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 Nnull = "";
87 private static Symbol Nfuncall = "funcall";
88 private static Symbol Nvarref = "varref";
89 private static Symbol Ninteger = "integer";
90 private static Symbol Nstring = "string";
91 private static Symbol Nsymbol = "symbol";
92 private static Symbol Nlist = "list";
94 private static Symbol Ndefun = "defun";
95 private static Symbol Nfname = "fname";
96 private static Symbol Nargs = "args";
97 private static Symbol Nargs_unevalled = "args-unevalled";
98 private static Symbol Nfixed = "fixed";
99 private static Symbol Noptional = "optional";
100 private static Symbol Nrest = "rest";
102 private static Symbol Ndefvar = "defvar";
103 private static Symbol Nvname = "vname";
104 private static Symbol Ndescription = "description";
105 private static Symbol Nrange = "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;
140 public override Term Call (Domain domain, Variable vari, Term[] args)
142 args = (Term[]) args.Clone ();
143 for (int i = 0; i < args.Length; i++)
145 args[i] = args[i].Eval (domain);
149 return builtin (domain, vari, args);
153 internal class SpecialForm : Function
155 public Builtin builtin;
157 public SpecialForm (Builtin builtin, Symbol name,
158 int min_arg, int max_arg)
159 : base (name, min_arg, max_arg)
161 this.builtin = builtin;
164 public override Term Call (Domain domain, Variable vari, Term[] args)
166 return builtin (domain, vari, args);
170 internal class Lambda : Function
172 internal bool args_evalled;
173 internal Variable[] args;
174 internal Term[] body;
176 public Lambda (Domain domain, XmlNode node)
181 name = node.Attributes[Nfname].Value;
183 node = node.FirstChild;
185 && (node.Name == Nargs || node.Name == Nargs_unevalled))
188 args_evalled = node.Name == Nargs;
189 for (n = node.FirstChild; n != null; n = n.NextSibling)
191 if (n.Name == Nfixed)
193 else if (n.Name == Noptional)
195 else if (n.Name == Nrest)
198 throw new Exception ("Invalid argument type: " + n);
201 max_arg = nfixed + noptional + nrest;
202 args = new Variable[max_arg];
204 for (int i = 0; i < max_arg; n = n.NextSibling)
205 args[i++] = domain.Defvar ((Symbol) n.Attributes[0].Value);
211 min_arg = max_arg = 0;
215 public Lambda (Domain domain, Symbol name, bool args_evalled, Symbol[] args)
222 this.args_evalled = args_evalled;
226 for (i = 0; i < args.Length; i++, nfixed++)
227 if (args[i] == Noptional || args[i] == Nrest)
231 if (args[i] == Noptional)
233 for (i++; i < args.Length; i++, noptional++)
234 if (args[i] == Nrest)
241 max_arg = nfixed + noptional + nrest;
242 this.args = new Variable[max_arg];
244 for (i = j = 0; j < this.args.Length; i++)
245 if (args[i] != Noptional || args[i] != Nrest)
246 this.args[j++] = domain.Defvar (args[i]);
250 min_arg = max_arg = 0;
254 public void SetBody (Domain domain, XmlNode node)
256 for (node = node.FirstChild; node != null; node = node.NextSibling)
257 if (node.Name != Ndescription
258 && node.Name != Nargs
259 && node.Name != Nargs_unevalled)
262 for (XmlNode n = node; n != null; n = n.NextSibling)
266 body = new Term[nterms];
267 for (nterms = 0; node != null; node = node.NextSibling, nterms++)
268 body[nterms] = new Term (domain, node);
272 public void SetBody (Term[] body)
277 public override Term Call (Domain domain, Variable vari, Term[] args)
279 Bindings current = domain.bindings;
286 Term[] newargs = new Term[args.Length];
287 for (i = 0; i < min_arg; i++)
288 newargs[i] = args[i].Eval (domain);
291 for (i = 0; i < min_arg; i++)
292 domain.Bind (this.args[i], args[i]);
297 domain.Catch (CatchTag.Return);
298 foreach (Term term in body)
300 result = term.Eval (domain);
310 domain.UnboundTo (current);
317 public class Variable : TermValue
319 public readonly Symbol name;
321 internal Term default_val;
325 public Variable (Symbol name, Term value)
332 public virtual bool ValueP (Term val) { return true; }
334 public override TermValue Clone ()
336 Variable v = new Variable (name, val);
338 v.default_val = default_val;
347 if (! ValueP (value))
348 throw new Exception ("Invalid value: " + value);
353 public Term DefaultValue
355 get { return default_val; }
357 if (! ValueP (value))
358 throw new Exception ("Invalid value: " + value);
363 public virtual object Range
365 get { return range; }
366 set { range = value; }
369 public override Term Eval (Domain domain) { return val; }
371 public override string ToString () { return name + "(" + val + ")"; }
373 public class Int : Variable
377 private static bool SubsetP (int[] r1, int[] r2)
381 for (int i = 0; i < r1.Length; i += 2)
384 for (j = 0; j < r2.Length; j += 2)
385 if (r2[j] <= r1[i] && r2[j + 1] >= r1[i + 1])
393 private static bool SubsetP (int val, int[] r)
397 for (int i = 0; i < r.Length; i += 2)
398 if (r[i] <= val && r[i + 1] >= val)
403 public Int (Symbol name, string description, int value, int[] range)
404 : base (name, new Term (value))
406 if (! SubsetP (value, range))
407 throw new Exception ("Invalid value: " + value);
413 public override bool ValueP (Term term)
417 return SubsetP (term.Intval, range);
420 public override object Range {
421 get { return range; }
423 int[] r = (int[]) value;
424 if (! SubsetP (r, range)
425 || ! SubsetP (val.Intval, r)
426 || ! SubsetP (default_val.Intval, r))
427 throw new Exception ("Invalid range");
433 public class Str : Variable
435 public string[] range;
437 private static bool SubsetP (string[] r1, string[] r2)
441 foreach (string s in r1)
442 if (! SubsetP (s, r2))
447 private static bool SubsetP (string str, string[] r)
451 foreach (string s in r)
457 public Str (Symbol name, string description, string value, string[] range)
458 : base (name, new Term (value))
460 if (! SubsetP (value, range))
461 throw new Exception ("Invalid value: " + value);
467 public override bool ValueP (Term term)
469 if (! (term.objval is string))
471 return SubsetP (term.Strval, range);
474 public override object Range {
475 get { return range; }
477 string[] r = (string[]) value;
478 if (! SubsetP (r, range)
479 || ! SubsetP (val.Strval, r)
480 || ! SubsetP (default_val.Strval, r))
481 throw new Exception ("Invalid range");
487 public class Sym : Variable
489 public Symbol[] range;
491 private static bool SubsetP (Symbol[] r1, Symbol[] r2)
495 foreach (Symbol n in r1)
496 if (! SubsetP (n, r2))
501 private static bool SubsetP (Symbol name, Symbol[] r)
505 foreach (Symbol n in r)
511 public Sym (Symbol name, string description, Symbol value, Symbol[] range)
512 : base (name, new Term (value))
514 if (! SubsetP (value, range))
515 throw new Exception ("Invalid value: " + value);
521 public override bool ValueP (Term term)
523 if (! (term.objval is Symbol))
525 return SubsetP (term.Symval, range);
528 public override object Range {
529 get { return range; }
531 Symbol[] r = (Symbol[]) value;
532 if (! SubsetP (r, range)
533 || ! SubsetP (val.Symval, r)
534 || ! SubsetP (default_val.Symval, r))
535 throw new Exception ("Invalid range");
542 internal class Bindings
544 private Variable vari;
545 private Term old_value;
546 private Bindings next;
548 private Bindings (Variable vari)
551 old_value = vari.val;
554 public static Bindings Bind (Bindings bindings, Variable vari, Term val)
556 Bindings b = new Bindings (vari);
563 internal Bindings UnboundTo (Bindings boundary)
565 for (Bindings b = this; b != boundary; b = b.next)
566 b.vari.val = b.old_value;
570 public override string ToString ()
572 string str = "(bindings";
573 for (Bindings b = this; b != null; b = b.next)
574 str += " " + vari.name + "=" + b.old_value;
580 internal class ThrowException : Exception
585 public ThrowException (Symbol tag, object value) : base ()
593 internal class CatchTag : IEquatable<CatchTag>
597 public CatchTag (Symbol name) { val = name.name; }
598 private CatchTag (int i) { val = i; }
600 public static CatchTag Return = new CatchTag (0);
601 public static CatchTag Break = new CatchTag (1);
603 public static bool operator== (CatchTag t1, CatchTag t2)
604 { return t1.val == t2.val; }
606 public static bool operator!= (CatchTag t1, CatchTag t2)
607 { return t1.val != t2.val; }
609 public bool Equals (CatchTag tag) { return this.val == tag.val; }
610 public override bool Equals (object val) { return this.val == val; }
612 public override int GetHashCode () { return val.GetHashCode (); }
617 public object context;
618 public int depth = 0;
620 internal Dictionary<Symbol, TermType> termtypes
621 = new Dictionary<Symbol, TermType> ();
622 internal Dictionary<Symbol, Function> functions
623 = new Dictionary<Symbol, Function> ();
624 internal Dictionary<Symbol, Variable> variables
625 = new Dictionary<Symbol, Variable> ();
626 internal Bindings bindings;
627 private Stack<CatchTag> catch_stack = new Stack<CatchTag> ();
628 private int catch_count = 0;
630 internal Domain () { }
632 public Domain (object context) : this (basic, context) { }
634 public Domain (Domain parent, object context)
636 functions = new Dictionary<Symbol, Function> (parent.functions);
637 variables = new Dictionary<Symbol, Variable> (parent.variables);
638 this.context = context;
641 internal void Bind (Variable vari, Term value)
643 bindings = Bindings.Bind (bindings, vari, value);
646 internal void UnboundTo (Bindings boundary)
648 if (bindings != null)
649 bindings = bindings.UnboundTo (boundary);
652 internal void Catch (CatchTag tag)
654 catch_stack.Push (tag);
658 internal void Uncatch ()
661 if (catch_count > catch_stack.Count)
666 get { return catch_count < catch_stack.Count; }
669 internal void ThrowReturn ()
671 foreach (CatchTag tag in catch_stack)
674 if (tag == CatchTag.Return)
679 internal void ThrowBreak ()
681 if (catch_stack.Peek () != CatchTag.Break)
682 throw new Exception ("No outer loop to break");
686 internal void ThrowTag (CatchTag tag)
688 foreach (CatchTag elt in catch_stack)
696 public void DefType (Symbol name, NewObject new_object)
698 termtypes[name] = new TermType (name, new_object);
701 public void DefSubr (Builtin builtin, string str, bool setvar,
702 int min_arg, int max_arg, params string[] aliases)
705 Function func = new Function.Subroutine (builtin, name, setvar,
707 functions[name] = func;
708 foreach (string a in aliases)
709 functions[(Symbol) a] = func;
712 public void DefSpecial (Builtin builtin, string str,
713 int min_arg, int max_arg,
714 params string[] aliases)
717 Function func = new Function.SpecialForm (builtin, name,
719 functions[name] = func;
720 foreach (string a in aliases)
721 functions[(Symbol) a] = func;
724 public void DefAlias (string alias, string str)
726 functions[(Symbol) alias] = functions[(Symbol) str];
729 public void Defun (Symbol name, bool args_evalled,
730 Symbol[] args, Term[] body, bool prototype)
734 if (prototype || ! functions.TryGetValue (name, out func))
736 func = new Function.Lambda (this, name, args_evalled, args);
737 functions[name] = func;
740 ((Function.Lambda) func).SetBody (body);
743 public void Defun (XmlNode node, bool prototype)
745 Symbol name = node.Attributes[Nfname].Value;
748 if (prototype || ! functions.TryGetValue (name, out func))
750 func = new Function.Lambda (this, node);
751 functions[name] = func;
754 ((Function.Lambda) func).SetBody (this, node);
757 public void Defun (Function func)
759 functions[func.name] = func;
762 public Variable Defvar (XmlNode node)
764 Symbol name = node.Attributes[0].Value;
768 node = node.FirstChild;
769 if (node != null && node.Name == Ndescription)
771 desc = node.InnerText;
772 node = node.NextSibling;
778 Symbol type = node.Name;
779 XmlNodeList range_list = null;
781 string val = node.InnerText;
783 node = node.NextSibling;
786 range_list = node.ChildNodes;
787 nranges = range_list.Count;
790 if (type == Ninteger)
792 int intval = parse_integer (val);
794 if (range_list != null)
796 range = new int[nranges * 2];
797 for (int i = 0; i < nranges; i++)
799 XmlNode n = range_list[i];
800 if (n.Name == Nrange)
803 = parse_integer (n.FirstChild.InnerText);
805 = parse_integer (n.LastChild.InnerText);
811 = parse_integer (n.FirstChild.InnerText);
816 if (variables.TryGetValue (name, out vari))
818 if (! (vari is Variable.Int))
819 throw new Exception ("Inalid value");
820 vari = (Variable) vari.Clone ();
821 Term v = new Term (intval);
823 vari.DefaultValue = v;
828 vari = new Variable.Int (name, desc, intval, range);
830 else if (type == Nstring)
832 string[] range = null;
833 if (range_list != null)
835 range = new string[nranges];
836 for (int i = 0; i < nranges; i++)
837 range[i] = range_list[i].FirstChild.InnerText;
840 if (variables.TryGetValue (name, out vari))
842 if (! (vari is Variable.Str))
843 throw new Exception ("Invalid value");
844 vari = (Variable) vari.Clone ();
845 Term v = new Term (val);
847 vari.DefaultValue = v;
852 vari = new Variable.Str (name, desc, val, range);
854 else if (type == Nsymbol)
856 Symbol[] range = null;
857 if (range_list != null)
859 range = new Symbol[nranges];
860 for (int i = 0; i < nranges; i++)
861 range[i] = range_list[i].FirstChild.InnerText;
864 if (variables.TryGetValue (name, out vari))
866 if (! (vari is Variable.Sym))
867 throw new Exception ("Invalid value");
868 vari = (Variable) vari.Clone ();
869 Term v = new Term (val);
871 vari.DefaultValue = v;
876 vari = new Variable.Sym (name, desc, val, range);
879 throw new Exception ("Unknown type: " + type);
883 if (variables.TryGetValue (name, out vari))
884 vari = (Variable) vari.Clone ();
886 vari = new Variable (name, Zero);
888 variables[name] = vari;
892 public Variable Defvar (Variable vari)
894 variables[vari.name] = vari;
898 internal Variable Defvar (Symbol name)
900 Variable vari = new Variable (name, Zero);
901 variables[name] = vari;
905 internal Function GetFunc (Symbol name)
909 if (! functions.TryGetValue (name, out func))
910 throw new Exception ("Unknown function: " + name);
914 public bool CopyFunc (Domain domain, Symbol name)
916 Function func = GetFunc (name);
918 domain.functions[name] = func;
922 public void CopyFunc (Domain domain)
924 foreach (KeyValuePair<Symbol, Function> kv in functions)
925 domain.functions[kv.Key] = kv.Value;
928 public Variable GetVar (Symbol name, bool create)
932 if (! variables.TryGetValue (name, out vari))
936 variables[name] = vari = new Variable (name, Zero);
941 public override string ToString ()
943 string str = "<(functions";
944 foreach (KeyValuePair<Symbol, Function> kv in functions)
946 str += ") (variabls";
947 foreach (KeyValuePair<Symbol, Variable> kv in variables)
950 if (bindings != null)
951 str += " " + bindings;
953 str += " (" + context + ")";
958 internal void DebugWrite (bool head, string fmt, params string[] arg)
960 if (debug_level > depth)
964 Console.WriteLine ();
965 for (int i = 0; i < depth; i++)
968 Console.Write (fmt, arg);
972 public object SaveValues ()
974 Dictionary<Variable,Term> values = new Dictionary<Variable,Term> ();
976 foreach (KeyValuePair<Symbol,Variable> kv in variables)
977 values[kv.Value] = kv.Value.val.Clone ();
981 public void RestoreValues (object values)
983 foreach (KeyValuePair<Variable,Term> kv
984 in (Dictionary<Variable,Term>) values)
985 kv.Key.val = kv.Value;
989 public delegate Term Builtin (Domain domain, Variable vari, Term[] args);
991 private static Domain basic = new Domain ();
993 static Xexpression ()
995 basic.DefType ("funcall", Funcall.New);
997 basic.DefSubr (Fset, "set", true, 1, 1, "=");
998 basic.DefSubr (Fnot, "not", false, 1, 1, "!");
999 basic.DefSubr (Fadd, "add", true, 1, -1, "+");
1000 basic.DefSubr (Fmul, "mul", true, 1, -1, "*");
1001 basic.DefSubr (Fsub, "sub", true, 1, -1, "-");
1002 basic.DefSubr (Fdiv, "div", true, 1, -1, "/");
1003 basic.DefSubr (Fmod, "mod", true, 1, 2, "%");
1004 basic.DefSubr (Flogior, "logior", true, 1, -1, "|");
1005 basic.DefSubr (Flogand, "logand", true, 1, -1, "&");
1006 basic.DefSubr (Flsh, "lsh", true, 1, 2, "<<");
1007 basic.DefSubr (Frsh, "rsh", true, 1, 2, ">>");
1008 basic.DefSubr (Feq, "eq", false, 2, -1, "==");
1009 basic.DefSubr (Fnoteq, "noteq", false, 2, 2, "!=");
1010 basic.DefSubr (Flt, "lt", false, 2, -1, "<");
1011 basic.DefSubr (Fle, "le", false, 2, -1, "<=");
1012 basic.DefSubr (Fgt, "gt", false, 2, -1, ">");
1013 basic.DefSubr (Fge, "ge", false, 2, -1, ">=");
1014 basic.DefSubr (Fappend, "append", true, 0, -1);
1015 basic.DefSubr (Fconcat, "concat", true, 0, -1);
1016 basic.DefSubr (Fnth, "nth", false, 2, 2);
1017 basic.DefSubr (Fcopy, "copy", false, 1, 1);
1018 basic.DefSubr (Fins, "ins", true, 2, 2);
1019 basic.DefSubr (Fdel, "del", true, 2, 2);
1020 basic.DefSubr (Feval, "eval", false, 1, 1);
1021 basic.DefSubr (Fbreak, "break", false, 0, 1);
1022 basic.DefSubr (Freturn, "return", false, 0, 1);
1024 basic.DefSpecial (Fand, "and", 1, -1, "&&");
1025 basic.DefSpecial (For, "or", 1, -1, "||");
1026 basic.DefSpecial (Fprogn, "progn", 0, -1, "expr");
1027 basic.DefSpecial (Fif, "if", 2, 3);
1028 basic.DefSpecial (Fwhen, "when", 1, -1);
1029 basic.DefSpecial (Floop, "loop", 1, -1);
1030 basic.DefSpecial (Fwhile, "while", 1, -1);
1031 basic.DefSpecial (Fcond, "cond", 1, -1);
1032 basic.DefSpecial (Fforeach, "foreach", 2, -1);
1033 basic.DefSpecial (Fquote, "quote", 1, 1);
1034 basic.DefSpecial (Ftype, "type", 1, 1);
1035 basic.DefSpecial (Fcatch, "catch", 2, 2);
1036 basic.DefSpecial (Fthrow, "throw", 1, 2);
1039 private static Term Fset (Domain domain, Variable vari, Term[] args)
1041 vari.Value = args[0];
1045 private static Term Fnot (Domain domain, Variable vari, Term[] args)
1047 return args[0].IsTrue ? Zero : One;
1050 private static Term Fadd (Domain domain, Variable vari, Term[] args)
1052 int n = vari == null ? 0 : vari.val.Intval;
1054 foreach (Term arg in args)
1057 return new Term (n);
1058 vari.val.intval = n;
1062 private static Term Fmul (Domain domain, Variable vari, Term[] args)
1064 int n = vari == null ? 1 : vari.val.Intval;
1065 foreach (Term arg in args)
1068 return new Term (n);
1069 vari.val.intval = n;
1073 private static Term Fsub (Domain domain, Variable vari, Term[] args)
1084 n = vari.val.Intval;
1087 while (i < args.Length)
1088 n -= args[i++].Intval;
1090 return new Term (n);
1091 vari.val.intval = n;
1095 private static Term Fdiv (Domain domain, Variable vari, Term[] args)
1106 n = vari.val.Intval;
1109 while (i < args.Length)
1110 n /= args[i++].Intval;
1112 return new Term (n);
1113 vari.val.intval = n;
1117 private static Term Fmod (Domain domain, Variable vari, Term[] args)
1120 return new Term (args[0].Intval % args[1].Intval);
1121 vari.val.intval = vari.val.Intval % args[0].Intval;
1125 private static Term Flogior (Domain domain, Variable vari, Term[] args)
1127 int n = vari == null ? 0 : vari.val.Intval;
1128 foreach (Term arg in args)
1131 return new Term (n);
1132 vari.val.intval = n;
1136 private static Term Flogand (Domain domain, Variable vari, Term[] args)
1147 n = vari.val.Intval;
1150 while (i < args.Length)
1151 n &= args[i++].Intval;
1153 return new Term (n);
1154 vari.val.intval = n;
1158 private static Term Flsh (Domain domain, Variable vari, Term[] args)
1161 return new Term (args[0].Intval << args[1].Intval);
1162 vari.val.intval = vari.val.Intval << args[0].Intval;
1166 private static Term Frsh (Domain domain, Variable vari, Term[] args)
1169 return new Term (args[0].Intval >> args[1].Intval);
1170 vari.val.intval = vari.val.Intval >> args[0].Intval;
1174 private static Term Feq (Domain domain, Variable vari, Term[] args)
1178 if (o.objval == null)
1180 for (int i = 1; i < args.Length; i++)
1181 if (args[i].objval != null || args[i].intval != o.intval)
1186 for (int i = 1; i < args.Length; i++)
1187 if (o.objval.Equals (args[i].objval))
1193 private static Term Fnoteq (Domain domain, Variable vari, Term[] args)
1195 return Feq (domain, vari, args);
1198 private static Term Flt (Domain domain, Variable vari, Term[] args)
1200 int n = args[0].Intval;
1202 for (int i = 1; i < args.Length; i++)
1204 int n1 = args[i].Intval;
1212 private static Term Fle (Domain domain, Variable vari, Term[] args)
1214 int n = args[0].Intval;
1215 for (int i = 1; i < args.Length; i++)
1217 int n1 = args[i].Intval;
1225 private static Term Fgt (Domain domain, Variable vari, Term[] args)
1227 int n = args[0].Intval;
1228 for (int i = 1; i < args.Length; i++)
1230 int n1 = args[i].Intval;
1238 private static Term Fge (Domain domain, Variable vari, Term[] args)
1240 int n = args[0].Intval;
1241 for (int i = 1; i < args.Length; i++)
1243 int n1 = args[i].Intval;
1251 private static Term Fappend (Domain domain, Variable vari, Term[] args)
1256 list = new List<Term> ();
1258 list = vari.val.Listval;
1260 foreach (Term arg in args)
1263 list.AddRange ((List<Term>) arg.objval);
1271 result.objval = list;
1277 private static Term Fconcat (Domain domain, Variable vari, Term[] args)
1284 str = vari.val.Strval;
1286 foreach (Term arg in args)
1289 str += (string) arg.objval;
1290 else if (arg.IsList)
1291 foreach (Term term in (List<Term>) arg.objval)
1292 str += (char) term.Intval;
1294 str += (char) arg.Intval;
1300 result.objval = str;
1303 vari.val.objval = str;
1307 private static Term Fnth (Domain domain, Variable vari, Term[] args)
1313 result.intval = ((string) args[1].objval)[args[0].Intval];
1314 result.objval = null;
1316 else if (args[1].IsList)
1318 result = ((List<Term>) args[1].objval)[args[0].Intval];
1321 throw new Exception ("Term is not enumelable: " + args[1]);
1325 private static Term Fcopy (Domain domain, Variable vari, Term[] args)
1330 result.objval = new List<Term> (args[0].Listval);
1334 private static Term Fins (Domain domain, Variable vari, Term[] args)
1338 = vari.val.Strval.Insert (args[0].Intval, args[1].Strval);
1339 else if (vari.val.IsList)
1340 vari.val.Listval.InsertRange (args[0].Intval, args[1].Listval);
1342 throw new Exception ("term is not collection: " + vari.val);
1346 private static Term Fdel (Domain domain, Variable vari, Term[] args)
1350 = vari.val.Strval.Remove (args[0].Intval,
1351 args[1].Intval - args[0].Intval);
1353 else if (vari.val.IsList)
1354 vari.val.Listval.RemoveRange (args[0].Intval,
1355 args[1].Intval - args[0].Intval);
1357 throw new Exception ("term is not collection: " + vari.val);
1361 private static Term Fand (Domain domain, Variable vari, Term[] args)
1363 foreach (Term arg in args)
1364 if (! arg.Eval (domain).IsTrue)
1369 private static Term For (Domain domain, Variable vari, Term[] args)
1371 foreach (Term arg in args)
1372 if (arg.Eval (domain).IsTrue)
1377 private static Term Feval (Domain domain, Variable vari, Term[] args)
1379 return (args[0].Eval (domain));
1382 private static Term Fprogn (Domain domain, Variable vari, Term[] args)
1386 foreach (Term arg in args)
1387 result = arg.Eval (domain);
1391 private static Term Fif (Domain domain, Variable vari, Term[] args)
1393 if (args[0].Eval (domain).IsTrue)
1394 return args[1].Eval (domain);
1395 if (args.Length == 2)
1397 return args[2].Eval (domain);
1400 private static Term Fwhen (Domain domain, Variable vari, Term[] args)
1402 if (! args[0].Eval (domain).IsTrue)
1405 for (int i = 1; i < args.Length; i++)
1406 result = args[i].Eval (domain);
1410 private static Term Freturn (Domain domain, Variable vari, Term[] args)
1412 domain.ThrowReturn ();
1413 return args.Length == 0 ? Zero : args[0];
1416 private static Term Fbreak (Domain domain, Variable vari, Term[] args)
1418 domain.ThrowBreak ();
1419 return args.Length == 0 ? Zero : args[0];
1422 private static Term Floop (Domain domain, Variable vari, Term[] args)
1426 domain.Catch (CatchTag.Break);
1427 while (! domain.Thrown)
1428 foreach (Term arg in args)
1430 result = arg.Eval (domain);
1440 private static Term Fwhile (Domain domain, Variable vari, Term[] args)
1444 domain.Catch (CatchTag.Break);
1445 while (! domain.Thrown && args[0].Eval (domain).IsTrue)
1446 for (int i = 1; i < args.Length; i++)
1448 result = args[i].Eval (domain);
1458 private static Term Fcond (Domain domain, Variable vari, Term[] args)
1460 foreach (Term arg in args)
1462 List<Term> list = arg.Listval;
1463 Term result = list[0].Eval (domain);
1467 for (int i = 1; i < list.Count; i++)
1468 result = list[i].Eval (domain);
1475 private static Term Fforeach (Domain domain, Variable vari,
1478 Term result = args[0].Eval (domain);
1481 List<Term> list = result.Listval;
1482 Bindings current = domain.bindings;
1485 domain.Catch (CatchTag.Break);
1486 foreach (Term term in list)
1488 domain.Bind (vari, term);
1490 for (int i = 1; i < args.Length; i++)
1492 result = args[i].Eval (domain);
1497 domain.UnboundTo (current);
1506 private static Term Fquote (Domain domain, Variable vari, Term[] args)
1508 return new Term (args[0]);
1511 private static Term Ftype (Domain domain, Variable vari, Term[] args)
1517 if (args[0].IsSymbol)
1524 public static Term Fcatch (Domain domain, Variable vari, Term[] args)
1528 domain.Catch (new CatchTag (args[0].Symval));
1529 result = args[1].Eval (domain);
1536 public static Term Fthrow (Domain domain, Variable vari, Term[] args)
1538 domain.ThrowTag (new CatchTag (args[0].Symval));
1539 return (args.Length == 1 ? Zero : args[1]);
1542 public delegate TermValue NewObject (Domain domain, XmlNode node);
1544 public class TermType
1546 public readonly Symbol type;
1547 internal readonly NewObject New;
1549 public TermType (Symbol type, NewObject new_object)
1556 public abstract class TermValue
1558 public virtual Term Eval (Domain domain) { return new Term (this); }
1559 public abstract TermValue Clone ();
1562 private class Funcall : TermValue
1564 internal Function func;
1565 internal Variable vari;
1566 internal Term[] args;
1568 private Funcall (Function func, Variable vari, Term[] args)
1575 public Funcall (Domain domain, Symbol fname, Term[] args)
1577 func = domain.GetFunc (fname);
1581 public Funcall (Domain domain, Symbol fname, Symbol vname, Term[] args)
1583 func = domain.GetFunc (fname);
1584 int nargs = args.Length;
1585 if (nargs < func.min_arg
1586 || (func.max_arg >= 0 && nargs > func.max_arg))
1587 throw new Exception ("Invalid number of arguments to: "
1588 + fname + " " + nargs);
1591 vari = domain.GetVar (vname, true);
1594 internal static TermValue New (Domain domain, XmlNode node)
1596 Symbol fname = node.Name;
1597 Symbol vname = Nnull;
1600 if (fname == Nfuncall)
1601 fname = node.Attributes[Nfname].Value;
1602 attr = node.Attributes[Nvname];
1606 XmlNodeList nlist = node.ChildNodes;
1607 int nargs = nlist.Count;
1608 Term[] args = new Term[nargs];
1609 for (int i = 0; i < nargs; i++)
1610 args[i] = new Term (domain, nlist[i]);
1611 return new Funcall (domain, fname, vname, args);
1614 public override Term Eval (Domain domain)
1616 domain.DebugWrite (true, "(({0}", func.name);
1617 for (int i = 0; i < args.Length; i++)
1618 domain.DebugWrite (false, " {0}", args[i].ToString ());
1619 domain.DebugWrite (false, ")");
1621 Term result = func.Call (domain, vari, args);
1623 domain.DebugWrite (true, " ==> {0})", result.ToString ());
1627 public override TermValue Clone ()
1629 return new Funcall (func, vari, args);
1632 public override string ToString ()
1634 string str = "<funcall fname=\"" + func.name;
1636 return str + "\"/>";
1638 foreach (Term e in args)
1640 return (str + "</funcall>");
1647 public object objval;
1649 public Term (int i) { intval = i; objval = null; }
1650 public Term (Symbol name) { intval = 0; objval = name; }
1651 public Term (string str) { intval = 0; objval = str; }
1652 public Term (List<Term> list) { intval = 0; objval = list; }
1653 public Term (Term term) { intval = term.intval; objval = term.objval; }
1654 public Term (TermValue obj) { intval = 0; objval = obj; }
1656 public Term (Domain domain, XmlNode node)
1658 Symbol name = node.Name;
1660 if (name == Ninteger)
1662 intval = parse_integer (node.InnerText);
1668 if (name == Nsymbol)
1669 objval = (Symbol) node.InnerText;
1670 else if (name == Nstring)
1671 objval = node.InnerText.Clone ();
1672 else if (name == Nvarref)
1673 objval = domain.GetVar ((Symbol) node.Attributes[0].Value, true);
1674 else if (name == Nlist)
1676 List<Term> list = new List<Term> ();
1677 for (node = node.FirstChild; node != null;
1678 node = node.NextSibling)
1679 list.Add (new Term (domain, node));
1686 if (domain.termtypes.TryGetValue (name, out term_type))
1687 objval = term_type.New (domain, node);
1689 objval = Funcall.New (domain, node);
1694 public Term (Domain domain, Symbol fname, Term[] args)
1697 objval = new Funcall (domain, fname, args);
1700 public Term (Domain domain, Symbol fname, Symbol vname, Term[] args)
1703 objval = new Funcall (domain, fname, vname, args);
1706 public object Objval {
1709 throw new Exception ("term is an integer: " + this);
1717 throw new Exception ("term is not integer: " + this);
1722 public string Strval {
1725 throw new Exception ("term is not string: " + this);
1726 return (string) objval;
1730 public string Symval {
1733 throw new Exception ("term is not symbol: " + this);
1734 return (Symbol) objval;
1738 public List<Term> Listval {
1741 throw new Exception ("term is not list: " + this);
1742 return (List<Term>) objval;
1746 public bool IsTrue {
1748 return (objval == null
1750 : objval is List<Term>
1751 ? (((List<Term>) objval).Count != 0)
1755 public bool IsInt { get { return (objval == null); } }
1756 public bool IsStr { get { return (objval is string); } }
1757 public bool IsSymbol { get { return (objval is Symbol); } }
1758 public bool IsList { get { return (objval is List<Term>); } }
1760 public bool IsType (Type type)
1762 return (objval == null ? type == typeof (int)
1763 : type == objval.GetType ());
1766 public Term Eval (Domain domain)
1768 if (objval == null || objval is Symbol || objval is string)
1770 if (objval is List<Term>)
1771 return new Term ((List<Term>) objval);
1772 return ((TermValue) objval).Eval (domain);
1775 public Term Clone ()
1777 if (objval == null || objval is Symbol || objval is string)
1779 if (objval is List<Term>)
1781 List<Term> list = new List<Term> ();
1782 list.InsertRange (0, ((List<Term>) objval));
1783 return new Term (list);
1785 return new Term (((TermValue) objval).Clone ());
1788 public override string ToString ()
1793 str = "<integer>" + intval + "</integer>";
1794 else if (objval is Symbol)
1795 str = "<symbol>" + objval + "</symbol>";
1796 else if (objval is string)
1797 str = "<string>" + objval + "</string>";
1798 else if (objval is List<Term>)
1801 foreach (Term e in (List<Term>) objval)
1805 else if (objval is Funcall)
1806 str = "<funcall fname=\"" + ((Funcall) objval).func.name + "\"/>";
1807 else if (objval is Variable)
1808 str = "<variable vname=\"" + ((Variable) objval).name + "\"/>";
1809 else if (objval is Term)
1810 str = "<quote>" + objval + "</quote>";
1812 throw new Exception ("invalid Term object: " + objval);
1817 static private Term Zero = new Term (0);
1818 static private Term One = new Term (1);
1819 static private Term TermInt = new Term (Ninteger);
1820 static private Term TermStr = new Term (Nstring);
1821 static private Term TermSymbol = new Term (Nsymbol);
1822 static private Term TermList = new Term (Nlist);
1823 static private Term TermTerm = new Term ((Symbol) "term");
1825 internal static int parse_integer (string str)
1827 int len = str.Length;
1828 bool negative = false;
1831 return (len == 0 ? 0 : str[0] - '0');
1838 if ((c == '0' || c == '#') && str[1] == 'x')
1841 for (int idx = 2; idx < len; idx++)
1847 i = i * 16 + (c - '0');
1851 i = i * 16 + (c - 'A');
1855 i = i * 16 + (c - 'a');
1864 for (int idx = 1; idx < len; idx++)
1867 if (c < '0' || c > '9')
1869 i = i * 10 + (c - '0');
1871 return negative ? - i : i;
1874 private Term[] terms;
1876 private void parse_terms (Domain domain, XmlNode node)
1879 for (XmlNode n = node; n != null; n = n.NextSibling)
1880 if (n.NodeType == XmlNodeType.Element)
1882 if (n.Name == Ndefun)
1883 domain.Defun (n, true);
1884 else if (n.Name == Ndefvar)
1890 terms = new Term[nterms];
1892 for (XmlNode n = node; n != null; n = n.NextSibling)
1893 if (n.NodeType == XmlNodeType.Element)
1895 if (n.Name == Ndefun)
1896 domain.Defun (n, false);
1897 else if (n.Name != Ndefvar)
1898 terms[i++]= new Term (domain, n);
1902 public Xexpression (Domain domain, XmlNode node)
1904 parse_terms (domain, node);
1907 public Xexpression (Domain domain, string url)
1909 XmlDocument doc = new XmlDocument (Symbol.Table);
1912 using (XmlTextReader reader = new XmlTextReader (url, Symbol.Table))
1916 } while (reader.NodeType != XmlNodeType.None
1917 && (reader.NodeType != XmlNodeType.Element
1918 || reader.Name != Nexpr));
1919 if (reader.NodeType == XmlNodeType.None)
1920 throw new Exception ("Node <expr> not found");
1921 node = doc.ReadNode (reader);
1923 parse_terms (domain, node.FirstChild);
1926 public Term Eval (Domain domain)
1932 domain.Catch (CatchTag.Return);
1933 foreach (Term term in terms)
1935 result = term.Eval (domain);
1945 public override string ToString ()
1948 for (int i = 0; i < terms.Length; i++)