static void _TestXbnfTokenizers(string[] args)
{
var cfg = CfgDocument.ReadFrom(@"..\..\..\xbnf.pck");
var lex = LexDocument.ReadFrom(@"..\..\..\xbnf.pck");
string input = null;
using (var sr = File.OpenText(@"..\..\..\xbnf.xbnf"))
input = sr.ReadToEnd();
var tokenizer1 = lex.ToTokenizer(input, cfg.EnumSymbols());
var tokenizer2 = tokenizer1; // new XbnfTokenizer(input);
var t1 = new List <Token>(tokenizer1);
var t2 = new List <Token>(tokenizer2);
if (t1.Count != t2.Count)
{
Console.Error.WriteLine("Counts are different.");
}
for (int ic = t1.Count, i = 0; i < ic; ++i)
{
if (!Equals(t1[i], t2[i]))
{
Console.Error.WriteLine("at index {0}", i);
Console.Error.WriteLine(t1[i]);
Console.Error.WriteLine(t2[i]);
break;
}
}
}
static void _RunLalr(string[] args)
{
// we need both a lexer and a CfgDocument.
// we read them from the same file.
var cfg = CfgDocument.ReadFrom(@"..\..\..\expr.pck");
var lex = LexDocument.ReadFrom(@"..\..\..\expr.pck");
// create a runtime tokenizer
var tokenizer = lex.ToTokenizer("3*(4+7)", cfg.EnumSymbols());
// create a parser
var parser = cfg.ToLalr1Parser(tokenizer);
/*parser.ShowHidden =false;
* while (parser.Read())
* {
* Console.WriteLine("{0}: {1}, {2} {3}", parser.NodeType, parser.Symbol, parser.Value,parser.Rule);
* }
* parser = new DebugLalr1Parser(cfg, tokenizer, pt);
*/
parser.ShowHidden = true;
while (LRNodeType.EndDocument != parser.NodeType)
{
Console.WriteLine(parser.ParseReductions(true));
}
return;
}
static void _RunLL(string[] args)
{
var cfg = CfgDocument.ReadFrom(@"..\..\..\expr.ll1.pck");
var lex = LexDocument.ReadFrom(@"..\..\..\expr.ll1.pck");
var tokenizer = lex.ToTokenizer("3+4*(2+1+1)" /*new FileReaderEnumerable(@"..\..\..\xbnf.xbnf")*/, cfg.FillSymbols());
var parser = cfg.ToLL1Parser(tokenizer); //new LL1DebugParser(cfg,tokenizer);
parser.ShowHidden = true;
while (LLNodeType.EndDocument != parser.NodeType)
{
Console.WriteLine(parser.ParseSubtree(true));
}
}
static void _RunXbnfGenerated(string[] args)
{
var cfg = CfgDocument.ReadFrom(@"..\..\..\xbnf.pck");
var lex = LexDocument.ReadFrom(@"..\..\..\xbnf.pck");
var tokenizer = new XbnfTokenizer(new FileReaderEnumerable(@"..\..\..\xbnf.xbnf"));
var parser = new XbnfParser(tokenizer);
parser.ShowHidden = true;
while (LRNodeType.EndDocument != parser.NodeType)
{
Console.WriteLine(parser.ParseReductions(true));
}
}
static void _RunLalrXbnf(string[] args)
{
var cfg = CfgDocument.ReadFrom(@"..\..\..\xbnf.pck");
var lex = LexDocument.ReadFrom(@"..\..\..\xbnf.pck");
var tokenizer = lex.ToTokenizer(new FileReaderEnumerable(@"..\..\..\xbnf.xbnf"), cfg.EnumSymbols());
//var pt = cfg.ToLalr1ParseTable();// new _ConsoleProgress());
var parser = cfg.ToLalr1Parser(tokenizer); //new Lalr1DebugParser(cfg, tokenizer, pt);
parser.ShowHidden = true;
while (LRNodeType.EndDocument != parser.NodeType)
{
Console.WriteLine(parser.ParseReductions(true));
}
}
static void Demo(string[] args)
{
if (0 == args.Length)
{
Console.Error.WriteLine("Must specify input CFG");
return;
}
var cfg = CfgDocument.ReadFrom(args[0]);
Console.WriteLine(cfg.ToString());
Console.WriteLine();
// not-necessary but faster access since we're not modifying:
cfg.RebuildCache();
Console.WriteLine("See: http://hackingoff.com/compilers/ll-1-parser-generator");
Console.WriteLine();
Console.WriteLine("CFG has {0} rules composed of {1} non-terminals and {2} terminals for a total of {3} symbols", cfg.Rules.Count, cfg.FillNonTerminals().Count, cfg.FillTerminals().Count, cfg.FillSymbols().Count);
Console.WriteLine();
Console.Write("Terminals:");
foreach (var t in cfg.FillTerminals())
{
Console.Write(" ");
Console.Write(t);
}
Console.WriteLine();
Console.WriteLine();
// compute the various aspects of the CFG
var predict = cfg.FillPredict();
// var firsts = cfg.FillFirsts(); // we don't need this because we have predict
var follows = cfg.FillFollows();
// enum some stuff
foreach (var nt in cfg.FillNonTerminals())
{
Console.WriteLine(nt + " has the following rules:");
foreach (var ntr in cfg.FillNonTerminalRules(nt))
{
Console.Write("\t");
Console.WriteLine(ntr);
}
Console.WriteLine();
Console.WriteLine(nt + " has the following PREDICT:");
foreach (var t in predict[nt])
{
Console.Write("\t");
Console.WriteLine((t.Symbol ?? "<empty>") + " - " + t.Rule);
}
Console.WriteLine();
// PREDICT makes this redundant
//Console.WriteLine(nt + " has the following FIRSTS:");
//foreach (var t in firsts[nt])
//{
// Console.Write("\t");
// Console.WriteLine(t);
//}
//Console.WriteLine();
Console.WriteLine(nt + " has the following FOLLOWS:");
foreach (var t in follows[nt])
{
Console.Write("\t");
Console.WriteLine(t);
}
Console.WriteLine();
}
// now lets parse some stuff
Console.WriteLine("Building simple parse table");
// the parse table is simply nested dictionaries where each outer key is a non-terminal
// and the inner key is each terminal, where they map to a single rule.
// lookups during parse are basically rule=parseTable[<topOfStack>][<currentToken>]
var parseTable = new Dictionary <string, Dictionary <string, CfgRule> >();
foreach (var nt in cfg.FillNonTerminals())
{
var d = new Dictionary <string, CfgRule>();
parseTable.Add(nt, d);
foreach (var p in predict[nt])
{
if (null != p.Symbol)
{
CfgRule or;
if (d.TryGetValue(p.Symbol, out or))
{
Console.Error.WriteLine("First-first conflict between " + p.Rule + " and " + or);
}
else
{
d.Add(p.Symbol, p.Rule);
}
}
else
{
foreach (var f in follows[nt])
{
CfgRule or;
if (d.TryGetValue(f, out or))
{
Console.Error.WriteLine("First-follows conflict between " + p.Rule + " and " + or);
}
else
{
d.Add(f, p.Rule);
}
}
}
}
}
#region Build a Lexer for our parser - out of scope of the CFG project but necessary
Console.WriteLine("Building simple lexer");
var fas = new FA[]
{
FA.Literal("+", "add"),
FA.Literal("*", "mul"),
FA.Literal("(", "lparen"),
FA.Literal(")", "rparen"),
FA.Repeat(FA.Set("0123456789"), "int")
};
var lexer = new FA();
for (var i = 0; i < fas.Length; i++)
{
lexer.EpsilonTransitions.Add(fas[i]);
}
Console.WriteLine();
#endregion
var text = "(1+3)*2";
Console.WriteLine("Creating tokenizer");
var tokenizer = new Tokenizer(lexer, text);
Console.WriteLine("Creating parser");
var parser = new LL1Parser(parseTable, tokenizer, "Expr");
Console.WriteLine();
Console.WriteLine("Parsing " + text);
Console.WriteLine(parser.ParseSubtree());
}