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 Qvarref = "varref";
89 private static Symbol Qinteger = "integer";
90 private static Symbol Qstring = "string";
91 private static Symbol Qsymbol = "symbol";
92 private static Symbol Qlist = "list";
94 private static Symbol Qdefun = "defun";
95 private static Symbol Qfname = "fname";
96 private static Symbol Qargs = "args";
97 private static Symbol Qargs_unevalled = "args-unevalled";
98 private static Symbol Qfixed = "fixed";
99 private static Symbol Qoptional = "optional";
100 private static Symbol Qrest = "rest";
102 private static Symbol Qdefvar = "defvar";
103 private static Symbol Qvname = "vname";
104 private static Symbol Qdescription = "description";
105 private static Symbol Qrange = "range";
107 public abstract class Function
110 public int min_arg, max_arg;
112 public Function () { }
114 public Function (Symbol name, int min_arg, int max_arg)
117 this.min_arg = min_arg;
118 this.max_arg = max_arg;
121 public abstract Term Call (Domain domain, Variable vari, Term[] args);
123 public override string ToString ()
128 internal class Subroutine : Function
130 public Builtin builtin;
133 public Subroutine (Builtin builtin, Symbol name, bool setvar,
134 int min_arg, int max_arg)
135 : base (name, min_arg, max_arg)
137 this.builtin = builtin;
138 this.setvar = setvar;
141 public override Term Call (Domain domain, Variable vari, Term[] args)
143 args = (Term[]) args.Clone ();
144 for (int i = 0; i < args.Length; i++)
146 args[i] = args[i].Eval (domain);
150 return builtin (domain, vari, args);
154 internal class SpecialForm : Function
156 public Builtin builtin;
158 public SpecialForm (Builtin builtin, Symbol name,
159 int min_arg, int max_arg)
160 : base (name, min_arg, max_arg)
162 this.builtin = builtin;
165 public override Term Call (Domain domain, Variable vari, Term[] args)
167 return builtin (domain, vari, args);
171 internal class Lambda : Function
173 internal bool args_evalled;
174 internal Variable[] args;
175 internal Term[] body;
177 public Lambda (Domain domain, XmlNode node)
182 name = node.Attributes[Qfname].Value;
184 node = node.FirstChild;
186 && (node.Name == Qargs || node.Name == Qargs_unevalled))
189 args_evalled = node.Name == Qargs;
190 for (n = node.FirstChild; n != null; n = n.NextSibling)
192 if (n.Name == Qfixed)
194 else if (n.Name == Qoptional)
196 else if (n.Name == Qrest)
199 throw new Exception ("Invalid argument type: " + n);
202 max_arg = nfixed + noptional + nrest;
203 args = new Variable[max_arg];
205 for (int i = 0; i < max_arg; n = n.NextSibling)
206 args[i++] = domain.Defvar ((Symbol) n.Attributes[0].Value);
212 min_arg = max_arg = 0;
216 public Lambda (Domain domain, Symbol name, bool args_evalled, Symbol[] args)
223 this.args_evalled = args_evalled;
227 for (i = 0; i < args.Length; i++, nfixed++)
228 if (args[i] == Qoptional || args[i] == Qrest)
232 if (args[i] == Qoptional)
234 for (i++; i < args.Length; i++, noptional++)
235 if (args[i] == Qrest)
242 max_arg = nfixed + noptional + nrest;
243 this.args = new Variable[max_arg];
245 for (i = j = 0; j < this.args.Length; i++)
246 if (args[i] != Qoptional || args[i] != Qrest)
247 this.args[j++] = domain.Defvar (args[i]);
251 min_arg = max_arg = 0;
255 public void SetBody (Domain domain, XmlNode node)
257 for (node = node.FirstChild; node != null; node = node.NextSibling)
258 if (node.Name != Qdescription
259 && node.Name != Qargs
260 && node.Name != Qargs_unevalled)
263 for (XmlNode n = node; n != null; n = n.NextSibling)
267 body = new Term[nterms];
268 for (nterms = 0; node != null; node = node.NextSibling, nterms++)
269 body[nterms] = new Term (domain, node);
273 public void SetBody (Term[] body)
278 public override Term Call (Domain domain, Variable vari, Term[] args)
280 Bindings current = domain.bindings;
287 Term[] newargs = new Term[args.Length];
288 for (i = 0; i < min_arg; i++)
289 newargs[i] = args[i].Eval (domain);
292 for (i = 0; i < min_arg; i++)
293 domain.Bind (this.args[i], args[i]);
298 domain.Catch (CatchTag.Return);
299 foreach (Term term in body)
301 result = term.Eval (domain);
311 domain.UnboundTo (current);
318 public class Variable : TermValue
320 public readonly Symbol name;
322 internal Term default_val;
326 public Variable (Symbol name, Term value)
333 public virtual bool ValueP (Term val) { return true; }
335 public override TermValue Clone ()
337 Variable v = new Variable (name, val);
339 v.default_val = default_val;
348 if (! ValueP (value))
349 throw new Exception ("Invalid value: " + value);
354 public Term DefaultValue
356 get { return default_val; }
358 if (! ValueP (value))
359 throw new Exception ("Invalid value: " + value);
364 public virtual object Range
366 get { return range; }
367 set { range = value; }
370 public override Term Eval (Domain domain) { return val; }
372 public override string ToString () { return name + "(" + val + ")"; }
374 public class Int : Variable
378 private static bool SubsetP (int[] r1, int[] r2)
382 for (int i = 0; i < r1.Length; i += 2)
385 for (j = 0; j < r2.Length; j += 2)
386 if (r2[j] <= r1[i] && r2[j + 1] >= r1[i + 1])
394 private static bool SubsetP (int val, int[] r)
398 for (int i = 0; i < r.Length; i += 2)
399 if (r[i] <= val && r[i + 1] >= val)
404 public Int (Symbol name, string description, int value, int[] range)
405 : base (name, new Term (value))
407 if (! SubsetP (value, range))
408 throw new Exception ("Invalid value: " + value);
414 public override bool ValueP (Term term)
418 return SubsetP (term.Intval, range);
421 public override object Range {
422 get { return range; }
424 int[] r = (int[]) value;
425 if (! SubsetP (r, range)
426 || ! SubsetP (val.Intval, r)
427 || ! SubsetP (default_val.Intval, r))
428 throw new Exception ("Invalid range");
434 public class Str : Variable
436 public string[] range;
438 private static bool SubsetP (string[] r1, string[] r2)
442 foreach (string s in r1)
443 if (! SubsetP (s, r2))
448 private static bool SubsetP (string str, string[] r)
452 foreach (string s in r)
458 public Str (Symbol name, string description, string value, string[] range)
459 : base (name, new Term (value))
461 if (! SubsetP (value, range))
462 throw new Exception ("Invalid value: " + value);
468 public override bool ValueP (Term term)
470 if (! (term.objval is string))
472 return SubsetP (term.Strval, range);
475 public override object Range {
476 get { return range; }
478 string[] r = (string[]) value;
479 if (! SubsetP (r, range)
480 || ! SubsetP (val.Strval, r)
481 || ! SubsetP (default_val.Strval, r))
482 throw new Exception ("Invalid range");
488 public class Sym : Variable
490 public Symbol[] range;
492 private static bool SubsetP (Symbol[] r1, Symbol[] r2)
496 foreach (Symbol n in r1)
497 if (! SubsetP (n, r2))
502 private static bool SubsetP (Symbol name, Symbol[] r)
506 foreach (Symbol n in r)
512 public Sym (Symbol name, string description, Symbol value, Symbol[] range)
513 : base (name, new Term (value))
515 if (! SubsetP (value, range))
516 throw new Exception ("Invalid value: " + value);
522 public override bool ValueP (Term term)
524 if (! (term.objval is Symbol))
526 return SubsetP (term.Symval, range);
529 public override object Range {
530 get { return range; }
532 Symbol[] r = (Symbol[]) value;
533 if (! SubsetP (r, range)
534 || ! SubsetP (val.Symval, r)
535 || ! SubsetP (default_val.Symval, r))
536 throw new Exception ("Invalid range");
543 internal class Bindings
545 private Variable vari;
546 private Term old_value;
547 private Bindings next;
549 private Bindings (Variable vari)
552 old_value = vari.val;
555 public static Bindings Bind (Bindings bindings, Variable vari, Term val)
557 Bindings b = new Bindings (vari);
564 internal Bindings UnboundTo (Bindings boundary)
566 for (Bindings b = this; b != boundary; b = b.next)
567 b.vari.val = b.old_value;
571 public override string ToString ()
573 string str = "(bindings";
574 for (Bindings b = this; b != null; b = b.next)
575 str += " " + vari.name + "=" + b.old_value;
581 internal class ThrowException : Exception
586 public ThrowException (Symbol tag, object value) : base ()
594 internal class CatchTag : IEquatable<CatchTag>
598 public CatchTag (Symbol name) { val = name.name; }
599 private CatchTag (int i) { val = i; }
601 public static CatchTag Return = new CatchTag (0);
602 public static CatchTag Break = new CatchTag (1);
604 public static bool operator== (CatchTag t1, CatchTag t2)
605 { return t1.val == t2.val; }
607 public static bool operator!= (CatchTag t1, CatchTag t2)
608 { return t1.val != t2.val; }
610 public bool Equals (CatchTag tag) { return this.val == tag.val; }
611 public override bool Equals (object val) { return this.val == val; }
613 public override int GetHashCode () { return val.GetHashCode (); }
618 public object context;
619 public int depth = 0;
621 internal Dictionary<Symbol, TermType> termtypes
622 = new Dictionary<Symbol, TermType> ();
623 internal Dictionary<Symbol, Function> functions
624 = new Dictionary<Symbol, Function> ();
625 internal Dictionary<Symbol, Variable> variables
626 = new Dictionary<Symbol, Variable> ();
627 internal Bindings bindings;
628 private Stack<CatchTag> catch_stack = new Stack<CatchTag> ();
629 private int catch_count = 0;
631 internal Domain () { }
633 public Domain (object context) : this (basic, context) { }
635 public Domain (Domain parent, object context)
637 termtypes = new Dictionary<Symbol, TermType> (parent.termtypes);
638 functions = new Dictionary<Symbol, Function> (parent.functions);
639 variables = new Dictionary<Symbol, Variable> (parent.variables);
640 this.context = context;
643 internal void Bind (Variable vari, Term value)
645 bindings = Bindings.Bind (bindings, vari, value);
648 internal void UnboundTo (Bindings boundary)
650 if (bindings != null)
651 bindings = bindings.UnboundTo (boundary);
654 internal void Catch (CatchTag tag)
656 catch_stack.Push (tag);
660 internal void Uncatch ()
663 if (catch_count > catch_stack.Count)
668 get { return catch_count < catch_stack.Count; }
671 internal void ThrowReturn ()
673 foreach (CatchTag tag in catch_stack)
676 if (tag == CatchTag.Return)
681 internal void ThrowBreak ()
683 if (catch_stack.Peek () != CatchTag.Break)
684 throw new Exception ("No outer loop to break");
688 internal void ThrowTag (CatchTag tag)
690 foreach (CatchTag elt in catch_stack)
698 public void DefTerm (Symbol name, TermParser parser)
700 termtypes[name] = new TermType (name, parser);
703 public void DefSubr (Builtin builtin, string str, bool setvar,
704 int min_arg, int max_arg, params string[] aliases)
707 Function func = new Function.Subroutine (builtin, name, setvar,
709 functions[name] = func;
710 foreach (string a in aliases)
711 functions[(Symbol) a] = func;
714 public void DefSpecial (Builtin builtin, string str,
715 int min_arg, int max_arg,
716 params string[] aliases)
719 Function func = new Function.SpecialForm (builtin, name,
721 functions[name] = func;
722 foreach (string a in aliases)
723 functions[(Symbol) a] = func;
726 public void DefAlias (string alias, string str)
728 functions[(Symbol) alias] = functions[(Symbol) str];
731 public void Defun (Symbol name, bool args_evalled,
732 Symbol[] args, Term[] body, bool prototype)
736 if (prototype || ! functions.TryGetValue (name, out func))
738 func = new Function.Lambda (this, name, args_evalled, args);
739 functions[name] = func;
742 ((Function.Lambda) func).SetBody (body);
745 public void Defun (XmlNode node, bool prototype)
747 Symbol name = node.Attributes[Qfname].Value;
750 if (prototype || ! functions.TryGetValue (name, out func))
752 func = new Function.Lambda (this, node);
753 functions[name] = func;
756 ((Function.Lambda) func).SetBody (this, node);
759 public void Defun (Function func)
761 functions[func.name] = func;
764 public Variable Defvar (XmlNode node)
766 Symbol name = node.Attributes[0].Value;
770 node = node.FirstChild;
771 if (node != null && node.Name == Qdescription)
773 desc = node.InnerText;
774 node = node.NextSibling;
780 Symbol type = node.Name;
781 XmlNodeList range_list = null;
783 string val = node.InnerText;
785 node = node.NextSibling;
788 range_list = node.ChildNodes;
789 nranges = range_list.Count;
792 if (type == Qinteger)
794 int intval = parse_integer (val);
796 if (range_list != null)
798 range = new int[nranges * 2];
799 for (int i = 0; i < nranges; i++)
801 XmlNode n = range_list[i];
802 if (n.Name == Qrange)
805 = parse_integer (n.FirstChild.InnerText);
807 = parse_integer (n.LastChild.InnerText);
813 = parse_integer (n.FirstChild.InnerText);
818 if (variables.TryGetValue (name, out vari))
820 if (! (vari is Variable.Int))
821 throw new Exception ("Inalid value");
822 vari = (Variable) vari.Clone ();
823 Term v = new Term (intval);
825 vari.DefaultValue = v;
830 vari = new Variable.Int (name, desc, intval, range);
832 else if (type == Qstring)
834 string[] range = null;
835 if (range_list != null)
837 range = new string[nranges];
838 for (int i = 0; i < nranges; i++)
839 range[i] = range_list[i].FirstChild.InnerText;
842 if (variables.TryGetValue (name, out vari))
844 if (! (vari is Variable.Str))
845 throw new Exception ("Invalid value");
846 vari = (Variable) vari.Clone ();
847 Term v = new Term (val);
849 vari.DefaultValue = v;
854 vari = new Variable.Str (name, desc, val, range);
856 else if (type == Qsymbol)
858 Symbol[] range = null;
859 if (range_list != null)
861 range = new Symbol[nranges];
862 for (int i = 0; i < nranges; i++)
863 range[i] = range_list[i].FirstChild.InnerText;
866 if (variables.TryGetValue (name, out vari))
868 if (! (vari is Variable.Sym))
869 throw new Exception ("Invalid value");
870 vari = (Variable) vari.Clone ();
871 Term v = new Term (val);
873 vari.DefaultValue = v;
878 vari = new Variable.Sym (name, desc, val, range);
881 throw new Exception ("Unknown type: " + type);
885 if (variables.TryGetValue (name, out vari))
886 vari = (Variable) vari.Clone ();
888 vari = new Variable (name, Zero);
890 variables[name] = vari;
894 public Variable Defvar (Variable vari)
896 variables[vari.name] = vari;
900 internal Variable Defvar (Symbol name)
902 Variable vari = new Variable (name, Zero);
903 variables[name] = vari;
907 internal Function GetFunc (Symbol name)
911 if (! functions.TryGetValue (name, out func))
912 throw new Exception ("Unknown function: " + name);
916 public bool CopyFunc (Domain domain, Symbol name)
918 Function func = GetFunc (name);
920 domain.functions[name] = func;
924 public void CopyFunc (Domain domain)
926 foreach (KeyValuePair<Symbol, Function> kv in functions)
927 domain.functions[kv.Key] = kv.Value;
930 public Variable GetVar (Symbol name, bool create)
934 if (! variables.TryGetValue (name, out vari))
938 variables[name] = vari = new Variable (name, Zero);
943 public override string ToString ()
945 string str = "<(functions";
946 foreach (KeyValuePair<Symbol, Function> kv in functions)
948 str += ") (variabls";
949 foreach (KeyValuePair<Symbol, Variable> kv in variables)
952 if (bindings != null)
953 str += " " + bindings;
955 str += " (" + context + ")";
960 internal void DebugWrite (bool head, string fmt, params string[] arg)
962 if (debug_level > depth)
966 Console.WriteLine ();
967 for (int i = 0; i < depth; i++)
970 Console.Write (fmt, arg);
974 public object SaveValues ()
976 Dictionary<Variable,Term> values = new Dictionary<Variable,Term> ();
978 foreach (KeyValuePair<Symbol,Variable> kv in variables)
979 values[kv.Value] = kv.Value.val.Clone ();
983 public void RestoreValues (object values)
985 foreach (KeyValuePair<Variable,Term> kv
986 in (Dictionary<Variable,Term>) values)
987 kv.Key.val = kv.Value;
991 public delegate Term Builtin (Domain domain, Variable vari, Term[] args);
993 private static Domain basic = new Domain ();
995 static Xexpression ()
997 basic.DefTerm ("funcall", Funcall.parser);
999 basic.DefSubr (Fset, "set", true, 1, 1, "=");
1000 basic.DefSubr (Fnot, "not", false, 1, 1, "!");
1001 basic.DefSubr (Fadd, "add", true, 1, -1, "+");
1002 basic.DefSubr (Fmul, "mul", true, 1, -1, "*");
1003 basic.DefSubr (Fsub, "sub", true, 1, -1, "-");
1004 basic.DefSubr (Fdiv, "div", true, 1, -1, "/");
1005 basic.DefSubr (Fmod, "mod", true, 1, 2, "%");
1006 basic.DefSubr (Flogior, "logior", true, 1, -1, "|");
1007 basic.DefSubr (Flogand, "logand", true, 1, -1, "&");
1008 basic.DefSubr (Flsh, "lsh", true, 1, 2, "<<");
1009 basic.DefSubr (Frsh, "rsh", true, 1, 2, ">>");
1010 basic.DefSubr (Feq, "eq", false, 2, -1, "==");
1011 basic.DefSubr (Fnoteq, "noteq", false, 2, 2, "!=");
1012 basic.DefSubr (Flt, "lt", false, 2, -1, "<");
1013 basic.DefSubr (Fle, "le", false, 2, -1, "<=");
1014 basic.DefSubr (Fgt, "gt", false, 2, -1, ">");
1015 basic.DefSubr (Fge, "ge", false, 2, -1, ">=");
1016 basic.DefSubr (Fappend, "append", true, 0, -1);
1017 basic.DefSubr (Fconcat, "concat", true, 0, -1);
1018 basic.DefSubr (Fnth, "nth", false, 2, 2);
1019 basic.DefSubr (Fcopy, "copy", false, 1, 1);
1020 basic.DefSubr (Fins, "ins", true, 2, 2);
1021 basic.DefSubr (Fdel, "del", true, 2, 2);
1022 basic.DefSubr (Feval, "eval", false, 1, 1);
1023 basic.DefSubr (Fbreak, "break", false, 0, 1);
1024 basic.DefSubr (Freturn, "return", false, 0, 1);
1026 basic.DefSpecial (Fand, "and", 1, -1, "&&");
1027 basic.DefSpecial (For, "or", 1, -1, "||");
1028 basic.DefSpecial (Fprogn, "progn", 0, -1, "expr");
1029 basic.DefSpecial (Fif, "if", 2, 3);
1030 basic.DefSpecial (Fwhen, "when", 1, -1);
1031 basic.DefSpecial (Floop, "loop", 1, -1);
1032 basic.DefSpecial (Fwhile, "while", 1, -1);
1033 basic.DefSpecial (Fcond, "cond", 1, -1);
1034 basic.DefSpecial (Fforeach, "foreach", 2, -1);
1035 basic.DefSpecial (Fquote, "quote", 1, 1);
1036 basic.DefSpecial (Ftype, "type", 1, 1);
1037 basic.DefSpecial (Fcatch, "catch", 2, 2);
1038 basic.DefSpecial (Fthrow, "throw", 1, 2);
1041 private static Term Fset (Domain domain, Variable vari, Term[] args)
1043 vari.Value = args[0];
1047 private static Term Fnot (Domain domain, Variable vari, Term[] args)
1049 return args[0].IsTrue ? Zero : One;
1052 private static Term Fadd (Domain domain, Variable vari, Term[] args)
1054 int n = vari == null ? 0 : vari.val.Intval;
1056 foreach (Term arg in args)
1059 return new Term (n);
1060 vari.val.intval = n;
1064 private static Term Fmul (Domain domain, Variable vari, Term[] args)
1066 int n = vari == null ? 1 : vari.val.Intval;
1067 foreach (Term arg in args)
1070 return new Term (n);
1071 vari.val.intval = n;
1075 private static Term Fsub (Domain domain, Variable vari, Term[] args)
1086 n = vari.val.Intval;
1089 while (i < args.Length)
1090 n -= args[i++].Intval;
1092 return new Term (n);
1093 vari.val.intval = n;
1097 private static Term Fdiv (Domain domain, Variable vari, Term[] args)
1108 n = vari.val.Intval;
1111 while (i < args.Length)
1112 n /= args[i++].Intval;
1114 return new Term (n);
1115 vari.val.intval = n;
1119 private static Term Fmod (Domain domain, Variable vari, Term[] args)
1122 return new Term (args[0].Intval % args[1].Intval);
1123 vari.val.intval = vari.val.Intval % args[0].Intval;
1127 private static Term Flogior (Domain domain, Variable vari, Term[] args)
1129 int n = vari == null ? 0 : vari.val.Intval;
1130 foreach (Term arg in args)
1133 return new Term (n);
1134 vari.val.intval = n;
1138 private static Term Flogand (Domain domain, Variable vari, Term[] args)
1149 n = vari.val.Intval;
1152 while (i < args.Length)
1153 n &= args[i++].Intval;
1155 return new Term (n);
1156 vari.val.intval = n;
1160 private static Term Flsh (Domain domain, Variable vari, Term[] args)
1163 return new Term (args[0].Intval << args[1].Intval);
1164 vari.val.intval = vari.val.Intval << args[0].Intval;
1168 private static Term Frsh (Domain domain, Variable vari, Term[] args)
1171 return new Term (args[0].Intval >> args[1].Intval);
1172 vari.val.intval = vari.val.Intval >> args[0].Intval;
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.val.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.val.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;
1302 result.objval = str;
1305 vari.val.objval = 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)
1340 = vari.val.Strval.Insert (args[0].Intval, args[1].Strval);
1341 else if (vari.val.IsList)
1342 vari.val.Listval.InsertRange (args[0].Intval, args[1].Listval);
1344 throw new Exception ("term is not collection: " + vari.val);
1348 private static Term Fdel (Domain domain, Variable vari, Term[] args)
1352 = vari.val.Strval.Remove (args[0].Intval,
1353 args[1].Intval - args[0].Intval);
1355 else if (vari.val.IsList)
1356 vari.val.Listval.RemoveRange (args[0].Intval,
1357 args[1].Intval - args[0].Intval);
1359 throw new Exception ("term is not collection: " + vari.val);
1363 private static Term Fand (Domain domain, Variable vari, Term[] args)
1365 foreach (Term arg in args)
1366 if (! arg.Eval (domain).IsTrue)
1371 private static Term For (Domain domain, Variable vari, Term[] args)
1373 foreach (Term arg in args)
1374 if (arg.Eval (domain).IsTrue)
1379 private static Term Feval (Domain domain, Variable vari, Term[] args)
1381 return (args[0].Eval (domain));
1384 private static Term Fprogn (Domain domain, Variable vari, Term[] args)
1388 foreach (Term arg in args)
1389 result = arg.Eval (domain);
1393 private static Term Fif (Domain domain, Variable vari, Term[] args)
1395 if (args[0].Eval (domain).IsTrue)
1396 return args[1].Eval (domain);
1397 if (args.Length == 2)
1399 return args[2].Eval (domain);
1402 private static Term Fwhen (Domain domain, Variable vari, Term[] args)
1404 if (! args[0].Eval (domain).IsTrue)
1407 for (int i = 1; i < args.Length; i++)
1408 result = args[i].Eval (domain);
1412 private static Term Freturn (Domain domain, Variable vari, Term[] args)
1414 domain.ThrowReturn ();
1415 return args.Length == 0 ? Zero : args[0];
1418 private static Term Fbreak (Domain domain, Variable vari, Term[] args)
1420 domain.ThrowBreak ();
1421 return args.Length == 0 ? Zero : args[0];
1424 private static Term Floop (Domain domain, Variable vari, Term[] args)
1428 domain.Catch (CatchTag.Break);
1429 while (! domain.Thrown)
1430 foreach (Term arg in args)
1432 result = arg.Eval (domain);
1442 private static Term Fwhile (Domain domain, Variable vari, Term[] args)
1446 domain.Catch (CatchTag.Break);
1447 while (! domain.Thrown && args[0].Eval (domain).IsTrue)
1448 for (int i = 1; i < args.Length; i++)
1450 result = args[i].Eval (domain);
1460 private static Term Fcond (Domain domain, Variable vari, Term[] args)
1462 foreach (Term arg in args)
1464 List<Term> list = arg.Listval;
1465 Term result = list[0].Eval (domain);
1469 for (int i = 1; i < list.Count; i++)
1470 result = list[i].Eval (domain);
1477 private static Term Fforeach (Domain domain, Variable vari,
1480 Term result = args[0].Eval (domain);
1483 List<Term> list = result.Listval;
1484 Bindings current = domain.bindings;
1487 domain.Catch (CatchTag.Break);
1488 foreach (Term term in list)
1490 domain.Bind (vari, term);
1492 for (int i = 1; i < args.Length; i++)
1494 result = args[i].Eval (domain);
1499 domain.UnboundTo (current);
1508 private static Term Fquote (Domain domain, Variable vari, Term[] args)
1510 return new Term (args[0]);
1513 private static Term Ftype (Domain domain, Variable vari, Term[] args)
1519 if (args[0].IsSymbol)
1526 public static Term Fcatch (Domain domain, Variable vari, Term[] args)
1530 domain.Catch (new CatchTag (args[0].Symval));
1531 result = args[1].Eval (domain);
1538 public static Term Fthrow (Domain domain, Variable vari, Term[] args)
1540 domain.ThrowTag (new CatchTag (args[0].Symval));
1541 return (args.Length == 1 ? Zero : args[1]);
1544 public delegate TermValue TermParser (Domain domain, XmlNode node);
1546 public class TermType
1548 public readonly Symbol type;
1549 internal readonly TermParser parser;
1551 public TermType (Symbol type, TermParser parser)
1554 this.parser = parser;
1558 public abstract class TermValue
1560 public virtual Term Eval (Domain domain) { return new Term (this); }
1561 public abstract TermValue Clone ();
1564 private class Funcall : TermValue
1566 internal Function func;
1567 internal Variable vari;
1568 internal Term[] args;
1570 private Funcall (Function func, Variable vari, Term[] args)
1577 public Funcall (Domain domain, Symbol fname, Term[] args)
1579 func = domain.GetFunc (fname);
1583 public Funcall (Domain domain, Symbol fname, Symbol vname, Term[] args)
1585 func = domain.GetFunc (fname);
1586 int nargs = args.Length;
1587 if (nargs < func.min_arg
1588 || (func.max_arg >= 0 && nargs > func.max_arg))
1589 throw new Exception ("Invalid number of arguments to: "
1590 + fname + " " + nargs);
1593 vari = domain.GetVar (vname, true);
1596 internal static TermValue parser (Domain domain, XmlNode node)
1598 Symbol fname = node.Name;
1599 Symbol vname = Qnull;
1602 if (fname == Qfuncall)
1603 fname = node.Attributes[Qfname].Value;
1604 attr = node.Attributes[Qvname];
1608 XmlNodeList nlist = node.ChildNodes;
1609 int nargs = nlist.Count;
1610 Term[] args = new Term[nargs];
1611 for (int i = 0; i < nargs; i++)
1612 args[i] = new Term (domain, nlist[i]);
1613 return new Funcall (domain, fname, vname, args);
1616 public override Term Eval (Domain domain)
1618 domain.DebugWrite (true, "(({0}", func.name);
1619 for (int i = 0; i < args.Length; i++)
1620 domain.DebugWrite (false, " {0}", args[i].ToString ());
1621 domain.DebugWrite (false, ")");
1623 Term result = func.Call (domain, vari, args);
1625 domain.DebugWrite (true, " ==> {0})", result.ToString ());
1629 public override TermValue Clone ()
1631 return new Funcall (func, vari, args);
1634 public override string ToString ()
1636 string str = "<funcall fname=\"" + func.name;
1638 return str + "\"/>";
1640 foreach (Term e in args)
1642 return (str + "</funcall>");
1649 public object objval;
1651 public Term (int i) { intval = i; objval = null; }
1652 public Term (Symbol name) { intval = 0; objval = name; }
1653 public Term (string str) { intval = 0; objval = str; }
1654 public Term (List<Term> list) { intval = 0; objval = list; }
1655 public Term (Term term) { intval = term.intval; objval = term.objval; }
1656 public Term (TermValue obj) { intval = 0; objval = obj; }
1658 public Term (Domain domain, XmlNode node)
1660 Symbol name = node.Name;
1662 if (name == Qinteger)
1664 intval = parse_integer (node.InnerText);
1670 if (name == Qsymbol)
1671 objval = (Symbol) node.InnerText;
1672 else if (name == Qstring)
1673 objval = node.InnerText.Clone ();
1674 else if (name == Qvarref)
1675 objval = domain.GetVar ((Symbol) node.Attributes[0].Value, true);
1676 else if (name == Qlist)
1678 List<Term> list = new List<Term> ();
1679 for (node = node.FirstChild; node != null;
1680 node = node.NextSibling)
1681 list.Add (new Term (domain, node));
1688 if (domain.termtypes.TryGetValue (name, out term_type))
1689 objval = term_type.parser (domain, node);
1691 objval = Funcall.parser (domain, node);
1696 public Term (Domain domain, Symbol vname)
1699 objval = domain.GetVar (vname, true);
1702 public Term (Domain domain, Symbol fname, Term[] args)
1705 objval = new Funcall (domain, fname, args);
1708 public Term (Domain domain, Symbol fname, Symbol vname, Term[] args)
1711 objval = new Funcall (domain, fname, vname, args);
1714 public object Objval {
1717 throw new Exception ("term is an integer: " + this);
1725 throw new Exception ("term is not integer: " + this);
1730 public string Strval {
1733 throw new Exception ("term is not string: " + this);
1734 return (string) objval;
1738 public string Symval {
1741 throw new Exception ("term is not symbol: " + this);
1742 return (Symbol) objval;
1746 public List<Term> Listval {
1749 throw new Exception ("term is not list: " + this);
1750 return (List<Term>) objval;
1754 public bool IsTrue {
1756 return (objval == null
1758 : objval is List<Term>
1759 ? (((List<Term>) objval).Count != 0)
1763 public bool IsInt { get { return (objval == null); } }
1764 public bool IsStr { get { return (objval is string); } }
1765 public bool IsSymbol { get { return (objval is Symbol); } }
1766 public bool IsList { get { return (objval is List<Term>); } }
1768 public bool IsType (Type type)
1770 return (objval == null ? type == typeof (int)
1771 : type == objval.GetType ());
1774 public Term Eval (Domain domain)
1776 if (objval == null || objval is Symbol || objval is string)
1778 if (objval is List<Term>)
1779 return new Term ((List<Term>) objval);
1780 return ((TermValue) objval).Eval (domain);
1783 public Term Clone ()
1785 if (objval == null || objval is Symbol || objval is string)
1787 if (objval is List<Term>)
1789 List<Term> list = new List<Term> ();
1790 list.InsertRange (0, ((List<Term>) objval));
1791 return new Term (list);
1793 return new Term (((TermValue) objval).Clone ());
1796 public override string ToString ()
1801 str = "<integer>" + intval + "</integer>";
1802 else if (objval is Symbol)
1803 str = "<symbol>" + objval + "</symbol>";
1804 else if (objval is string)
1805 str = "<string>" + objval + "</string>";
1806 else if (objval is List<Term>)
1809 foreach (Term e in (List<Term>) objval)
1813 else if (objval is Funcall)
1814 str = "<funcall fname=\"" + ((Funcall) objval).func.name + "\"/>";
1815 else if (objval is Variable)
1816 str = "<variable vname=\"" + ((Variable) objval).name + "\"/>";
1817 else if (objval is Term)
1818 str = "<quote>" + objval + "</quote>";
1820 throw new Exception ("invalid Term object: " + objval);
1825 static private Term Zero = new Term (0);
1826 static private Term One = new Term (1);
1827 static private Term TermInt = new Term (Qinteger);
1828 static private Term TermStr = new Term (Qstring);
1829 static private Term TermSymbol = new Term (Qsymbol);
1830 static private Term TermList = new Term (Qlist);
1831 static private Term TermTerm = new Term ((Symbol) "term");
1833 internal static int parse_integer (string str)
1835 int len = str.Length;
1836 bool negative = false;
1839 return (len == 0 ? 0 : str[0] - '0');
1846 if ((c == '0' || c == '#') && str[1] == 'x')
1849 for (int idx = 2; idx < len; idx++)
1855 i = i * 16 + (c - '0');
1859 i = i * 16 + (c - 'A');
1863 i = i * 16 + (c - 'a');
1872 for (int idx = 1; idx < len; idx++)
1875 if (c < '0' || c > '9')
1877 i = i * 10 + (c - '0');
1879 return negative ? - i : i;
1882 private Term[] terms;
1884 public static Term[] ParseTerms (Domain domain, XmlNode node)
1887 for (XmlNode n = node; n != null; n = n.NextSibling)
1888 if (n.NodeType == XmlNodeType.Element)
1890 if (n.Name == Qdefun)
1891 domain.Defun (n, true);
1892 else if (n.Name == Qdefvar)
1897 Term[] terms = new Term[nterms];
1899 for (XmlNode n = node; n != null; n = n.NextSibling)
1900 if (n.NodeType == XmlNodeType.Element)
1902 if (n.Name == Qdefun)
1903 domain.Defun (n, false);
1904 else if (n.Name != Qdefvar)
1905 terms[i++]= new Term (domain, n);
1910 public Xexpression (Domain domain, XmlNode node)
1912 terms = ParseTerms (domain, node);
1915 public Xexpression (Domain domain, string url)
1917 XmlDocument doc = new XmlDocument (Symbol.Table);
1920 using (XmlTextReader reader = new XmlTextReader (url, Symbol.Table))
1924 } while (reader.NodeType != XmlNodeType.None
1925 && (reader.NodeType != XmlNodeType.Element
1926 || reader.Name != Qexpr));
1927 if (reader.NodeType == XmlNodeType.None)
1928 throw new Exception ("Node <expr> not found");
1929 node = doc.ReadNode (reader);
1931 terms = ParseTerms (domain, node.FirstChild);
1934 public Term Eval (Domain domain)
1940 domain.Catch (CatchTag.Return);
1941 foreach (Term term in terms)
1943 result = term.Eval (domain);
1953 public override string ToString ()
1956 for (int i = 0; i < terms.Length; i++)