2 using System.Collections;
3 using System.Collections.Generic;
7 namespace System.Xml.Expression
9 public class Xexpression
11 public static int debug_level = 0;
13 public struct Symbol : IEquatable<Symbol>
15 private static NameTable nt = new NameTable ();
19 public Symbol (string str)
24 public static implicit operator Symbol (string str)
26 return new Symbol (str);
29 public static implicit operator string (Symbol name)
34 public static bool operator== (Symbol n1, Symbol n2)
36 return (object) n1.name == (object) n2.name;
39 public static bool operator!= (Symbol n1, Symbol n2)
41 return (object) n1.name != (object) n2.name;
44 public static bool operator== (Symbol n1, string n2)
46 return (object) n1.name == (object) n2;
49 public static bool operator!= (Symbol n1, string n2)
51 return (object) n1.name != (object) n2;
54 public static bool operator== (string n1, Symbol n2)
56 return (object) n1 == (object) n2.name;
59 public static bool operator!= (string n1, Symbol n2)
61 return (object) n1 != (object) n2.name;
64 public bool Equals (Symbol name)
66 return Object.ReferenceEquals (this.name, name.name);
69 public override bool Equals (object obj)
71 return Object.ReferenceEquals (this.name, obj);
74 public override int GetHashCode ()
76 return name.GetHashCode ();
79 public static NameTable Table { get { return nt; } }
81 public override string ToString () { return name; }
84 private static Symbol Qexpr = "expr";
86 private static Symbol Qnull = "";
87 private static Symbol Qfuncall = "funcall";
88 private static Symbol Qinteger = "integer";
89 private static Symbol Qstring = "string";
90 private static Symbol Qsymbol = "symbol";
91 private static Symbol Qlist = "list";
93 private static Symbol Qdefun = "defun";
94 private static Symbol Qfname = "fname";
95 private static Symbol Qargs = "args";
96 private static Symbol Qargs_unevalled = "args-unevalled";
97 private static Symbol Qfixed = "fixed";
98 private static Symbol Qoptional = "optional";
99 private static Symbol Qrest = "rest";
101 private static Symbol Qdefvar = "defvar";
102 private static Symbol Qvname = "vname";
103 private static Symbol Qdescription = "description";
104 private static Symbol Qrange = "range";
106 public abstract class Function
109 public int min_arg, max_arg;
111 public Function () { }
113 public Function (Symbol name, int min_arg, int max_arg)
116 this.min_arg = min_arg;
117 this.max_arg = max_arg;
120 public abstract Term Call (Domain domain, Variable vari, Term[] args);
122 public override string ToString ()
127 internal class Subroutine : Function
129 public Builtin builtin;
132 public Subroutine (Builtin builtin, Symbol name, bool setvar,
133 int min_arg, int max_arg)
134 : base (name, min_arg, max_arg)
136 this.builtin = builtin;
137 this.setvar = setvar;
140 public override Term Call (Domain domain, Variable vari, Term[] args)
144 args = (Term[]) args.Clone ();
145 for (int i = 0; i < args.Length; i++)
147 args[i] = args[i].Eval (domain);
152 return builtin (domain, vari, args);
156 internal class SpecialForm : Function
158 public Builtin builtin;
160 public SpecialForm (Builtin builtin, Symbol name,
161 int min_arg, int max_arg)
162 : base (name, min_arg, max_arg)
164 this.builtin = builtin;
167 public override Term Call (Domain domain, Variable vari, Term[] args)
169 return builtin (domain, vari, args);
173 internal class Lambda : Function
175 internal bool args_evalled;
176 internal Variable[] args;
177 internal Term[] body;
179 public Lambda (Domain domain, XmlNode node)
184 name = node.Attributes[Qfname].Value;
186 node = node.FirstChild;
188 && (node.Name == Qargs || node.Name == Qargs_unevalled))
191 args_evalled = node.Name == Qargs;
192 for (n = node.FirstChild; n != null; n = n.NextSibling)
194 if (n.Name == Qfixed)
196 else if (n.Name == Qoptional)
198 else if (n.Name == Qrest)
201 throw new Exception ("Invalid argument type: " + n);
204 max_arg = nfixed + noptional + nrest;
205 args = new Variable[max_arg];
207 for (int i = 0; i < max_arg; n = n.NextSibling)
208 args[i++] = domain.Defvar ((Symbol) n.Attributes[0].Value);
214 min_arg = max_arg = 0;
218 public Lambda (Domain domain, Symbol name,
219 bool args_evalled, Symbol[] args)
226 this.args_evalled = args_evalled;
230 for (i = 0; i < args.Length; i++, nfixed++)
231 if (args[i] == Qoptional || args[i] == Qrest)
235 if (args[i] == Qoptional)
237 for (i++; i < args.Length; i++, noptional++)
238 if (args[i] == Qrest)
245 max_arg = nfixed + noptional + nrest;
246 this.args = new Variable[max_arg];
248 for (i = j = 0; j < this.args.Length; i++)
249 if (args[i] != Qoptional || args[i] != Qrest)
250 this.args[j++] = domain.Defvar (args[i]);
254 min_arg = max_arg = 0;
258 public void SetBody (Domain domain, XmlNode node)
260 for (node = node.FirstChild; node != null; node = node.NextSibling)
261 if (node.Name != Qdescription
262 && node.Name != Qargs
263 && node.Name != Qargs_unevalled)
266 for (XmlNode n = node; n != null; n = n.NextSibling)
270 body = new Term[nterms];
271 for (nterms = 0; node != null; node = node.NextSibling, nterms++)
272 body[nterms] = new Term (domain, node);
276 public void SetBody (Term[] body)
281 public override Term Call (Domain domain, Variable vari, Term[] args)
283 Bindings current = domain.bindings;
290 Term[] newargs = new Term[args.Length];
291 for (i = 0; i < min_arg; i++)
292 newargs[i] = args[i].Eval (domain);
295 for (i = 0; i < min_arg; i++)
296 domain.Bind (this.args[i], args[i]);
301 domain.Catch (CatchTag.Return);
302 foreach (Term term in body)
304 result = term.Eval (domain);
314 domain.UnboundTo (current);
321 public class Variable
323 public Domain domain;
324 public readonly Symbol name;
326 protected Term default_val;
330 public Variable (Domain domain, Symbol name, Term val)
332 this.domain = domain;
338 public virtual bool ValueP (Term val) { return true; }
340 public Variable Clone (Domain domain)
342 Variable v = new Variable (domain, name, val);
344 v.default_val = default_val;
353 if (! ValueP (value))
354 throw new Exception ("Invalid value: " + value);
359 public Term SetValue (int i)
366 public Term SetValue (string s)
372 public Term DefaultValue
374 get { return default_val; }
376 if (! ValueP (value))
377 throw new Exception ("Invalid value: " + value);
382 public virtual object Range
384 get { return range; }
385 set { range = value; }
388 public override string ToString () { return name + "(" + val + ")"; }
390 public class Int : Variable
394 private static bool SubsetP (int[] r1, int[] r2)
398 for (int i = 0; i < r1.Length; i += 2)
401 for (j = 0; j < r2.Length; j += 2)
402 if (r2[j] <= r1[i] && r2[j + 1] >= r1[i + 1])
410 private static bool SubsetP (int val, int[] r)
414 for (int i = 0; i < r.Length; i += 2)
415 if (r[i] <= val && r[i + 1] >= val)
420 public Int (Domain domain, Symbol name, string description,
421 int value, int[] range)
422 : base (domain, name, new Term (value))
424 if (! SubsetP (value, range))
425 throw new Exception ("Invalid value: " + value);
431 public override bool ValueP (Term term)
435 return SubsetP (term.Intval, range);
438 public override object Range {
439 get { return range; }
441 int[] r = (int[]) value;
442 if (! SubsetP (r, range)
443 || ! SubsetP (val.Intval, r)
444 || ! SubsetP (default_val.Intval, r))
445 throw new Exception ("Invalid range");
451 public class Str : Variable
453 public string[] range;
455 private static bool SubsetP (string[] r1, string[] r2)
459 foreach (string s in r1)
460 if (! SubsetP (s, r2))
465 private static bool SubsetP (string str, string[] r)
469 foreach (string s in r)
475 public Str (Domain domain, Symbol name, string description,
476 string value, string[] range)
477 : base (domain, name, new Term (value))
479 if (! SubsetP (value, range))
480 throw new Exception ("Invalid value: " + value);
486 public override bool ValueP (Term term)
488 if (! (term.objval is string))
490 return SubsetP (term.Strval, range);
493 public override object Range {
494 get { return range; }
496 string[] r = (string[]) value;
497 if (! SubsetP (r, range)
498 || ! SubsetP (val.Strval, r)
499 || ! SubsetP (default_val.Strval, r))
500 throw new Exception ("Invalid range");
506 public class Sym : Variable
508 public Symbol[] range;
510 private static bool SubsetP (Symbol[] r1, Symbol[] r2)
514 foreach (Symbol n in r1)
515 if (! SubsetP (n, r2))
520 private static bool SubsetP (Symbol name, Symbol[] r)
524 foreach (Symbol n in r)
530 public Sym (Domain domain, Symbol name, string description,
531 Symbol value, Symbol[] range)
532 : base (domain, name, new Term (value))
534 if (! SubsetP (value, range))
535 throw new Exception ("Invalid value: " + value);
541 public override bool ValueP (Term term)
543 if (! (term.objval is Symbol))
545 return SubsetP (term.Symval, range);
548 public override object Range {
549 get { return range; }
551 Symbol[] r = (Symbol[]) value;
552 if (! SubsetP (r, range)
553 || ! SubsetP (val.Symval, r)
554 || ! SubsetP (default_val.Symval, r))
555 throw new Exception ("Invalid range");
562 internal class Bindings
564 private Variable vari;
565 private Term old_value;
566 private Bindings next;
568 private Bindings (Variable vari)
571 old_value = vari.Value;
574 public static Bindings Bind (Bindings bindings, Variable vari, Term val)
576 Bindings b = new Bindings (vari);
583 internal Bindings UnboundTo (Bindings boundary)
585 for (Bindings b = this; b != boundary; b = b.next)
586 b.vari.Value = b.old_value;
590 public override string ToString ()
592 string str = "(bindings";
593 for (Bindings b = this; b != null; b = b.next)
594 str += " " + vari.name + "=" + b.old_value;
600 internal class ThrowException : Exception
605 public ThrowException (Symbol tag, object value) : base ()
613 internal class CatchTag : IEquatable<CatchTag>
617 public CatchTag (Symbol name) { val = name.name; }
618 private CatchTag (int i) { val = i; }
620 public static CatchTag Return = new CatchTag (0);
621 public static CatchTag Break = new CatchTag (1);
623 public static bool operator== (CatchTag t1, CatchTag t2)
624 { return t1.val == t2.val; }
626 public static bool operator!= (CatchTag t1, CatchTag t2)
627 { return t1.val != t2.val; }
629 public bool Equals (CatchTag tag) { return this.val == tag.val; }
630 public override bool Equals (object val) { return this.val == val; }
632 public override int GetHashCode () { return val.GetHashCode (); }
638 public object context;
639 public int depth = 0;
641 internal Dictionary<Symbol, TermType> termtypes
642 = new Dictionary<Symbol, TermType> ();
643 internal Dictionary<Symbol, Function> functions
644 = new Dictionary<Symbol, Function> ();
645 internal Dictionary<Symbol, Variable> variables
646 = new Dictionary<Symbol, Variable> ();
647 internal Bindings bindings;
648 private Stack<CatchTag> catch_stack = new Stack<CatchTag> ();
649 private int catch_count = 0;
651 internal Domain (Symbol name) { this.name = name; }
653 public Domain (Symbol name, object context)
654 : this (name, basic, context) { }
656 public Domain (Symbol name, Domain parent, object context) : this (name)
658 termtypes = new Dictionary<Symbol, TermType> (parent.termtypes);
659 functions = new Dictionary<Symbol, Function> (parent.functions);
660 variables = new Dictionary<Symbol, Variable> (parent.variables);
661 this.context = context;
664 internal void Bind (Variable vari, Term value)
666 bindings = Bindings.Bind (bindings, vari, value);
669 internal void UnboundTo (Bindings boundary)
671 if (bindings != null)
672 bindings = bindings.UnboundTo (boundary);
675 internal void Catch (CatchTag tag)
677 catch_stack.Push (tag);
681 internal void Uncatch ()
684 if (catch_count > catch_stack.Count)
689 get { return catch_count < catch_stack.Count; }
692 internal void ThrowReturn ()
694 foreach (CatchTag tag in catch_stack)
697 if (tag == CatchTag.Return)
702 internal void ThrowBreak ()
704 if (catch_stack.Peek () != CatchTag.Break)
705 throw new Exception ("No outer loop to break");
709 internal void ThrowTag (CatchTag tag)
711 foreach (CatchTag elt in catch_stack)
719 public void DefTerm (Symbol name, TermParser parser)
721 termtypes[name] = new TermType (name, parser);
724 public void DefSubr (Builtin builtin, string str, bool setvar,
725 int min_arg, int max_arg, params string[] aliases)
728 Function func = new Function.Subroutine (builtin, name, setvar,
730 functions[name] = func;
731 foreach (string a in aliases)
732 functions[(Symbol) a] = func;
735 public void DefSpecial (Builtin builtin, string str,
736 int min_arg, int max_arg,
737 params string[] aliases)
740 Function func = new Function.SpecialForm (builtin, name,
742 functions[name] = func;
743 foreach (string a in aliases)
744 functions[(Symbol) a] = func;
747 public void DefAlias (string alias, string str)
749 functions[(Symbol) alias] = functions[(Symbol) str];
752 public void Defun (Symbol name, bool args_evalled,
753 Symbol[] args, Term[] body, bool prototype)
757 if (prototype || ! functions.TryGetValue (name, out func))
759 func = new Function.Lambda (this, name, args_evalled, args);
760 functions[name] = func;
763 ((Function.Lambda) func).SetBody (body);
766 public void Defun (XmlNode node, bool prototype)
768 Symbol name = node.Attributes[Qfname].Value;
771 if (prototype || ! functions.TryGetValue (name, out func))
773 func = new Function.Lambda (this, node);
774 functions[name] = func;
777 ((Function.Lambda) func).SetBody (this, node);
780 public void Defun (Function func)
782 functions[func.name] = func;
785 public Variable Defvar (XmlNode node)
787 Symbol name = node.Attributes[0].Value;
791 node = node.FirstChild;
792 if (node != null && node.Name == Qdescription)
794 desc = node.InnerText;
795 node = node.NextSibling;
801 Symbol type = node.Name;
802 XmlNodeList range_list = null;
804 string val = node.InnerText;
806 node = node.NextSibling;
809 range_list = node.ChildNodes;
810 nranges = range_list.Count;
813 if (type == Qinteger)
815 int intval = parse_integer (val);
817 if (range_list != null)
819 range = new int[nranges * 2];
820 for (int i = 0; i < nranges; i++)
822 XmlNode n = range_list[i];
823 if (n.Name == Qrange)
826 = parse_integer (n.FirstChild.InnerText);
828 = parse_integer (n.LastChild.InnerText);
834 = parse_integer (n.FirstChild.InnerText);
839 if (variables.TryGetValue (name, out vari))
841 if (! (vari is Variable.Int))
842 throw new Exception ("Inalid value");
843 vari = (Variable) vari.Clone (this);
844 Term v = new Term (intval);
846 vari.DefaultValue = v;
851 vari = new Variable.Int (this, name, desc, intval, range);
853 else if (type == Qstring)
855 string[] range = null;
856 if (range_list != null)
858 range = new string[nranges];
859 for (int i = 0; i < nranges; i++)
860 range[i] = range_list[i].FirstChild.InnerText;
863 if (variables.TryGetValue (name, out vari))
865 if (! (vari is Variable.Str))
866 throw new Exception ("Invalid value");
867 vari = (Variable) vari.Clone (this);
868 Term v = new Term (val);
870 vari.DefaultValue = v;
875 vari = new Variable.Str (this, name, desc, val, range);
877 else if (type == Qsymbol)
879 Symbol[] range = null;
880 if (range_list != null)
882 range = new Symbol[nranges];
883 for (int i = 0; i < nranges; i++)
884 range[i] = range_list[i].FirstChild.InnerText;
887 if (variables.TryGetValue (name, out vari))
889 if (! (vari is Variable.Sym))
890 throw new Exception ("Invalid value");
891 vari = (Variable) vari.Clone (this);
892 Term v = new Term (val);
894 vari.DefaultValue = v;
899 vari = new Variable.Sym (this, name, desc, val, range);
902 throw new Exception ("Unknown type: " + type);
906 if (variables.TryGetValue (name, out vari))
907 vari = (Variable) vari.Clone (this);
909 vari = new Variable (this, name, Zero);
911 variables[name] = vari;
915 public Variable Defvar (Variable vari)
917 vari = vari.Clone (this);
918 variables[vari.name] = vari;
922 internal Variable Defvar (Symbol name)
924 Variable vari = new Variable (this, name, Zero);
925 variables[name] = vari;
929 internal Function GetFunc (Symbol name)
933 if (! functions.TryGetValue (name, out func))
934 throw new Exception ("Unknown function: " + name);
938 public bool CopyFunc (Domain domain, Symbol name)
940 Function func = GetFunc (name);
942 domain.functions[name] = func;
946 public void CopyFunc (Domain domain)
948 foreach (KeyValuePair<Symbol, Function> kv in functions)
949 domain.functions[kv.Key] = kv.Value;
952 public Variable GetVar (Symbol name, bool create)
956 if (! variables.TryGetValue (name, out vari))
960 variables[name] = vari = new Variable (this, name, Zero);
965 public override string ToString ()
967 string str = "<(functions";
968 foreach (KeyValuePair<Symbol, Function> kv in functions)
970 str += ") (variabls";
971 foreach (KeyValuePair<Symbol, Variable> kv in variables)
972 str += " " + kv.Value;
974 if (bindings != null)
975 str += " " + bindings;
977 str += " (" + context + ")";
982 internal void DebugWrite (bool head, string fmt, params string[] arg)
984 if (debug_level > depth)
988 Console.WriteLine ();
989 for (int i = 0; i < depth; i++)
992 Console.Write (fmt, arg);
996 public object SaveValues ()
998 Dictionary<Variable,Term> values = new Dictionary<Variable,Term> ();
1000 foreach (KeyValuePair<Symbol,Variable> kv in variables)
1001 values[kv.Value] = kv.Value.Value.Clone ();
1005 public void RestoreValues (object values)
1007 foreach (KeyValuePair<Variable,Term> kv
1008 in (Dictionary<Variable,Term>) values)
1009 kv.Key.Value = kv.Value;
1013 public delegate Term Builtin (Domain domain, Variable vari, Term[] args);
1015 private static Domain basic = new Domain ("basic");
1017 static Xexpression ()
1019 basic.DefTerm ("funcall", Funcall.parser);
1020 basic.DefTerm ("varref", Varref.parser);
1022 basic.DefSubr (Fset, "set", true, 1, 1, "=");
1023 basic.DefSubr (Fnot, "not", false, 1, 1, "!");
1024 basic.DefSubr (Fadd, "add", true, 1, -1, "+");
1025 basic.DefSubr (Fmul, "mul", true, 1, -1, "*");
1026 basic.DefSubr (Fsub, "sub", true, 1, -1, "-");
1027 basic.DefSubr (Fdiv, "div", true, 1, -1, "/");
1028 basic.DefSubr (Fmod, "mod", true, 1, 2, "%");
1029 basic.DefSubr (Flogior, "logior", true, 1, -1, "|");
1030 basic.DefSubr (Flogand, "logand", true, 1, -1, "&");
1031 basic.DefSubr (Flsh, "lsh", true, 1, 2, "<<");
1032 basic.DefSubr (Frsh, "rsh", true, 1, 2, ">>");
1033 basic.DefSubr (Feq, "eq", false, 2, -1, "==");
1034 basic.DefSubr (Fnoteq, "noteq", false, 2, 2, "!=");
1035 basic.DefSubr (Flt, "lt", false, 2, -1, "<");
1036 basic.DefSubr (Fle, "le", false, 2, -1, "<=");
1037 basic.DefSubr (Fgt, "gt", false, 2, -1, ">");
1038 basic.DefSubr (Fge, "ge", false, 2, -1, ">=");
1039 basic.DefSubr (Fappend, "append", true, 0, -1);
1040 basic.DefSubr (Fconcat, "concat", true, 0, -1);
1041 basic.DefSubr (Fnth, "nth", false, 2, 2);
1042 basic.DefSubr (Fcopy, "copy", false, 1, 1);
1043 basic.DefSubr (Fins, "ins", true, 2, 2);
1044 basic.DefSubr (Fdel, "del", true, 2, 2);
1045 basic.DefSubr (Feval, "eval", false, 1, 1);
1046 basic.DefSubr (Fbreak, "break", false, 0, 1);
1047 basic.DefSubr (Freturn, "return", false, 0, 1);
1049 basic.DefSpecial (Fand, "and", 1, -1, "&&");
1050 basic.DefSpecial (For, "or", 1, -1, "||");
1051 basic.DefSpecial (Fprogn, "progn", 0, -1, "expr");
1052 basic.DefSpecial (Fif, "if", 2, 3);
1053 basic.DefSpecial (Fwhen, "when", 1, -1);
1054 basic.DefSpecial (Floop, "loop", 1, -1);
1055 basic.DefSpecial (Fwhile, "while", 1, -1);
1056 basic.DefSpecial (Fcond, "cond", 1, -1);
1057 basic.DefSpecial (Fforeach, "foreach", 2, -1);
1058 basic.DefSpecial (Fquote, "quote", 1, 1);
1059 basic.DefSpecial (Ftype, "type", 1, 1);
1060 basic.DefSpecial (Fcatch, "catch", 2, 2);
1061 basic.DefSpecial (Fthrow, "throw", 1, 2);
1064 private static Term Fset (Domain domain, Variable vari, Term[] args)
1066 vari.Value = args[0];
1070 private static Term Fnot (Domain domain, Variable vari, Term[] args)
1072 return args[0].IsTrue ? Zero : One;
1075 private static Term Fadd (Domain domain, Variable vari, Term[] args)
1077 int n = vari == null ? 0 : vari.Value.Intval;
1079 foreach (Term arg in args)
1081 return (vari == null ? new Term (n) : vari.SetValue (n));
1084 private static Term Fmul (Domain domain, Variable vari, Term[] args)
1086 int n = vari == null ? 1 : vari.Value.Intval;
1087 foreach (Term arg in args)
1089 return (vari == null ? new Term (n) : vari.SetValue (n));
1092 private static Term Fsub (Domain domain, Variable vari, Term[] args)
1103 n = vari.Value.Intval;
1106 while (i < args.Length)
1107 n -= args[i++].Intval;
1108 return (vari == null ? new Term (n) : vari.SetValue (n));
1111 private static Term Fdiv (Domain domain, Variable vari, Term[] args)
1122 n = vari.Value.Intval;
1125 while (i < args.Length)
1126 n /= args[i++].Intval;
1127 return (vari == null ? new Term (n) : vari.SetValue (n));
1130 private static Term Fmod (Domain domain, Variable vari, Term[] args)
1132 int n = args[0].Intval % args[1].Intval;
1134 return (vari == null ? new Term (n) : vari.SetValue (n));
1137 private static Term Flogior (Domain domain, Variable vari, Term[] args)
1139 int n = vari == null ? 0 : vari.Value.Intval;
1140 foreach (Term arg in args)
1142 return (vari == null ? new Term (n) : vari.SetValue (n));
1145 private static Term Flogand (Domain domain, Variable vari, Term[] args)
1156 n = vari.Value.Intval;
1159 while (i < args.Length)
1160 n &= args[i++].Intval;
1161 return (vari == null ? new Term (n) : vari.SetValue (n));
1164 private static Term Flsh (Domain domain, Variable vari, Term[] args)
1166 int n = args[0].Intval << args[1].Intval;
1167 return (vari == null ? new Term (n) : vari.SetValue (n));
1170 private static Term Frsh (Domain domain, Variable vari, Term[] args)
1172 int n = args[0].Intval >> args[1].Intval;
1173 return (vari == null ? new Term (n) : vari.SetValue (n));
1176 private static Term Feq (Domain domain, Variable vari, Term[] args)
1180 if (o.objval == null)
1182 for (int i = 1; i < args.Length; i++)
1183 if (args[i].objval != null || args[i].intval != o.intval)
1188 for (int i = 1; i < args.Length; i++)
1189 if (o.objval.Equals (args[i].objval))
1195 private static Term Fnoteq (Domain domain, Variable vari, Term[] args)
1197 return Feq (domain, vari, args);
1200 private static Term Flt (Domain domain, Variable vari, Term[] args)
1202 int n = args[0].Intval;
1204 for (int i = 1; i < args.Length; i++)
1206 int n1 = args[i].Intval;
1214 private static Term Fle (Domain domain, Variable vari, Term[] args)
1216 int n = args[0].Intval;
1217 for (int i = 1; i < args.Length; i++)
1219 int n1 = args[i].Intval;
1227 private static Term Fgt (Domain domain, Variable vari, Term[] args)
1229 int n = args[0].Intval;
1230 for (int i = 1; i < args.Length; i++)
1232 int n1 = args[i].Intval;
1240 private static Term Fge (Domain domain, Variable vari, Term[] args)
1242 int n = args[0].Intval;
1243 for (int i = 1; i < args.Length; i++)
1245 int n1 = args[i].Intval;
1253 private static Term Fappend (Domain domain, Variable vari, Term[] args)
1258 list = new List<Term> ();
1260 list = vari.Value.Listval;
1262 foreach (Term arg in args)
1265 list.AddRange ((List<Term>) arg.objval);
1273 result.objval = list;
1279 private static Term Fconcat (Domain domain, Variable vari, Term[] args)
1286 str = vari.Value.Strval;
1288 foreach (Term arg in args)
1291 str += (string) arg.objval;
1292 else if (arg.IsList)
1293 foreach (Term term in (List<Term>) arg.objval)
1294 str += (char) term.Intval;
1296 str += (char) arg.Intval;
1306 return vari.SetValue (str);
1309 private static Term Fnth (Domain domain, Variable vari, Term[] args)
1315 result.intval = ((string) args[1].objval)[args[0].Intval];
1316 result.objval = null;
1318 else if (args[1].IsList)
1320 result = ((List<Term>) args[1].objval)[args[0].Intval];
1323 throw new Exception ("Term is not enumelable: " + args[1]);
1327 private static Term Fcopy (Domain domain, Variable vari, Term[] args)
1332 result.objval = new List<Term> (args[0].Listval);
1336 private static Term Fins (Domain domain, Variable vari, Term[] args)
1338 Term term = vari.Value;
1342 string str = term.Strval.Insert (args[0].Intval, args[1].Strval);
1343 vari.SetValue (str);
1345 else if (vari.Value.IsList)
1346 vari.Value.Listval.InsertRange (args[0].Intval, args[1].Listval);
1348 throw new Exception ("term is not collection: " + vari.Value);
1352 private static Term Fdel (Domain domain, Variable vari, Term[] args)
1354 if (vari.Value.IsStr)
1357 = vari.Value.Strval.Remove (args[0].Intval,
1358 args[1].Intval - args[0].Intval);
1359 vari.SetValue (str);
1361 else if (vari.Value.IsList)
1362 vari.Value.Listval.RemoveRange (args[0].Intval,
1363 args[1].Intval - args[0].Intval);
1365 throw new Exception ("term is not collection: " + vari.Value);
1369 private static Term Fand (Domain domain, Variable vari, Term[] args)
1371 foreach (Term arg in args)
1372 if (! arg.Eval (domain).IsTrue)
1377 private static Term For (Domain domain, Variable vari, Term[] args)
1379 foreach (Term arg in args)
1380 if (arg.Eval (domain).IsTrue)
1385 private static Term Feval (Domain domain, Variable vari, Term[] args)
1387 return (args[0].Eval (domain));
1390 private static Term Fprogn (Domain domain, Variable vari, Term[] args)
1394 foreach (Term arg in args)
1395 result = arg.Eval (domain);
1399 private static Term Fif (Domain domain, Variable vari, Term[] args)
1401 if (args[0].Eval (domain).IsTrue)
1402 return args[1].Eval (domain);
1403 if (args.Length == 2)
1405 return args[2].Eval (domain);
1408 private static Term Fwhen (Domain domain, Variable vari, Term[] args)
1410 if (! args[0].Eval (domain).IsTrue)
1413 for (int i = 1; i < args.Length; i++)
1414 result = args[i].Eval (domain);
1418 private static Term Freturn (Domain domain, Variable vari, Term[] args)
1420 domain.ThrowReturn ();
1421 return args.Length == 0 ? Zero : args[0];
1424 private static Term Fbreak (Domain domain, Variable vari, Term[] args)
1426 domain.ThrowBreak ();
1427 return args.Length == 0 ? Zero : args[0];
1430 private static Term Floop (Domain domain, Variable vari, Term[] args)
1434 domain.Catch (CatchTag.Break);
1435 while (! domain.Thrown)
1436 foreach (Term arg in args)
1438 result = arg.Eval (domain);
1448 private static Term Fwhile (Domain domain, Variable vari, Term[] args)
1452 domain.Catch (CatchTag.Break);
1453 while (! domain.Thrown && args[0].Eval (domain).IsTrue)
1454 for (int i = 1; i < args.Length; i++)
1456 result = args[i].Eval (domain);
1466 private static Term Fcond (Domain domain, Variable vari, Term[] args)
1468 foreach (Term arg in args)
1470 List<Term> list = arg.Listval;
1471 Term result = list[0].Eval (domain);
1475 for (int i = 1; i < list.Count; i++)
1476 result = list[i].Eval (domain);
1483 private static Term Fforeach (Domain domain, Variable vari,
1486 Term result = args[0].Eval (domain);
1489 List<Term> list = result.Listval;
1490 Bindings current = domain.bindings;
1493 domain.Catch (CatchTag.Break);
1494 foreach (Term term in list)
1496 domain.Bind (vari, term);
1498 for (int i = 1; i < args.Length; i++)
1500 result = args[i].Eval (domain);
1505 domain.UnboundTo (current);
1514 private static Term Fquote (Domain domain, Variable vari, Term[] args)
1516 return new Term (args[0]);
1519 private static Term Ftype (Domain domain, Variable vari, Term[] args)
1525 if (args[0].IsSymbol)
1532 public static Term Fcatch (Domain domain, Variable vari, Term[] args)
1536 domain.Catch (new CatchTag (args[0].Symval));
1537 result = args[1].Eval (domain);
1544 public static Term Fthrow (Domain domain, Variable vari, Term[] args)
1546 domain.ThrowTag (new CatchTag (args[0].Symval));
1547 return (args.Length == 1 ? Zero : args[1]);
1550 public delegate TermValue TermParser (Domain domain, XmlNode node);
1552 public class TermType
1554 public readonly Symbol type;
1555 internal readonly TermParser parser;
1557 public TermType (Symbol type, TermParser parser)
1560 this.parser = parser;
1564 public abstract class TermValue
1566 public virtual Term Eval (Domain domain) { return new Term (this); }
1567 public virtual TermValue Clone () { return this; }
1570 private class Varref : TermValue
1572 private Symbol name;
1573 private Variable vari;
1575 public Varref (Symbol name) { this.name = name; }
1577 public override Term Eval (Domain domain)
1579 if (vari == null || vari.domain != domain)
1580 vari = domain.GetVar (name, true);
1584 internal static TermValue parser (Domain domain, XmlNode node)
1586 return new Varref ((Symbol) node.Attributes[Qvname].Value);
1589 public override string ToString ()
1591 return "<varref vname=\"" + name + "\"/>";
1595 private class Funcall : TermValue
1597 internal Function func;
1598 internal Variable vari;
1599 internal Term[] args;
1601 private Funcall (Function func, Variable vari, Term[] args)
1608 public Funcall (Domain domain, Symbol fname, Term[] args)
1610 func = domain.GetFunc (fname);
1613 int nargs = args.Length;
1614 if (nargs < func.min_arg
1615 || (func.max_arg >= 0 && nargs > func.max_arg))
1616 throw new Exception ("Invalid number of arguments to: "
1617 + fname + " " + nargs);
1622 public Funcall (Domain domain, Symbol fname, Symbol vname, Term[] args)
1624 func = domain.GetFunc (fname);
1627 int nargs = args.Length;
1628 if (nargs < func.min_arg
1629 || (func.max_arg >= 0 && nargs > func.max_arg))
1630 throw new Exception ("Invalid number of arguments to: "
1631 + fname + " " + nargs);
1635 vari = domain.GetVar (vname, true);
1638 internal static TermValue parser (Domain domain, XmlNode node)
1640 Symbol fname = node.Name;
1641 Symbol vname = Qnull;
1644 if (fname == Qfuncall)
1645 fname = node.Attributes[Qfname].Value;
1646 attr = node.Attributes[Qvname];
1650 XmlNodeList nlist = node.ChildNodes;
1651 int nargs = nlist.Count;
1652 Term[] args = new Term[nargs];
1653 for (int i = 0; i < nargs; i++)
1654 args[i] = new Term (domain, nlist[i]);
1655 return new Funcall (domain, fname, vname, args);
1658 public override Term Eval (Domain domain)
1660 domain.DebugWrite (true, ToString ());
1662 Term result = func.Call (domain, vari, args);
1664 domain.DebugWrite (true, " ==> {0}", result.ToString ());
1668 public override TermValue Clone ()
1670 return new Funcall (func, vari, args);
1673 public override string ToString ()
1675 string str = "<" + func.name;
1677 str += " vname=\"" + vari.name + "\"";
1681 if (func is Function.SpecialForm)
1682 str += String.Format ("({0})...", args.Length);
1684 foreach (Term e in args)
1686 return (str + "</" + func.name + ">");
1693 public object objval;
1695 // <integer>...</integer>
1696 public Term (int i) { intval = i; objval = null; }
1697 // <symbol>...</symbol>
1698 public Term (Symbol name) { intval = 0; objval = name; }
1699 // <string>...</string>
1700 public Term (string str) { intval = 0; objval = str; }
1702 public Term (List<Term> list) { intval = 0; objval = list; }
1704 public Term (Term term) { intval = term.intval; objval = term.objval; }
1705 public Term (TermValue obj) { intval = 0; objval = obj; }
1707 public Term (Domain domain, XmlNode node)
1709 Symbol name = node.Name;
1711 if (name == Qinteger)
1713 intval = parse_integer (node.InnerText);
1719 if (name == Qsymbol)
1720 objval = (Symbol) node.InnerText;
1721 else if (name == Qstring)
1722 objval = node.InnerText.Clone ();
1723 else if (name == Qlist)
1725 List<Term> list = new List<Term> ();
1726 for (node = node.FirstChild; node != null;
1727 node = node.NextSibling)
1728 list.Add (new Term (domain, node));
1735 if (domain.termtypes.TryGetValue (name, out term_type))
1736 objval = term_type.parser (domain, node);
1738 objval = Funcall.parser (domain, node);
1743 // <varref vname="VNAME"/>
1744 public Term (Domain domain, Symbol vname)
1747 objval = new Varref (vname);
1750 // <funcall fname="FNAME">...</funcall>
1751 public Term (Domain domain, Symbol fname, Term[] args)
1754 objval = new Funcall (domain, fname, args);
1757 // <funcall fname="FNAME" vname="VNAME">...</funcall>
1758 public Term (Domain domain, Symbol fname, Symbol vname, Term[] args)
1761 objval = new Funcall (domain, fname, vname, args);
1764 public object Objval {
1767 throw new Exception ("term is an integer: " + this);
1775 throw new Exception ("term is not integer: " + this);
1780 public string Strval {
1783 throw new Exception ("term is not string: " + this);
1784 return (string) objval;
1788 public string Symval {
1791 throw new Exception ("term is not symbol: " + this);
1792 return (Symbol) objval;
1796 public List<Term> Listval {
1799 throw new Exception ("term is not list: " + this);
1800 return (List<Term>) objval;
1804 public bool IsTrue {
1806 return (objval == null
1808 : objval is List<Term>
1809 ? (((List<Term>) objval).Count != 0)
1813 public bool IsInt { get { return (objval == null); } }
1814 public bool IsStr { get { return (objval is string); } }
1815 public bool IsSymbol { get { return (objval is Symbol); } }
1816 public bool IsList { get { return (objval is List<Term>); } }
1818 public bool IsType (Type type)
1820 return (objval == null ? type == typeof (int)
1821 : type == objval.GetType ());
1824 public Term Eval (Domain domain)
1826 if (objval == null || objval is Symbol || objval is string)
1828 if (objval is List<Term>)
1829 return new Term ((List<Term>) objval);
1830 return ((TermValue) objval).Eval (domain);
1833 public Term Clone ()
1835 if (objval == null || objval is Symbol || objval is string)
1837 if (objval is List<Term>)
1839 List<Term> list = new List<Term> ();
1840 list.InsertRange (0, ((List<Term>) objval));
1841 return new Term (list);
1843 return new Term (((TermValue) objval).Clone ());
1846 public override string ToString ()
1851 str = "<integer>" + intval + "</integer>";
1852 else if (objval is Symbol)
1853 str = "<symbol>" + objval + "</symbol>";
1854 else if (objval is string)
1855 str = "<string>" + objval + "</string>";
1856 else if (objval is List<Term>)
1859 foreach (Term e in (List<Term>) objval)
1863 else if (objval is Term)
1864 str = "<quote>" + objval + "</quote>";
1865 else if (objval is TermValue)
1866 str = ((TermValue) objval).ToString ();
1868 throw new Exception ("invalid Term object: " + objval);
1873 static private Term Zero = new Term (0);
1874 static private Term One = new Term (1);
1875 static private Term TermInt = new Term (Qinteger);
1876 static private Term TermStr = new Term (Qstring);
1877 static private Term TermSymbol = new Term (Qsymbol);
1878 static private Term TermList = new Term (Qlist);
1879 static private Term TermTerm = new Term ((Symbol) "term");
1881 internal static int parse_integer (string str)
1883 int len = str.Length;
1884 bool negative = false;
1887 return (len == 0 ? 0 : str[0] - '0');
1894 if ((c == '0' || c == '#') && str[1] == 'x')
1897 for (int idx = 2; idx < len; idx++)
1903 i = i * 16 + (c - '0');
1907 i = i * 16 + (c - 'A');
1911 i = i * 16 + (c - 'a');
1920 for (int idx = 1; idx < len; idx++)
1923 if (c < '0' || c > '9')
1925 i = i * 10 + (c - '0');
1927 return negative ? - i : i;
1930 private Term[] terms;
1932 public static Term[] ParseTerms (Domain domain, XmlNode node)
1935 for (XmlNode n = node; n != null; n = n.NextSibling)
1936 if (n.NodeType == XmlNodeType.Element)
1938 if (n.Name == Qdefun)
1939 domain.Defun (n, true);
1940 else if (n.Name == Qdefvar)
1945 Term[] terms = new Term[nterms];
1947 for (XmlNode n = node; n != null; n = n.NextSibling)
1948 if (n.NodeType == XmlNodeType.Element)
1950 if (n.Name == Qdefun)
1951 domain.Defun (n, false);
1952 else if (n.Name != Qdefvar)
1953 terms[i++]= new Term (domain, n);
1958 public static Term Eval (Domain domain, Term[] terms)
1960 Term result = new Term (0);
1961 foreach (Term term in terms)
1964 if (result.Objval is Funcall)
1965 while ((result = result.Eval (domain)).Objval is Funcall);
1971 public Xexpression (Domain domain, XmlNode node)
1973 terms = ParseTerms (domain, node);
1976 public Xexpression (Domain domain, string url)
1978 XmlDocument doc = new XmlDocument (Symbol.Table);
1981 using (XmlTextReader reader = new XmlTextReader (url, Symbol.Table))
1985 } while (reader.NodeType != XmlNodeType.None
1986 && (reader.NodeType != XmlNodeType.Element
1987 || reader.Name != Qexpr));
1988 if (reader.NodeType == XmlNodeType.None)
1989 throw new Exception ("Node <expr> not found");
1990 node = doc.ReadNode (reader);
1992 terms = ParseTerms (domain, node.FirstChild);
1995 public Term Eval (Domain domain)
2001 domain.Catch (CatchTag.Return);
2002 foreach (Term term in terms)
2004 result = term.Eval (domain);
2014 public override string ToString ()
2017 for (int i = 0; i < terms.Length; i++)