<(const Token& rhs) const {
+      return (begin < rhs.begin) ||
+             (begin == rhs.begin && end < rhs.end);
+    }
+             
   };
 }
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