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 + "" + func.name + ">");
}
}
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; }
}
}
}