2 using System.Collections;
3 using System.Collections.Generic;
7 namespace System.Xml.Expression
9 public abstract class Xex
11 public struct Name : IEquatable<Name>
13 private static NameTable nt = new NameTable ();
17 public Name (string str)
22 public static implicit operator Name (string str)
24 return new Name (str);
27 public static implicit operator string (Name name)
32 public static bool operator== (Name n1, Name n2)
34 return (object) n1.name == (object) n2.name;
37 public static bool operator!= (Name n1, Name n2)
39 return (object) n1.name != (object) n2.name;
42 public static bool operator== (Name n1, string n2)
44 return (object) n1.name == (object) n2;
47 public static bool operator!= (Name n1, string n2)
49 return (object) n1.name != (object) n2;
52 public static bool operator== (string n1, Name n2)
54 return (object) n1 == (object) n2.name;
57 public static bool operator!= (string n1, Name n2)
59 return (object) n1 != (object) n2.name;
62 public bool Equals (Name name)
64 return Object.ReferenceEquals (this.name, name.name);
67 public override bool Equals (object obj)
69 return Object.ReferenceEquals (this.name, obj);
72 public override int GetHashCode ()
74 return name.GetHashCode ();
77 public static NameTable Table { get { return nt; } }
79 public override string ToString () { return name; }
82 private static Name Nexpr = "expr";
84 private static Name Nfuncall = "funcall";
85 private static Name Nvariable = "variable";
86 private static Name Ninteger = "integer";
87 private static Name Nstring = "string";
88 private static Name Nboolean = "boolean";
89 private static Name Nsymbol = "symbol";
90 private static Name Nlist = "list";
91 private static Name Nobject = "object";
93 private static Name Ndefun = "defun";
94 private static Name Nfname = "fname";
95 private static Name Nargs = "args";
96 private static Name Noptional = "optional";
97 private static Name Nrest = "rest";
98 private static Name Nbody = "body";
100 private static Name Ndefvar = "defvar";
101 private static Name Ndescription = "description";
102 private static Name Nrange = "range";
104 private static Name Nprogn = "progn";
106 internal abstract class Function
108 public readonly Name name;
109 public int min_arg, max_arg;
111 public Function (Name name, int min_arg, int max_arg)
114 this.min_arg = min_arg;
115 this.max_arg = max_arg;
118 public abstract object Call (Xex[] args, Domain domain);
120 public override string ToString ()
125 internal class Subroutine : Function
127 public Builtin builtin;
129 public Subroutine (Builtin builtin, Name name,
130 int min_arg, int max_arg)
131 : base (name, min_arg, max_arg)
133 this.builtin = builtin;
136 public override object Call (Xex[] args, Domain domain)
140 foreach (Xex a in args)
141 if (a.Eval (domain) == null)
142 throw new Exception (a + ":evaled to null");
143 Console.Write ("calling (" + this);
144 foreach (Xex a in args)
145 Console.Write (" " + a);
146 Console.Write (") => ");
147 result = builtin (args, domain);
148 Console.WriteLine (result);
153 internal class SpecialForm : Function
155 public Builtin builtin;
157 public SpecialForm (Builtin builtin, Name name,
158 int min_arg, int max_arg)
159 : base (name, min_arg, max_arg)
161 this.builtin = builtin;
164 public override object Call (Xex[] args, Domain domain)
168 Console.Write ("calling (" + this);
169 foreach (Xex a in args)
170 Console.Write (" " + a);
171 Console.Write (") => ");
172 result = builtin (args, domain);
173 Console.WriteLine (result);
178 internal class Lambda : Function
183 public Lambda (Name name, int min_arg, int max_arg)
184 : base (name, min_arg, max_arg)
188 public void SetArgs (XmlNode node, int nargs, Domain domain)
190 args = new Xex[nargs];
191 node = node.FirstChild;
192 for (int i = 0; i < nargs; node = node.NextSibling)
193 if (node.Name != Noptional && node.Name != Nrest)
194 args[i++] = New (node, domain);
197 public void SetBody (XmlNode node, Domain domain)
199 XmlNodeList nlist = node.ChildNodes;
201 body = new Xex[nlist.Count];
202 for (int i = 0; i < nlist.Count; i++)
203 body[i] = New (nlist[i], domain);
206 public void Setup (XmlNode node, Domain domain)
208 node = node.FirstChild;
209 if (node.Name == Nargs)
211 SetArgs (node, max_arg, domain);
212 node = node.NextSibling;
214 if (node.Name == Nbody)
215 SetBody (node, domain);
218 public override object Call (Xex[] args, Domain domain)
220 Bindings current = domain.bindings;
221 object result = false;
225 for (i = 0; i < min_arg; i++)
227 Xex a = this.args[i];
228 bool isdirect = a is Xex.Const;
229 Name name = (isdirect
230 ? (Name) a.val : ((Xex.Varref) a).vari.name);
231 Variable var = domain.GetVar (name);
234 domain.Bind (var, args[i].val);
236 domain.Bind (var, args[i].Eval (domain));
238 Console.Write ("calling (" + this);
239 foreach (Xex e in body)
240 result = e.Eval (domain);
241 Console.WriteLine (result);
243 domain.UnboundTo (current);
248 public override string ToString ()
250 string str = "(" + name;
251 foreach (Xex a in args)
258 internal abstract class Variable
260 public readonly Name name;
261 public readonly Name type;
264 public Variable (Name name, Name type, object value)
277 if (! ValueP (value))
278 throw new Exception ("Invalid value type: " + value);
283 public abstract bool ValueP (object value);
285 public override string ToString () { return name + "=" + val; }
288 internal class VarInt : Variable
295 public Range[] ranges;
297 public VarInt (Name name, object value) : base (name, Ninteger, value) { }
299 public override bool ValueP (object value)
303 if (! (value is int))
308 foreach (Range r in ranges)
309 if (i >= r.from && i <= r.to)
315 internal class VarStr : Variable
317 public string[] ranges;
319 public VarStr (Name name, object value) : base (name, Nstring, value) { }
321 public override bool ValueP (object value)
325 if (! (value is string))
329 str = (string) value;
330 foreach (string s in ranges)
337 internal class VarBool : Variable
339 public VarBool (Name name, object value)
340 : base (name, Nboolean, value) { }
342 public override bool ValueP (object value)
344 if (! (value is bool))
350 internal class VarMisc : Variable
352 public VarMisc (Name name, object value) : base (name, Nobject, value) { }
354 public override bool ValueP (object value)
360 internal class Bindings
362 private Variable vari;
363 private object old_value;
364 private Bindings next;
366 private Bindings (Variable vari, object value)
372 public static Bindings Bind (Bindings bindings,
373 Variable vari, object value)
375 Bindings b = new Bindings (vari, vari.val);
377 b.vari.Value = value;
382 internal Bindings UnboundTo (Bindings boundary)
384 for (Bindings b = this; b != boundary; b = b.next)
385 vari.val = b.old_value;
389 public override string ToString ()
391 string str = "(bindings";
392 for (Bindings b = this; b != null; b = b.next)
399 internal class ThrowException : Exception
404 public ThrowException (Name tag, object value) : base ()
414 public object context;
416 internal Dictionary<Name, Function> functions;
417 internal Dictionary<Name, Variable> variables;
418 internal Bindings bindings;
422 functions = new Dictionary<Name, Function> ();
423 variables = new Dictionary<Name, Variable> ();
426 public Domain (object context) : this (basic, context)
430 public Domain (Domain parent, object context)
432 functions = new Dictionary<Name, Function> (parent.functions);
433 variables = new Dictionary<Name, Variable> (parent.variables);
434 this.context = context;
437 internal void Bind (Variable vari, object value)
439 bindings = Bindings.Bind (bindings, vari, value);
440 Console.WriteLine ("binding " + vari);
443 internal void UnboundTo (Bindings boundary)
445 if (bindings != null)
446 bindings = bindings.UnboundTo (boundary);
449 public void DefSubr (Builtin builtin, string str,
450 int min_arg, int max_arg)
454 = new Function.Subroutine (builtin, name, min_arg, max_arg);
457 public void DefSpecial (Builtin builtin, string str,
458 int min_arg, int max_arg)
462 = new Function.SpecialForm (builtin, name, min_arg, max_arg);
465 private static Name ParseHead (XmlNode node,
466 out int min_arg, out int max_arg)
468 Name name = node.Attributes[Nfname].Value;
469 int nargs = 0, noptions = 0, nrest = 0;
472 for (n = node.FirstChild; n != null; n = n.NextSibling)
474 if (n.Name == Noptional || n.Name == Nrest)
478 if (n != null && n.Name == Noptional)
479 for (n = n.NextSibling; n != null; n = n.NextSibling)
485 if (n != null && n.Name == Nrest)
486 for (n = n.NextSibling; n != null; n = n.NextSibling)
489 max_arg = nargs + noptions + nrest;
495 internal Function.Lambda RegisterFunction (XmlNode node)
497 int min_arg, max_arg;
498 Name name = ParseHead (node, out min_arg, out max_arg);
499 Function.Lambda lambda = new Function.Lambda (name, min_arg, max_arg);
501 functions[name] = lambda;
505 internal Function Defun (XmlNode node)
507 Name name = node.Attributes[Nfname].Value;
508 Function.Lambda lambda;
510 if (! functions.TryGetValue (name, out lambda))
511 lambda = RegisterFunction (node);
512 lambda.Setup (node, this);
516 public void Defvar (Name name, XmlNode node)
520 if (node.Name == Ndescription)
521 node = node.NextSibling;
524 Name type = node.Name;
525 string val = node.Value;
526 XmlNodeList range_list = null;
529 node = node.NextSibling;
532 range_list = node.ChildNodes;
533 nranges = range_list.Count;
536 if (type == Ninteger)
538 VarInt vi = new VarInt (name, parse_integer (val));
539 if (range_list != null)
541 vi.ranges = new VarInt.Range[nranges];
543 for (int i = 0; i < nranges; i++)
545 XmlNode n = range_list[i];
547 if (n.Name == Nrange)
550 parse_integer (n.FirstChild.Value);
552 parse_integer (n.LastChild.Value);
556 int num = parse_integer (n.Value);
557 vi.ranges[i].from = vi.ranges[i].to = num;
563 else if (type == Nstring)
565 VarStr vs = new VarStr (name, val);
566 if (range_list != null)
567 vs.ranges = new string[nranges];
568 for (int i = 0; i < nranges; i++)
569 vs.ranges[i] = range_list[i].Value;
572 else if (type == Nboolean)
574 vari = new VarBool (name, val == "true");
577 throw new Exception ("Unknown type: " + type);
580 vari = new VarMisc (name, null);
581 variables[name] = vari;
584 internal Function GetFunc (Name name)
588 if (! functions.TryGetValue (name, out func))
589 throw new Exception ("Unknown function: " + name);
593 public bool CopyFunc (Domain domain, Name name)
595 Function func = GetFunc (name);
597 domain.functions[name] = func;
601 public void CopyFunc (Domain domain)
603 foreach (KeyValuePair<Name, Function> kv in functions)
604 domain.functions[kv.Key] = kv.Value;
607 internal Variable GetVar (Name name)
611 if (! variables.TryGetValue (name, out vari))
612 variables[name] = vari = new VarMisc (name, null);
616 internal Variable GetVar (Xex e)
618 if (! (e.val is Name))
619 throw new Exception ("Not a symbol" + e.val);
620 return GetVar ((Name) e.val);
623 public override string ToString ()
625 string str = "<(functions";
626 foreach (KeyValuePair<Name, Function> kv in functions)
628 str += ") (variabls";
629 foreach (KeyValuePair<Name, Variable> kv in variables)
632 if (bindings != null)
633 str += " " + bindings;
635 str += " (" + context + ")";
641 public delegate object Builtin (Xex[] args, Domain domain);
643 private static Domain basic = new Domain ();
645 internal static Function Fprogn;
649 basic.DefSubr (set_value, "set", 2, 2);
650 basic.DefSubr (set_value, "=", 2, 2);
651 basic.DefSubr (and, "and", 1, -1);
652 basic.DefSubr (and, "&&", 1, -1);
653 basic.DefSubr (or, "or", 1, -1);
654 basic.DefSubr (or, "||", 1, -1);
655 basic.DefSubr (not, "not", 1, 1);
656 basic.DefSubr (not, "!", 1, 1);
657 basic.DefSubr (add, "add", 2, -1);
658 basic.DefSubr (add, "+", 2, -1);
659 basic.DefSubr (mul, "mul", 2, -1);
660 basic.DefSubr (mul, "*", 2, -1);
661 basic.DefSubr (sub, "sub", 1, -1);
662 basic.DefSubr (sub, "-", 1, -1);
663 basic.DefSubr (div, "div", 2, -1);
664 basic.DefSubr (div, "/", 2, -1);
665 basic.DefSubr (mod, "mod", 2, 2);
666 basic.DefSubr (mod, "%", 2, 2);
667 basic.DefSubr (logior, "logior", 2, -1);
668 basic.DefSubr (logior, "|", 2, -1);
669 basic.DefSubr (logand, "logand", 2, -1);
670 basic.DefSubr (logand, "&", 2, -1);
671 basic.DefSubr (add_set, "add-set", 2, -1);
672 basic.DefSubr (add_set, "+=", 2, -1);
673 basic.DefSubr (mul_set, "mul-set", 2, -1);
674 basic.DefSubr (mul_set, "*=", 2, -1);
675 basic.DefSubr (sub_set, "sub-set", 2, -1);
676 basic.DefSubr (sub_set, "-=", 2, -1);
677 basic.DefSubr (div_set, "div-set", 2, -1);
678 basic.DefSubr (div_set, "/=", 2, -1);
679 basic.DefSubr (mod_set, "mod-set", 2, 2);
680 basic.DefSubr (mod_set, "%=", 2, 2);
681 basic.DefSubr (logior_set, "logior-set", 2, -1);
682 basic.DefSubr (logior_set, "|=", 2, -1);
683 basic.DefSubr (logand_set, "logand-set", 2, -1);
684 basic.DefSubr (logand_set, "&=", 2, -1);
685 basic.DefSubr (lsh, "lsh", 2, 2);
686 basic.DefSubr (lsh, "<<", 2, 2);
687 basic.DefSubr (rsh, "rsh", 2, 2);
688 basic.DefSubr (rsh, ">>", 2, 2);
689 basic.DefSubr (lsh_set, "lsh-set", 2, 2);
690 basic.DefSubr (lsh_set, "<<=", 2, 2);
691 basic.DefSubr (rsh_set, "rsh-set", 2, 2);
692 basic.DefSubr (rsh_set, ">>=", 2, 2);
693 basic.DefSubr (eq, "eq", 2, -1);
694 basic.DefSubr (eq, "==", 2, -1);
695 basic.DefSubr (noteq, "noteq", 2, 2);
696 basic.DefSubr (noteq, "!=", 2, 2);
697 basic.DefSubr (less_than, "lt", 2, -1);
698 basic.DefSubr (less_than, "<", 2, -1);
699 basic.DefSubr (less_eq, "le", 2, -1);
700 basic.DefSubr (less_eq, "<=", 2, -1);
701 basic.DefSubr (greater_than, "gt", 2, -1);
702 basic.DefSubr (greater_than, ">", 2, -1);
703 basic.DefSubr (greater_eq, "ge", 2, -1);
704 basic.DefSubr (greater_eq, ">=", 2, -1);
705 basic.DefSubr (eval_clause, "eval", 1, 1);
706 basic.DefSpecial (progn_clause, "progn", 0, -1);
707 basic.DefSpecial (progn_clause, "expr", 0, -1);
708 basic.DefSpecial (if_clause, "if", 2, -1);
709 basic.DefSpecial (when_clause, "when", 1, -1);
710 basic.DefSpecial (while_clause, "while", 1, -1);
712 Fprogn = basic.GetFunc (Nprogn);
715 private static bool is_true (object val)
717 return (val is bool ? (bool) val
718 : val is int ? (int) val == 0
722 private static object set_value (Xex[] args, Domain domain)
724 Variable vari = domain.GetVar (args[0]);
726 vari.Value = args[1].val;
730 private static object and (Xex[] args, Domain domain)
732 foreach (Xex arg in args)
733 if (! is_true (arg.val))
738 private static object or (Xex[] args, Domain domain)
740 foreach (Xex arg in args)
741 if (is_true (arg.val))
746 private static object not (Xex[] args, Domain domain)
748 return ! is_true (args[0].val);
751 private static object add (Xex[] args, Domain domain)
754 foreach (Xex e in args)
759 private static object mul (Xex[] args, Domain domain)
762 foreach (Xex e in args)
767 private static object sub (Xex[] args, Domain domain)
769 int n = (int) args[0].val;
770 if (args.Length == 1)
772 for (int i = 1; i < args.Length; i++)
773 n -= (int) args[i].val;
777 private static object div (Xex[] args, Domain domain)
779 int n = (int) args[0].val;
780 for (int i = 1; i < args.Length; i++)
781 n /= (int) args[i].val;
785 private static object mod (Xex[] args, Domain domain)
787 return ((int) args[0].val % (int) args[1].val);
790 private static object logior (Xex[] args, Domain domain)
793 foreach (Xex e in args)
798 private static object logand (Xex[] args, Domain domain)
800 int n = (int) args[0].val;
801 for (int i = 1; i < args.Length; i++)
802 n &= (int) args[i].val;
806 private static object add_set (Xex[] args, Domain domain)
808 Variable vari = domain.GetVar (args[0]);
809 int n = (int) vari.val;
811 for (int i = 1; i < args.Length; i++)
812 n += (int) args[i].val;
817 private static object mul_set (Xex[] args, Domain domain)
819 Variable vari = domain.GetVar (args[0]);
820 int n = (int) vari.val;
822 for (int i = 1; i < args.Length; i++)
823 n *= (int) args[i].val;
828 private static object sub_set (Xex[] args, Domain domain)
830 Variable vari = domain.GetVar (args[0]);
831 int n = (int) vari.val;
833 for (int i = 1; i < args.Length; i++)
834 n -= (int) args[i].val;
839 private static object div_set (Xex[] args, Domain domain)
841 Variable vari = domain.GetVar (args[0]);
842 int n = (int) vari.val;
844 for (int i = 1; i < args.Length; i++)
845 n /= (int) args[i].val;
850 private static object mod_set (Xex[] args, Domain domain)
852 Variable vari = domain.GetVar (args[0]);
853 int n = (int) vari.val;
855 for (int i = 1; i < args.Length; i++)
856 n %= (int) args[i].val;
861 private static object logior_set (Xex[] args, Domain domain)
863 Variable vari = domain.GetVar (args[0]);
864 int n = (int) vari.val;
866 for (int i = 1; i < args.Length; i++)
867 n |= (int) args[i].val;
872 private static object logand_set (Xex[] args, Domain domain)
874 Variable vari = domain.GetVar (args[0]);
875 int n = (int) vari.val;
877 for (int i = 1; i < args.Length; i++)
878 n &= (int) args[i].val;
883 private static object lsh (Xex[] args, Domain domain)
885 return (int) args[0].val << (int) args[1].val;
888 private static object lsh_set (Xex[] args, Domain domain)
890 Variable vari = domain.GetVar (args[0]);
891 int n = (int) vari.val;
893 n <<= (int) args[1].val;
898 private static object rsh (Xex[] args, Domain domain)
900 return (int) args[0].val >> (int) args[1].val;
903 private static object rsh_set (Xex[] args, Domain domain)
905 Variable vari = domain.GetVar (args[0]);
906 int n = (int) vari.val;
908 n >>= (int) args[1].val;
913 private static object eq (Xex[] args, Domain domain)
915 int n = (int) args[0].val;
917 for (int i = 1; i < args.Length; i++)
918 if (n != (int) args[i].val)
923 private static object noteq (Xex[] args, Domain domain)
925 return ((int) args[0].val != (int) args[1].val);
928 private static object less_than (Xex[] args, Domain domain)
930 int n = (int) args[0].val;
932 for (int i = 1; i < args.Length; i++)
934 int n1 = (int) args[i].val;
942 private static object less_eq (Xex[] args, Domain domain)
944 int n = (int) args[0].val;
945 for (int i = 1; i < args.Length; i++)
947 int n1 = (int) args[i].val;
955 private static object greater_than (Xex[] args, Domain domain)
957 int n = (int) args[0].val;
958 for (int i = 1; i < args.Length; i++)
960 int n1 = (int) args[i].val;
968 private static object greater_eq (Xex[] args, Domain domain)
970 int n = (int) args[0].val;
971 for (int i = 1; i < args.Length; i++)
973 int n1 = (int) args[i].val;
981 private static object eval_clause (Xex[] args, Domain domain)
983 return args[0].Eval (domain);
986 private static object progn_clause (Xex[] args, Domain domain)
988 object result = true;
990 foreach (Xex e in args)
991 result = e.Eval (domain);
995 private static object if_clause (Xex[] args, Domain domain)
999 if (is_true (args[0].Eval (domain)))
1000 result = args[1].Eval (domain);
1004 for (int i = 2; i < args.Length; i++)
1005 result = args[i].Eval (domain);
1010 private static object when_clause (Xex[] args, Domain domain)
1012 if (! is_true (args[0].Eval (domain)))
1015 object result = true;
1016 for (int i = 1; i < args.Length; i++)
1017 result = args[i].Eval (domain);
1021 private static object while_clause (Xex[] args, Domain domain)
1023 while (is_true (args[0].Eval (domain)))
1024 for (int i = 1; i < args.Length; i++)
1025 args[i].Eval (domain);
1029 // FUNCALL: function != null
1030 // VARREF: function == null, args[0] = DIRECT-SYMBOL
1031 // DIRECT: function == null, args == null
1034 public abstract object Eval (Domain domain);
1035 public object Val { get { return val; } }
1037 private class Funcall : Xex
1039 internal Function func;
1040 internal Xex[] args;
1042 public Funcall (Function func, Xex[] args)
1048 public override object Eval (Domain domain)
1050 val = func.Call (args, domain);
1054 public override string ToString ()
1056 string str = "(" + func.name;
1058 foreach (Xex e in args)
1059 str += " " + e.ToString ();
1064 private class Varref : Xex
1066 internal Variable vari;
1068 public Varref (Variable vari)
1073 public override object Eval (Domain domain)
1079 public override string ToString ()
1081 return "$" + vari.name + "/" + vari.val;
1085 private class Const : Xex
1087 public Const (object val)
1092 public override object Eval (Domain domain)
1097 public override string ToString ()
1099 return val.ToString ();
1103 internal static int parse_integer (string str)
1105 int len = str.Length;
1106 bool negative = false;
1109 return (len == 0 ? 0 : str[0] - '0');
1114 if (c == '0' && str[1] == 'x')
1117 for (int idx = 2; idx < len; idx++)
1123 i = i * 16 + (c - '0');
1127 i = i * 16 + (c - 'A');
1131 i = i * 16 + (c - 'a');
1140 for (int idx = 1; idx < len; idx++)
1143 if (c < '0' || c > '9')
1145 i = i * 10 + (c - '0');
1147 return negative ? - i : i;
1150 private static int pre_parse (XmlNodeList nlist, Domain domain)
1153 foreach (XmlNode node in nlist)
1155 if (node.Name == Ndefun)
1156 domain.RegisterFunction (node);
1157 else if (node.Name == Ndefvar)
1158 domain.Defvar ((Name) node.Attributes[0].Value, node.FirstChild);
1165 private static void post_parse (XmlNodeList nlist, Xex[] args,
1168 for (int i = 0, j = 0; i < nlist.Count; i++)
1170 XmlNode node = nlist[i];
1172 if (node.Name == Ndefun)
1173 domain.Defun (node);
1174 else if (node.Name != Ndefvar)
1175 args[j++] = New (node, domain);
1179 public static Xex New (string url, Domain domain)
1181 XmlDocument doc = new XmlDocument (Name.Table);
1184 using (XmlTextReader reader = new XmlTextReader (url, Name.Table))
1188 } while (reader.NodeType != XmlNodeType.None
1189 && (reader.NodeType != XmlNodeType.Element
1190 || Nexpr != reader.Name));
1191 if (reader.NodeType == XmlNodeType.None)
1192 throw new Exception ("Node <expr> not found");
1193 node = doc.ReadNode (reader);
1196 return New (node, domain);
1199 // EXPR = SYMBOL | MTEXT | INTEGER | FUNCALL | PROGN
1200 // FUNCALL = '(' SYMBOL EXPR* ')'
1201 // PROGN = '(' EXPR * ')'
1202 public static Xex New (XmlNode node, Domain domain)
1204 Name name = node.Name;
1206 if (name == Nvariable)
1208 Variable vari = domain.GetVar ((Name) node.Attributes[0].Value);
1209 xex = new Xex.Varref (vari);
1211 else if (name == Ninteger)
1212 xex = new Xex.Const (parse_integer (node.InnerText));
1213 else if (name == Nstring)
1214 xex = new Xex.Const (node.InnerText);
1215 else if (name == Nsymbol)
1216 xex = new Xex.Const ((Name) node.InnerText);
1217 else if (name == Nboolean)
1218 xex = new Xex.Const (node.InnerText == "true");
1219 else if (name == Nlist)
1221 List<Xex> list = new List<Xex> ();
1222 for (XmlNode n = node.FirstChild; n != null; n = n.NextSibling)
1223 list.Add (New (n, domain));
1224 xex = new Xex.Const (list);
1228 if (name == Nfuncall)
1229 name = node.Attributes[0].Value;
1230 Function func = domain.GetFunc (name);
1232 XmlNodeList nlist = node.ChildNodes;
1233 int nargs = nlist.Count;
1235 if (nargs < func.min_arg
1236 || (func.max_arg >= 0 && nargs > func.max_arg))
1237 throw new Exception ("Invalid number of arguments to: "
1238 + name + " " + nargs);
1239 nargs = pre_parse (nlist, domain);
1240 Xex[] args = new Xex[nargs];
1241 post_parse (nlist, args, domain);
1242 xex = new Xex.Funcall (func, args);