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)
145 args = (Term[]) args.Clone ();
146 for (int i = 0; i < args.Length; i++)
148 args[i] = args[i].Eval (domain);
153 return builtin (domain, vari, args);
157 internal class SpecialForm : Function
159 public Builtin builtin;
161 public SpecialForm (Builtin builtin, Symbol name,
162 int min_arg, int max_arg)
163 : base (name, min_arg, max_arg)
165 this.builtin = builtin;
168 public override Term Call (Domain domain, Variable vari, Term[] args)
170 return builtin (domain, vari, args);
174 internal class Lambda : Function
176 internal bool args_evalled;
177 internal Variable[] args;
178 internal Term[] body;
180 public Lambda (Domain domain, XmlNode node)
185 name = node.Attributes[Qfname].Value;
187 node = node.FirstChild;
189 && (node.Name == Qargs || node.Name == Qargs_unevalled))
192 args_evalled = node.Name == Qargs;
193 for (n = node.FirstChild; n != null; n = n.NextSibling)
195 if (n.Name == Qfixed)
197 else if (n.Name == Qoptional)
199 else if (n.Name == Qrest)
202 throw new Exception ("Invalid argument type: " + n);
205 max_arg = nfixed + noptional + nrest;
206 args = new Variable[max_arg];
208 for (int i = 0; i < max_arg; n = n.NextSibling)
209 args[i++] = domain.Defvar ((Symbol) n.Attributes[0].Value);
215 min_arg = max_arg = 0;
219 public Lambda (Domain domain, Symbol name,
220 bool args_evalled, Symbol[] args)
227 this.args_evalled = args_evalled;
231 for (i = 0; i < args.Length; i++, nfixed++)
232 if (args[i] == Qoptional || args[i] == Qrest)
236 if (args[i] == Qoptional)
238 for (i++; i < args.Length; i++, noptional++)
239 if (args[i] == Qrest)
246 max_arg = nfixed + noptional + nrest;
247 this.args = new Variable[max_arg];
249 for (i = j = 0; j < this.args.Length; i++)
250 if (args[i] != Qoptional || args[i] != Qrest)
251 this.args[j++] = domain.Defvar (args[i]);
255 min_arg = max_arg = 0;
259 public void SetBody (Domain domain, XmlNode node)
261 for (node = node.FirstChild; node != null; node = node.NextSibling)
262 if (node.Name != Qdescription
263 && node.Name != Qargs
264 && node.Name != Qargs_unevalled)
267 for (XmlNode n = node; n != null; n = n.NextSibling)
271 body = new Term[nterms];
272 for (nterms = 0; node != null; node = node.NextSibling, nterms++)
273 body[nterms] = new Term (domain, node);
277 public void SetBody (Term[] body)
282 public override Term Call (Domain domain, Variable vari, Term[] args)
284 Bindings current = domain.bindings;
291 Term[] newargs = new Term[args.Length];
292 for (i = 0; i < min_arg; i++)
293 newargs[i] = args[i].Eval (domain);
296 for (i = 0; i < min_arg; i++)
297 domain.Bind (this.args[i], args[i]);
302 domain.Catch (CatchTag.Return);
303 foreach (Term term in body)
305 result = term.Eval (domain);
315 domain.UnboundTo (current);
322 public class Variable : TermValue
324 public readonly Symbol name;
326 internal Term default_val;
330 public Variable (Symbol name, Term value)
337 public virtual bool ValueP (Term val) { return true; }
339 public override TermValue Clone ()
341 Variable v = new Variable (name, val);
343 v.default_val = default_val;
352 if (! ValueP (value))
353 throw new Exception ("Invalid value: " + value);
358 public Term DefaultValue
360 get { return default_val; }
362 if (! ValueP (value))
363 throw new Exception ("Invalid value: " + value);
368 public virtual object Range
370 get { return range; }
371 set { range = value; }
374 public override Term Eval (Domain domain) { return val; }
376 public override string ToString () { return name + "(" + val + ")"; }
378 public class Int : Variable
382 private static bool SubsetP (int[] r1, int[] r2)
386 for (int i = 0; i < r1.Length; i += 2)
389 for (j = 0; j < r2.Length; j += 2)
390 if (r2[j] <= r1[i] && r2[j + 1] >= r1[i + 1])
398 private static bool SubsetP (int val, int[] r)
402 for (int i = 0; i < r.Length; i += 2)
403 if (r[i] <= val && r[i + 1] >= val)
408 public Int (Symbol name, string description, int value, int[] range)
409 : base (name, new Term (value))
411 if (! SubsetP (value, range))
412 throw new Exception ("Invalid value: " + value);
418 public override bool ValueP (Term term)
422 return SubsetP (term.Intval, range);
425 public override object Range {
426 get { return range; }
428 int[] r = (int[]) value;
429 if (! SubsetP (r, range)
430 || ! SubsetP (val.Intval, r)
431 || ! SubsetP (default_val.Intval, r))
432 throw new Exception ("Invalid range");
438 public class Str : Variable
440 public string[] range;
442 private static bool SubsetP (string[] r1, string[] r2)
446 foreach (string s in r1)
447 if (! SubsetP (s, r2))
452 private static bool SubsetP (string str, string[] r)
456 foreach (string s in r)
462 public Str (Symbol name, string description, string value, string[] range)
463 : base (name, new Term (value))
465 if (! SubsetP (value, range))
466 throw new Exception ("Invalid value: " + value);
472 public override bool ValueP (Term term)
474 if (! (term.objval is string))
476 return SubsetP (term.Strval, range);
479 public override object Range {
480 get { return range; }
482 string[] r = (string[]) value;
483 if (! SubsetP (r, range)
484 || ! SubsetP (val.Strval, r)
485 || ! SubsetP (default_val.Strval, r))
486 throw new Exception ("Invalid range");
492 public class Sym : Variable
494 public Symbol[] range;
496 private static bool SubsetP (Symbol[] r1, Symbol[] r2)
500 foreach (Symbol n in r1)
501 if (! SubsetP (n, r2))
506 private static bool SubsetP (Symbol name, Symbol[] r)
510 foreach (Symbol n in r)
516 public Sym (Symbol name, string description, Symbol value, Symbol[] range)
517 : base (name, new Term (value))
519 if (! SubsetP (value, range))
520 throw new Exception ("Invalid value: " + value);
526 public override bool ValueP (Term term)
528 if (! (term.objval is Symbol))
530 return SubsetP (term.Symval, range);
533 public override object Range {
534 get { return range; }
536 Symbol[] r = (Symbol[]) value;
537 if (! SubsetP (r, range)
538 || ! SubsetP (val.Symval, r)
539 || ! SubsetP (default_val.Symval, r))
540 throw new Exception ("Invalid range");
547 internal class Bindings
549 private Variable vari;
550 private Term old_value;
551 private Bindings next;
553 private Bindings (Variable vari)
556 old_value = vari.val;
559 public static Bindings Bind (Bindings bindings, Variable vari, Term val)
561 Bindings b = new Bindings (vari);
568 internal Bindings UnboundTo (Bindings boundary)
570 for (Bindings b = this; b != boundary; b = b.next)
571 b.vari.val = b.old_value;
575 public override string ToString ()
577 string str = "(bindings";
578 for (Bindings b = this; b != null; b = b.next)
579 str += " " + vari.name + "=" + b.old_value;
585 internal class ThrowException : Exception
590 public ThrowException (Symbol tag, object value) : base ()
598 internal class CatchTag : IEquatable<CatchTag>
602 public CatchTag (Symbol name) { val = name.name; }
603 private CatchTag (int i) { val = i; }
605 public static CatchTag Return = new CatchTag (0);
606 public static CatchTag Break = new CatchTag (1);
608 public static bool operator== (CatchTag t1, CatchTag t2)
609 { return t1.val == t2.val; }
611 public static bool operator!= (CatchTag t1, CatchTag t2)
612 { return t1.val != t2.val; }
614 public bool Equals (CatchTag tag) { return this.val == tag.val; }
615 public override bool Equals (object val) { return this.val == val; }
617 public override int GetHashCode () { return val.GetHashCode (); }
622 public object context;
623 public int depth = 0;
625 internal Dictionary<Symbol, TermType> termtypes
626 = new Dictionary<Symbol, TermType> ();
627 internal Dictionary<Symbol, Function> functions
628 = new Dictionary<Symbol, Function> ();
629 internal Dictionary<Symbol, Variable> variables
630 = new Dictionary<Symbol, Variable> ();
631 internal Bindings bindings;
632 private Stack<CatchTag> catch_stack = new Stack<CatchTag> ();
633 private int catch_count = 0;
635 internal Domain () { }
637 public Domain (object context) : this (basic, context) { }
639 public Domain (Domain parent, object context)
641 termtypes = new Dictionary<Symbol, TermType> (parent.termtypes);
642 functions = new Dictionary<Symbol, Function> (parent.functions);
643 variables = new Dictionary<Symbol, Variable> (parent.variables);
644 this.context = context;
647 internal void Bind (Variable vari, Term value)
649 bindings = Bindings.Bind (bindings, vari, value);
652 internal void UnboundTo (Bindings boundary)
654 if (bindings != null)
655 bindings = bindings.UnboundTo (boundary);
658 internal void Catch (CatchTag tag)
660 catch_stack.Push (tag);
664 internal void Uncatch ()
667 if (catch_count > catch_stack.Count)
672 get { return catch_count < catch_stack.Count; }
675 internal void ThrowReturn ()
677 foreach (CatchTag tag in catch_stack)
680 if (tag == CatchTag.Return)
685 internal void ThrowBreak ()
687 if (catch_stack.Peek () != CatchTag.Break)
688 throw new Exception ("No outer loop to break");
692 internal void ThrowTag (CatchTag tag)
694 foreach (CatchTag elt in catch_stack)
702 public void DefTerm (Symbol name, TermParser parser)
704 termtypes[name] = new TermType (name, parser);
707 public void DefSubr (Builtin builtin, string str, bool setvar,
708 int min_arg, int max_arg, params string[] aliases)
711 Function func = new Function.Subroutine (builtin, name, setvar,
713 functions[name] = func;
714 foreach (string a in aliases)
715 functions[(Symbol) a] = func;
718 public void DefSpecial (Builtin builtin, string str,
719 int min_arg, int max_arg,
720 params string[] aliases)
723 Function func = new Function.SpecialForm (builtin, name,
725 functions[name] = func;
726 foreach (string a in aliases)
727 functions[(Symbol) a] = func;
730 public void DefAlias (string alias, string str)
732 functions[(Symbol) alias] = functions[(Symbol) str];
735 public void Defun (Symbol name, bool args_evalled,
736 Symbol[] args, Term[] body, bool prototype)
740 if (prototype || ! functions.TryGetValue (name, out func))
742 func = new Function.Lambda (this, name, args_evalled, args);
743 functions[name] = func;
746 ((Function.Lambda) func).SetBody (body);
749 public void Defun (XmlNode node, bool prototype)
751 Symbol name = node.Attributes[Qfname].Value;
754 if (prototype || ! functions.TryGetValue (name, out func))
756 func = new Function.Lambda (this, node);
757 functions[name] = func;
760 ((Function.Lambda) func).SetBody (this, node);
763 public void Defun (Function func)
765 functions[func.name] = func;
768 public Variable Defvar (XmlNode node)
770 Symbol name = node.Attributes[0].Value;
774 node = node.FirstChild;
775 if (node != null && node.Name == Qdescription)
777 desc = node.InnerText;
778 node = node.NextSibling;
784 Symbol type = node.Name;
785 XmlNodeList range_list = null;
787 string val = node.InnerText;
789 node = node.NextSibling;
792 range_list = node.ChildNodes;
793 nranges = range_list.Count;
796 if (type == Qinteger)
798 int intval = parse_integer (val);
800 if (range_list != null)
802 range = new int[nranges * 2];
803 for (int i = 0; i < nranges; i++)
805 XmlNode n = range_list[i];
806 if (n.Name == Qrange)
809 = parse_integer (n.FirstChild.InnerText);
811 = parse_integer (n.LastChild.InnerText);
817 = parse_integer (n.FirstChild.InnerText);
822 if (variables.TryGetValue (name, out vari))
824 if (! (vari is Variable.Int))
825 throw new Exception ("Inalid value");
826 vari = (Variable) vari.Clone ();
827 Term v = new Term (intval);
829 vari.DefaultValue = v;
834 vari = new Variable.Int (name, desc, intval, range);
836 else if (type == Qstring)
838 string[] range = null;
839 if (range_list != null)
841 range = new string[nranges];
842 for (int i = 0; i < nranges; i++)
843 range[i] = range_list[i].FirstChild.InnerText;
846 if (variables.TryGetValue (name, out vari))
848 if (! (vari is Variable.Str))
849 throw new Exception ("Invalid value");
850 vari = (Variable) vari.Clone ();
851 Term v = new Term (val);
853 vari.DefaultValue = v;
858 vari = new Variable.Str (name, desc, val, range);
860 else if (type == Qsymbol)
862 Symbol[] range = null;
863 if (range_list != null)
865 range = new Symbol[nranges];
866 for (int i = 0; i < nranges; i++)
867 range[i] = range_list[i].FirstChild.InnerText;
870 if (variables.TryGetValue (name, out vari))
872 if (! (vari is Variable.Sym))
873 throw new Exception ("Invalid value");
874 vari = (Variable) vari.Clone ();
875 Term v = new Term (val);
877 vari.DefaultValue = v;
882 vari = new Variable.Sym (name, desc, val, range);
885 throw new Exception ("Unknown type: " + type);
889 if (variables.TryGetValue (name, out vari))
890 vari = (Variable) vari.Clone ();
892 vari = new Variable (name, Zero);
894 variables[name] = vari;
898 public Variable Defvar (Variable vari)
900 variables[vari.name] = vari;
904 internal Variable Defvar (Symbol name)
906 Variable vari = new Variable (name, Zero);
907 variables[name] = vari;
911 internal Function GetFunc (Symbol name)
915 if (! functions.TryGetValue (name, out func))
916 throw new Exception ("Unknown function: " + name);
920 public bool CopyFunc (Domain domain, Symbol name)
922 Function func = GetFunc (name);
924 domain.functions[name] = func;
928 public void CopyFunc (Domain domain)
930 foreach (KeyValuePair<Symbol, Function> kv in functions)
931 domain.functions[kv.Key] = kv.Value;
934 public Variable GetVar (Symbol name, bool create)
938 if (! variables.TryGetValue (name, out vari))
942 variables[name] = vari = new Variable (name, Zero);
947 public override string ToString ()
949 string str = "<(functions";
950 foreach (KeyValuePair<Symbol, Function> kv in functions)
952 str += ") (variabls";
953 foreach (KeyValuePair<Symbol, Variable> kv in variables)
956 if (bindings != null)
957 str += " " + bindings;
959 str += " (" + context + ")";
964 internal void DebugWrite (bool head, string fmt, params string[] arg)
966 if (debug_level > depth)
970 Console.WriteLine ();
971 for (int i = 0; i < depth; i++)
974 Console.Write (fmt, arg);
978 public object SaveValues ()
980 Dictionary<Variable,Term> values = new Dictionary<Variable,Term> ();
982 foreach (KeyValuePair<Symbol,Variable> kv in variables)
983 values[kv.Value] = kv.Value.val.Clone ();
987 public void RestoreValues (object values)
989 foreach (KeyValuePair<Variable,Term> kv
990 in (Dictionary<Variable,Term>) values)
991 kv.Key.val = kv.Value;
995 public delegate Term Builtin (Domain domain, Variable vari, Term[] args);
997 private static Domain basic = new Domain ();
999 static Xexpression ()
1001 basic.DefTerm ("funcall", Funcall.parser);
1003 basic.DefSubr (Fset, "set", true, 1, 1, "=");
1004 basic.DefSubr (Fnot, "not", false, 1, 1, "!");
1005 basic.DefSubr (Fadd, "add", true, 1, -1, "+");
1006 basic.DefSubr (Fmul, "mul", true, 1, -1, "*");
1007 basic.DefSubr (Fsub, "sub", true, 1, -1, "-");
1008 basic.DefSubr (Fdiv, "div", true, 1, -1, "/");
1009 basic.DefSubr (Fmod, "mod", true, 1, 2, "%");
1010 basic.DefSubr (Flogior, "logior", true, 1, -1, "|");
1011 basic.DefSubr (Flogand, "logand", true, 1, -1, "&");
1012 basic.DefSubr (Flsh, "lsh", true, 1, 2, "<<");
1013 basic.DefSubr (Frsh, "rsh", true, 1, 2, ">>");
1014 basic.DefSubr (Feq, "eq", false, 2, -1, "==");
1015 basic.DefSubr (Fnoteq, "noteq", false, 2, 2, "!=");
1016 basic.DefSubr (Flt, "lt", false, 2, -1, "<");
1017 basic.DefSubr (Fle, "le", false, 2, -1, "<=");
1018 basic.DefSubr (Fgt, "gt", false, 2, -1, ">");
1019 basic.DefSubr (Fge, "ge", false, 2, -1, ">=");
1020 basic.DefSubr (Fappend, "append", true, 0, -1);
1021 basic.DefSubr (Fconcat, "concat", true, 0, -1);
1022 basic.DefSubr (Fnth, "nth", false, 2, 2);
1023 basic.DefSubr (Fcopy, "copy", false, 1, 1);
1024 basic.DefSubr (Fins, "ins", true, 2, 2);
1025 basic.DefSubr (Fdel, "del", true, 2, 2);
1026 basic.DefSubr (Feval, "eval", false, 1, 1);
1027 basic.DefSubr (Fbreak, "break", false, 0, 1);
1028 basic.DefSubr (Freturn, "return", false, 0, 1);
1030 basic.DefSpecial (Fand, "and", 1, -1, "&&");
1031 basic.DefSpecial (For, "or", 1, -1, "||");
1032 basic.DefSpecial (Fprogn, "progn", 0, -1, "expr");
1033 basic.DefSpecial (Fif, "if", 2, 3);
1034 basic.DefSpecial (Fwhen, "when", 1, -1);
1035 basic.DefSpecial (Floop, "loop", 1, -1);
1036 basic.DefSpecial (Fwhile, "while", 1, -1);
1037 basic.DefSpecial (Fcond, "cond", 1, -1);
1038 basic.DefSpecial (Fforeach, "foreach", 2, -1);
1039 basic.DefSpecial (Fquote, "quote", 1, 1);
1040 basic.DefSpecial (Ftype, "type", 1, 1);
1041 basic.DefSpecial (Fcatch, "catch", 2, 2);
1042 basic.DefSpecial (Fthrow, "throw", 1, 2);
1045 private static Term Fset (Domain domain, Variable vari, Term[] args)
1047 vari.Value = args[0];
1051 private static Term Fnot (Domain domain, Variable vari, Term[] args)
1053 return args[0].IsTrue ? Zero : One;
1056 private static Term Fadd (Domain domain, Variable vari, Term[] args)
1058 int n = vari == null ? 0 : vari.val.Intval;
1060 foreach (Term arg in args)
1063 return new Term (n);
1064 vari.val.intval = n;
1068 private static Term Fmul (Domain domain, Variable vari, Term[] args)
1070 int n = vari == null ? 1 : vari.val.Intval;
1071 foreach (Term arg in args)
1074 return new Term (n);
1075 vari.val.intval = n;
1079 private static Term Fsub (Domain domain, Variable vari, Term[] args)
1090 n = vari.val.Intval;
1093 while (i < args.Length)
1094 n -= args[i++].Intval;
1096 return new Term (n);
1097 vari.val.intval = n;
1101 private static Term Fdiv (Domain domain, Variable vari, Term[] args)
1112 n = vari.val.Intval;
1115 while (i < args.Length)
1116 n /= args[i++].Intval;
1118 return new Term (n);
1119 vari.val.intval = n;
1123 private static Term Fmod (Domain domain, Variable vari, Term[] args)
1126 return new Term (args[0].Intval % args[1].Intval);
1127 vari.val.intval = vari.val.Intval % args[0].Intval;
1131 private static Term Flogior (Domain domain, Variable vari, Term[] args)
1133 int n = vari == null ? 0 : vari.val.Intval;
1134 foreach (Term arg in args)
1137 return new Term (n);
1138 vari.val.intval = n;
1142 private static Term Flogand (Domain domain, Variable vari, Term[] args)
1153 n = vari.val.Intval;
1156 while (i < args.Length)
1157 n &= args[i++].Intval;
1159 return new Term (n);
1160 vari.val.intval = n;
1164 private static Term Flsh (Domain domain, Variable vari, Term[] args)
1167 return new Term (args[0].Intval << args[1].Intval);
1168 vari.val.intval = vari.val.Intval << args[0].Intval;
1172 private static Term Frsh (Domain domain, Variable vari, Term[] args)
1175 return new Term (args[0].Intval >> args[1].Intval);
1176 vari.val.intval = vari.val.Intval >> args[0].Intval;
1180 private static Term Feq (Domain domain, Variable vari, Term[] args)
1184 if (o.objval == null)
1186 for (int i = 1; i < args.Length; i++)
1187 if (args[i].objval != null || args[i].intval != o.intval)
1192 for (int i = 1; i < args.Length; i++)
1193 if (o.objval.Equals (args[i].objval))
1199 private static Term Fnoteq (Domain domain, Variable vari, Term[] args)
1201 return Feq (domain, vari, args);
1204 private static Term Flt (Domain domain, Variable vari, Term[] args)
1206 int n = args[0].Intval;
1208 for (int i = 1; i < args.Length; i++)
1210 int n1 = args[i].Intval;
1218 private static Term Fle (Domain domain, Variable vari, Term[] args)
1220 int n = args[0].Intval;
1221 for (int i = 1; i < args.Length; i++)
1223 int n1 = args[i].Intval;
1231 private static Term Fgt (Domain domain, Variable vari, Term[] args)
1233 int n = args[0].Intval;
1234 for (int i = 1; i < args.Length; i++)
1236 int n1 = args[i].Intval;
1244 private static Term Fge (Domain domain, Variable vari, Term[] args)
1246 int n = args[0].Intval;
1247 for (int i = 1; i < args.Length; i++)
1249 int n1 = args[i].Intval;
1257 private static Term Fappend (Domain domain, Variable vari, Term[] args)
1262 list = new List<Term> ();
1264 list = vari.val.Listval;
1266 foreach (Term arg in args)
1269 list.AddRange ((List<Term>) arg.objval);
1277 result.objval = list;
1283 private static Term Fconcat (Domain domain, Variable vari, Term[] args)
1290 str = vari.val.Strval;
1292 foreach (Term arg in args)
1295 str += (string) arg.objval;
1296 else if (arg.IsList)
1297 foreach (Term term in (List<Term>) arg.objval)
1298 str += (char) term.Intval;
1300 str += (char) arg.Intval;
1306 result.objval = str;
1309 vari.val.objval = str;
1313 private static Term Fnth (Domain domain, Variable vari, Term[] args)
1319 result.intval = ((string) args[1].objval)[args[0].Intval];
1320 result.objval = null;
1322 else if (args[1].IsList)
1324 result = ((List<Term>) args[1].objval)[args[0].Intval];
1327 throw new Exception ("Term is not enumelable: " + args[1]);
1331 private static Term Fcopy (Domain domain, Variable vari, Term[] args)
1336 result.objval = new List<Term> (args[0].Listval);
1340 private static Term Fins (Domain domain, Variable vari, Term[] args)
1344 = vari.val.Strval.Insert (args[0].Intval, args[1].Strval);
1345 else if (vari.val.IsList)
1346 vari.val.Listval.InsertRange (args[0].Intval, args[1].Listval);
1348 throw new Exception ("term is not collection: " + vari.val);
1352 private static Term Fdel (Domain domain, Variable vari, Term[] args)
1356 = vari.val.Strval.Remove (args[0].Intval,
1357 args[1].Intval - args[0].Intval);
1359 else if (vari.val.IsList)
1360 vari.val.Listval.RemoveRange (args[0].Intval,
1361 args[1].Intval - args[0].Intval);
1363 throw new Exception ("term is not collection: " + vari.val);
1367 private static Term Fand (Domain domain, Variable vari, Term[] args)
1369 foreach (Term arg in args)
1370 if (! arg.Eval (domain).IsTrue)
1375 private static Term For (Domain domain, Variable vari, Term[] args)
1377 foreach (Term arg in args)
1378 if (arg.Eval (domain).IsTrue)
1383 private static Term Feval (Domain domain, Variable vari, Term[] args)
1385 return (args[0].Eval (domain));
1388 private static Term Fprogn (Domain domain, Variable vari, Term[] args)
1392 foreach (Term arg in args)
1393 result = arg.Eval (domain);
1397 private static Term Fif (Domain domain, Variable vari, Term[] args)
1399 if (args[0].Eval (domain).IsTrue)
1400 return args[1].Eval (domain);
1401 if (args.Length == 2)
1403 return args[2].Eval (domain);
1406 private static Term Fwhen (Domain domain, Variable vari, Term[] args)
1408 if (! args[0].Eval (domain).IsTrue)
1411 for (int i = 1; i < args.Length; i++)
1412 result = args[i].Eval (domain);
1416 private static Term Freturn (Domain domain, Variable vari, Term[] args)
1418 domain.ThrowReturn ();
1419 return args.Length == 0 ? Zero : args[0];
1422 private static Term Fbreak (Domain domain, Variable vari, Term[] args)
1424 domain.ThrowBreak ();
1425 return args.Length == 0 ? Zero : args[0];
1428 private static Term Floop (Domain domain, Variable vari, Term[] args)
1432 domain.Catch (CatchTag.Break);
1433 while (! domain.Thrown)
1434 foreach (Term arg in args)
1436 result = arg.Eval (domain);
1446 private static Term Fwhile (Domain domain, Variable vari, Term[] args)
1450 domain.Catch (CatchTag.Break);
1451 while (! domain.Thrown && args[0].Eval (domain).IsTrue)
1452 for (int i = 1; i < args.Length; i++)
1454 result = args[i].Eval (domain);
1464 private static Term Fcond (Domain domain, Variable vari, Term[] args)
1466 foreach (Term arg in args)
1468 List<Term> list = arg.Listval;
1469 Term result = list[0].Eval (domain);
1473 for (int i = 1; i < list.Count; i++)
1474 result = list[i].Eval (domain);
1481 private static Term Fforeach (Domain domain, Variable vari,
1484 Term result = args[0].Eval (domain);
1487 List<Term> list = result.Listval;
1488 Bindings current = domain.bindings;
1491 domain.Catch (CatchTag.Break);
1492 foreach (Term term in list)
1494 domain.Bind (vari, term);
1496 for (int i = 1; i < args.Length; i++)
1498 result = args[i].Eval (domain);
1503 domain.UnboundTo (current);
1512 private static Term Fquote (Domain domain, Variable vari, Term[] args)
1514 return new Term (args[0]);
1517 private static Term Ftype (Domain domain, Variable vari, Term[] args)
1523 if (args[0].IsSymbol)
1530 public static Term Fcatch (Domain domain, Variable vari, Term[] args)
1534 domain.Catch (new CatchTag (args[0].Symval));
1535 result = args[1].Eval (domain);
1542 public static Term Fthrow (Domain domain, Variable vari, Term[] args)
1544 domain.ThrowTag (new CatchTag (args[0].Symval));
1545 return (args.Length == 1 ? Zero : args[1]);
1548 public delegate TermValue TermParser (Domain domain, XmlNode node);
1550 public class TermType
1552 public readonly Symbol type;
1553 internal readonly TermParser parser;
1555 public TermType (Symbol type, TermParser parser)
1558 this.parser = parser;
1562 public abstract class TermValue
1564 public virtual Term Eval (Domain domain) { return new Term (this); }
1565 public virtual TermValue Clone () { return this; }
1568 private class Funcall : TermValue
1570 internal Function func;
1571 internal Variable vari;
1572 internal Term[] args;
1574 private Funcall (Function func, Variable vari, Term[] args)
1581 public Funcall (Domain domain, Symbol fname, Term[] args)
1583 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);
1595 public Funcall (Domain domain, Symbol fname, Symbol vname, Term[] args)
1597 func = domain.GetFunc (fname);
1600 int nargs = args.Length;
1601 if (nargs < func.min_arg
1602 || (func.max_arg >= 0 && nargs > func.max_arg))
1603 throw new Exception ("Invalid number of arguments to: "
1604 + fname + " " + nargs);
1608 vari = domain.GetVar (vname, true);
1611 internal static TermValue parser (Domain domain, XmlNode node)
1613 Symbol fname = node.Name;
1614 Symbol vname = Qnull;
1617 if (fname == Qfuncall)
1618 fname = node.Attributes[Qfname].Value;
1619 attr = node.Attributes[Qvname];
1623 XmlNodeList nlist = node.ChildNodes;
1624 int nargs = nlist.Count;
1625 Term[] args = new Term[nargs];
1626 for (int i = 0; i < nargs; i++)
1627 args[i] = new Term (domain, nlist[i]);
1628 return new Funcall (domain, fname, vname, args);
1631 public override Term Eval (Domain domain)
1633 domain.DebugWrite (true, ToString ());
1635 Term result = func.Call (domain, vari, args);
1637 domain.DebugWrite (true, " ==> {0})", result.ToString ());
1641 public override TermValue Clone ()
1643 return new Funcall (func, vari, args);
1646 public override string ToString ()
1648 string str = "<" + func.name;
1650 str += " vname=\"" + vari.name + "\"";
1654 if (func is Function.SpecialForm)
1657 foreach (Term e in args)
1659 return (str + "</" + func.name + ">");
1666 public object objval;
1668 // <integer>...</integer>
1669 public Term (int i) { intval = i; objval = null; }
1670 // <symbol>...</symbol>
1671 public Term (Symbol name) { intval = 0; objval = name; }
1672 // <string>...</string>
1673 public Term (string str) { intval = 0; objval = str; }
1675 public Term (List<Term> list) { intval = 0; objval = list; }
1677 public Term (Term term) { intval = term.intval; objval = term.objval; }
1678 public Term (TermValue obj) { intval = 0; objval = obj; }
1680 public Term (Domain domain, XmlNode node)
1682 Symbol name = node.Name;
1684 if (name == Qinteger)
1686 intval = parse_integer (node.InnerText);
1692 if (name == Qsymbol)
1693 objval = (Symbol) node.InnerText;
1694 else if (name == Qstring)
1695 objval = node.InnerText.Clone ();
1696 else if (name == Qvarref)
1697 objval = domain.GetVar ((Symbol) node.Attributes[0].Value, true);
1698 else if (name == Qlist)
1700 List<Term> list = new List<Term> ();
1701 for (node = node.FirstChild; node != null;
1702 node = node.NextSibling)
1703 list.Add (new Term (domain, node));
1710 if (domain.termtypes.TryGetValue (name, out term_type))
1711 objval = term_type.parser (domain, node);
1713 objval = Funcall.parser (domain, node);
1718 // <varref vname="VNAME"/>
1719 public Term (Domain domain, Symbol vname)
1722 objval = domain.GetVar (vname, true);
1725 // <funcall fname="FNAME">...</funcall>
1726 public Term (Domain domain, Symbol fname, Term[] args)
1729 objval = new Funcall (domain, fname, args);
1732 // <funcall fname="FNAME" vname="VNAME">...</funcall>
1733 public Term (Domain domain, Symbol fname, Symbol vname, Term[] args)
1736 objval = new Funcall (domain, fname, vname, args);
1739 public object Objval {
1742 throw new Exception ("term is an integer: " + this);
1750 throw new Exception ("term is not integer: " + this);
1755 public string Strval {
1758 throw new Exception ("term is not string: " + this);
1759 return (string) objval;
1763 public string Symval {
1766 throw new Exception ("term is not symbol: " + this);
1767 return (Symbol) objval;
1771 public List<Term> Listval {
1774 throw new Exception ("term is not list: " + this);
1775 return (List<Term>) objval;
1779 public bool IsTrue {
1781 return (objval == null
1783 : objval is List<Term>
1784 ? (((List<Term>) objval).Count != 0)
1788 public bool IsInt { get { return (objval == null); } }
1789 public bool IsStr { get { return (objval is string); } }
1790 public bool IsSymbol { get { return (objval is Symbol); } }
1791 public bool IsList { get { return (objval is List<Term>); } }
1793 public bool IsType (Type type)
1795 return (objval == null ? type == typeof (int)
1796 : type == objval.GetType ());
1799 public Term Eval (Domain domain)
1801 if (objval == null || objval is Symbol || objval is string)
1803 if (objval is List<Term>)
1804 return new Term ((List<Term>) objval);
1805 return ((TermValue) objval).Eval (domain);
1808 public Term Clone ()
1810 if (objval == null || objval is Symbol || objval is string)
1812 if (objval is List<Term>)
1814 List<Term> list = new List<Term> ();
1815 list.InsertRange (0, ((List<Term>) objval));
1816 return new Term (list);
1818 return new Term (((TermValue) objval).Clone ());
1821 public override string ToString ()
1826 str = "<integer>" + intval + "</integer>";
1827 else if (objval is Symbol)
1828 str = "<symbol>" + objval + "</symbol>";
1829 else if (objval is string)
1830 str = "<string>" + objval + "</string>";
1831 else if (objval is List<Term>)
1834 foreach (Term e in (List<Term>) objval)
1838 else if (objval is Term)
1839 str = "<quote>" + objval + "</quote>";
1840 else if (objval is TermValue)
1841 str = ((TermValue) objval).ToString ();
1843 throw new Exception ("invalid Term object: " + objval);
1848 static private Term Zero = new Term (0);
1849 static private Term One = new Term (1);
1850 static private Term TermInt = new Term (Qinteger);
1851 static private Term TermStr = new Term (Qstring);
1852 static private Term TermSymbol = new Term (Qsymbol);
1853 static private Term TermList = new Term (Qlist);
1854 static private Term TermTerm = new Term ((Symbol) "term");
1856 internal static int parse_integer (string str)
1858 int len = str.Length;
1859 bool negative = false;
1862 return (len == 0 ? 0 : str[0] - '0');
1869 if ((c == '0' || c == '#') && str[1] == 'x')
1872 for (int idx = 2; idx < len; idx++)
1878 i = i * 16 + (c - '0');
1882 i = i * 16 + (c - 'A');
1886 i = i * 16 + (c - 'a');
1895 for (int idx = 1; idx < len; idx++)
1898 if (c < '0' || c > '9')
1900 i = i * 10 + (c - '0');
1902 return negative ? - i : i;
1905 private Term[] terms;
1907 public static Term[] ParseTerms (Domain domain, XmlNode node)
1910 for (XmlNode n = node; n != null; n = n.NextSibling)
1911 if (n.NodeType == XmlNodeType.Element)
1913 if (n.Name == Qdefun)
1914 domain.Defun (n, true);
1915 else if (n.Name == Qdefvar)
1920 Term[] terms = new Term[nterms];
1922 for (XmlNode n = node; n != null; n = n.NextSibling)
1923 if (n.NodeType == XmlNodeType.Element)
1925 if (n.Name == Qdefun)
1926 domain.Defun (n, false);
1927 else if (n.Name != Qdefvar)
1928 terms[i++]= new Term (domain, n);
1933 public static Term Eval (Domain domain, Term[] terms)
1935 Term result = new Term (0);
1936 foreach (Term term in terms)
1939 if (result.Objval is Funcall)
1940 while ((result = result.Eval (domain)).Objval is Funcall);
1946 public Xexpression (Domain domain, XmlNode node)
1948 terms = ParseTerms (domain, node);
1951 public Xexpression (Domain domain, string url)
1953 XmlDocument doc = new XmlDocument (Symbol.Table);
1956 using (XmlTextReader reader = new XmlTextReader (url, Symbol.Table))
1960 } while (reader.NodeType != XmlNodeType.None
1961 && (reader.NodeType != XmlNodeType.Element
1962 || reader.Name != Qexpr));
1963 if (reader.NodeType == XmlNodeType.None)
1964 throw new Exception ("Node <expr> not found");
1965 node = doc.ReadNode (reader);
1967 terms = ParseTerms (domain, node.FirstChild);
1970 public Term Eval (Domain domain)
1976 domain.Catch (CatchTag.Return);
1977 foreach (Term term in terms)
1979 result = term.Eval (domain);
1989 public override string ToString ()
1992 for (int i = 0; i < terms.Length; i++)