namespace System.Xml.Expression
{
- public abstract class Xex
+ public class Xexpression
{
- public static bool Debug = false;
+ public static int debug_level = 0;
public struct Name : IEquatable<Name>
{
private static Name Nvariable = "variable";
private static Name Ninteger = "integer";
private static Name Nstring = "string";
- private static Name Nboolean = "boolean";
private static Name Nsymbol = "symbol";
private static Name Nlist = "list";
- private static Name Nobject = "object";
private static Name Ndefun = "defun";
private static Name Nfname = "fname";
this.max_arg = max_arg;
}
- public abstract object Call (object[] args, Domain domain);
+ public abstract Term Call (Domain domain, Term[] args);
public override string ToString ()
{
this.builtin = builtin;
}
- public override object Call (object[] args, Domain domain)
+ public override Term Call (Domain domain, Term[] args)
{
- object result;
+ Term[] newargs = new Term[args.Length];
for (int i = 0; i < args.Length; i++)
- {
- object val = args[i];
- if (val is Xex)
- val = ((Xex) val).Eval (domain);
- if (val == null)
- throw new Exception (args[i] + ":evaled to null");
- args[i] = val;
- }
- result = builtin (args, domain);
- return result;
+ newargs[i] = args[i].Eval (domain);
+ return builtin (domain, newargs);
}
}
this.builtin = builtin;
}
- public override object Call (object[] args, Domain domain)
+ public override Term Call (Domain domain, Term[] args)
{
- return builtin (args, domain);
+ return builtin (domain, args);
}
}
internal class Lambda : Function
{
internal bool args_evalled;
- internal Name[] args;
- internal Xex[] body;
+ internal Term[] args;
+ internal Term[] body;
public Lambda (XmlNode node)
{
nrest++;
min_arg = nargs;
max_arg = nargs + noptions + nrest;
- if (nrest == 1)
- max_arg = - max_arg;
- args = new Name[max_arg];
+ args = new Term[max_arg];
n = node.FirstChild;
for (int i = 0; i < max_arg; n = n.NextSibling)
if (n.Name == Nsymbol)
- args[i++] = n.InnerText;
+ args[i++] = new Term (n, null);
+ if (nrest == 1)
+ max_arg = - max_arg;
}
else
{
{
XmlNodeList nlist = node.ChildNodes;
- body = new Xex[nlist.Count];
+ body = new Term[nlist.Count];
for (int i = 0; i < nlist.Count; i++)
- body[i] = New (nlist[i], domain);
+ body[i] = new Term (nlist[i], domain);
}
}
- public override object Call (object[] args, Domain domain)
+ public override Term Call (Domain domain, Term[] args)
{
Bindings current = domain.bindings;
- object result = false;
+ Term result = Zero;
try {
int i;
if (args_evalled)
- for (i = 0; i < min_arg; i++)
- args[i] = ((Xex) args[i]).Eval (domain);
+ {
+ Term[] newargs = new Term[args.Length];
+ for (i = 0; i < min_arg; i++)
+ newargs[i] = args[i].Eval (domain);
+ args = newargs;
+ }
for (i = 0; i < min_arg; i++)
{
- Variable var = domain.GetVar (this.args[i]);
+ Variable var = domain.GetVar ((Name) this.args[i]);
domain.Bind (var, args[i]);
}
- foreach (Xex e in body)
- result = e.Eval (domain);
+ if (body != null)
+ foreach (Term term in body)
+ result = term.Eval (domain);
} finally {
domain.UnboundTo (current);
}
return result;
}
-
- public override string ToString ()
- {
- string str = "(" + name;
- foreach (Name a in args)
- str += " " + a;
- return (str + ")");
- }
}
}
internal abstract class Variable
{
public readonly Name name;
- public readonly Name type;
- internal object val;
+ internal Term val;
- public Variable (Name name, Name type, object value)
+ public Variable (Name name, Term term)
{
- if (value != null)
- Value = value;
this.name = name;
- this.type = type;
+ Value = term;
}
- public object Value
+ public Term Value
{
get { return val; }
set
}
}
- public abstract bool ValueP (object value);
+ public abstract bool ValueP (Term term);
public override string ToString () { return name + "(" + val + ")"; }
- }
- internal class VarInt : Variable
- {
- public struct Range
+ internal class Int : Variable
{
- public int from, to;
- }
+ public struct Range
+ {
+ public int from, to;
+ }
- public Range[] ranges;
+ public Range[] ranges;
- public VarInt (Name name, object value) : base (name, Ninteger, value) { }
+ public Int (Name name, int i) : base (name, new Term (i)) { }
- public override bool ValueP (object value)
- {
- int i;
+ public override bool ValueP (Term term)
+ {
+ int i;
- if (! (value is int))
- return false;
- if (ranges == null)
- return true;
- i = (int) value;
- foreach (Range r in ranges)
- if (i >= r.from && i <= r.to)
+ if (term.objval != null)
+ return false;
+ if (ranges == null)
return true;
- return false;
+ i = term.intval;
+ foreach (Range r in ranges)
+ if (i >= r.from && i <= r.to)
+ return true;
+ return false;
+ }
}
- }
-
- internal class VarStr : Variable
- {
- public string[] ranges;
-
- public VarStr (Name name, object value) : base (name, Nstring, value) { }
- public override bool ValueP (object value)
+ internal class Str : Variable
{
- string str;
-
- if (! (value is string))
- return false;
- if (ranges == null)
- return true;
- str = (string) value;
- foreach (string s in ranges)
- if (s == str)
- return true;
- return false;
- }
- }
+ public string[] ranges;
- internal class VarBool : Variable
- {
- public VarBool (Name name, object value)
- : base (name, Nboolean, value) { }
+ public Str (Name name, string str) : base (name, new Term (str)) { }
- public override bool ValueP (object value)
- {
- if (! (value is bool))
+ public override bool ValueP (Term term)
+ {
+ if (! (term.objval is string))
+ return false;
+ if (ranges == null)
+ return true;
+ string str = (string) term.objval;
+ foreach (string s in ranges)
+ if (s == str)
+ return true;
return false;
- return true;
+ }
}
- }
- internal class VarMisc : Variable
- {
- public VarMisc (Name name, object value) : base (name, Nobject, value) { }
-
- public override bool ValueP (object value)
+ internal class Misc : Variable
{
- return true;
+ public Misc (Name name, Term term) : base (name, term) { }
+
+ public override bool ValueP (Term term) { return true; }
}
}
internal class Bindings
{
private Variable vari;
- private object old_value;
+ private Term old_value;
private Bindings next;
private Bindings (Variable vari)
old_value = vari.val;
}
- public static Bindings Bind (Bindings bindings,
- Variable vari, object value)
+ public static Bindings Bind (Bindings bindings, Variable vari, Term val)
{
Bindings b = new Bindings (vari);
- b.vari.Value = value;
+ b.vari.Value = val;
b.next = bindings;
return b;
}
this.context = context;
}
- internal void Bind (Variable vari, object value)
+ internal void Bind (Variable vari, Term value)
{
bindings = Bindings.Bind (bindings, vari, value);
}
return func;
}
- public void Defvar (Name name, XmlNode node)
+ public void Defvar (XmlNode node)
{
+ Name name = node.Attributes[0].Value;
Variable vari;
+ node = node.FirstChild;
if (node.Name == Ndescription)
node = node.NextSibling;
if (node != null)
if (type == Ninteger)
{
- VarInt vi = new VarInt (name, parse_integer (val));
+ Variable.Int vi = new Variable.Int (name, parse_integer (val));
if (range_list != null)
{
- vi.ranges = new VarInt.Range[nranges];
+ vi.ranges = new Variable.Int.Range[nranges];
for (int i = 0; i < nranges; i++)
{
}
else if (type == Nstring)
{
- VarStr vs = new VarStr (name, val);
+ Variable.Str vs = new Variable.Str (name, val);
if (range_list != null)
vs.ranges = new string[nranges];
for (int i = 0; i < nranges; i++)
vs.ranges[i] = range_list[i].Value;
vari = vs;
}
- else if (type == Nboolean)
- {
- vari = new VarBool (name, val == "true");
- }
else
throw new Exception ("Unknown type: " + type);
}
else
- vari = new VarMisc (name, null);
+ vari = new Variable.Misc (name, Zero);
variables[name] = vari;
}
Variable vari;
if (! variables.TryGetValue (name, out vari))
- variables[name] = vari = new VarMisc (name, null);
+ variables[name] = vari = new Variable.Misc (name, Zero);
return vari;
}
return str;
}
- public void DebugWrite (bool head, string fmt, params object[] arg)
+ public void DebugWrite (bool head, string fmt, params string[] arg)
{
- if (Debug)
+ if (debug_level > depth)
{
if (head)
{
}
}
- public delegate object Builtin (object[] args, Domain domain);
+ public delegate Term Builtin (Domain domain, Term[] args);
private static Domain basic = new Domain ();
internal static Function Fprogn;
- static Xex ()
+ static Xexpression ()
{
basic.DefSubr (set_value, "set", 2, 2);
basic.DefSubr (set_value, "=", 2, 2);
basic.DefSubr (greater_than, ">", 2, -1);
basic.DefSubr (greater_eq, "ge", 2, -1);
basic.DefSubr (greater_eq, ">=", 2, -1);
+ basic.DefSubr (copy, "copy", 1, 1);
+ basic.DefSubr (append, "append", 1, -1);
+ basic.DefSpecial (quote_clause, "quote", 1, 1);
basic.DefSubr (eval_clause, "eval", 1, 1);
basic.DefSpecial (progn_clause, "progn", 0, -1);
basic.DefSpecial (progn_clause, "expr", 0, -1);
Fprogn = basic.GetFunc (Nprogn);
}
- private static bool is_true (object val)
- {
- return (val is bool ? (bool) val
- : val is int ? (int) val == 0
- : true);
- }
-
- private static object set_value (object[] args, Domain domain)
+ private static Term set_value (Domain domain, Term[] args)
{
Variable vari = domain.GetVar ((Name) args[0]);
return vari.val;
}
- private static object and (object[] args, Domain domain)
+ private static Term and (Domain domain, Term[] args)
{
- foreach (object arg in args)
- if (! is_true (((Xex) arg).Eval (domain)))
- return false;
- return true;
+ foreach (Term arg in args)
+ if (! arg.Eval (domain).IsTrue)
+ return Zero;
+ return One;
}
- private static object or (object[] args, Domain domain)
+ private static Term or (Domain domain, Term[] args)
{
- foreach (object arg in args)
- if (is_true (((Xex) arg).Eval (domain)))
- return true;
- return false;
+ foreach (Term arg in args)
+ if (arg.Eval (domain).IsTrue)
+ return One;
+ return Zero;
}
- private static object not (object[] args, Domain domain)
+ private static Term not (Domain domain, Term[] args)
{
- return ! is_true (args);
+ return args[0].IsTrue ? Zero : One;
}
- private static object add (object[] args, Domain domain)
+ private static Term add (Domain domain, Term[] args)
{
int n = 0;
- foreach (object arg in args)
+ foreach (Term arg in args)
n += (int) arg;
return n;
}
- private static object mul (object[] args, Domain domain)
+ private static Term mul (Domain domain, Term[] args)
{
int n = 1;
- foreach (object arg in args)
+ foreach (Term arg in args)
n *= (int) arg;
return n;
}
- private static object sub (object[] args, Domain domain)
+ private static Term sub (Domain domain, Term[] args)
{
int n = (int) args[0];
if (args.Length == 1)
return n;
}
- private static object div (object[] args, Domain domain)
+ private static Term div (Domain domain, Term[] args)
{
int n = (int) args[0];
for (int i = 1; i < args.Length; i++)
return n;
}
- private static object mod (object[] args, Domain domain)
+ private static Term mod (Domain domain, Term[] args)
{
return ((int) args[0] % (int) args[1]);
}
- private static object logior (object[] args, Domain domain)
+ private static Term logior (Domain domain, Term[] args)
{
int n = 0;
- foreach (object arg in args)
+ foreach (Term arg in args)
n |= (int) arg;
return n;
}
- private static object logand (object[] args, Domain domain)
+ private static Term logand (Domain domain, Term[] args)
{
int n = (int) args[0];
for (int i = 1; i < args.Length; i++)
return n;
}
- private static object add_set (object[] args, Domain domain)
+ private static Term add_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n += (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object mul_set (object[] args, Domain domain)
+ private static Term mul_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n *= (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object sub_set (object[] args, Domain domain)
+ private static Term sub_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n -= (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object div_set (object[] args, Domain domain)
+ private static Term div_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n /= (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object mod_set (object[] args, Domain domain)
+ private static Term mod_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n %= (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object logior_set (object[] args, Domain domain)
+ private static Term logior_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n |= (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object logand_set (object[] args, Domain domain)
+ private static Term logand_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
for (int i = 1; i < args.Length; i++)
n &= (int) args[i];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object lsh (object[] args, Domain domain)
+ private static Term lsh (Domain domain, Term[] args)
{
return (int) args[0] << (int) args[1];
}
- private static object lsh_set (object[] args, Domain domain)
+ private static Term lsh_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
n <<= (int) args[1];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object rsh (object[] args, Domain domain)
+ private static Term rsh (Domain domain, Term[] args)
{
return (int) args[0] >> (int) args[1];
}
- private static object rsh_set (object[] args, Domain domain)
+ private static Term rsh_set (Domain domain, Term[] args)
{
- Variable vari = domain.GetVar ((Name) ((Xex.Const) args[0]).val);
+ Variable vari = domain.GetVar ((Name) args[0]);
int n = (int) vari.val;
n >>= (int) args[1];
vari.val = n;
- return n;
+ return vari.val;
}
- private static object eq (object[] args, Domain domain)
+ private static Term eq (Domain domain, Term[] args)
{
- object o = args[0];
+ Term o = args[0];
- for (int i = 1; i < args.Length; i++)
- if (o != args[i])
- return false;
- return true;
+ 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 object noteq (object[] args, Domain domain)
+ private static Term noteq (Domain domain, Term[] args)
{
- return (args[0] != args[1]);
+ return eq (domain, args);
}
- private static object less_than (object[] args, Domain domain)
+ private static Term less_than (Domain domain, Term[] args)
{
int n = (int) args[0];
{
int n1 = (int) args[i];
if (n >= n1)
- return false;
+ return Zero;
n = n1;
}
- return true;
+ return One;
}
- private static object less_eq (object[] args, Domain domain)
+ private static Term less_eq (Domain domain, Term[] args)
{
int n = (int) args[0];
for (int i = 1; i < args.Length; i++)
{
int n1 = (int) args[i];
if (n > n1)
- return false;
+ return Zero;
n = n1;
}
- return true;
+ return One;
}
- private static object greater_than (object[] args, Domain domain)
+ private static Term greater_than (Domain domain, Term[] args)
{
int n = (int) args[0];
for (int i = 1; i < args.Length; i++)
{
int n1 = (int) args[i];
if (n <= n1)
- return false;
+ return Zero;
n = n1;
}
- return true;
+ return One;
}
- private static object greater_eq (object[] args, Domain domain)
+ private static Term greater_eq (Domain domain, Term[] args)
{
int n = (int) args[0];
for (int i = 1; i < args.Length; i++)
{
int n1 = (int) args[i];
if (n < n1)
- return false;
+ return Zero;
n = n1;
}
- return true;
+ return One;
+ }
+
+ private static Term copy (Domain domain, Term[] args)
+ {
+ object obj = args[0].objval;
+
+ if (! (obj is List<Term>))
+ throw new Exception ("Invalid arg to copy: " + args[0]);
+ return new Term (new List<Term> ((List<Term>) obj));
+ }
+
+ private static Term append (Domain domain, Term[] args)
+ {
+ object obj = args[0].objval;
+ if (obj is string)
+ {
+ string str = "";
+ foreach (Term arg in args)
+ str += arg;
+ return new Term (str);
+ }
+ else if (obj is List<Term>)
+ {
+ List<Term> list = new List<Term> ();
+ foreach (Term arg in args)
+ list.AddRange ((List<Term>) arg.objval);
+ return new Term (list);
+ }
+ throw new Exception ("Invalid term to append: " + obj);
+ }
+
+ private static Term quote_clause (Domain domain, Term[] args)
+ {
+ return new Term (args[0]);
}
- private static object eval_clause (object[] args, Domain domain)
+ private static Term eval_clause (Domain domain, Term[] args)
{
- return ((Xex) args[0]).Eval (domain);
+ return (args[0].Eval (domain));
}
- private static object progn_clause (object[] args, Domain domain)
+ private static Term progn_clause (Domain domain, Term[] args)
{
- object result = true;
+ Term result = One;
- foreach (object arg in args)
- result = ((Xex) arg).Eval (domain);
+ foreach (Term arg in args)
+ result = arg.Eval (domain);
return result;
}
- private static object if_clause (object[] args, Domain domain)
+ private static Term if_clause (Domain domain, Term[] args)
{
- object result;
+ if (args[0].Eval (domain).IsTrue)
+ return args[1].Eval (domain);
- if (is_true (((Xex) args[0]).Eval (domain)))
- result = ((Xex) args[1]).Eval (domain);
- else
- {
- result = false;
- for (int i = 2; i < args.Length; i++)
- result = ((Xex) args[i]).Eval (domain);
- }
+ Term result = Zero;
+ for (int i = 2; i < args.Length; i++)
+ result = args[i].Eval (domain);
return result;
}
- private static object when_clause (object[] args, Domain domain)
+ private static Term when_clause (Domain domain, Term[] args)
{
- if (! is_true (((Xex) args[0]).Eval (domain)))
- return false;
+ if (! args[0].Eval (domain).IsTrue)
+ return Zero;
- object result = true;
+ Term result = One;
for (int i = 1; i < args.Length; i++)
- result = ((Xex) args[i]).Eval (domain);
+ result = args[i].Eval (domain);
return result;
}
- private static object while_clause (object[] args, Domain domain)
+ private static Term while_clause (Domain domain, Term[] args)
{
- while (is_true (((Xex) args[0]).Eval (domain)))
+ while (args[0].Eval (domain).IsTrue)
for (int i = 1; i < args.Length; i++)
- ((Xex) args[i]).Eval (domain);
- return false;
+ args[i].Eval (domain);
+ return Zero;
}
- public abstract object Eval (Domain domain);
- public abstract Name TypeOf { get; }
-
- private class Funcall : Xex
+ public struct Term
{
- internal Function func;
- internal Xex[] args;
- internal object[] real_args;
+ public int intval;
+ public object objval;
+
+ public Term (int i) { intval = i; objval = null; }
+ public Term (Name name) { intval = 0; objval = name; }
+ public Term (string str) { intval = 0; objval = str; }
+ public Term (List<Term> list) { intval = 0; objval = list; }
+ public Term (Term term) { intval = 0; objval = term; }
+
+ public Term (XmlNode node, Domain domain)
+ {
+ Name name = node.Name;
- public Funcall (Function func, Xex[] args)
+ if (name == Ninteger)
+ {
+ intval = parse_integer (node.InnerText);
+ objval = null;
+ }
+ else
+ {
+ intval = 0;
+ if (name == Nsymbol)
+ objval = (Name) node.InnerText;
+ else if (name == Nstring)
+ objval = node.InnerText.Clone ();
+ else if (name == Nvariable)
+ objval = domain.GetVar ((Name) node.Attributes[0].Value);
+ else if (name == Nlist)
+ {
+ List<Term> list = new List<Term> ();
+ for (node = node.FirstChild; node != null;
+ node = node.NextSibling)
+ list.Add (new Term (node, domain));
+ objval = list;
+ }
+ else
+ {
+ if (name == Nfuncall)
+ name = node.Attributes[0].Value;
+
+ Function func = domain.GetFunc (name);
+ XmlNodeList nlist = node.ChildNodes;
+ int nargs = nlist.Count;
+
+ if (nargs < func.min_arg
+ || (func.max_arg >= 0 && nargs > func.max_arg))
+ throw new Exception ("Invalid number of arguments to: "
+ + name + " " + nargs);
+ Term[] args = new Term[nargs];
+ for (int i = 0; i < nlist.Count; i++)
+ args[i] = new Term (nlist[i], domain);
+ objval = new Funcall (func, args);
+ }
+ }
+ }
+
+ private class Funcall
+ {
+ internal Function func;
+ internal Term[] args;
+
+ public Funcall (Function func, Term[] args)
{
this.func = func;
this.args = args;
- real_args = new object[args.Length];
}
- public override object Eval (Domain domain)
- {
- domain.DebugWrite (true, "(({0}", func);
- for (int i = 0; i < args.Length; i++)
- {
- domain.DebugWrite (false, " {0}", args[i]);
- real_args[i] = args[i];
- }
- domain.DebugWrite (false, ")");
- domain.depth += 2;
- object result = func.Call (real_args, domain);
- domain.depth -= 2;
- domain.DebugWrite (true, " => {0})", result);
- return result;
+ public Term Eval (Domain domain)
+ {
+ domain.DebugWrite (true, "(({0}", func.name);
+ for (int i = 0; i < args.Length; i++)
+ domain.DebugWrite (false, " {0}", args[i].ToString ());
+ domain.DebugWrite (false, ")");
+ domain.depth += 2;
+ Term result = func.Call (domain, args);
+ domain.depth -= 2;
+ domain.DebugWrite (true, " => {0})", result.ToString ());
+ return result;
+ }
+
+ public override string ToString ()
+ {
+ string str = "<funcall fname=\"" + func.name;
+ if (args == null)
+ return str + "\"/>";
+ str += "\">";
+ foreach (Term e in args)
+ str += e;
+ return (str + "</funcall>");
+ }
}
- public override Name TypeOf { get { return Nfuncall; } }
+ public bool IsTrue {
+ get {
+ return (objval == null
+ ? (intval != 0)
+ : objval is List<Term>
+ ? (((List<Term>) objval).Count != 0)
+ : true);
+ }
+ }
- public override string ToString ()
+ public Term Eval (Domain domain)
{
- string str = "(" + func.name;
- if (args != null)
- foreach (Xex e in args)
- str += " " + e.ToString ();
- return (str + ")");
+ if (objval == null || objval is Name || objval is string)
+ return this;
+ if (objval is List<Term>)
+ return new Term ((List<Term>) objval);
+ if (objval is Funcall)
+ return ((Funcall) objval).Eval (domain);
+ if (objval is Variable)
+ return ((Variable) objval).val;
+ if (objval is Term)
+ return (Term) objval;
+ throw new Exception ("invalid Term object: " + objval);
}
- }
-
- private class Varref : Xex
- {
- internal Variable vari;
- public Varref (Variable vari) { this.vari = vari; }
-
- public override object Eval (Domain domain)
+ public static explicit operator int (Term term)
{
- domain.DebugWrite (true, "(get-value {0})", vari);
- return vari.val;
+ if (term.objval != null)
+ throw new Exception ("Not an integer term: " + term);
+ return term.intval;
}
- public override Name TypeOf { get { return Nvariable; } }
-
- public override string ToString ()
+ public static explicit operator Name (Term term)
{
- return "$" + vari.name + "/" + vari.val;
+ return (Name) term.objval;
}
- }
-
- private class Const : Xex
- {
- public object val;
-
- public Const (object val) { this.val = val; }
- public override object Eval (Domain domain)
+ public static implicit operator Term (int i)
{
- domain.DebugWrite (true, "(const {0})\n", val);
- return val;
+ return new Term (i);
}
- public override Name TypeOf {
- get
+ public override string ToString ()
+ {
+ if (objval == null)
+ return "<integer>" + intval + "</integer>";
+ if (objval is Name)
+ return "<symbol>" + objval + "</symbol>";
+ if (objval is string)
+ return "<string>" + objval + "</string>";
+ if (objval is List<Term>)
{
- return (val is int ? Ninteger
- : val is string ? Nstring
- : val is bool ? Nboolean
- : val is Name ? Nsymbol
- : Nlist);
+ string str = "<list>";
+ foreach (Term e in (List<Term>) objval)
+ str += e;
+ return str + "</list>";
}
+ if (objval is Funcall)
+ return "<funcall fname=\"" + ((Funcall) objval).func.name + "\"/>";
+ if (objval is Variable)
+ return "<variable vname=\"" + ((Variable) objval).name + "\"/>";
+ if (objval is Term)
+ return "<quote>" + objval + "</quote>";
+ throw new Exception ("invalid Term object: " + objval);
}
-
- public override string ToString () { return val.ToString (); }
}
+ static Term Zero = new Term (0);
+ static Term One = new Term (1);
+
internal static int parse_integer (string str)
{
int len = str.Length;
return negative ? - i : i;
}
- private static int pre_parse (XmlNodeList nlist, Domain domain)
- {
- int len = 0;
- foreach (XmlNode node in nlist)
- {
- if (node.Name == Ndefun)
- domain.RegisterFunction (node);
- else if (node.Name == Ndefvar)
- domain.Defvar ((Name) node.Attributes[0].Value, node.FirstChild);
- else
- len++;
- }
- return len;
- }
-
- private static void post_parse (XmlNodeList nlist, Xex[] args,
- Domain domain)
- {
- for (int i = 0, j = 0; i < nlist.Count; i++)
- {
- XmlNode node = nlist[i];
+ private Term[] terms;
- if (node.Name == Ndefun)
- domain.Defun (node);
- else if (node.Name != Ndefvar)
- args[j++] = New (node, domain);
- }
- }
-
- public static Xex New (string url, Domain domain)
+ public Xexpression (string url, Domain domain)
{
XmlDocument doc = new XmlDocument (Name.Table);
XmlNode node;
reader.Read ();
} while (reader.NodeType != XmlNodeType.None
&& (reader.NodeType != XmlNodeType.Element
- || Nexpr != reader.Name));
+ || reader.Name != Nexpr));
if (reader.NodeType == XmlNodeType.None)
throw new Exception ("Node <expr> not found");
node = doc.ReadNode (reader);
}
- return New (node, domain);
+ int nterms = 0;
+ for (XmlNode n = node.FirstChild; n != null; n = n.NextSibling)
+ if (n.NodeType == XmlNodeType.Element)
+ {
+ if (n.Name == Ndefun)
+ domain.RegisterFunction (n);
+ else if (n.Name == Ndefvar)
+ domain.Defvar (n);
+ else
+ nterms++;
+ }
+
+ terms = new Term[nterms];
+ int i = 0;
+ for (XmlNode n = node.FirstChild; n != null; n = n.NextSibling)
+ if (n.NodeType == XmlNodeType.Element)
+ {
+ if (n.Name == Ndefun)
+ domain.Defun (n);
+ else if (n.Name != Ndefvar)
+ terms[i]= new Term (n, domain);
+ }
}
- public static Xex New (XmlNode node, Domain domain)
+ public Term Eval (Domain domain)
{
- Name name = node.Name;
- Xex xex;
- if (name == Nvariable)
- {
- Variable vari = domain.GetVar ((Name) node.Attributes[0].Value);
- xex = new Xex.Varref (vari);
- }
- else if (name == Ninteger)
- xex = new Xex.Const (parse_integer (node.InnerText));
- else if (name == Nstring)
- xex = new Xex.Const (node.InnerText);
- else if (name == Nsymbol)
- xex = new Xex.Const ((Name) node.InnerText);
- else if (name == Nboolean)
- xex = new Xex.Const (node.InnerText == "true");
- else if (name == Nlist)
- {
- List<Xex> list = new List<Xex> ();
- for (XmlNode n = node.FirstChild; n != null; n = n.NextSibling)
- list.Add (New (n, domain));
- xex = new Xex.Const (list);
- }
- else
+ Term result = Zero;
+
+ domain.depth = 0;
+ foreach (Term term in terms)
{
- if (name == Nfuncall)
- name = node.Attributes[0].Value;
- Function func = domain.GetFunc (name);
-
- XmlNodeList nlist = node.ChildNodes;
- int nargs = nlist.Count;
-
- if (nargs < func.min_arg
- || (func.max_arg >= 0 && nargs > func.max_arg))
- throw new Exception ("Invalid number of arguments to: "
- + name + " " + nargs);
- nargs = pre_parse (nlist, domain);
- Xex[] args = new Xex[nargs];
- post_parse (nlist, args, domain);
- xex = new Xex.Funcall (func, args);
+ result = term.Eval (domain);
+ Console.WriteLine (result);
}
- return xex;
+ return result;
}
}
}
projects / m17n / m17n-lib-cs.git / commitdiff