using System; using System.Collections; using System.Collections.Generic; using System.IO; using System.Reflection; using System.Text; using System.Text.RegularExpressions; using System.Xml; namespace System.Xml { /// /// Static class to provide XmlExpression loader and evaluator. /// public static class Xexpression { /// /// Exception thrown while loading and evaluating XmlExpression. /// public class Error : Exception { private readonly Symbol name; private Term[] stack; private XmlNode node; public Error (Symbol name, XmlNode node, string fmt, params object[] args) : base (String.Format (fmt, args)) { this.name = name; this.node = node; } public Error (Symbol name, XmlNode node, Exception e, string fmt, params object[] args) : base (String.Format (fmt, args), e) { this.name = name; this.node = node; } public Error (Symbol name, string fmt, params object[] args) : base (String.Format (fmt, args)) { this.name = name; } public Symbol Name { get { return name; } } public XmlNode Node { get { return node; } internal set { node = value; } } public Term[] Stack { get { return stack; } internal set { stack = value; } } public override string ToString () { string str = (InnerException != null ? InnerException.ToString () : base.ToString ()) + "\n" + "Xexpression:" + name + "\n"; if (node != null) str += " at " + node.OuterXml + "\n"; if (stack != null) { str += "Call stack: "; foreach (Term term in stack) str += term.ToString (false); } return str; } // All time errors. // System.OutOfMemoryException or System.InsufficientMemoryException public static Symbol MemoryError = "memory-error"; // System.Exception public static Symbol UnknownError = "unknown-error"; public static Symbol WrongArgument = "wrong-argument"; // Load time errors. public static Symbol InvalidInteger = "invalid-integer"; public static Symbol TermTypeInvalid = "term-type-invalid"; public static Symbol FunctionConflict = "function-conflict"; public static Symbol VariableTypeConflict = "variable-type-conflict"; public static Symbol VariableRangeConflict = "variable-range-conflict"; public static Symbol VariableWrongRange = "variable-wrong-range"; public static Symbol VariableWrongValue = "variable-wrong-value"; public static Symbol UnknownFunction = "unknown-function"; public static Symbol MacroExpansionError = "macro-expansion-error"; public static Symbol NoVariableName = "no-variable-anme"; // Run time errors. public static Symbol ArithmeticError = "arithmetic-error"; public static Symbol WrongType = "wrong-type"; public static Symbol IndexOutOfRange = "index-out-of-range"; public static Symbol ValueOutOfRange = "value-out-of-range"; public static Symbol NoLoopToBreak = "no-loop-to-break"; public static Symbol UncaughtThrow = "uncaught-throw"; } public struct Symbol : IEquatable { private static NameTable nt = new NameTable (); private string name; public Symbol (string str) { name = nt.Add (str); } public static implicit operator Symbol (string str) { return new Symbol (str); } public static implicit operator string (Symbol sym) { return sym.name; } public static bool operator== (Symbol n1, Symbol n2) { return (object) n1.name == (object) n2.name; } public static bool operator!= (Symbol n1, Symbol n2) { return (object) n1.name != (object) n2.name; } public static bool operator== (Symbol n1, string n2) { return (object) n1.name == (object) n2; } public static bool operator!= (Symbol n1, string n2) { return (object) n1.name != (object) n2; } public static bool operator== (string n1, Symbol n2) { return (object) n1 == (object) n2.name; } public static bool operator!= (string n1, Symbol n2) { return (object) n1 != (object) n2.name; } public bool Equals (Symbol name) { return Object.ReferenceEquals (this.name, name.name); } public override bool Equals (object obj) { return (obj is Symbol ? this == (Symbol) obj : obj is string ? this.name == (string) obj : false); } public override int GetHashCode () { return name.GetHashCode (); } public static NameTable NameTable { get { return nt; } } public override string ToString () { return name; } } private static Symbol Qexpr = "expr"; private static Symbol Qnull = ""; private static Symbol Qfuncall = "funcall"; private static Symbol Qinteger = "integer"; private static Symbol Qstring = "string"; private static Symbol Qsymbol = "symbol"; private static Symbol Qlist = "list"; public static Symbol Qdefun = "defun"; public static Symbol Qdefmacro = "defmacro"; private static Symbol Qfname = "fname"; private static Symbol Qargs = "args"; private static Symbol Qfixed = "fixed"; private static Symbol Qoptional = "optional"; private static Symbol Qrest = "rest"; public static Symbol Qdefvar = "defvar"; private static Symbol Qvname = "vname"; private static Symbol Qdescription = "description"; private static Symbol Qrange = "range"; private static Symbol Qename = "ename"; public class Variable { public Domain domain; public readonly Symbol name; protected Term val; public Variable (Domain domain, Symbol name, Term val) { this.domain = domain; this.name = name; this.val = val; } public Term Value { get { return val; } } public virtual Term SetValue (Term val) { this.val = val; return val; } public virtual Variable Clone (Domain domain) { return new Variable (domain, name, val); } public virtual void Reset () { val = Zero; } public override string ToString () { return name + "(" + val + ")"; } public abstract class Typed : Variable { protected string desc; private Term default_val; protected Typed (Domain domain, Symbol name, Term val, string desc) : base (domain, name, val) { this.desc = desc; default_val = val; } public override void Reset () { val = default_val; } public string Description { get { return desc; } set { desc = value; } } public override Term SetValue (Term val) { if (! CheckValue (val)) throw new Error (Error.VariableWrongValue, "Wrong value for variable {0}: {1}", name, val); this.val = val; return val; } public abstract bool CheckValue (Term val); } public class IntType : Typed { private int[] range; public IntType (Domain domain, Symbol name, int n, string desc, int[] range) : base (domain, name, new Term (n), desc) { if (range != null && range.Length % 2 == 1) throw new Error (Error.VariableWrongRange, "Range length for {0} not even", name); this.range = range; CheckValue (val); } public override bool CheckValue (Term term) { if (term.IsInt) { if (range == null) return true; int n = term.Intval; for (int i = 0; i < range.Length; i += 2) if (range[i] <= n && range[i + 1] >= n) return true; } return false; } public override Variable Clone (Domain domain) { return new IntType (domain, name, val.Intval, desc, range); } public int[] Range { get { return range; } set { range = value; } } } public class StrType : Typed { private string[] range; public StrType (Domain domain, Symbol name, Str str, string desc, string[] range) : base (domain, name, new Term (str), desc) { this.range = range; CheckValue (val); } public override bool CheckValue (Term val) { if (val.IsStr) { if (range == null) return true; Str str = val.Strval; foreach (string s in range) if (str.Equals (s)) return true; } return false; } public override Variable Clone (Domain domain) { return new StrType (domain, name, val.Strval, desc, range); } public string[] Range { get { return range; } set { range = value; } } } public class SymType : Typed { public Symbol[] range; public SymType (Domain domain, Symbol name, Symbol sym, string desc, Symbol[] range) : base (domain, name, new Term (sym), desc) { this.range = range; CheckValue (val); } public override bool CheckValue (Term val) { if (val.IsSymbol) { if (range == null) return true; Symbol sym = val.Symval; foreach (Symbol n in range) if (sym == n) return true; } return false; } public override Variable Clone (Domain domain) { return new SymType (domain, name, val.Symval, desc, range); } public Symbol[] Range { get { return range; } set { range = value; } } } } public abstract class Function { public Symbol name; // True iff the function can be called with vname="VNAME" attribute. internal readonly bool with_var; // Minimum number of positional arguments. internal readonly int min_args; // If non-nengative, maximum number of arguments. If negative, // maxinum number of positional arguments is (-1 - max_args), // and the remaining unlimit number of arguments are given as a // single list. internal readonly int max_args; public delegate Term Builtin (Domain domain, Variable vari, Term[] terms); public Function () { } public Function (Symbol name, bool with_var, int min_args, int max_args) { this.name = name; this.with_var = with_var; this.min_args = min_args; this.max_args = max_args; } public abstract Term Call (Domain domain, Variable vari, Term[] args); public override string ToString () { return name; } internal class Subroutine : Function { public Builtin builtin; public Subroutine (Builtin builtin, Symbol name, bool with_var, int min_args, int max_args) : base (name, with_var, min_args, max_args) { this.builtin = builtin; } public override Term Call (Domain domain, Variable vari, Term[] args) { if (args.Length > 0) { args = (Term[]) args.Clone (); for (int i = 0; i < args.Length; i++) { args[i] = args[i].Eval (domain); if (domain.Thrown ()) return args[i]; } } return builtin (domain, vari, args); } } internal class SpecialForm : Function { public Builtin builtin; public SpecialForm (Builtin builtin, Symbol name, bool with_var, int min_args, int max_args) : base (name, with_var, min_args, max_args) { this.builtin = builtin; } public override Term Call (Domain domain, Variable vari, Term[] args) { return builtin (domain, vari, args); } } internal class Lambda : Function { private Variable[] args; private Term[] body; public Lambda (Symbol name, int min_args, int max_args, Variable[] args, Term[] body) : base (name, false, min_args, max_args) { this.args = args; this.body = body; } public void SetBody (Term[] body) { this.body = body; } public override Term Call (Domain domain, Variable vari, Term[] args) { Bindings current = domain.bindings; Term result = Zero; int limit = max_args >= 0 ? args.Length : args.Length - 1; try { for (int i = 0; i < limit; i++) { result = args[i].Eval (domain); if (domain.Thrown ()) return result; domain.Bind (this.args[i], result); } if (max_args < 0) { List list = new List (); list.InsertRange (0, args[limit].Listval); for (int i = 0; i < list.Count; i++) { result = list[i].Eval (domain); if (domain.Thrown ()) return result; list[i] = result; } domain.Bind (this.args[limit], new Term (list)); } try { domain.Catch (CatchTag.Return); foreach (Term term in body) { result = term.Eval (domain); if (domain.Thrown ()) return result; } } finally { domain.Uncatch (); } } finally { domain.UnboundTo (current); } return result; } } internal class Macro : Function { private Variable[] args; private Term[] body; public Macro (Symbol name, int min_args, int max_args, Variable[] args, Term[] body) : base (name, false, min_args, max_args) { this.args = args; this.body = body; } public void SetBody (Term[] body) { this.body = body; } public override Term Call (Domain domain, Variable vari, Term[] args) { Bindings current = domain.bindings; Term result = Zero; try { for (int i = 0; i < args.Length; i++) domain.Bind (this.args[i], args[i]); try { domain.Catch (CatchTag.Return); foreach (Term term in body) { result = term.Eval (domain); if (domain.Thrown ()) break; } } finally { domain.Uncatch (); } } finally { domain.UnboundTo (current); } return result; } } } internal class Bindings { private Variable vari; private Term old_value; private Bindings next; private Bindings (Variable vari) { this.vari = vari; old_value = vari.Value; } public static Bindings Bind (Bindings bindings, Variable vari, Term val) { Bindings b = new Bindings (vari); b.vari.SetValue (val); b.next = bindings; return b; } internal Bindings UnboundTo (Bindings boundary) { for (Bindings b = this; b != boundary; b = b.next) b.vari.SetValue (b.old_value); return boundary; } public override string ToString () { string str = "(bindings"; for (Bindings b = this; b != null; b = b.next) str += " " + vari.name + "=" + b.old_value; return str + ")"; } } internal struct CatchTag { private Term tag; public Term Tag { get { return tag; } } // Normal symbolic catch-tag. public CatchTag (Symbol sym) { tag = new Term (sym); } // Special catch-tag for return and break. private CatchTag (int i) { tag = new Term (i); } public static CatchTag Return = new CatchTag (0); public static CatchTag Break = new CatchTag (1); } public class Domain { public Symbol name; public object context; public int depth = 0; private Stack call_stack = new Stack (); internal Dictionary termtypes = new Dictionary (); internal Dictionary functions = new Dictionary (); internal Dictionary variables = new Dictionary (); internal Bindings bindings; private Stack catch_stack = new Stack (); private int catch_count = 0; internal Domain (Symbol name) { this.name = name; } public Domain (Symbol name, object context) : this (name, basic, context) { } public Domain (Symbol name, Domain parent, object context) : this (name) { termtypes = new Dictionary (parent.termtypes); functions = new Dictionary (parent.functions); variables = new Dictionary (parent.variables); this.context = context; } public int CallStackCount { get { return call_stack.Count; } } public void CallStackPush (Term term) { call_stack.Push (term); } public void CallStackPop () { call_stack.Pop (); } public void CallStackPop (int count) { while (count < call_stack.Count) call_stack.Pop (); } public Term[] CallStack { get { return call_stack.ToArray (); } } internal void Bind (Variable vari, Term value) { bindings = Bindings.Bind (bindings, vari, value); } internal void UnboundTo (Bindings boundary) { if (bindings != null) bindings = bindings.UnboundTo (boundary); } internal void Catch (CatchTag tag) { catch_stack.Push (tag); catch_count++; } internal void Uncatch () { catch_stack.Pop (); if (catch_count > catch_stack.Count) catch_count--; } public bool Thrown () { return catch_count < catch_stack.Count; } public bool Thrown (out bool caught) { if (catch_count < catch_stack.Count) { caught = catch_count == catch_stack.Count - 1; return true; } caught = false; return false; } internal void ThrowReturn () { foreach (CatchTag elt in catch_stack) { catch_count--; if (elt.Tag == CatchTag.Return.Tag) break; } } internal void ThrowBreak () { if (catch_stack.Peek ().Tag != CatchTag.Break.Tag) throw new Error (Error.NoLoopToBreak, "No surrounding loop to break"); catch_count--; } internal void ThrowSymbol (Term tag) { int i = catch_count; foreach (CatchTag elt in catch_stack) { i--; if (elt.Tag.Matches (tag)) { catch_count = i; return; } } throw new Error (Error.UncaughtThrow, "No corresponding catch: {0}", tag); } public void DefType (Type type) { if (! type.IsSubclassOf (typeof (TermValue))) throw new Error (Error.TermTypeInvalid, "Not a subclass of TermValue: {0}", type); BindingFlags flags = BindingFlags.Static | BindingFlags.NonPublic; FieldInfo finfo = type.GetField ("name", flags); if (finfo == null || finfo.FieldType != typeof (Symbol)) throw new Error (Error.TermTypeInvalid, "No \"name\" field of string type: {0}", type); Symbol name = (Symbol) finfo.GetValue (null); if (termtypes.ContainsKey (name)) throw new Error (Error.TermTypeInvalid, "Already defined: {0}", name); if (functions.ContainsKey (name)) throw new Error (Error.TermTypeInvalid, "Already defined as a function or a macro: {0}", name); Type[] types = new Type[] { typeof (Domain), typeof (XmlNode) }; MethodInfo parser = type.GetMethod ("Parser", types); if (parser == null || parser.ReturnType != typeof (TermValue)) throw new Error (Error.TermTypeInvalid, "No \"Parser\" method of correct type: {0}", type); termtypes[name] = parser; } private void check_func_head (Symbol name, bool with_var, int min_args, int max_args, bool as_macro) { if (termtypes.ContainsKey (name)) throw new Error (Error.FunctionConflict, "Already defined as a term type: {0}", name); Function func; if (functions.TryGetValue (name, out func)) { if ((func is Function.Macro) != as_macro) throw new Error (Error.FunctionConflict, "Already defined as a {0}: {1}", as_macro ? "function" : "macro", name); if (func.with_var != with_var || func.min_args != min_args || func.max_args != max_args) throw new Error (Error.FunctionConflict, "Conflicting arguments: {0}", name); } } public void DefSubr (Function.Builtin builtin, Symbol name, bool with_var, int min_args, int max_args) { check_func_head (name, with_var, min_args, max_args, false); functions[name] = new Function.Subroutine (builtin, name, with_var, min_args, max_args); } public void DefSpecial (Function.Builtin builtin, Symbol name, bool with_var, int min_args, int max_args) { check_func_head (name, with_var, min_args, max_args, false); functions[name] = new Function.SpecialForm (builtin, name, with_var, min_args, max_args); } public void Defun (Symbol name, int min_args, int max_args, Variable[] args, Term[] body) { check_func_head (name, false, min_args, max_args, false); functions[name] = new Function.Lambda (name, min_args, max_args, args, body); } public void Defun (Function func) { functions[func.name] = func; } public void Defmacro (Symbol name, int min_args, int max_args, Variable[] args, Term[] body) { check_func_head (name, false, min_args, max_args, true); functions[name] = new Function.Macro (name, min_args, max_args, args, body); } public void DefAlias (Symbol alias, Symbol fname) { Function func; if (termtypes.ContainsKey (alias)) throw new Error (Error.FunctionConflict, "Alread defined as a term type: {0}", alias); if (functions.ContainsKey (alias)) throw new Error (Error.FunctionConflict, "Alread defined as a function: {0}", alias); if (! functions.TryGetValue (fname, out func)) throw new Error (Error.UnknownFunction, fname); functions[alias] = func; } public Variable Defvar (Variable vari) { vari = vari.Clone (this); variables[vari.name] = vari; return vari; } internal Variable Defvar (Symbol name) { Variable vari; if (variables.TryGetValue (name, out vari)) { Variable.Typed typed = vari as Variable.Typed; if (typed != null) throw new Error (Error.VariableTypeConflict, "Not a non-typed variable: {0}", name); } else { vari = new Variable (this, name, Zero); variables[name] = vari; } return vari; } public Variable Defvar (Symbol name, int n, string desc, int[] range) { Variable vari; if (variables.TryGetValue (name, out vari)) { Variable.IntType intvari = vari as Variable.IntType; if (intvari == null) throw new Error (Error.VariableTypeConflict, "Not an integer variable: {0}", name); if (range != null) intvari.Range = range;; if (desc != null) intvari.Description = desc; } else { vari = new Variable.IntType (this, name, n, desc, range); variables[name] = vari; } return vari; } public Variable Defvar (Symbol name, Symbol sym, string desc, Symbol[] range) { Variable vari; if (variables.TryGetValue (name, out vari)) { Variable.SymType symvari = vari as Variable.SymType; if (symvari == null) throw new Error (Error.VariableTypeConflict, "Not a symbol variable: {0}", name); if (range != null) symvari.Range = range; if (desc != null) symvari.Description = desc; } else { vari = new Variable.SymType (this, name, sym, desc, range); variables[name] = vari; } return vari; } public Variable Defvar (Symbol name, string str, string desc, string[] range) { Variable vari; if (variables.TryGetValue (name, out vari)) { Variable.StrType strvari = vari as Variable.StrType; if (strvari == null) throw new Error (Error.VariableTypeConflict, "Not a string variable: {0}", name); if (range != null) strvari.Range = range; if (desc != null) strvari.Description = desc; } else { vari = new Variable.StrType (this, name, new Str (str), desc, range); variables[name] = vari; } return vari; } internal Function GetFunc (Symbol name) { Function func; if (! functions.TryGetValue (name, out func)) throw new Error (Error.UnknownFunction, "Unknown function: {0}", name); return func; } public bool CopyFunc (Domain domain, Symbol name) { Function func = GetFunc (name); domain.functions[name] = func; return true; } public void CopyFunc (Domain domain) { foreach (KeyValuePair kv in functions) domain.functions[kv.Key] = kv.Value; } public Variable GetVarCreate (Symbol name) { Variable vari; if (! variables.TryGetValue (name, out vari)) variables[name] = vari = new Variable (this, name, Zero); return vari; } public Variable GetVar (Symbol name) { Variable vari; if (! variables.TryGetValue (name, out vari)) return null; return vari; } public override string ToString () { string str = "<(functions"; foreach (KeyValuePair kv in functions) str += " " + kv.Key; str += ") (variabls"; foreach (KeyValuePair kv in variables) str += " " + kv.Value; str += ")"; if (bindings != null) str += " " + bindings; if (context != null) str += " (" + context + ")"; str += ">"; return str; } internal void TraceWrite (string fmt, params string[] arg) { if (trace_depth > depth) { for (int i = 0; i < depth; i++) Console.Write (" "); Console.WriteLine (fmt, arg); } } public object SaveValues () { Dictionary values = new Dictionary (); foreach (KeyValuePair kv in variables) values[kv.Value] = kv.Value.Value.Clone (); return values; } public void RestoreValues (object values) { foreach (KeyValuePair kv in (Dictionary) values) kv.Key.SetValue (kv.Value); } } private static Domain basic = new Domain ("basic"); static Xexpression () { basic.DefType (typeof (Varref)); basic.DefType (typeof (Funcall)); basic.DefType (typeof (ErrorTerm)); basic.DefSubr (Fset, "set", true, 1, 1); basic.DefAlias ("=", "set"); basic.DefSubr (Fnot, "not", false, 1, 1); basic.DefAlias ("!", "not"); basic.DefSubr (Fadd, "add", true, 1, -1); basic.DefAlias ("+", "add"); basic.DefSubr (Fmul, "mul", true, 1, -1); basic.DefAlias ("*", "mul"); basic.DefSubr (Fsub, "sub", true, 1, -1); basic.DefAlias ("-", "sub"); basic.DefSubr (Fdiv, "div", true, 1, -1); basic.DefAlias ("/", "div"); basic.DefSubr (Fmod, "mod", true, 1, 2); basic.DefAlias ("%", "mod"); basic.DefSubr (Flogior, "logior", true, 1, -1); basic.DefAlias ("|", "logior"); basic.DefSubr (Flogand, "logand", true, 1, -1); basic.DefAlias ("&", "logand"); basic.DefSubr (Flsh, "lsh", true, 1, 2); basic.DefAlias ("<<", "lsh"); basic.DefSubr (Frsh, "rsh", true, 1, 2); basic.DefAlias (">>", "rsh"); basic.DefSubr (Feq, "eq", false, 2, -1); basic.DefAlias ("==", "eq"); basic.DefSubr (Fnoteq, "noteq", false, 2, 2); basic.DefAlias ("!=", "noteq"); basic.DefSubr (Flt, "lt", false, 2, -1); basic.DefAlias ("<", "lt"); basic.DefSubr (Fle, "le", false, 2, -1); basic.DefAlias ("<=", "le"); basic.DefSubr (Fgt, "gt", false, 2, -1); basic.DefAlias (">", "gt"); basic.DefSubr (Fge, "ge", false, 2, -1); basic.DefAlias (">=", "ge"); basic.DefSubr (Fappend, "append", true, 0, -1); basic.DefSubr (Fconcat, "concat", true, 0, -1); basic.DefSubr (Fnth, "nth", false, 2, 2); basic.DefSubr (Fcopy, "copy", false, 1, 1); basic.DefSubr (Fins, "ins", true, 2, 2); basic.DefSubr (Fdel, "del", true, 2, 2); basic.DefSubr (Feval, "eval", false, 1, 1); basic.DefSubr (Fbreak, "break", false, 0, 1); basic.DefSubr (Freturn, "return", false, 0, 1); basic.DefSubr (Fthrow, "throw", false, 1, 2); basic.DefSpecial (Fand, "and", false, 1, -1); basic.DefAlias ("&&", "and"); basic.DefSpecial (For, "or", false, 1, -1); basic.DefAlias ("||", "or"); basic.DefSpecial (Fprogn, "progn", false, 0, -1); basic.DefAlias ("expr", "progn"); basic.DefSpecial (Fif, "if", false, 2, 3); basic.DefSpecial (Fwhen, "when", false, 1, -1); basic.DefSpecial (Floop, "loop", false, 1, -1); basic.DefSpecial (Fwhile, "while", false, 1, -1); basic.DefSpecial (Fcond, "cond", false, 1, -1); basic.DefSpecial (Fforeach, "foreach", true, 2, -1); basic.DefSpecial (Fquote, "quote", false, 1, 1); basic.DefSpecial (Ftype, "type", false, 1, 1); basic.DefSpecial (Fcatch, "catch", true, 2, -1); } private static Term Fset (Domain domain, Variable vari, Term[] args) { if (vari == null) throw new Error (Error.NoVariableName, "No variable name to set"); vari.SetValue (args[0]); return args[0]; } private static Term Fnot (Domain domain, Variable vari, Term[] args) { return args[0].IsTrue ? Zero : One; } static Term maybe_set_intvar (Variable vari, int n) { Term term = new Term (n); if (vari != null) vari.SetValue (term); return term; } private static Term Fadd (Domain domain, Variable vari, Term[] args) { int n = vari == null ? 0 : vari.Value.Intval; foreach (Term arg in args) n += arg.Intval; return maybe_set_intvar (vari, n); } private static Term Fmul (Domain domain, Variable vari, Term[] args) { int n = vari == null ? 1 : vari.Value.Intval; foreach (Term arg in args) n *= arg.Intval; return maybe_set_intvar (vari, n); } private static Term Fsub (Domain domain, Variable vari, Term[] args) { int n, i; if (vari == null) { n = args[0].Intval; i = 1; } else { n = vari.Value.Intval; i = 0; } while (i < args.Length) n -= args[i++].Intval; return maybe_set_intvar (vari, n); } private static Term Fdiv (Domain domain, Variable vari, Term[] args) { int n, i; if (vari == null) { n = args[0].Intval; i = 1; } else { n = vari.Value.Intval; i = 0; } while (i < args.Length) n /= args[i++].Intval; return maybe_set_intvar (vari, n); } private static Term Fmod (Domain domain, Variable vari, Term[] args) { return maybe_set_intvar (vari, args[0].Intval % args[1].Intval); } private static Term Flogior (Domain domain, Variable vari, Term[] args) { int n = vari == null ? 0 : vari.Value.Intval; foreach (Term arg in args) n |= arg.Intval; return maybe_set_intvar (vari, n); } private static Term Flogand (Domain domain, Variable vari, Term[] args) { int n, i; if (vari == null) { n = args[0].Intval; i = 1; } else { n = vari.Value.Intval; i = 0; } while (i < args.Length) n &= args[i++].Intval; return maybe_set_intvar (vari, n); } private static Term Flsh (Domain domain, Variable vari, Term[] args) { return maybe_set_intvar (vari, args[0].Intval << args[1].Intval); } private static Term Frsh (Domain domain, Variable vari, Term[] args) { return maybe_set_intvar (vari, args[0].Intval >> args[1].Intval); } private static Term Feq (Domain domain, Variable vari, Term[] args) { Term o = args[0]; if (o.objval == null) { for (int i = 1; i < args.Length; i++) if (args[i].objval != null || args[i].intval != o.intval) return Zero; } else { for (int i = 1; i < args.Length; i++) if (o.objval.Equals (args[i].objval)) return Zero; } return One; } private static Term Fnoteq (Domain domain, Variable vari, Term[] args) { return Feq (domain, vari, args); } private static Term Flt (Domain domain, Variable vari, Term[] args) { int n = args[0].Intval; for (int i = 1; i < args.Length; i++) { int n1 = args[i].Intval; if (n >= n1) return Zero; n = n1; } return One; } private static Term Fle (Domain domain, Variable vari, Term[] args) { int n = args[0].Intval; for (int i = 1; i < args.Length; i++) { int n1 = args[i].Intval; if (n > n1) return Zero; n = n1; } return One; } private static Term Fgt (Domain domain, Variable vari, Term[] args) { int n = args[0].Intval; for (int i = 1; i < args.Length; i++) { int n1 = args[i].Intval; if (n <= n1) return Zero; n = n1; } return One; } private static Term Fge (Domain domain, Variable vari, Term[] args) { int n = args[0].Intval; for (int i = 1; i < args.Length; i++) { int n1 = args[i].Intval; if (n < n1) return Zero; n = n1; } return One; } private static Term Fappend (Domain domain, Variable vari, Term[] args) { List list; if (vari == null) list = new List (); else list = vari.Value.Listval; foreach (Term arg in args) { if (arg.IsList) list.AddRange ((List) arg.objval); else list.Add (arg); } if (vari == null) { Term result; result.intval = 0; result.objval = list; return result; } return vari.Value; } private static Term Fconcat (Domain domain, Variable vari, Term[] args) { Str str = vari == null ? new Str ("") : vari.Value.Strval; foreach (Term arg in args) { if (arg.IsStr) str.Insert (-1, arg.Strval); else if (arg.IsList) foreach (Term term in arg.Listval) str.Insert (-1, (char) term.Intval); else str.Insert (-1, (char) arg.Intval); } return vari == null ? new Term (str) : vari.Value; } private static Term Fnth (Domain domain, Variable vari, Term[] args) { if (args[1].IsStr) return new Term (args[1].Strval.Nth (args[0].Intval)); if (args[1].IsList) return args[1].Listval[args[0].Intval]; throw new Error (Error.WrongType, "Not a string nor a list: {0}", args[1]); } private static Term Fcopy (Domain domain, Variable vari, Term[] args) { return args[0].Clone (); } private static Term Fins (Domain domain, Variable vari, Term[] args) { if (vari == null) throw new Error (Error.NoVariableName, "No variable name to set"); if (vari.Value.IsStr) vari.Value.Strval.Insert (args[0].Intval, args[1].Strval); else if (vari.Value.IsList) vari.Value.Listval.InsertRange (args[0].Intval, args[1].Listval); else throw new Error (Error.WrongType, "Not a string nor a list: {0}", vari.Value); return vari.Value; } private static Term Fdel (Domain domain, Variable vari, Term[] args) { if (vari == null) throw new Error (Error.NoVariableName, "No variable name to set"); if (vari.Value.IsStr) vari.Value.Strval.Delete (args[0].Intval, args[1].Intval); else if (vari.Value.IsList) vari.Value.Listval.RemoveRange (args[0].Intval, args[1].Intval - args[0].Intval); else throw new Error (Error.WrongType, "Not a string nor a list: {0}", vari.Value); return vari.Value; } private static Term Fand (Domain domain, Variable vari, Term[] args) { foreach (Term arg in args) { Term result = arg.Eval (domain); if (domain.Thrown ()) return result; if (! result.IsTrue) return Zero; } return One; } private static Term For (Domain domain, Variable vari, Term[] args) { foreach (Term arg in args) { Term result = arg.Eval (domain); if (domain.Thrown ()) return result; if (result.IsTrue) return One; } return Zero; } private static Term Feval (Domain domain, Variable vari, Term[] args) { return (args[0].Eval (domain)); } private static Term Fprogn (Domain domain, Variable vari, Term[] args) { Term result = One; foreach (Term arg in args) { result = arg.Eval (domain); if (domain.Thrown ()) return result; } return result; } private static Term Fif (Domain domain, Variable vari, Term[] args) { Term result = args[0].Eval (domain); if (domain.Thrown ()) return result; if (result.IsTrue) return args[1].Eval (domain); if (args.Length == 2) return Zero; return args[2].Eval (domain); } private static Term Fwhen (Domain domain, Variable vari, Term[] args) { Term result = args[0].Eval (domain); if (domain.Thrown ()) return result; if (! result.IsTrue) return Zero; result = One; for (int i = 1; i < args.Length; i++) { result = args[i].Eval (domain); if (domain.Thrown ()) return result; } return result; } private static Term Freturn (Domain domain, Variable vari, Term[] args) { domain.ThrowReturn (); return args.Length == 0 ? Zero : args[0]; } private static Term Fbreak (Domain domain, Variable vari, Term[] args) { domain.ThrowBreak (); return args.Length == 0 ? Zero : args[0]; } private static Term Floop (Domain domain, Variable vari, Term[] args) { Term result = Zero; try { domain.Catch (CatchTag.Break); while (! domain.Thrown ()) foreach (Term arg in args) { result = arg.Eval (domain); if (domain.Thrown ()) return result; } } finally { domain.Uncatch (); } return result; } private static Term Fwhile (Domain domain, Variable vari, Term[] args) { Term result = Zero; try { domain.Catch (CatchTag.Break); while (! domain.Thrown () && args[0].Eval (domain).IsTrue) for (int i = 1; i < args.Length; i++) { result = args[i].Eval (domain); if (domain.Thrown ()) return result; } } finally { domain.Uncatch (); } return result; } private static Term Fcond (Domain domain, Variable vari, Term[] args) { foreach (Term arg in args) { List list = arg.Listval; Term result = list[0].Eval (domain); if (result.IsTrue) { for (int i = 1; i < list.Count; i++) { domain.depth++; result = list[i].Eval (domain); domain.depth--; if (domain.Thrown ()) return result; } return result; } } return Zero; } private static Term Fforeach (Domain domain, Variable vari, Term[] args) { Term result = args[0].Eval (domain); if (domain.Thrown ()) return result; List list = result.Listval; Bindings current = domain.bindings; try { domain.Catch (CatchTag.Break); foreach (Term term in list) { domain.Bind (vari, term); try { for (int i = 1; i < args.Length; i++) { result = args[i].Eval (domain); if (domain.Thrown ()) return result; } } finally { domain.UnboundTo (current); } } } finally { domain.Uncatch (); } return result; } private static Term Fquote (Domain domain, Variable vari, Term[] args) { return args[0]; } private static Term Ftype (Domain domain, Variable vari, Term[] args) { if (args[0].IsInt) return TermInt; if (args[0].IsStr) return TermStr; if (args[0].IsSymbol) return TermSymbol; if (args[0].IsList) return TermList; return TermTerm; } private static Term eval_terms (Domain domain, Term[] terms, int idx, out bool caught) { Term result= Zero; caught = false; for (int i = idx; i < terms.Length; i++) { result = terms[i].Eval (domain); if (domain.Thrown (out caught)) return result; } return result; } public static Term Fcatch (Domain domain, Variable vari, Term[] args) { Term result; bool caught = false; if (args.Length < 2) throw new Error (Error.WrongArgument, "Too few arguments: {0}", args.Length); ErrorTerm err = args[0].objval as ErrorTerm; if (err != null) { try { result = eval_terms (domain, args, 1, out caught); } catch (System.Exception exception) { Term term; Error e = exception as Error; if (e != null) term = new Term (new ErrorTerm (e.Name, e.Message, e.Stack)); else term = new Term (new ErrorTerm (exception)); if (! args[0].Matches (term)) throw exception; if (vari != null) vari.SetValue (term); return One; } } else if (args[0].IsSymbol) { try { domain.Catch (new CatchTag (args[0].Symval)); result = eval_terms (domain, args, 1, out caught); if (caught) { if (vari != null) vari.SetValue (result); return One; } return Zero; } finally { domain.Uncatch (); } } throw new Error (Error.WrongArgument, "Not a symbol nor an error: {0}", args[0]); } public static Term Fthrow (Domain domain, Variable vari, Term[] args) { if (args[0].IsSymbol) { domain.ThrowSymbol (args[0]); return (args[args.Length - 1]); } if (args[0].IsError) { ErrorTerm err = (ErrorTerm) args[0].objval; throw new Error (err.ErrorName, err.ErrorMessage); } throw new Error (Error.WrongArgument, "Not a symbol nor an error: {0}", args[0]); } public abstract class TermValue { public virtual Term Eval (Domain domain) { return new Term (this); } public virtual TermValue Clone () { return this; } public virtual bool IsTrue { get { return true; } } public virtual bool Matches (TermValue other) { return Equals (other); } public override abstract bool Equals (object obj); public override abstract int GetHashCode (); public virtual string ToString (bool detail) { return ToString (); } } private class Varref : TermValue { private static Symbol name = "varref"; public static Symbol Name { get { return name; } } private Symbol vname; private Variable vari; public Varref (Symbol vname) { this.vname = vname; } public override Term Eval (Domain domain) { if (vari == null || vari.domain != domain) vari = domain.GetVarCreate (vname); return vari.Value; } public static TermValue Parser (Domain domain, XmlNode node) { return new Varref ((Symbol) node.Attributes[Qvname].Value); } public override bool Equals (object obj) { Varref varref = obj as Varref; return (varref != null && varref.vari.name == vari.name); } public override int GetHashCode () { return vari.name.GetHashCode (); } public override string ToString () { return ToString (true); } public override string ToString (bool detail) { return ""; } } private class Funcall : TermValue { private static Symbol name = "funcall"; public static Symbol Name { get { return name; } } private static Term[] null_args = new Term[0]; internal Function func; internal Variable vari; internal Term[] args; public Funcall (Function func, Variable vari, Term[] args) { if (args == null) args = null_args; int nargs = args.Length; if (nargs < func.min_args || (func.max_args >= 0 && nargs > func.max_args)) throw new Error (Error.WrongArgument, "Wrong number of arguments to {0}: {1}", func.name, nargs); if (! func.with_var && vari != null) throw new Error (Error.WrongArgument, "Wrong vname attribute to {0}: {1}", func.name, vari.name); this.func = func; this.vari = vari; this.args = args; } public static TermValue Parser (Domain domain, XmlNode node) { Symbol fname = node.Name; XmlAttribute attr; if (fname == Qfuncall) fname = node.Attributes[Qfname].Value; Function func = domain.GetFunc (fname); Variable vari; attr = node.Attributes[Qvname]; vari = attr == null ? null : domain.GetVarCreate (attr.Value); XmlNodeList nlist = node.ChildNodes; int nargs = nlist.Count; Term[] args = new Term[nargs]; for (int i = 0; i < nargs; i++) args[i] = Parse (domain, nlist[i]); return new Funcall (func, vari, args); } public override Term Eval (Domain domain) { Term result; domain.TraceWrite (ToString ()); try { domain.depth++; result = func.Call (domain, vari, args); } finally { domain.depth--; } domain.TraceWrite ("=> {0}", result.ToString ()); return result; } public override TermValue Clone () { return new Funcall (func, vari, args); } public override bool Equals (object obj) { Funcall funcall = obj as Funcall; return (obj != null && funcall.func == func && funcall.vari == vari && funcall.args.Length == args.Length); } public override int GetHashCode () { return func.GetHashCode () ^ args.Length; } public override string ToString () { return ToString (true); } public override string ToString (bool detail) { string str = "<" + func.name; if (vari != null) { str += " vname=\"" + vari.name + "\""; if (detail) str += " val=" + vari.Value.ToString (); } if (args.Length == 0 || ! detail) return str + "/>"; str += ">"; if (func is Function.SpecialForm) { for (int i = 0; i < args.Length; i++) str += "."; } else foreach (Term e in args) str += e; return (str + ""); } } internal class ErrorTerm : TermValue { private static Symbol name = "error"; public static Symbol Name { get { return name; } } private readonly Symbol ename; public Symbol ErrorName { get { return ename; } } private string message; public string ErrorMessage { get { return message; } } private Term[] stack; public ErrorTerm (Symbol ename, string message) : this (ename, message, null) { } internal ErrorTerm (Symbol ename, string message, Term[] stack) { this.ename = ename; this.message = message; this.stack = stack; } internal ErrorTerm (Exception e) { if (e is ArithmeticException) ename = Error.ArithmeticError; else if (e is IndexOutOfRangeException) ename = Error.IndexOutOfRange; else if (e is InsufficientMemoryException || e is OutOfMemoryException) ename = Error.MemoryError; else ename = Error.UnknownError; message = e.Message; } public static TermValue Parser (Domain domain, XmlNode node) { XmlAttribute attr = node.Attributes[Qename]; Symbol ename = attr == null ? Qnull : (Symbol) attr.Value; string message = node.InnerText; return new ErrorTerm (ename, message); } public Term[] CallStack { get { return stack; } internal set { stack = value; } } public override TermValue Clone () { return new ErrorTerm (ename, message); } public override bool Equals (object obj) { ErrorTerm e = obj as ErrorTerm; return (e != null && e.ename == ename && e.message == message && (e.stack == null ? stack == null : (stack != null && e.stack.Length == stack.Length))); } public override int GetHashCode () { return ename.GetHashCode (); } public override bool Matches (TermValue term) { ErrorTerm e = term as ErrorTerm; return (e != null && (ename == Qnull || e.ename == ename)); } public override string ToString () { return ToString (true); } public override string ToString (bool detail) { string str = ""; if (message != null) str += message; if (stack != null) for (int i = 0; i < stack.Length; i++) str += stack[i].ToString (false); return str + ""; } } public class Str { private string str; private Regex regex; public Str (string str) { this.str = str; } public Str Clone (Str str) { return new Str (str.str); } public bool Equals (string str) { return this.str == str; } public bool Equals (Str str) { return this.str == str.str; } public bool Matches (Str str) { if (regex != null) regex = new Regex (this.str); return regex.IsMatch (str.str); } public int Nth (int index) { return (int) str[index]; } public void Insert (int index, Str str) { if (index < 0) this.str = this.str + str.str; else this.str = this.str.Insert (index, str.str); regex = null; } public void Insert (int index, char c) { if (index < 0) this.str = this.str + c; else this.str = this.str.Insert (index, new string (c, 1)); regex = null; } public void Delete (int from, int to) { this.str = this.str.Remove (from, to - from); regex = null; } public override string ToString () { return str; } } /// Structure of term object. public struct Term { internal int intval; internal object objval; /// Create an integer term. /// Integer value of the term. /// An integer term. /// Create an integer term that has the integer value /// specified by . This is an constant /// term; i.e. the integer value never changes. public Term (int i) { intval = i; objval = null; } /// Create a symbol term. /// Symbol value of the term. /// A symbol term. /// Create a symbol term that has the symbol value /// specified by . This is an constant /// term; i.e. the symbol value never changes. It is evaluated /// to itself. public Term (Symbol name) { intval = 0; objval = name; } /// Create a string term. /// String value of the term. /// A string term. /// Create a string term that has the string value /// specified by . It is evaluated to /// itself. The string value can be modified by "ins", "del", /// and "concat" functions. public Term (string str) { intval = 0; objval = new Str (str); } // ... /// Create a list term. /// List value of the term. /// A list term. /// Create a list term that has the list value /// specified by . It is evaluated to /// itself. The list value can be modified by "ins", "del", and /// "append" functions. public Term (List list) { intval = 0; objval = list; } // ERROR-MESSASGE /// Create an error term. /// Name of the error. /// Error message. /// An error term. /// Create an error term whose error name is and error message is . It is evaluated to itself. public Term (Symbol name, string message) { intval = 0; objval = new ErrorTerm (name, message); } /// Create a term of a specific value /// Value of the term. /// A term. /// Create a term whose value is . /// It is evaluated to a term that is returned by "Eval" method /// of . public Term (TermValue val) { intval = 0; objval = val; } internal Term (Str str) { intval = 0; objval = str; } /// Create a varref term. /// Domain to create the term in. /// Name of the referred variable. /// A varref term. /// Create a varref term that is evaluated to the value /// of the referring variable. public Term (Domain domain, Symbol vname) { intval = 0; objval = new Varref (vname); } /// Create a funcall term. /// Domain to create the term in. /// Name of the calling function. /// Array of terms that are given to the /// function as arguments. /// A funcall term. /// Create a funcall term that is evaluated to a term /// returned by the function when called /// with . public Term (Domain domain, Symbol fname, Term[] args) : this (domain, fname, Qnull, args) { } // ... public Term (Domain domain, Symbol fname, Symbol vname, Term[] args) { intval = 0; Function func = domain.GetFunc (fname); Variable vari = vname == Qnull ? null : domain.GetVarCreate(vname); Funcall funcall = new Funcall (func, vari, args); if (func is Function.Macro) { Term result = funcall.Eval (domain); intval = result.intval; objval = result.objval; } else objval = funcall; } public object Objval { get { if (objval == null) throw new Error (Error.WrongType, "term is an integer: {0}", this); return objval; } } public int Intval { get { if (objval != null) throw new Error (Error.WrongType, "{0} is not an integer", this); return intval; } } public Str Strval { get { if (! IsStr) throw new Error (Error.WrongType, "{0} is not a string", this); return (Str) objval; } } public string Symval { get { if (! IsSymbol) throw new Error (Error.WrongType, "{0} is not a symbol", this); return (Symbol) objval; } } public List Listval { get { if (! IsList) throw new Error (Error.WrongType, "{0} is not a list"); return (List) objval; } } public bool IsTrue { get { return (objval == null ? (intval != 0) : objval is List ? (((List) objval).Count != 0) : objval is TermValue ? ((TermValue) objval).IsTrue : true); } } public bool IsInt { get { return (objval == null); } } public bool IsStr { get { return (objval is Str); } } public bool IsSymbol { get { return (objval is Symbol); } } public bool IsList { get { return (objval is List); } } public bool IsError { get { return (objval is ErrorTerm); } } internal Term Eval (Domain domain) { if (objval == null || objval is Symbol || objval is Str || objval is List) return this; try { domain.CallStackPush (this); return ((TermValue) objval).Eval (domain); } catch (Error e) { if (e.Stack == null) e.Stack = domain.CallStack; throw e; } finally { domain.CallStackPop (); } } public Term Clone () { if (objval == null || objval is Symbol) return this; if (objval is Str) return new Term (((Str) objval).ToString ()); if (objval is List) { List list = new List (); list.InsertRange (0, ((List) objval)); return new Term (list); } return new Term (((TermValue) objval).Clone ()); } public static bool operator== (Term t1, Term t2) { return t1.Equals (t2); } public static bool operator!= (Term t1, Term t2) { return ! (t1 == t2); } public override bool Equals (object obj) { if (! (obj is Term)) return false; Term term = (Term) obj; if (IsInt) return term.IsInt && term.Intval == Intval; if (IsSymbol) return term.IsSymbol && term.Symval == Symval; if (IsStr) return (term.IsStr && term.Strval.Equals (Strval)); if (IsList) { if (! term.IsList) return false; List l1 = objval as List; List l2 = term.objval as List; if (l1.Count != l2.Count) return false; for (int i = 0; i < l1.Count; i++) if (! l1[i].Equals (l2[i])) return false; return true; } return ((TermValue) objval).Equals (obj); } public override int GetHashCode () { return intval; } public bool Matches (Term term) { if (IsInt) return term.IsInt && Intval == term.Intval; if (IsSymbol) return term.IsSymbol && Symval == term.Symval; if (IsStr) return term.IsStr && Strval.Matches (term.Strval); if (IsList) { if (! term.IsList) return false; List l1 = objval as List; List l2 = term.objval as List; if (l1.Count > l2.Count) return false; for (int i = 0; i < l1.Count; i++) if (! l1[i].Equals (l2[i])) return false; return true; } return ((TermValue) objval).Matches ((TermValue) term.objval); } public override string ToString () { return ToString (true); } public string ToString (bool detail) { string str; if (objval == null) str = "" + intval + ""; else if (objval is Symbol) str = "" + objval + ""; else if (objval is Str) str = "" + objval + ""; else if (objval is List) { if (detail) { str = ""; foreach (Term e in (List) objval) str += e; str += ""; } else str = ""; } else if (objval is Term) str = "" + objval + ""; else str = ((TermValue) objval).ToString (detail); return str; } } private static Term Zero = new Term (0); private static Term One = new Term (1); private static Term TermInt = new Term (Qinteger); private static Term TermStr = new Term (Qstring); private static Term TermSymbol = new Term (Qsymbol); private static Term TermList = new Term (Qlist); private static Term TermTerm = new Term ((Symbol) "term"); private static int parse_integer (XmlNode node) { string str = node.InnerText; int len = str.Length; int i, c; if (len == 2 && str[0] == '?') return str[1]; if (len > 2 && str[1] == 'x' && ((c = str[0]) == '0' || c == '#')) { if (! int.TryParse (str.Substring (2), Globalization.NumberStyles.HexNumber, null, out i)) throw new Error (Error.InvalidInteger, node, "Not a integer string: {0}", str); return i; } if (! int.TryParse (str, out i)) throw new Error (Error.InvalidInteger, node, "Not a integer string: {0}", str); return i; } private static Symbol parse_defvar (Domain domain, XmlNode node) { XmlAttribute name = node.Attributes[Qvname]; if (name == null) throw new Error (Error.NoVariableName, node, "No variable name to define"); Symbol vname = name.Value; String desc; Variable vari; node = node.FirstChild; if (node != null && node.Name == Qdescription) { desc = node.InnerText; node = node.NextSibling; } else desc = null; if (node != null) { Symbol type = node.Name; XmlNodeList range_list = null; int nranges = 0; XmlNode n = node.NextSibling; if (n != null) { range_list = n.ChildNodes; nranges = range_list.Count; } if (type == Qinteger) { int val = parse_integer (node); int[] range = null; if (range_list != null) { range = new int[nranges * 2]; for (int i = 0; i < nranges; i++) { XmlNode nd = range_list[i]; if (nd.Name == Qrange) { range[i * 2] = parse_integer (nd.FirstChild); range[i * 2 + 1] = parse_integer (nd.LastChild); } else { range[i * 2] = range[i * 2 + 1] = parse_integer (nd.FirstChild); } } } vari = domain.Defvar (vname, val, desc, range); } else if (type == Qstring) { string[] range = null; if (range_list != null) { range = new string[nranges]; for (int i = 0; i < nranges; i++) range[i] = range_list[i].FirstChild.InnerText; } vari = domain.Defvar (vname, node.InnerText, desc, range); } else if (type == Qsymbol) { Symbol[] range = null; if (range_list != null) { range = new Symbol[nranges]; for (int i = 0; i < nranges; i++) range[i] = range_list[i].FirstChild.InnerText; } vari = domain.Defvar (vname, (Symbol) node.InnerText, desc, range); } else throw new Error (Error.TermTypeInvalid, "Unknown type: {0}", type); } else { if (domain.variables.TryGetValue (vname, out vari)) vari = vari.Clone (domain); else vari = new Variable (domain, vname, Zero); domain.variables[vname] = vari; } return vname; } private static Variable[] parse_args (Domain domain, XmlNode node, out int min_args, out int max_args) { int nfixed = 0; int noptional = 0; int nrest = 0; Variable[] args; node = node.FirstChild; if (node != null && node.Name == Qargs) { XmlNode n; for (n = node.FirstChild; n != null; n = n.NextSibling) { if (n.Name == Qfixed) nfixed++; else if (n.Name == Qoptional) noptional++; else if (n.Name == Qrest) { if (nrest > 0) throw new Error (Error.WrongType, n, "Too many "); nrest++; } else throw new Error (Error.WrongType, n, "Not fixed, optional, nor rest: {0}", n.Name); } min_args = nfixed; max_args = nfixed + noptional + nrest; args = new Variable[max_args]; n = node.FirstChild; for (int i = 0; i < max_args; n = n.NextSibling) args[i++] = domain.Defvar ((Symbol) n.Attributes[0].Value); if (nrest == 1) max_args = - max_args; } else { min_args = max_args = 0; args = new Variable[0]; } return args; } private static Symbol parse_defun_head (Domain domain, XmlNode node) { Symbol name = node.Attributes[Qfname].Value; int min_args, max_args; Variable[] args; args = parse_args (domain, node, out min_args, out max_args); if (node.Name == Qdefun) domain.Defun (name, min_args, max_args, args, null); else domain.Defmacro (name, min_args, max_args, args, null); return name; } private static void parse_defun_body (Domain domain, XmlNode node) { bool is_defun = node.Name == Qdefun; Symbol name = node.Attributes[Qfname].Value; Function func = domain.GetFunc (name); for (node = node.FirstChild; node != null; node = node.NextSibling) if (node.Name != Qdescription && node.Name != Qargs) break; Console.WriteLine ("found body " + node.Name); Term[] body = Parse (domain, node, null); if (is_defun) ((Function.Lambda) func).SetBody (body); else ((Function.Macro) func).SetBody (body); } public static Term Parse (Domain domain, XmlNode node) { Symbol name = node.Name; try { if (name == Qinteger) return new Term (parse_integer (node)); if (name == Qsymbol) return new Term ((Symbol) node.InnerText); if (name == Qstring) return new Term (node.InnerText); if (name == Qlist) { List list = new List (); for (node = node.FirstChild; node != null; node = node.NextSibling) list.Add (Parse (domain, node)); return new Term (list); } if (name == Qdefun || name == Qdefmacro) { name = parse_defun_head (domain, node); parse_defun_body (domain, node); return new Term (name); } if (name == Qdefvar) { name = parse_defvar (domain, node); return new Term (name); } MethodInfo parser; if (domain.termtypes.TryGetValue (name, out parser)) { object[] arg = new object[] { domain, node }; return new Term ((TermValue) parser.Invoke (null, arg)); } Funcall funcall = (Funcall) Funcall.Parser (domain, node); if (funcall.func is Function.Macro) return funcall.Eval (domain); return new Term (funcall); } catch (Error e) { if (e.Node == null) e.Node = node; throw e; } catch (Exception e) { throw new Error (Error.UnknownError, node, e, "Parsing error"); } } /// Parse a node and the following siblings as "term"s in a /// specific domain. /// /// /// /// Array of terms. public static Term[] Parse (Domain domain, XmlNode start, XmlNode stop) { XmlNode n; for (n = start; n != stop && n != null; n = n.NextSibling) if (n.NodeType == XmlNodeType.Element && (n.Name == Qdefun || n.Name == Qdefmacro)) { try { parse_defun_head (domain, n); } catch (Error e) { if (e.Node == null) e.Node = n; throw e; } catch (Exception e) { throw new Error (Error.UnknownError, n, e, "Parsing error"); } } List terms = new List (); for (; start != n; start = start.NextSibling) if (start.NodeType == XmlNodeType.Element) { try { if (start.Name == Qdefun || start.Name == Qdefmacro) parse_defun_body (domain, start); else if (start.Name == Qdefvar) parse_defvar (domain, start); else terms.Add (Parse (domain, start)); } catch (Error e) { if (e.Node == null) e.Node = start; throw e; } catch (Exception e) { throw new Error (Error.UnknownError, start, e, "Parsing error"); } } return terms.ToArray (); } public static Term[] Parse (Domain domain, string url) { XmlDocument doc = new XmlDocument (Symbol.NameTable); XmlNode node; using (XmlTextReader reader = new XmlTextReader (url, Symbol.NameTable)) { reader.WhitespaceHandling = WhitespaceHandling.None; do { reader.Read (); } while (reader.NodeType != XmlNodeType.None && (reader.NodeType != XmlNodeType.Element || reader.Name != Qexpr)); if (reader.NodeType == XmlNodeType.None) throw new Exception ("Node not found"); node = doc.ReadNode (reader); } return Parse (domain, node.FirstChild, null); } /// Evaluate a term in a specific domain. /// Domain to evaluate the term in. /// The term to evaluate. /// The result of evaluating the . public static Term Eval (Domain domain, Term term) { return Eval (domain, new Term[] { term }); } /// Evaluate terms in a specific domain. /// Domain to evaluate terms in. /// Array of terms to evaluate. /// The result of evaluating the last term of . public static Term Eval (Domain domain, Term[] terms) { Term result = Zero; try { foreach (Term term in terms) { result = term.Eval (domain); if (domain.Thrown ()) return result; } return result; } catch (Error e) { throw e; } catch (Exception e) { throw new Error (Error.UnknownError, null, e, "Runtime error"); } } // TRACING private static int trace_depth = 0; /// TraceDepth specifies the minimum depth of call stack /// to suppress tracing. 0 means no tracing. public static int TraceDepth { get { return trace_depth; } set { trace_depth = value; } } } }