Fixed substitution method.

coffeequate/build/coffeequate.js

@@ -2652,7 +2652,7 @@ define("lib/almond", function(){});
           evaluateSymbolicConstants = false;
         }
         for (variable in substitutions) {
-          if (!(substitutions[variable] instanceof terminals.Terminal || substitutions[variable] instanceof nodes.BasicNode)) {
+          if (substitutions[variable].copy == null) {
             substitutions[variable] = new terminals.Constant(substitutions[variable]);
           }
         }
@@ -3355,7 +3355,7 @@ define("lib/almond", function(){});
           evaluateSymbolicConstants = false;
         }
         for (variable in substitutions) {
-          if (!(substitutions[variable] instanceof terminals.Terminal || substitutions[variable] instanceof nodes.BasicNode)) {
+          if (substitutions[variable].copy == null) {
             substitutions[variable] = new terminals.Constant(substitutions[variable]);
           }
         }
@@ -3956,7 +3956,7 @@ define("lib/almond", function(){});
           evaluateSymbolicConstants = false;
         }
         for (variable in substitutions) {
-          if (!(substitutions[variable] instanceof terminals.Terminal || substitutions[variable] instanceof nodes.BasicNode)) {
+          if (substitutions[variable].copy == null) {
             substitutions[variable] = new terminals.Constant(substitutions[variable]);
           }
         }
@@ -4253,7 +4253,7 @@ define("lib/almond", function(){});
       function Expression(val) {
         if (val instanceof String || typeof val === "string") {
           this.expr = parse.stringToExpression(val);
-        } else if (val instanceof nodes.BasicNode) {
+        } else if (val.copy != null) {
           this.expr = val.copy();
         } else {
           throw new Error("Unknown argument: `" + val + "'.");
@@ -4264,6 +4264,31 @@ define("lib/almond", function(){});
         return this.expr.toString();
       };
 
+      Expression.prototype.solve = function(variable) {
+        return this.expr.solve(variable);
+      };
+
+      Expression.prototype.sub = function(substitutions) {
+        var key, newsubs;
+        newsubs = {};
+        for (key in substitutions) {
+          if (substitutions[key] instanceof Expression) {
+            newsubs[key] = substitutions[key].expr;
+          } else {
+            newsubs[key] = substitutions[key];
+          }
+        }
+        return this.expr.sub(newsubs, null, null).simplify();
+      };
+
+      Expression.prototype.copy = function() {
+        return new Expression(this.expr.copy());
+      };
+
+      Expression.prototype.simplify = function() {
+        return this.expr.simplify();
+      };
+
       return Expression;
 
     })();

coffeequate/compile.sh

@@ -1,2 +1,3 @@
+coffee -c .
 node ./src/lib/r.js -o ./src/build.js
-node ./src/lib/r.js -o ./src/build-min.js
+node ./src/lib/r.js -o ./src/build-min.js

coffeequate/src/Expression.coffee

@@ -7,7 +7,7 @@ define ["parse", "nodes"], (parse, nodes) ->
 			if val instanceof String or typeof val == "string"
 				# The string we pass in is just a representation to parse.
 				@expr = parse.stringToExpression(val)
-			else if val instanceof nodes.BasicNode
+			else if val.copy?
 				@expr = val.copy()
 			else
 				throw new Error("Unknown argument: `#{val}'.")
@@ -22,7 +22,19 @@ define ["parse", "nodes"], (parse, nodes) ->
 		sub: (substitutions) ->
 			# TODO: Uncertainties, equivalencies, options.
 			# TODO: Seems that the way I implemented substituting expressions was different last time for no real reason. Fix.
-			@expr.sub(substitutions, null, null).simplify()
+
+			# If there are any Expressions in here, we should remove them.
+			newsubs = {}
+			for key of substitutions
+				if substitutions[key] instanceof Expression
+					newsubs[key] = substitutions[key].expr
+				else
+					newsubs[key] = substitutions[key]
+
+			return @expr.sub(newsubs, null, null).simplify()
+
+		copy: ->
+			new Expression(@expr.copy())
 
 		simplify: ->
 			@expr.simplify()

coffeequate/src/operators/Add.coffee

@@ -576,7 +576,7 @@ define [
 
 			# Interpret substitutions.
 			for variable of substitutions
-				unless substitutions[variable] instanceof terminals.Terminal or substitutions[variable] instanceof nodes.BasicNode
+				unless substitutions[variable].copy? # All nodes and terminals should implement this.
 					substitutions[variable] = new terminals.Constant(substitutions[variable])
 
 			unless equivalencies?

coffeequate/src/operators/Mul.coffee

@@ -404,7 +404,7 @@ define [
 
 			# Interpret substitutions.
 			for variable of substitutions
-				unless substitutions[variable] instanceof terminals.Terminal or substitutions[variable] instanceof nodes.BasicNode
+				unless substitutions[variable].copy?
 					substitutions[variable] = new terminals.Constant(substitutions[variable])
 
 			unless equivalencies?

coffeequate/src/operators/Pow.coffee

@@ -234,7 +234,7 @@ define [
 
 			# Interpret substitutions.
 			for variable of substitutions
-				unless substitutions[variable] instanceof terminals.Terminal or substitutions[variable] instanceof nodes.BasicNode
+				unless substitutions[variable].copy?
 					substitutions[variable] = new terminals.Constant(substitutions[variable])
 
 			unless equivalencies?