         }
     }
 
+    // Transform source string into compiled phrase.  Return phrase on success
+    // or nil on error.
     func compile(input: String) -> CompiledPhrase? {
         let tokens = splitInBlankSeparatedWords(input)
         

        return true
    }
    
    func compileSpecialForm(handler: String) -> Bool {
        switch (handler) {
        case ":":

        return isCompiling ? CompiledPhrase() : phraseBeingCompiled.getAndReset()
    }
 
    // Compile single token into phraseBeingCompiled.  Return true on success.
    func compileToken(token: String) -> Bool {
        if let n = token.toForthInt() {
            phraseBeingCompiled.appendInstruction(.PushConstant(n))
