8de5b49cdf 2010-11-09        kinaba: /**
4198578702 2010-11-07        kinaba:  * Authors: k.inaba
4198578702 2010-11-07        kinaba:  * License: NYSL 0.9982 http://www.kmonos.net/nysl/
4198578702 2010-11-07        kinaba:  *
4198578702 2010-11-07        kinaba:  * Evaluator for Polemy programming language.
423f308350 2010-11-07        kinaba:  */
4198578702 2010-11-07        kinaba: module polemy.eval;
4198578702 2010-11-07        kinaba: import polemy._common;
0569f7b8c2 2010-11-07        kinaba: import polemy.lex : LexPosition;
423f308350 2010-11-07        kinaba: import polemy.ast;
3f5dc76a75 2010-11-07        kinaba: import polemy.parse;
b0d8d7875b 2010-11-08        kinaba: import polemy.value;
0569f7b8c2 2010-11-07        kinaba: import std.typecons;
820e7198cc 2010-11-07        kinaba: import std.stdio;
423f308350 2010-11-07        kinaba: 
8de5b49cdf 2010-11-09        kinaba: Table createGlobalContext()
423f308350 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	auto ctx = new Table;
8de5b49cdf 2010-11-09        kinaba: 	// [TODO] autogenerate these typechecks
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("+", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
5d4cb856d8 2010-11-07        kinaba: 		if( args.length != 2 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "+ takes two arguments!!");
5d4cb856d8 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
5d4cb856d8 2010-11-07        kinaba: 			if( auto y = cast(IntValue)args[1] )
5d4cb856d8 2010-11-07        kinaba: 				return new IntValue(x.data+y.data);
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "cannot add non-integers");
5d4cb856d8 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("-", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
5d4cb856d8 2010-11-07        kinaba: 		if( args.length != 2 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "- takes two arguments!!");
5d4cb856d8 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
5d4cb856d8 2010-11-07        kinaba: 			if( auto y = cast(IntValue)args[1] )
5d4cb856d8 2010-11-07        kinaba: 				return new IntValue(x.data-y.data);
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "cannot subtract non-integers");
5d4cb856d8 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("*", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
5d4cb856d8 2010-11-07        kinaba: 		if( args.length != 2 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "* takes two arguments!!");
5d4cb856d8 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
5d4cb856d8 2010-11-07        kinaba: 			if( auto y = cast(IntValue)args[1] )
5d4cb856d8 2010-11-07        kinaba: 				return new IntValue(x.data*y.data);
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "cannot multiply non-integers");
5d4cb856d8 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("/", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
5d4cb856d8 2010-11-07        kinaba: 		if( args.length != 2 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "/ takes two arguments!!");
5d4cb856d8 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
5d4cb856d8 2010-11-07        kinaba: 			if( auto y = cast(IntValue)args[1] )
5d4cb856d8 2010-11-07        kinaba: 				return new IntValue(x.data/y.data);
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "cannot divide non-integers");
172a537bea 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("<", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
172a537bea 2010-11-07        kinaba: 		if( args.length != 2 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "< takes two arguments!!");
172a537bea 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
172a537bea 2010-11-07        kinaba: 			if( auto y = cast(IntValue)args[1] )
172a537bea 2010-11-07        kinaba: 				return new IntValue(BigInt(to!int(x.data < y.data)));
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "cannot compare non-integers");
172a537bea 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set(">", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
172a537bea 2010-11-07        kinaba: 		if( args.length != 2 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "> takes two arguments!!");
172a537bea 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
172a537bea 2010-11-07        kinaba: 			if( auto y = cast(IntValue)args[1] )
172a537bea 2010-11-07        kinaba: 				return new IntValue(BigInt(to!int(x.data>y.data)));
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "cannot compare non-integers");
820e7198cc 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("print", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
820e7198cc 2010-11-07        kinaba: 		foreach(a; args)
820e7198cc 2010-11-07        kinaba: 			write(a);
820e7198cc 2010-11-07        kinaba: 		writeln("");
8de5b49cdf 2010-11-09        kinaba: 		return new IntValue(BigInt(178));
633e700889 2010-11-07        kinaba: 	}));
8de5b49cdf 2010-11-09        kinaba: 	ctx.set("if", "@val", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
633e700889 2010-11-07        kinaba: 		if( args.length != 3 )
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(pos, "if takes three arguments!!");
633e700889 2010-11-07        kinaba: 		if( auto x = cast(IntValue)args[0] )
633e700889 2010-11-07        kinaba: 		if( auto ft = cast(FunValue)args[1] )
633e700889 2010-11-07        kinaba: 		if( auto fe = cast(FunValue)args[2] )
633e700889 2010-11-07        kinaba: 			return (x.data == 0 ? fe : ft).call(pos,[]);
8de5b49cdf 2010-11-09        kinaba: 		throw new RuntimeException(pos, "type mismatch in if");
0569f7b8c2 2010-11-07        kinaba: 	}));
423f308350 2010-11-07        kinaba: 	return ctx;
423f308350 2010-11-07        kinaba: }
423f308350 2010-11-07        kinaba: 
8de5b49cdf 2010-11-09        kinaba: /// Entry point of this module
8de5b49cdf 2010-11-09        kinaba: 
8de5b49cdf 2010-11-09        kinaba: Tuple!(Value,"val",Table,"ctx") evalString(S,T...)(S str, T fn_ln_cn)
0569f7b8c2 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	return eval( polemy.parse.parseString(str, fn_ln_cn) );
0569f7b8c2 2010-11-07        kinaba: }
0569f7b8c2 2010-11-07        kinaba: 
7de80acfb8 2010-11-09        kinaba: Tuple!(Value,"val",Table,"ctx") evalFile(S, T...)(S filename, T ln_cn)
0569f7b8c2 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	return eval( polemy.parse.parseFile(filename, ln_cn) );
0569f7b8c2 2010-11-07        kinaba: }
0569f7b8c2 2010-11-07        kinaba: 
8de5b49cdf 2010-11-09        kinaba: Tuple!(Value,"val",Table,"ctx") eval(AST e)
423f308350 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	Table ctx = createGlobalContext();
8de5b49cdf 2010-11-09        kinaba: 	return typeof(return)(eval(e, ctx), ctx);
423f308350 2010-11-07        kinaba: }
423f308350 2010-11-07        kinaba: 
8de5b49cdf 2010-11-09        kinaba: Value eval(AST _e, Table ctx, bool splitCtx = true)
423f308350 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	if( auto e = cast(StrLiteral)_e )
423f308350 2010-11-07        kinaba: 	{
423f308350 2010-11-07        kinaba: 		return new StrValue(e.data);
423f308350 2010-11-07        kinaba: 	}
423f308350 2010-11-07        kinaba: 	else
8de5b49cdf 2010-11-09        kinaba: 	if( auto e = cast(IntLiteral)_e )
423f308350 2010-11-07        kinaba: 	{
423f308350 2010-11-07        kinaba: 		return new IntValue(e.data);
423f308350 2010-11-07        kinaba: 	}
423f308350 2010-11-07        kinaba: 	else
423f308350 2010-11-07        kinaba: 	if( auto e = cast(VarExpression)_e )
423f308350 2010-11-07        kinaba: 	{
8de5b49cdf 2010-11-09        kinaba: 		return ctx.get(e.var, "@val", e.pos);
5d4cb856d8 2010-11-07        kinaba: 	}
5d4cb856d8 2010-11-07        kinaba: 	else
8de5b49cdf 2010-11-09        kinaba: 	if( auto e = cast(LetExpression)_e )
5d4cb856d8 2010-11-07        kinaba: 	{
8de5b49cdf 2010-11-09        kinaba: 		// for letrec, we need this, but should avoid overwriting????
8de5b49cdf 2010-11-09        kinaba: 		// ctx.set(e.var, "@val", new UndefinedValue, e.pos);
8de5b49cdf 2010-11-09        kinaba: 		Value v = eval(e.init, ctx, true);
8de5b49cdf 2010-11-09        kinaba: 		ctx.set(e.var, "@val", v, e.pos);
8de5b49cdf 2010-11-09        kinaba: 		return eval(e.expr, ctx);
5d4cb856d8 2010-11-07        kinaba: 	}
5d4cb856d8 2010-11-07        kinaba: 	else
5d4cb856d8 2010-11-07        kinaba: 	if( auto e = cast(FuncallExpression)_e )
5d4cb856d8 2010-11-07        kinaba: 	{
5d4cb856d8 2010-11-07        kinaba: 		Value _f = eval(e.fun, ctx);
5d4cb856d8 2010-11-07        kinaba: 		if( auto f = cast(FunValue)_f ) {
5d4cb856d8 2010-11-07        kinaba: 			Value[] args;
5d4cb856d8 2010-11-07        kinaba: 			foreach(a; e.args)
5d4cb856d8 2010-11-07        kinaba: 				args ~= eval(a, ctx);
0569f7b8c2 2010-11-07        kinaba: 			return f.call(e.pos, args);
5d4cb856d8 2010-11-07        kinaba: 		} else
8de5b49cdf 2010-11-09        kinaba: 			throw new RuntimeException(e.pos, "Non-funcion is applied");
0569f7b8c2 2010-11-07        kinaba: 	}
0569f7b8c2 2010-11-07        kinaba: 	else
8de5b49cdf 2010-11-09        kinaba: 	if( auto e = cast(FunLiteral)_e )
0569f7b8c2 2010-11-07        kinaba: 	{
0569f7b8c2 2010-11-07        kinaba: 		return new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
0569f7b8c2 2010-11-07        kinaba: 			if( e.params.length != args.length )
8de5b49cdf 2010-11-09        kinaba: 				throw new RuntimeException(e.pos, sprintf!"Argument Number Mismatch (%d required but %d given)"
8de5b49cdf 2010-11-09        kinaba: 					(e.params.length, args.length));
8de5b49cdf 2010-11-09        kinaba: 			Table ctxNeo = new Table(ctx, Table.Kind.NotPropagateSet);
0569f7b8c2 2010-11-07        kinaba: 			foreach(i,p; e.params)
8de5b49cdf 2010-11-09        kinaba: 				ctxNeo.set(p, "@val", args[i]);
0569f7b8c2 2010-11-07        kinaba: 			return eval(e.funbody, ctxNeo);
0569f7b8c2 2010-11-07        kinaba: 		});
423f308350 2010-11-07        kinaba: 	}
8de5b49cdf 2010-11-09        kinaba: 	throw new RuntimeException(_e.pos, sprintf!"Unknown Kind of Expression %s"(typeid(_e)));
423f308350 2010-11-07        kinaba: }
423f308350 2010-11-07        kinaba: 
5e407d7cf8 2010-11-08        kinaba: unittest
5e407d7cf8 2010-11-08        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	auto r = assert_nothrow( evalString(`var x = 21; x + x*x;`) );
8de5b49cdf 2010-11-09        kinaba: 	assert_eq( r.val, new IntValue(BigInt(21+21*21)) );
8de5b49cdf 2010-11-09        kinaba: 	assert_eq( r.ctx.get("x","@val"), new IntValue(BigInt(21)) );
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( r.ctx.get("x","@val") );
8de5b49cdf 2010-11-09        kinaba: 	assert_throw!RuntimeException( r.ctx.get("y","@val") );
5e407d7cf8 2010-11-08        kinaba: }
0569f7b8c2 2010-11-07        kinaba: unittest
0569f7b8c2 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	auto r = assert_nothrow( evalString(`var x = 21; var x = x + x*x;`) );
8de5b49cdf 2010-11-09        kinaba: 	assert_eq( r.val, new IntValue(BigInt(21+21*21)) );
8de5b49cdf 2010-11-09        kinaba: 	assert_eq( r.ctx.get("x","@val"), new IntValue(BigInt(21+21*21)) );
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( r.ctx.get("x","@val") );
8de5b49cdf 2010-11-09        kinaba: 	assert_throw!RuntimeException( r.ctx.get("y","@val") );
0569f7b8c2 2010-11-07        kinaba: }
423f308350 2010-11-07        kinaba: unittest
423f308350 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( evalString(`print("Hello, world!");`) );
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( evalString(`print(fun(){});`) );
423f308350 2010-11-07        kinaba: }
423f308350 2010-11-07        kinaba: unittest
423f308350 2010-11-07        kinaba: {
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( evalString(`var fac = fun(x){
633e700889 2010-11-07        kinaba: 		1;
633e700889 2010-11-07        kinaba: 	};
8de5b49cdf 2010-11-09        kinaba: 	print(fac(3));`));
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( evalString(`var fac = fun(x){
633e700889 2010-11-07        kinaba: 		if(x)
633e700889 2010-11-07        kinaba: 			{ x*fac(x-1); }
633e700889 2010-11-07        kinaba: 		else
633e700889 2010-11-07        kinaba: 			{ 1; };
633e700889 2010-11-07        kinaba: 	};
8de5b49cdf 2010-11-09        kinaba: 	print(fac(10));`));
8de5b49cdf 2010-11-09        kinaba: 	assert_nothrow( evalString(`var fib = fun(x){
172a537bea 2010-11-07        kinaba: 		if(x<2)
172a537bea 2010-11-07        kinaba: 			{ 1; }
172a537bea 2010-11-07        kinaba: 		else
172a537bea 2010-11-07        kinaba: 			{ fib(x-1) + fib(x-2); };
172a537bea 2010-11-07        kinaba: 	};
8de5b49cdf 2010-11-09        kinaba: 	print(fib(10));`));
423f308350 2010-11-07        kinaba: }