Ejemplo n.º 1
0
            public bool DoesTokenMatch(AstMacroTerm tkn, CatExpr x, out bool bRecoverable)
            {
                bRecoverable = true;

                if (tkn is AstMacroName)
                {
                    bRecoverable = false;
                    if (x.Count != 1)
                    {
                        return(false);
                    }
                    Function f     = x[0];
                    string   sName = f.GetName();
                    return(sName == tkn.ToString());
                }
                else if (tkn is AstMacroTypeVar)
                {
                    if (x.GetFxnType() == null)
                    {
                        return(false);
                    }

                    if (!CatFxnType.CompareFxnTypes(x.GetFxnType(), CatFxnType.PushSomethingType))
                    {
                        return(false);
                    }

                    mCapturedVars.Add(tkn.ToString(), x);
                    return(true);
                }
                else if (tkn is AstMacroQuote)
                {
                    AstMacroQuote macroQuote = tkn as AstMacroQuote;
                    if (x.Count != 1)
                    {
                        return(false);
                    }
                    PushFunction quote = x[0] as PushFunction;
                    if (quote == null)
                    {
                        return(false);
                    }

                    for (int i = 0; i < macroQuote.mTerms.Count; ++i)
                    {
                        // Are we are at a stack variable in the matching pattern
                        // if so it must be the last token in the pattern
                        // e.g. [1 2 $A] is legal [1 $A 2] is not.
                        if (macroQuote.mTerms[i] is AstMacroStackVar)
                        {
                            if (i != macroQuote.mTerms.Count - 1)
                            {
                                throw new Exception("within a quotation, expression variables can only be used in the right-most postition");
                            }
                            AstMacroStackVar v    = macroQuote.mTerms[0] as AstMacroStackVar;
                            CatExpr          expr = quote.GetChildren().GetRangeFrom(i);
                            mCapturedVars.Add(v.msName, expr);
                            return(true);
                        }
                        else if (macroQuote.mTerms[i] is AstMacroName)
                        {
                            // Well this is just an ordinary name pattern
                            AstMacroName name = macroQuote.mTerms[i] as AstMacroName;
                            if (quote.GetChildren().Count <= i)
                            {
                                return(false);
                            }
                            Function f = quote.GetChildren()[i];
                            if (!f.GetName().Equals(name.ToString()))
                            {
                                return(false);
                            }
                        }
                        else
                        {
                            return(false);
                        }
                    }

                    // No stack variable was encountered in the pattern
                    // therefore the match must have been perfect, which means there are no
                    // more terms in the input
                    if (quote.GetChildren().Count != macroQuote.mTerms.Count)
                    {
                        return(false);
                    }

                    return(true);
                }
                else if (tkn is AstMacroStackVar)
                {
                    AstMacroStackVar v = tkn as AstMacroStackVar;

                    if (v.mType == null)
                    {
                        return(false);
                    }

                    if (x.GetFxnType() == null)
                    {
                        return(false);
                    }

                    if (!CatFxnType.CompareFxnTypes(x.GetFxnType(), v.mType))
                    {
                        return(false);
                    }

                    mCapturedVars.Add(v.msName, x);
                    return(true);
                }
                else
                {
                    throw new Exception("unrecognized macro term " + tkn.ToString());
                }
            }
Ejemplo n.º 2
0
            public CatExpr PatternToFxns(INameLookup names, List <AstMacroTerm> pattern)
            {
                CatExpr ret = new CatExpr();

                foreach (AstMacroTerm t in pattern)
                {
                    if (t is AstMacroTypeVar)
                    {
                        string s = t.ToString();
                        if (!mCapturedVars.ContainsKey(s))
                        {
                            throw new Exception("macro variable " + s + " was not captured");
                        }
                        CatExpr expr = mCapturedVars[s];
                        ret.AddRange(expr);
                    }
                    else if (t is AstMacroStackVar)
                    {
                        string s = (t as AstMacroStackVar).msName;
                        if (!mCapturedVars.ContainsKey(s))
                        {
                            throw new Exception("macro variable " + s + " was not captured");
                        }
                        CatExpr expr = mCapturedVars[s];
                        ret.AddRange(expr);
                    }
                    else if (t is AstMacroName)
                    {
                        string s = t.ToString();
                        if (s.Length < 1)
                        {
                            throw new Exception("internal error: macro name is empty string");
                        }

                        Function f = names.ThrowingLookup(s);

                        if (f == null)
                        {
                            if (Char.IsDigit(s[0]))
                            {
                                f = new PushInt(int.Parse(s));
                            }
                            else
                            {
                                throw new Exception("Could not find function " + s);
                            }
                        }
                        ret.Add(f);
                    }
                    else if (t is AstMacroQuote)
                    {
                        // TODO: handle typed terms within a quotation.
                        AstMacroQuote       macroQuote   = t as AstMacroQuote;
                        List <AstMacroTerm> localPattern = macroQuote.mTerms;
                        PushFunction        q            = new PushFunction(PatternToFxns(names, localPattern));
                        ret.Add(q);
                    }
                    else
                    {
                        throw new Exception("unrecognized macro term " + t.ToString());
                    }
                }
                return(ret);
            }