No longer doing single-pass parsing/expansion. Building up a queue of pending…

No longer doing single-pass parsing/expansion. Building up a queue of pending expansions/evaluations, then performing them after parse. Should combine the efficiency of single-pass with the ease of multi-pass. Small bug that needs fixing.

context.hpp

@@ -3,15 +3,15 @@ namespace Sass {
   
   struct Context {
     map<Token, Node> environment;
-    map<Token, Node> mixins;
-    vector<Node*> pending;
+    // map<Token, Node> mixins;
+    vector<Node> pending;
     vector<char*> source_refs;
     size_t ref_count;
 
     Context()
     : environment(map<Token, Node>()),
-      mixins(map<Token, Node>()),
-      pending(vector<Node*>()),
+      // mixins(map<Token, Node>()),
+      pending(vector<Node>()),
       source_refs(vector<char*>()),
       ref_count(0)
     { }

document.hpp

@@ -112,11 +112,11 @@ namespace Sass {
     void parse_scss();
     Node parse_import();
     Node parse_include();
-    void parse_mixin_def();
+    Node parse_mixin_def();
     Node parse_parameter();
     Node parse_arguments();
     Node parse_mixin_params();
-    void parse_assignment();
+    Node parse_assignment();
     Node parse_ruleset();
     Node parse_selector_group();
     Node parse_selector();
@@ -145,6 +145,7 @@ namespace Sass {
     const char* look_for_pseudo(const char* start = 0);
     const char* look_for_attrib(const char* start = 0);
     
+    void eval_pending();
     string emit_css(CSS_Style style);
 
   };

document_evaluator.cpp

+#include "document.hpp"
+#include "evaluator.hpp"
+
+namespace Sass {
+  
+  void Document::eval_pending()
+  {
+    for (int i = 0; i < context.pending.size(); ++i) {
+      Node n(context.pending[i]);
+      switch (n.type)
+      {
+        case Node::assignment:
+          context.environment[n[0].token] = eval(n[1], context.environment);
+          break;
+        case Node::rule:
+          n[1] = eval(n[1], context.environment);
+          break;
+      }
+    }
+  }
+}
\ No newline at end of file

document_parser.cpp

@@ -28,7 +28,7 @@ namespace Sass {
       //   parse_mixin_def();
       // }
       else if (peek< variable >(position)) {
-        parse_assignment();
+        context.pending.push_back(parse_assignment());
         lex< exactly<';'> >();
       }
       else {
@@ -128,20 +128,22 @@ namespace Sass {
   //   }
   // }
 
-  void Document::parse_assignment()
+  Node Document::parse_assignment()
   {
     lex< variable >();
-    Token key(lexed);
+    Node var(line_number, Node::variable, lexed);
     lex< exactly<':'> >();
-    // context.environment[key] = parse_values();
     Node val(parse_list());
-    val.from_variable = true;
-    val.eval_me = true;
+    // val.from_variable = true;
+    // val.eval_me = true;
+    Node assn(line_number, Node::assignment, 2);
+    assn << var << val;
+    return assn;
     
-    Node evaled(eval(val));
-    evaled.from_variable = true;
-    val.eval_me = true;
-    context.environment[key] = evaled;
+    // Node evaled(eval(val));
+    // evaled.from_variable = true;
+    // val.eval_me = true;
+    // context.environment[key] = evaled;
   }
 
   Node Document::parse_ruleset()
@@ -325,7 +327,7 @@ namespace Sass {
       //   semicolon = true;
       // }
       else if (lex< variable >()) {
-        parse_assignment();
+        context.pending.push_back(parse_assignment());
         semicolon = true;
       }
       // else if (look_for_rule(position)) {
@@ -358,23 +360,23 @@ namespace Sass {
     lex< exactly<':'> >();
     // rule << parse_values();
     rule << parse_list();
+    if (rule[1].eval_me) context.pending.push_back(rule);
     return rule;
   }
   
   Node Document::parse_list()
   {
-
     Node val(parse_comma_list());
-    if (val.type != Node::comma_list && val.type != Node::space_list && val.eval_me) {
-      return eval(val);
-    }
-    else if (val.type == Node::comma_list || val.type == Node::space_list) {
-      for (int i = 0; i < val.children->size(); ++i) {
-        if (val.children->at(i).eval_me) {
-          val.children->at(i) = eval(val.children->at(i));
-        }
-      }
-    }
+    // if (val.type != Node::comma_list && val.type != Node::space_list && val.eval_me) {
+    //   return eval(val);
+    // }
+    // else if (val.type == Node::comma_list || val.type == Node::space_list) {
+    //   for (int i = 0; i < val.children->size(); ++i) {
+    //     if (val.children->at(i).eval_me) {
+    //       val.children->at(i) = eval(val.children->at(i));
+    //     }
+    //   }
+    // }
     return val;
   }
   
@@ -391,9 +393,14 @@ namespace Sass {
     
     Node comma_list(line_number, Node::comma_list, 2);
     comma_list << list1;
+    comma_list.eval_me |= list1.eval_me;
     
     while (lex< exactly<','> >())
-    { comma_list << parse_space_list(); }
+    {
+      Node list(parse_space_list());
+      comma_list << list;
+      comma_list.eval_me |= list.eval_me;
+    }
     
     return comma_list;
   }
@@ -406,20 +413,21 @@ namespace Sass {
         peek< exactly<'}'> >(position) ||
         peek< exactly<')'> >(position) ||
         peek< exactly<','> >(position))
-    // { return expr1.eval_me ? eval(expr1) : expr1; }
     { return expr1; }
     
     Node space_list(line_number, Node::space_list, 2);
     space_list << expr1;
-    // space_list << (expr1.eval_me ? eval(expr1) : expr1);
+    space_list.eval_me |= expr1.eval_me;
     
     while (!(peek< exactly<';'> >(position) ||
              peek< exactly<'}'> >(position) ||
              peek< exactly<')'> >(position) ||
              peek< exactly<','> >(position)))
-    // { Node expr(parse_expression());
-    //       space_list << (expr.eval_me ? eval(expr) : expr); }
-    {  space_list << parse_expression(); }
+    {
+      Node expr(parse_expression());
+      space_list << expr;
+      space_list.eval_me |= expr.eval_me;
+    }
     
     return space_list;
   }
@@ -473,7 +481,7 @@ namespace Sass {
 
     Node term(line_number, Node::term, 3);
     term << fact1;
-    if (fact1.from_variable || fact1.eval_me) term.eval_me = true;
+    if (fact1.eval_me) term.eval_me = true;
 
     while (lex< exactly<'*'> >() || lex< exactly<'/'> >()) {
       if (lexed.begin[0] == '*') {
@@ -484,7 +492,7 @@ namespace Sass {
         term << Node(line_number, Node::div, lexed);
       }
       Node fact(parse_factor());
-      if (fact.from_variable || fact.eval_me) term.eval_me = true;
+      if (fact.eval_me) term.eval_me = true;
       term << fact;
     }
 
@@ -556,8 +564,11 @@ namespace Sass {
     if (lex< string_constant >())
     { return Node(line_number, Node::string_constant, lexed); }
 
-    if (lex< variable >()) {
-      return context.environment[lexed];
+    if (lex< variable >())
+    {
+      Node var(line_number, Node::variable, lexed);
+      var.eval_me = true;
+      return var;
     }
   }
 

evaluator.cpp

@@ -5,39 +5,40 @@
 namespace Sass {
   using std::cerr; using std::endl;
 
-  Node eval(const Node& expr)
+  Node eval(const Node& expr, map<Token, Node>& g_env)
   {
     switch (expr.type)
     {
       case Node::comma_list:
       case Node::space_list: {
         if (expr.eval_me) {
-          *(expr.children->begin()) = eval(expr.children->front());
+          // *(expr.children->begin()) = eval(expr[0], g_env);
+          expr[0] = eval(expr[0], g_env);
         }
         return expr;
       } break;
 
       case Node::expression: {
-        Node acc(expr.line_number, Node::expression, eval(expr.children->at(0)));
-        Node rhs(eval(expr.children->at(2)));
-        accumulate(expr.children->at(1).type, acc, rhs);
-        for (int i = 3; i < expr.children->size(); i += 2) {
-          Node rhs(eval(expr.children->at(i+1)));
-          accumulate(expr.children->at(i).type, acc, rhs);
-        }
-        return acc.children->size() == 1 ? acc.children->front() : acc;
+        Node acc(expr.line_number, Node::expression, eval(expr[0], g_env));
+        Node rhs(eval(expr[2], g_env));
+        accumulate(expr[1].type, acc, rhs);
+        for (int i = 3; i < expr.size(); i += 2) {
+          Node rhs(eval(expr[i+1], g_env));
+          accumulate(expr[i].type, acc, rhs);
+        }
+        return acc.size() == 1 ? acc[0] : acc;
       } break;
 
       case Node::term: {
         if (expr.eval_me) {
-          Node acc(expr.line_number, Node::expression, eval(expr.children->at(0)));
-          Node rhs(eval(expr.children->at(2)));
-          accumulate(expr.children->at(1).type, acc, rhs);
-          for (int i = 3; i < expr.children->size(); i += 2) {
-            Node rhs(eval(expr.children->at(i+1)));
-            accumulate(expr.children->at(i).type, acc, rhs);
+          Node acc(expr.line_number, Node::expression, eval(expr[0], g_env));
+          Node rhs(eval(expr[2], g_env));
+          accumulate(expr[1].type, acc, rhs);
+          for (int i = 3; i < expr.size(); i += 2) {
+            Node rhs(eval(expr[i+1], g_env));
+            accumulate(expr[i].type, acc, rhs);
           }
-          return acc.children->size() == 1 ? acc.children->front() : acc;
+          return acc.size() == 1 ? acc[0] : acc;
         }
         else {
           return expr;
@@ -73,6 +74,10 @@ namespace Sass {
         return triple;       
       } break;
       
+      case Node::variable: {
+        return g_env[expr.token];
+      } break;
+      
       default: {
         return expr;
       }

evaluator.hpp

+#include <map>
+
 #ifndef SASS_NODE_INCLUDED
 #include "node.hpp"
 #endif
 
 namespace Sass {
-  Node eval(const Node& expr);
+  using std::map;
+  
+  Node eval(const Node& expr, map<Token, Node>& g_env);
   Node accumulate(const Node::Type op, Node& acc, Node& rhs);
   double operate(const Node::Type op, double lhs, double rhs);
 }
\ No newline at end of file

sassc.cpp

@@ -30,6 +30,7 @@ int main(int argc, char* argv[]) {
   Document doc(path, 0);
   doc.parse_scss();
   cerr << "successfully parsed document" << endl;
+  doc.eval_pending();
   string output = doc.emit_css(style);
   cout << output;