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 Nexpr = "expr";
86 private static Symbol Nfuncall = "funcall";
87 private static Symbol Nvarref = "varref";
88 private static Symbol Ninteger = "integer";
89 private static Symbol Nstring = "string";
90 private static Symbol Nsymbol = "symbol";
91 private static Symbol Nlist = "list";
93 private static Symbol Ndefun = "defun";
94 private static Symbol Nfname = "fname";
95 private static Symbol Nargs = "args";
96 private static Symbol Nargs_unevalled = "args-unevalled";
97 private static Symbol Nfixed = "fixed";
98 private static Symbol Noptional = "optional";
99 private static Symbol Nrest = "rest";
101 private static Symbol Ndefvar = "defvar";
102 private static Symbol Nvname = "vname";
103 private static Symbol Ndescription = "description";
104 private static Symbol Nrange = "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;
139 public override Term Call (Domain domain, Variable vari, Term[] args)
141 args = (Term[]) args.Clone ();
142 for (int i = 0; i < args.Length; i++)
144 args[i] = args[i].Eval (domain);
148 return builtin (domain, vari, args);
152 internal class SpecialForm : Function
154 public Builtin builtin;
156 public SpecialForm (Builtin builtin, Symbol name,
157 int min_arg, int max_arg)
158 : base (name, min_arg, max_arg)
160 this.builtin = builtin;
163 public override Term Call (Domain domain, Variable vari, Term[] args)
165 return builtin (domain, vari, args);
169 internal class Lambda : Function
171 internal bool args_evalled;
172 internal Variable[] args;
173 internal Term[] body;
175 public Lambda (Domain domain, XmlNode node)
180 name = node.Attributes[Nfname].Value;
182 node = node.FirstChild;
184 && (node.Name == Nargs || node.Name == Nargs_unevalled))
187 args_evalled = node.Name == Nargs;
188 for (n = node.FirstChild; n != null; n = n.NextSibling)
190 if (n.Name == Nfixed)
192 else if (n.Name == Noptional)
194 else if (n.Name == Nrest)
197 throw new Exception ("Invalid argument type: " + n);
200 max_arg = nfixed + noptional + nrest;
201 args = new Variable[max_arg];
203 for (int i = 0; i < max_arg; n = n.NextSibling)
204 args[i++] = domain.Defvar ((Symbol) n.Attributes[0].Value);
210 min_arg = max_arg = 0;
214 public Lambda (Domain domain, Symbol name, bool args_evalled, Symbol[] args)
221 this.args_evalled = args_evalled;
225 for (i = 0; i < args.Length; i++, nfixed++)
226 if (args[i] == Noptional || args[i] == Nrest)
230 if (args[i] == Noptional)
232 for (i++; i < args.Length; i++, noptional++)
233 if (args[i] == Nrest)
240 max_arg = nfixed + noptional + nrest;
241 this.args = new Variable[max_arg];
243 for (i = j = 0; j < this.args.Length; i++)
244 if (args[i] != Noptional || args[i] != Nrest)
245 this.args[j++] = domain.Defvar (args[i]);
249 min_arg = max_arg = 0;
253 public void SetBody (Domain domain, XmlNode node)
255 for (node = node.FirstChild; node != null; node = node.NextSibling)
256 if (node.Name != Ndescription
257 && node.Name != Nargs
258 && node.Name != Nargs_unevalled)
261 for (XmlNode n = node; n != null; n = n.NextSibling)
265 body = new Term[nterms];
266 for (nterms = 0; node != null; node = node.NextSibling, nterms++)
267 body[nterms] = new Term (node, domain);
271 public void SetBody (Term[] body)
276 public override Term Call (Domain domain, Variable vari, Term[] args)
278 Bindings current = domain.bindings;
285 Term[] newargs = new Term[args.Length];
286 for (i = 0; i < min_arg; i++)
287 newargs[i] = args[i].Eval (domain);
290 for (i = 0; i < min_arg; i++)
291 domain.Bind (this.args[i], args[i]);
296 domain.Catch (CatchTag.Return);
297 foreach (Term term in body)
299 result = term.Eval (domain);
309 domain.UnboundTo (current);
316 public class Variable : TermValue
318 public readonly Symbol name;
320 internal Term default_val;
324 public Variable (Symbol name, Term value)
331 public virtual bool ValueP (Term val) { return true; }
333 public override TermValue Clone ()
335 Variable v = new Variable (name, val);
337 v.default_val = default_val;
346 if (! ValueP (value))
347 throw new Exception ("Invalid value: " + value);
352 public Term DefaultValue
354 get { return default_val; }
356 if (! ValueP (value))
357 throw new Exception ("Invalid value: " + value);
362 public virtual object Range
364 get { return range; }
365 set { range = value; }
368 public override Term Eval (Domain domain) { return val; }
370 public override string ToString () { return name + "(" + val + ")"; }
372 public class Int : Variable
376 private static bool SubsetP (int[] r1, int[] r2)
380 for (int i = 0; i < r1.Length; i += 2)
383 for (j = 0; j < r2.Length; j += 2)
384 if (r2[j] <= r1[i] && r2[j + 1] >= r1[i + 1])
392 private static bool SubsetP (int val, int[] r)
396 for (int i = 0; i < r.Length; i += 2)
397 if (r[i] <= val && r[i + 1] >= val)
402 public Int (Symbol name, string description, int value, int[] range)
403 : base (name, new Term (value))
405 if (! SubsetP (value, range))
406 throw new Exception ("Invalid value: " + value);
412 public override bool ValueP (Term term)
416 return SubsetP (term.Intval, range);
419 public override object Range {
420 get { return range; }
422 int[] r = (int[]) value;
423 if (! SubsetP (r, range)
424 || ! SubsetP (val.Intval, r)
425 || ! SubsetP (default_val.Intval, r))
426 throw new Exception ("Invalid range");
432 public class Str : Variable
434 public string[] range;
436 private static bool SubsetP (string[] r1, string[] r2)
440 foreach (string s in r1)
441 if (! SubsetP (s, r2))
446 private static bool SubsetP (string str, string[] r)
450 foreach (string s in r)
456 public Str (Symbol name, string description, string value, string[] range)
457 : base (name, new Term (value))
459 if (! SubsetP (value, range))
460 throw new Exception ("Invalid value: " + value);
466 public override bool ValueP (Term term)
468 if (! (term.objval is string))
470 return SubsetP (term.Strval, range);
473 public override object Range {
474 get { return range; }
476 string[] r = (string[]) value;
477 if (! SubsetP (r, range)
478 || ! SubsetP (val.Strval, r)
479 || ! SubsetP (default_val.Strval, r))
480 throw new Exception ("Invalid range");
486 public class Sym : Variable
488 public Symbol[] range;
490 private static bool SubsetP (Symbol[] r1, Symbol[] r2)
494 foreach (Symbol n in r1)
495 if (! SubsetP (n, r2))
500 private static bool SubsetP (Symbol name, Symbol[] r)
504 foreach (Symbol n in r)
510 public Sym (Symbol name, string description, Symbol value, Symbol[] range)
511 : base (name, new Term (value))
513 if (! SubsetP (value, range))
514 throw new Exception ("Invalid value: " + value);
520 public override bool ValueP (Term term)
522 if (! (term.objval is Symbol))
524 return SubsetP (term.Symval, range);
527 public override object Range {
528 get { return range; }
530 Symbol[] r = (Symbol[]) value;
531 if (! SubsetP (r, range)
532 || ! SubsetP (val.Symval, r)
533 || ! SubsetP (default_val.Symval, r))
534 throw new Exception ("Invalid range");
541 internal class Bindings
543 private Variable vari;
544 private Term old_value;
545 private Bindings next;
547 private Bindings (Variable vari)
550 old_value = vari.val;
553 public static Bindings Bind (Bindings bindings, Variable vari, Term val)
555 Bindings b = new Bindings (vari);
562 internal Bindings UnboundTo (Bindings boundary)
564 for (Bindings b = this; b != boundary; b = b.next)
565 b.vari.val = b.old_value;
569 public override string ToString ()
571 string str = "(bindings";
572 for (Bindings b = this; b != null; b = b.next)
573 str += " " + vari.name + "=" + b.old_value;
579 internal class ThrowException : Exception
584 public ThrowException (Symbol tag, object value) : base ()
592 internal class CatchTag : IEquatable<CatchTag>
596 public CatchTag (Symbol name) { val = name.name; }
597 private CatchTag (int i) { val = i; }
599 public static CatchTag Return = new CatchTag (0);
600 public static CatchTag Break = new CatchTag (1);
602 public static bool operator== (CatchTag t1, CatchTag t2)
603 { return t1.val == t2.val; }
605 public static bool operator!= (CatchTag t1, CatchTag t2)
606 { return t1.val != t2.val; }
608 public bool Equals (CatchTag tag) { return this.val == tag.val; }
609 public override bool Equals (object val) { return this.val == val; }
611 public override int GetHashCode () { return val.GetHashCode (); }
616 public object context;
617 public int depth = 0;
619 internal Dictionary<Symbol, Function> functions
620 = new Dictionary<Symbol, Function> ();
621 internal Dictionary<Symbol, Variable> variables
622 = new Dictionary<Symbol, Variable> ();
623 internal Bindings bindings;
624 private Stack<CatchTag> catch_stack = new Stack<CatchTag> ();
625 private int catch_count = 0;
627 internal Domain () { }
629 public Domain (object context) : this (basic, context) { }
631 public Domain (Domain parent, object context)
633 functions = new Dictionary<Symbol, Function> (parent.functions);
634 variables = new Dictionary<Symbol, Variable> (parent.variables);
635 this.context = context;
638 internal void Bind (Variable vari, Term value)
640 bindings = Bindings.Bind (bindings, vari, value);
643 internal void UnboundTo (Bindings boundary)
645 if (bindings != null)
646 bindings = bindings.UnboundTo (boundary);
649 internal void Catch (CatchTag tag)
651 catch_stack.Push (tag);
655 internal void Uncatch ()
658 if (catch_count > catch_stack.Count)
663 get { return catch_count < catch_stack.Count; }
666 internal void ThrowReturn ()
668 foreach (CatchTag tag in catch_stack)
671 if (tag == CatchTag.Return)
676 internal void ThrowBreak ()
678 if (catch_stack.Peek () != CatchTag.Break)
679 throw new Exception ("No outer loop to break");
683 internal void ThrowTag (CatchTag tag)
685 foreach (CatchTag elt in catch_stack)
693 public void DefSubr (Builtin builtin, string str, bool setvar,
694 int min_arg, int max_arg, params string[] aliases)
697 Function func = new Function.Subroutine (builtin, name, setvar,
699 functions[name] = func;
700 foreach (string a in aliases)
701 functions[(Symbol) a] = func;
704 public void DefSpecial (Builtin builtin, string str,
705 int min_arg, int max_arg,
706 params string[] aliases)
709 Function func = new Function.SpecialForm (builtin, name,
711 functions[name] = func;
712 foreach (string a in aliases)
713 functions[(Symbol) a] = func;
716 public void DefAlias (string alias, string str)
718 functions[(Symbol) alias] = functions[(Symbol) str];
721 public void Defun (Symbol name, bool args_evalled,
722 Symbol[] args, Term[] body, bool prototype)
726 if (prototype || ! functions.TryGetValue (name, out func))
728 func = new Function.Lambda (this, name, args_evalled, args);
729 functions[name] = func;
732 ((Function.Lambda) func).SetBody (body);
735 public void Defun (XmlNode node, bool prototype)
737 Symbol name = node.Attributes[Nfname].Value;
740 if (prototype || ! functions.TryGetValue (name, out func))
742 func = new Function.Lambda (this, node);
743 functions[name] = func;
746 ((Function.Lambda) func).SetBody (this, node);
749 public void Defun (Function func)
751 functions[func.name] = func;
754 public Variable Defvar (XmlNode node)
756 Symbol name = node.Attributes[0].Value;
760 node = node.FirstChild;
761 if (node != null && node.Name == Ndescription)
763 desc = node.InnerText;
764 node = node.NextSibling;
771 if (node.Name == "value")
772 nn = node.FirstChild;
775 Symbol type = nn.Name;
776 XmlNodeList range_list = null;
778 string val = nn.InnerText;
780 node = node.NextSibling;
783 range_list = node.ChildNodes;
784 nranges = range_list.Count;
787 if (type == Ninteger)
789 int intval = parse_integer (val);
791 if (range_list != null)
793 range = new int[nranges * 2];
794 for (int i = 0; i < nranges; i++)
796 XmlNode n = range_list[i];
797 if (n.Name == Nrange)
800 = parse_integer (n.FirstChild.InnerText);
802 = parse_integer (n.LastChild.InnerText);
808 = parse_integer (n.FirstChild.InnerText);
813 if (variables.TryGetValue (name, out vari))
815 if (! (vari is Variable.Int))
816 throw new Exception ("Inalid value");
817 vari = (Variable) vari.Clone ();
818 Term v = new Term (intval);
820 vari.DefaultValue = v;
825 vari = new Variable.Int (name, desc, intval, range);
827 else if (type == Nstring)
829 string[] range = null;
830 if (range_list != null)
832 range = new string[nranges];
833 for (int i = 0; i < nranges; i++)
834 range[i] = range_list[i].FirstChild.InnerText;
837 if (variables.TryGetValue (name, out vari))
839 if (! (vari is Variable.Str))
840 throw new Exception ("Invalid value");
841 vari = (Variable) vari.Clone ();
842 Term v = new Term (val);
844 vari.DefaultValue = v;
849 vari = new Variable.Str (name, desc, val, range);
851 else if (type == Nsymbol)
853 Symbol[] range = null;
854 if (range_list != null)
856 range = new Symbol[nranges];
857 for (int i = 0; i < nranges; i++)
858 range[i] = range_list[i].FirstChild.InnerText;
861 if (variables.TryGetValue (name, out vari))
863 if (! (vari is Variable.Sym))
864 throw new Exception ("Invalid value");
865 vari = (Variable) vari.Clone ();
866 Term v = new Term (val);
868 vari.DefaultValue = v;
873 vari = new Variable.Sym (name, desc, val, range);
876 throw new Exception ("Unknown type: " + type);
880 if (variables.TryGetValue (name, out vari))
881 vari = (Variable) vari.Clone ();
883 vari = new Variable (name, Zero);
885 variables[name] = vari;
889 public Variable Defvar (Variable vari)
891 variables[vari.name] = vari;
895 internal Variable Defvar (Symbol name)
897 Variable vari = new Variable (name, Zero);
898 variables[name] = vari;
902 internal Function GetFunc (Symbol name)
906 if (! functions.TryGetValue (name, out func))
907 throw new Exception ("Unknown function: " + name);
911 public bool CopyFunc (Domain domain, Symbol name)
913 Function func = GetFunc (name);
915 domain.functions[name] = func;
919 public void CopyFunc (Domain domain)
921 foreach (KeyValuePair<Symbol, Function> kv in functions)
922 domain.functions[kv.Key] = kv.Value;
925 public Variable GetVar (Symbol name, bool create)
929 if (! variables.TryGetValue (name, out vari))
933 variables[name] = vari = new Variable (name, Zero);
938 public override string ToString ()
940 string str = "<(functions";
941 foreach (KeyValuePair<Symbol, Function> kv in functions)
943 str += ") (variabls";
944 foreach (KeyValuePair<Symbol, Variable> kv in variables)
947 if (bindings != null)
948 str += " " + bindings;
950 str += " (" + context + ")";
955 internal void DebugWrite (bool head, string fmt, params string[] arg)
957 if (debug_level > depth)
961 Console.WriteLine ();
962 for (int i = 0; i < depth; i++)
965 Console.Write (fmt, arg);
969 public object SaveValues ()
971 Dictionary<Variable,Term> values = new Dictionary<Variable,Term> ();
973 foreach (KeyValuePair<Symbol,Variable> kv in variables)
974 values[kv.Value] = kv.Value.val.Clone ();
978 public void RestoreValues (object values)
980 foreach (KeyValuePair<Variable,Term> kv
981 in (Dictionary<Variable,Term>) values)
982 kv.Key.val = kv.Value;
986 public delegate Term Builtin (Domain domain, Variable vari, Term[] args);
988 private static Domain basic = new Domain ();
990 static Xexpression ()
992 basic.DefSubr (Fset, "set", true, 1, 1, "=");
993 basic.DefSubr (Fnot, "not", false, 1, 1, "!");
994 basic.DefSubr (Fadd, "add", true, 1, -1, "+");
995 basic.DefSubr (Fmul, "mul", true, 1, -1, "*");
996 basic.DefSubr (Fsub, "sub", true, 1, -1, "-");
997 basic.DefSubr (Fdiv, "div", true, 1, -1, "/");
998 basic.DefSubr (Fmod, "mod", true, 1, 2, "%");
999 basic.DefSubr (Flogior, "logior", true, 1, -1, "|");
1000 basic.DefSubr (Flogand, "logand", true, 1, -1, "&");
1001 basic.DefSubr (Flsh, "lsh", true, 1, 2, "<<");
1002 basic.DefSubr (Frsh, "rsh", true, 1, 2, ">>");
1003 basic.DefSubr (Feq, "eq", false, 2, -1, "==");
1004 basic.DefSubr (Fnoteq, "noteq", false, 2, 2, "!=");
1005 basic.DefSubr (Flt, "lt", false, 2, -1, "<");
1006 basic.DefSubr (Fle, "le", false, 2, -1, "<=");
1007 basic.DefSubr (Fgt, "gt", false, 2, -1, ">");
1008 basic.DefSubr (Fge, "ge", false, 2, -1, ">=");
1009 basic.DefSubr (Fappend, "append", true, 0, -1);
1010 basic.DefSubr (Fconcat, "concat", true, 0, -1);
1011 basic.DefSubr (Fnth, "nth", false, 2, 2);
1012 basic.DefSubr (Fcopy, "copy", false, 1, 1);
1013 basic.DefSubr (Fins, "ins", true, 2, 2);
1014 basic.DefSubr (Fdel, "del", true, 2, 2);
1015 basic.DefSubr (Feval, "eval", false, 1, 1);
1016 basic.DefSubr (Fbreak, "break", false, 0, 1);
1017 basic.DefSubr (Freturn, "return", false, 0, 1);
1018 basic.DefSpecial (Fand, "and", 1, -1, "&&");
1019 basic.DefSpecial (For, "or", 1, -1, "||");
1020 basic.DefSpecial (Fprogn, "progn", 0, -1, "expr");
1021 basic.DefSpecial (Fif, "if", 2, 3);
1022 basic.DefSpecial (Fwhen, "when", 1, -1);
1023 basic.DefSpecial (Floop, "loop", 1, -1);
1024 basic.DefSpecial (Fwhile, "while", 1, -1);
1025 basic.DefSpecial (Fcond, "cond", 1, -1);
1026 basic.DefSpecial (Fforeach, "foreach", 2, -1);
1027 basic.DefSpecial (Fquote, "quote", 1, 1);
1028 basic.DefSpecial (Ftype, "type", 1, 1);
1029 basic.DefSpecial (Fcatch, "catch", 2, 2);
1030 basic.DefSpecial (Fthrow, "throw", 1, 2);
1033 private static Term Fset (Domain domain, Variable vari, Term[] args)
1035 vari.Value = args[0];
1039 private static Term Fnot (Domain domain, Variable vari, Term[] args)
1041 return args[0].IsTrue ? Zero : One;
1044 private static Term Fadd (Domain domain, Variable vari, Term[] args)
1046 int n = vari == null ? 0 : vari.val.Intval;
1048 foreach (Term arg in args)
1051 return new Term (n);
1052 vari.val.intval = n;
1056 private static Term Fmul (Domain domain, Variable vari, Term[] args)
1058 int n = vari == null ? 1 : vari.val.Intval;
1059 foreach (Term arg in args)
1062 return new Term (n);
1063 vari.val.intval = n;
1067 private static Term Fsub (Domain domain, Variable vari, Term[] args)
1078 n = vari.val.Intval;
1081 while (i < args.Length)
1082 n -= args[i++].Intval;
1084 return new Term (n);
1085 vari.val.intval = n;
1089 private static Term Fdiv (Domain domain, Variable vari, Term[] args)
1100 n = vari.val.Intval;
1103 while (i < args.Length)
1104 n /= args[i++].Intval;
1106 return new Term (n);
1107 vari.val.intval = n;
1111 private static Term Fmod (Domain domain, Variable vari, Term[] args)
1114 return new Term (args[0].Intval % args[1].Intval);
1115 vari.val.intval = vari.val.Intval % args[0].Intval;
1119 private static Term Flogior (Domain domain, Variable vari, Term[] args)
1121 int n = vari == null ? 0 : vari.val.Intval;
1122 foreach (Term arg in args)
1125 return new Term (n);
1126 vari.val.intval = n;
1130 private static Term Flogand (Domain domain, Variable vari, Term[] args)
1141 n = vari.val.Intval;
1144 while (i < args.Length)
1145 n &= args[i++].Intval;
1147 return new Term (n);
1148 vari.val.intval = n;
1152 private static Term Flsh (Domain domain, Variable vari, Term[] args)
1155 return new Term (args[0].Intval << args[1].Intval);
1156 vari.val.intval = vari.val.Intval << args[0].Intval;
1160 private static Term Frsh (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 Feq (Domain domain, Variable vari, Term[] args)
1172 if (o.objval == null)
1174 for (int i = 1; i < args.Length; i++)
1175 if (args[i].objval != null || args[i].intval != o.intval)
1180 for (int i = 1; i < args.Length; i++)
1181 if (o.objval.Equals (args[i].objval))
1187 private static Term Fnoteq (Domain domain, Variable vari, Term[] args)
1189 return Feq (domain, vari, args);
1192 private static Term Flt (Domain domain, Variable vari, Term[] args)
1194 int n = args[0].Intval;
1196 for (int i = 1; i < args.Length; i++)
1198 int n1 = args[i].Intval;
1206 private static Term Fle (Domain domain, Variable vari, Term[] args)
1208 int n = args[0].Intval;
1209 for (int i = 1; i < args.Length; i++)
1211 int n1 = args[i].Intval;
1219 private static Term Fgt (Domain domain, Variable vari, Term[] args)
1221 int n = args[0].Intval;
1222 for (int i = 1; i < args.Length; i++)
1224 int n1 = args[i].Intval;
1232 private static Term Fge (Domain domain, Variable vari, Term[] args)
1234 int n = args[0].Intval;
1235 for (int i = 1; i < args.Length; i++)
1237 int n1 = args[i].Intval;
1245 private static Term Fappend (Domain domain, Variable vari, Term[] args)
1250 list = new List<Term> ();
1252 list = vari.val.Listval;
1254 foreach (Term arg in args)
1257 list.AddRange ((List<Term>) arg.objval);
1265 result.objval = list;
1271 private static Term Fconcat (Domain domain, Variable vari, Term[] args)
1278 str = vari.val.Strval;
1280 foreach (Term arg in args)
1283 str += (string) arg.objval;
1284 else if (arg.IsList)
1285 foreach (Term term in (List<Term>) arg.objval)
1286 str += (char) term.Intval;
1288 str += (char) arg.Intval;
1294 result.objval = str;
1297 vari.val.objval = str;
1301 private static Term Fnth (Domain domain, Variable vari, Term[] args)
1307 result.intval = ((string) args[1].objval)[args[0].Intval];
1308 result.objval = null;
1310 else if (args[1].IsList)
1312 result = ((List<Term>) args[1].objval)[args[0].Intval];
1315 throw new Exception ("Term is not enumelable: " + args[1]);
1319 private static Term Fcopy (Domain domain, Variable vari, Term[] args)
1324 result.objval = new List<Term> (args[0].Listval);
1328 private static Term Fins (Domain domain, Variable vari, Term[] args)
1332 = vari.val.Strval.Insert (args[0].Intval, args[1].Strval);
1333 else if (vari.val.IsList)
1334 vari.val.Listval.InsertRange (args[0].Intval, args[1].Listval);
1336 throw new Exception ("term is not collection: " + vari.val);
1340 private static Term Fdel (Domain domain, Variable vari, Term[] args)
1344 = vari.val.Strval.Remove (args[0].Intval,
1345 args[1].Intval - args[0].Intval);
1347 else if (vari.val.IsList)
1348 vari.val.Listval.RemoveRange (args[0].Intval,
1349 args[1].Intval - args[0].Intval);
1351 throw new Exception ("term is not collection: " + vari.val);
1355 private static Term Fand (Domain domain, Variable vari, Term[] args)
1357 foreach (Term arg in args)
1358 if (! arg.Eval (domain).IsTrue)
1363 private static Term For (Domain domain, Variable vari, Term[] args)
1365 foreach (Term arg in args)
1366 if (arg.Eval (domain).IsTrue)
1371 private static Term Feval (Domain domain, Variable vari, Term[] args)
1373 return (args[0].Eval (domain));
1376 private static Term Fprogn (Domain domain, Variable vari, Term[] args)
1380 foreach (Term arg in args)
1381 result = arg.Eval (domain);
1385 private static Term Fif (Domain domain, Variable vari, Term[] args)
1387 if (args[0].Eval (domain).IsTrue)
1388 return args[1].Eval (domain);
1389 if (args.Length == 2)
1391 return args[2].Eval (domain);
1394 private static Term Fwhen (Domain domain, Variable vari, Term[] args)
1396 if (! args[0].Eval (domain).IsTrue)
1399 for (int i = 1; i < args.Length; i++)
1400 result = args[i].Eval (domain);
1404 private static Term Freturn (Domain domain, Variable vari, Term[] args)
1406 domain.ThrowReturn ();
1407 return args.Length == 0 ? Zero : args[0];
1410 private static Term Fbreak (Domain domain, Variable vari, Term[] args)
1412 domain.ThrowBreak ();
1413 return args.Length == 0 ? Zero : args[0];
1416 private static Term Floop (Domain domain, Variable vari, Term[] args)
1420 domain.Catch (CatchTag.Break);
1421 while (! domain.Thrown)
1422 foreach (Term arg in args)
1424 result = arg.Eval (domain);
1434 private static Term Fwhile (Domain domain, Variable vari, Term[] args)
1438 domain.Catch (CatchTag.Break);
1439 while (! domain.Thrown && args[0].Eval (domain).IsTrue)
1440 for (int i = 1; i < args.Length; i++)
1442 result = args[i].Eval (domain);
1452 private static Term Fcond (Domain domain, Variable vari, Term[] args)
1454 foreach (Term arg in args)
1456 List<Term> list = arg.Listval;
1457 Term result = list[0].Eval (domain);
1461 for (int i = 1; i < list.Count; i++)
1462 result = list[i].Eval (domain);
1469 private static Term Fforeach (Domain domain, Variable vari,
1472 Term result = args[0].Eval (domain);
1475 List<Term> list = result.Listval;
1476 Bindings current = domain.bindings;
1479 domain.Catch (CatchTag.Break);
1480 foreach (Term term in list)
1482 domain.Bind (vari, term);
1484 for (int i = 1; i < args.Length; i++)
1486 result = args[i].Eval (domain);
1491 domain.UnboundTo (current);
1500 private static Term Fquote (Domain domain, Variable vari, Term[] args)
1502 return new Term (args[0]);
1505 private static Term Ftype (Domain domain, Variable vari, Term[] args)
1511 if (args[0].IsSymbol)
1518 public static Term Fcatch (Domain domain, Variable vari, Term[] args)
1522 domain.Catch (new CatchTag (args[0].Symval));
1523 result = args[1].Eval (domain);
1530 public static Term Fthrow (Domain domain, Variable vari, Term[] args)
1532 domain.ThrowTag (new CatchTag (args[0].Symval));
1533 return (args.Length == 1 ? Zero : args[1]);
1536 public abstract class TermValue
1538 public virtual Term Eval (Domain domain) { return new Term (this); }
1539 public abstract TermValue Clone ();
1542 private class Funcall : TermValue
1544 internal Function func;
1545 internal Variable vari;
1546 internal Term[] args;
1548 private Funcall (Function func, Variable vari, Term[] args)
1555 public Funcall (XmlNode node, Domain domain)
1558 Symbol name = node.Name;
1560 if (name == Nfuncall)
1561 name = node.Attributes[0].Value;
1562 else if (node.Attributes[Nvname] != null)
1563 vari = domain.GetVar (node.Attributes[Nvname].Value, true);
1564 func = domain.GetFunc (name);
1565 XmlNodeList nlist = node.ChildNodes;
1566 int nargs = nlist.Count;
1568 if (nargs < func.min_arg
1569 || (func.max_arg >= 0 && nargs > func.max_arg))
1570 throw new Exception ("Invalid number of arguments to: "
1571 + name + " " + nargs);
1572 args = new Term[nargs];
1573 for (int i = 0; i < nlist.Count; i++)
1574 args[i] = new Term (nlist[i], domain);
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 vari = domain.GetVar (vname, true);
1590 public override Term Eval (Domain domain)
1592 domain.DebugWrite (true, "(({0}", func.name);
1593 for (int i = 0; i < args.Length; i++)
1594 domain.DebugWrite (false, " {0}", args[i].ToString ());
1595 domain.DebugWrite (false, ")");
1597 Term result = func.Call (domain, vari, args);
1599 domain.DebugWrite (true, " ==> {0})", result.ToString ());
1603 public override TermValue Clone ()
1605 return new Funcall (func, vari, args);
1608 public override string ToString ()
1610 string str = "<funcall fname=\"" + func.name;
1612 return str + "\"/>";
1614 foreach (Term e in args)
1616 return (str + "</funcall>");
1623 public object objval;
1625 public Term (int i) { intval = i; objval = null; }
1626 public Term (Symbol name) { intval = 0; objval = name; }
1627 public Term (string str) { intval = 0; objval = str; }
1628 public Term (List<Term> list) { intval = 0; objval = list; }
1629 public Term (Term term) { intval = term.intval; objval = term.objval; }
1630 public Term (TermValue obj) { intval = 0; objval = obj; }
1632 public Term (XmlNode node, Domain domain)
1634 Symbol name = node.Name;
1636 if (name == Ninteger)
1638 intval = parse_integer (node.InnerText);
1644 if (name == Nsymbol)
1645 objval = (Symbol) node.InnerText;
1646 else if (name == Nstring)
1647 objval = node.InnerText.Clone ();
1648 else if (name == Nvarref)
1649 objval = domain.GetVar ((Symbol) node.Attributes[0].Value, true);
1650 else if (name == Nlist)
1652 List<Term> list = new List<Term> ();
1653 for (node = node.FirstChild; node != null;
1654 node = node.NextSibling)
1655 list.Add (new Term (node, domain));
1659 objval = new Funcall (node, domain);
1663 public Term (Domain domain, Symbol fname, Term[] args)
1666 objval = new Funcall (domain, fname, args);
1669 public Term (Domain domain, Symbol fname, Symbol vname, Term[] args)
1672 objval = new Funcall (domain, fname, vname, args);
1675 public object Objval {
1678 throw new Exception ("term is an integer: " + this);
1686 throw new Exception ("term is not integer: " + this);
1691 public string Strval {
1694 throw new Exception ("term is not string: " + this);
1695 return (string) objval;
1699 public string Symval {
1702 throw new Exception ("term is not symbol: " + this);
1703 return (Symbol) objval;
1707 public List<Term> Listval {
1710 throw new Exception ("term is not list: " + this);
1711 return (List<Term>) objval;
1715 public bool IsTrue {
1717 return (objval == null
1719 : objval is List<Term>
1720 ? (((List<Term>) objval).Count != 0)
1724 public bool IsInt { get { return (objval == null); } }
1725 public bool IsStr { get { return (objval is string); } }
1726 public bool IsSymbol { get { return (objval is Symbol); } }
1727 public bool IsList { get { return (objval is List<Term>); } }
1729 public bool IsType (Type type)
1731 return (objval == null ? type == typeof (int)
1732 : type == objval.GetType ());
1735 public Term Eval (Domain domain)
1737 if (objval == null || objval is Symbol || objval is string)
1739 if (objval is List<Term>)
1740 return new Term ((List<Term>) objval);
1741 return ((TermValue) objval).Eval (domain);
1744 public Term Clone ()
1746 if (objval == null || objval is Symbol || objval is string)
1748 if (objval is List<Term>)
1750 List<Term> list = new List<Term> ();
1751 list.InsertRange (0, ((List<Term>) objval));
1752 return new Term (list);
1754 return new Term (((TermValue) objval).Clone ());
1757 public override string ToString ()
1762 str = "<integer>" + intval + "</integer>";
1763 else if (objval is Symbol)
1764 str = "<symbol>" + objval + "</symbol>";
1765 else if (objval is string)
1766 str = "<string>" + objval + "</string>";
1767 else if (objval is List<Term>)
1770 foreach (Term e in (List<Term>) objval)
1774 else if (objval is Funcall)
1775 str = "<funcall fname=\"" + ((Funcall) objval).func.name + "\"/>";
1776 else if (objval is Variable)
1777 str = "<variable vname=\"" + ((Variable) objval).name + "\"/>";
1778 else if (objval is Term)
1779 str = "<quote>" + objval + "</quote>";
1781 throw new Exception ("invalid Term object: " + objval);
1786 static private Term Zero = new Term (0);
1787 static private Term One = new Term (1);
1788 static private Term TermInt = new Term (Ninteger);
1789 static private Term TermStr = new Term (Nstring);
1790 static private Term TermSymbol = new Term (Nsymbol);
1791 static private Term TermList = new Term (Nlist);
1792 static private Term TermTerm = new Term ((Symbol) "term");
1794 internal static int parse_integer (string str)
1796 int len = str.Length;
1797 bool negative = false;
1800 return (len == 0 ? 0 : str[0] - '0');
1807 if ((c == '0' || c == '#') && str[1] == 'x')
1810 for (int idx = 2; idx < len; idx++)
1816 i = i * 16 + (c - '0');
1820 i = i * 16 + (c - 'A');
1824 i = i * 16 + (c - 'a');
1833 for (int idx = 1; idx < len; idx++)
1836 if (c < '0' || c > '9')
1838 i = i * 10 + (c - '0');
1840 return negative ? - i : i;
1843 private Term[] terms;
1845 private void parse_terms (Domain domain, XmlNode node)
1848 for (XmlNode n = node; n != null; n = n.NextSibling)
1849 if (n.NodeType == XmlNodeType.Element)
1851 if (n.Name == Ndefun)
1852 domain.Defun (n, true);
1853 else if (n.Name == Ndefvar)
1859 terms = new Term[nterms];
1861 for (XmlNode n = node; n != null; n = n.NextSibling)
1862 if (n.NodeType == XmlNodeType.Element)
1864 if (n.Name == Ndefun)
1865 domain.Defun (n, false);
1866 else if (n.Name != Ndefvar)
1867 terms[i++]= new Term (n, domain);
1871 public Xexpression (Domain domain, XmlNode node)
1873 parse_terms (domain, node);
1876 public Xexpression (Domain domain, string url)
1878 XmlDocument doc = new XmlDocument (Symbol.Table);
1881 using (XmlTextReader reader = new XmlTextReader (url, Symbol.Table))
1885 } while (reader.NodeType != XmlNodeType.None
1886 && (reader.NodeType != XmlNodeType.Element
1887 || reader.Name != Nexpr));
1888 if (reader.NodeType == XmlNodeType.None)
1889 throw new Exception ("Node <expr> not found");
1890 node = doc.ReadNode (reader);
1892 parse_terms (domain, node.FirstChild);
1895 public Term Eval (Domain domain)
1901 domain.Catch (CatchTag.Return);
1902 foreach (Term term in terms)
1904 result = term.Eval (domain);
1914 public override string ToString ()
1917 for (int i = 0; i < terms.Length; i++)