public Object eval(Env env)
{
Object f = fexpr.eval(env);
Object[] args = new Object[argexprs.Length];
for (Int32 i = 0; i < args.Length; i++)
args[i] = argexprs[i].eval(env);
Boolean doTrace = fsym != null &&
interpreter.traceList.Contains(fsym);
try
{
if (doTrace)
{
interpreter.trace(fsym.name, args);
Trace.Indent();
Object ret = Util.InvokeObject(f, args);
Trace.Unindent();
return ret;
}
else
return Util.InvokeObject(f, args);
}
catch (Exception ex)
{
if (fsym != null && !fsym.name.Equals("throw"))
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, fsym, args)
, interpreter);
}
else
{
throw ex;
}
}
}
internal Closure(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.interpreter = interpreter;
this.loc = loc;
ArgSpecs specs = analyzeArgSpec((Cons)args.first, env, loc);
//create an env expanded by params in which to analyze body
Env env2 = new Env(specs.parameters, null, env);
this.argSpecs = specs;
this.body = interpreter.analyze(new Cons(interpreter.BLOCK, args.rest), env2, loc);
this.env = env;
}
internal ApplyExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
fexpr = interpreter.analyze(args.first, env, loc);
if (fexpr is IVar)
{
fsym = ((IVar)fexpr).getSymbol();
}
Int32 len = Cons.Length(args.rest);
argexprs = new IExpression[len];
args = args.rest;
for (Int32 i = 0; i < argexprs.Length; i++, args = args.rest)
{
argexprs[i] = interpreter.analyze(args.first, env, loc);
}
}
public Interpreter()
{
globalenv = new Env(null, null, null);
reader = new Reader(this);
symbolTable = new SymbolTable();
Assembly[] asm = AppDomain.CurrentDomain.GetAssemblies();
foreach (Assembly a in asm)
{
addTypesFrom(a);
}
internBuiltins();
Primitives.internAll(this);
LASTVAL.setGlobalValue(null);
NEXTLASTVAL.setGlobalValue(null);
THIRDLASTVAL.setGlobalValue(null);
//these primitives are here, rather than in Primitives, because their implementation
//requires calls to gfs bound to symbols
Intern("intern", new Function(internf));
Intern("eval", new Function(evalf));
Intern("load", new Function(loadf));
Intern("map->list", new Function(map_to_list));
Intern("apply", new Function(apply));
Intern("<", new Function(lt));
Intern("<=", new Function(lteq));
Intern(">", new Function(gt));
Intern(">=", new Function(gteq));
Intern("==", new Function(eqeq));
Intern("!=", new Function(noteq));
strgf = (GenericFunction)intern("str").getGlobalValue();
get_enum_gf = (GenericFunction)intern("get-enum").getGlobalValue();
compare_gf = (BinOp)intern("compare").getGlobalValue();
Intern("interpreter", this);
}
public Object eval(Env env)
{
try
{
Object retval = val.eval(env);
var.setval(retval, env);
return retval;
}
catch (BacktraceException bex)
{
throw bex;
}
catch (Exception ex)
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, "set", null), interpreter);
}
}
internal SetExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Int32 len = Cons.Length(args);
if (len != 2)
throw new Exception("Wrong number of args for set");
var = (IVar)interpreter.analyze(args.first, env, loc);
val = interpreter.analyze(Cons.Second(args), env, loc);
}
//parse out params from spec (which may contain &optional, &key, &rest, initforms etc
internal ArgSpecs analyzeArgSpec(Cons arglist, Env env, Loc loc)
{
//count the params
int nParams = 0;
Cons a = arglist;
while (a != null)
{
Object p = a.first;
if (p != interpreter.AMPOPT && p != interpreter.AMPKEY && p != interpreter.AMPREST)
++nParams;
a = a.rest;
}
ArgSpecs ret = new ArgSpecs(env);
ret.parameters = new Parameter[nParams];
Parameter.Spec state = Parameter.Spec.REQ;
int param = 0;
a = arglist;
while (a != null)
{
Object p = a.first;
switch (state)
{
case Parameter.Spec.REQ:
if (p == interpreter.AMPOPT)
state = Parameter.Spec.OPT;
else if (p == interpreter.AMPKEY)
state = Parameter.Spec.KEY;
else if (p == interpreter.AMPREST)
state = Parameter.Spec.REST;
else
{
if (p is Symbol)
{
ret.parameters[param++] =
new Parameter((Symbol)p, Parameter.Spec.REQ, null);
++ret.numReq;
}
else if (p is Cons)
{
ret.parameters[param] =
new Parameter((Symbol)((Cons)p).first, Parameter.Spec.REQ, null);
ret.parameters[param].typeSpec = interpreter.eval(Cons.Second((Cons)p), env);
++param;
++ret.numReq;
}
}
break;
case Parameter.Spec.OPT:
if (p == interpreter.AMPOPT)
throw new Exception("&optional can appear only once in arg list");
else if (p == interpreter.AMPKEY)
state = Parameter.Spec.KEY;
else if (p == interpreter.AMPREST)
state = Parameter.Spec.REST;
else
{
if (p is Symbol)
{
ret.parameters[param++] =
new Parameter((Symbol)p, Parameter.Spec.OPT, null);
++ret.numOpt;
}
else if (p is Cons)
{
ret.parameters[param++] =
new Parameter((Symbol)((Cons)p).first, Parameter.Spec.OPT,
interpreter.analyze(Cons.Second((Cons)p), env, loc));
++ret.numOpt;
}
else
throw new Exception("&optional parameters must be symbols or (symbol init-form)");
}
break;
case Parameter.Spec.KEY:
if (p == interpreter.AMPOPT)
throw new Exception("&optional must appear before &key in arg list");
else if (p == interpreter.AMPKEY)
throw new Exception("&key can appear only once in arg list");
else if (p == interpreter.AMPREST)
state = Parameter.Spec.REST;
else
{
if (p is Symbol)
{
ret.parameters[param] =
new Parameter((Symbol)p, Parameter.Spec.KEY, null);
ret.parameters[param].key = interpreter.intern(":" + ((Symbol)p).name);
++param;
++ret.numKey;
}
else if (p is Cons)
{
ret.parameters[param] =
new Parameter((Symbol)((Cons)p).first, Parameter.Spec.KEY,
interpreter.analyze(Cons.Second((Cons)p), env, loc));
ret.parameters[param].key =
interpreter.intern(":" + ((Symbol)((Cons)p).first).name);
++param;
++ret.numKey;
}
else
throw new Exception("&key parameters must be symbols or (symbol init-form)");
}
break;
case Parameter.Spec.REST:
if (p == interpreter.AMPOPT)
throw new Exception("&optional must appear before &rest in arg list");
else if (p == interpreter.AMPKEY)
throw new Exception("&key must appear before &rest in arg list");
else if (p == interpreter.AMPREST)
throw new Exception("&rest can appear only once in arg list");
else
{
if (!(p is Symbol))
throw new Exception("&rest parameter must be a symbol");
else
{
if (ret.numRest > 0) //already got a rest param
throw new Exception("Only one &rest arg can be specified");
ret.parameters[param++] =
new Parameter((Symbol)p, Parameter.Spec.REST, null);
++ret.numRest;
}
}
break;
}
a = a.rest;
}
return ret;
}
internal IExpression analyze(Object expr, Env env, Loc enclosingLoc)
{
Symbol symbol = expr as Symbol;
if (symbol != null)
{
if (symbol.isDynamic)
return new DynamicVar(symbol);
Object var = env.lookup(symbol);
if (var is LocalVariable)
return new LocalVar((LocalVariable)var);
else
return new GlobalVar((Symbol)var);
}
if (!(expr is Cons)) //must be literal
return new QuoteExpr(expr);
Cons exprs = (Cons)expr;
Loc loc = (Loc)reader.locTable[expr];
if (loc != null)
reader.locTable.Remove(expr);
else
loc = enclosingLoc;
Object f = exprs.first;
Cons args = exprs.rest;
//see if it's a macro
Symbol s = f as Symbol;
if (s != null && s.isDefined() && s.getGlobalValue() is Macro)
{
Macro m = (Macro)s.getGlobalValue();
Object[] argarray = Cons.ToVector(args);
Object mexprs = null;
try
{
mexprs = m.Invoke(argarray);
}
catch (Exception ex)
{
BacktraceFrame frame = new BacktraceFrame(loc, s, args);
throw BacktraceException.push(ex, frame, this);
}
try
{
return analyze(mexprs, env, loc);
}
catch (Exception ex)
{
BacktraceFrame frame = new BacktraceFrame(loc, "when expanding ", exprs);
throw BacktraceException.push(ex, frame, this);
}
}
Int32 numargs = Cons.Length(args);
if (f == DLET)
return new DynamicLet(args, env, this, loc);
else if (f == FN)
return new Closure(args, env, this, loc);
else if (f == MACRO)
return new Macro(args, env, this, loc);
else if (f == WHILE)
return new WhileExpression(args, env, this, loc);
else if (f == BLOCK)
{
if (numargs == 0)
return new QuoteExpr(null);
//remove block from block of one
else if (numargs == 1)
return analyze(args.first, env, loc);
else
return new BlockExpression(args, env, this, loc);
}
else if (f == OR)
{
if (numargs == 0)
return new QuoteExpr(null);
else
return new OrExpression(args, env, this, loc);
}
else if (f == IF)
return new IfExpression(args, env, this, loc);
else if (f == QUOTE)
return new QuoteExpr(args.first);
else if (f == SET)
return new SetExpression(args, env, this, loc);
else //presume funcall
return new ApplyExpression(exprs, env, this, loc);
}
internal DynamicLet(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Cons bindlist = (Cons)args.first;
Int32 blen = Cons.Length(bindlist);
if ((blen % 2) != 0) //odd
{
throw new Exception("Odd number of args in dynamic-let binding list");
}
binds = new BindPair[blen / 2];
for (int i = 0; i < binds.Length; i++)
{
binds[i].dvar = (DynamicVar)interpreter.analyze(bindlist.first, env, loc);
bindlist = bindlist.rest;
binds[i].expr = interpreter.analyze(bindlist.first, env, loc);
bindlist = bindlist.rest;
}
this.body = interpreter.analyze(new Cons(interpreter.BLOCK, args.rest), env, loc);
}
public Object eval(Env env)
{
try
{
while (Util.isTrue(test.eval(env)))
{
body.eval(env);
}
return null;
}
catch (BacktraceException bex)
{
throw bex;
}
catch (Exception ex)
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, "set", null), interpreter);
}
}
public Object eval(Env env)
{
try
{
if (Util.isTrue(test.eval(env)))
return brtrue.eval(env);
return brfalse.eval(env);
}
catch (BacktraceException bex)
{
throw bex;
}
catch (Exception ex)
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, "if", null), interpreter);
}
}
internal IfExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Int32 len = Cons.Length(args);
if (len < 2 || len > 3)
throw new Exception("Wrong number of args for if");
test = interpreter.analyze(args.first, env, loc);
brtrue = interpreter.analyze(Cons.Second(args), env, loc);
if (len == 3)
brfalse = interpreter.analyze(Cons.Third(args), env, loc);
else
brfalse = new QuoteExpr(null);
}
public void setval(Object val, Env env)
{
sym.setGlobalValue(val);
}
public Object eval(Env env)
{
return sym.getGlobalValue();
}
public void setval(Object val, Env env)
{
DynamicEnv d = DynamicEnv.find(sym);
if (d != null)
d.val = val;
sym.setGlobalValue(val);
}
public Object eval(Env env)
{
DynamicEnv d = DynamicEnv.find(sym);
if (d != null)
return d.val;
return sym.getGlobalValue();
}
public Object eval(Env env)
{
DynamicEnv olddenv = DynamicEnv.current();
try
{
for (int i = 0; i < binds.Length; i++)
{
DynamicEnv.extend(binds[i].dvar.sym,
binds[i].expr.eval(env));
}
return body.eval(env);
}
catch (BacktraceException bex)
{
throw bex;
}
catch (Exception ex)
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, "set", null), interpreter);
}
finally
{
DynamicEnv.restore(olddenv);
}
}
internal WhileExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
this.test = interpreter.analyze(args.first, env, loc);
this.body = interpreter.analyze(new Cons(interpreter.BLOCK, args.rest), env, loc);
}
internal Env(Parameter[] vars, Object[] vals, Env parent)
{
this.vars = vars; this.vals = vals; this.parent = parent;
}
internal ArgSpecs copy(Env env)
{
ArgSpecs a = (ArgSpecs)MemberwiseClone();
a.env = env;
return a;
}
public Object eval(Env env)
{
return env.getValue(var);
}
public Object eval(Env env)
{
try
{
for (Int32 i = 0; i < exprs.Length - 1; i++)
exprs[i].eval(env);
return exprs[exprs.Length - 1].eval(env);
}
catch (BacktraceException bex)
{
throw bex;
}
catch (Exception ex)
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, "set", null), interpreter);
}
}
internal ArgSpecs(Env env)
{
this.env = env;
}
public void setval(Object val, Env env)
{
env.setValue(var, val);
}
internal IExpression analyze(Object expr, Env env)
{
return analyze(expr, env, null);
}
internal OrExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
exprs = new IExpression[Cons.Length(args)];
for (Int32 i = 0; i < exprs.Length; i++, args = args.rest)
{
exprs[i] = interpreter.analyze(args.first, env, loc);
}
}
internal Object eval(Object x, Env env)
{
IExpression analyzedCode = analyze(x, env);
return analyzedCode.eval(env);
//Object analyzedCode = analyze(x,env);
//return execute(analyzedCode, env);
}
public Object eval(Env env)
{
try
{
for (Int32 i = 0; i < exprs.Length - 1; i++)
{
Object result = exprs[i].eval(env);
if (Util.isTrue(result)) return result;
}
return exprs[exprs.Length - 1].eval(env);
}
catch (BacktraceException bex)
{
throw bex;
}
catch (Exception ex)
{
throw BacktraceException.push(ex, new BacktraceFrame(loc, "set", null), interpreter);
}
}
internal Macro(Cons args, Env env, Interpreter interpreter, Loc loc)
: base(args, env, interpreter, loc)
{
}
public Object eval(Env env)
{
return val;
}