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script.d
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script.d
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/**
FIXME: prettier stack trace when sent to D
FIXME: interpolated string: "$foo" or "#{expr}" or something.
FIXME: support more escape things in strings like \n, \t etc.
FIXME: add easy to use premade packages for the global object.
FIXME: maybe simplify the json!q{ } thing a bit.
FIXME: the debugger statement from javascript might be cool to throw in too.
FIXME: add continuations or something too
FIXME: Also ability to get source code for function something so you can mixin.
Script features:
FIXME: add COM support on Windows
OVERVIEW
* easy interop with D thanks to arsd.jsvar. When interpreting, pass a var object to use as globals.
This object also contains the global state when interpretation is done.
* mostly familiar syntax, hybrid of D and Javascript
* simple implementation is moderately small and fairly easy to hack on (though it gets messier by the day), but it isn't made for speed.
SPECIFICS
* string literals come in "foo" or 'foo', like Javascript, or `raw string` like D. Also come as “nested “double quotes” are an option!”
* mixin aka eval (does it at runtime, so more like eval than mixin, but I want it to look like D)
* scope guards, like in D
* try/catch/finally/throw
You can use try as an expression without any following catch to return the exception:
var a = try throw "exception";; // the double ; is because one closes the try, the second closes the var
// a is now the thrown exception
* for/while/foreach
* D style operators: +-/* on all numeric types, ~ on strings and arrays, |&^ on integers.
Operators can coerce types as needed: 10 ~ "hey" == "10hey". 10 + "3" == 13.
Any math, except bitwise math, with a floating point component returns a floating point component, but pure int math is done as ints (unlike Javascript btw).
Any bitwise math coerces to int.
So you can do some type coercion like this:
a = a|0; // forces to int
a = "" ~ a; // forces to string
a = a+0.0; // coerces to float
Though casting is probably better.
* Type coercion via cast, similarly to D.
var a = "12";
a.typeof == "String";
a = cast(int) a;
a.typeof == "Integral";
a == 12;
Supported types for casting to: int/long (both actually an alias for long, because of how var works), float/double/real, string, char/dchar (these return *integral* types), and arrays, int[], string[], and float[].
This forwards directly to the D function var.opCast.
* some operator overloading on objects, passing opBinary(op, rhs), length, and perhaps others through like they would be in D.
opIndex(name)
opIndexAssign(value, name) // same order as D, might some day support [n1, n2] => (value, n1, n2)
obj.__prop("name", value); // bypasses operator overloading, useful for use inside the opIndexAssign especially
Note: if opIndex is not overloaded, getting a non-existent member will actually add it to the member. This might be a bug but is needed right now in the D impl for nice chaining. Or is it? FIXME
* if/else
* array slicing, but note that slices are rvalues currently
* variables must start with A-Z, a-z, _, or $, then must be [A-Za-z0-9_]*.
(The $ can also stand alone, and this is a special thing when slicing, so you probably shouldn't use it at all.).
Variable names that start with __ are reserved and you shouldn't use them.
* int, float, string, array, bool, and json!q{} literals
* var.prototype, var.typeof. prototype works more like Mozilla's __proto__ than standard javascript prototype.
* classes:
// inheritance works
class Foo : bar {
// constructors, D style
this(var a) { ctor.... }
// static vars go on the auto created prototype
static var b = 10;
// instance vars go on this instance itself
var instancevar = 20;
// "virtual" functions can be overridden kinda like you expect in D, though there is no override keyword
function virt() {
b = 30; // lexical scoping is supported for static variables and functions
// but be sure to use this. as a prefix for any class defined instance variables in here
this.instancevar = 10;
}
}
var foo = new Foo(12);
foo.newFunc = function() { this.derived = 0; }; // this is ok too, and scoping, including 'this', works like in Javascript
You can also use 'new' on another object to get a copy of it.
* return, break, continue, but currently cannot do labeled breaks and continues
* __FILE__, __LINE__, but currently not as default arguments for D behavior (they always evaluate at the definition point)
* most everything are expressions, though note this is pretty buggy! But as a consequence:
for(var a = 0, b = 0; a < 10; a+=1, b+=1) {}
won't work but this will:
for(var a = 0, b = 0; a < 10; {a+=1; b+=1}) {}
You can encase things in {} anywhere instead of a comma operator, and it works kinda similarly.
{} creates a new scope inside it and returns the last value evaluated.
* functions:
var fn = function(args...) expr;
or
function fn(args....) expr;
Special function local variables:
_arguments = var[] of the arguments passed
_thisfunc = reference to the function itself
this = reference to the object on which it is being called - note this is like Javascript, not D.
args can say var if you want, but don't have to
default arguments supported in any position
when calling, you can use the default keyword to use the default value in any position
* macros:
A macro is defined just like a function, except with the
macro keyword instead of the function keyword. The difference
is a macro must interpret its own arguments - it is passed
AST objects instead of values. Still a WIP.
FIXME:
* make sure superclass ctors are called
Might be nice:
varargs
lambdas
*/
module arsd.script;
public import arsd.jsvar;
import std.stdio;
import std.traits;
import std.conv;
import std.json;
import std.array;
import std.range;
/***************************************
script to follow
****************************************/
class ScriptCompileException : Exception {
this(string msg, int lineNumber, string file = __FILE__, size_t line = __LINE__) {
super(to!string(lineNumber) ~ ": " ~ msg, file, line);
}
}
class ScriptRuntimeException : Exception {
this(string msg, int lineNumber, string file = __FILE__, size_t line = __LINE__) {
super(to!string(lineNumber) ~ ": " ~ msg, file, line);
}
}
class ScriptException : Exception {
var payload;
int lineNumber;
this(var payload, int lineNumber, string file = __FILE__, size_t line = __LINE__) {
this.payload = payload;
this.lineNumber = lineNumber;
super("script@" ~ to!string(lineNumber) ~ ": " ~ to!string(payload), file, line);
}
override string toString() {
return "script@" ~ to!string(lineNumber) ~ ": " ~ payload.get!string;
}
}
struct ScriptToken {
enum Type { identifier, keyword, symbol, string, int_number, float_number }
Type type;
string str;
string scriptFilename;
int lineNumber;
string wasSpecial;
}
// these need to be ordered from longest to shortest
// some of these aren't actually used, like struct and goto right now, but I want them reserved for later
private enum string[] keywords = [
"function", "continue",
"__FILE__", "__LINE__", // these two are special to the lexer
"foreach", "json!q{", "default", "finally",
"return", "static", "struct", "import", "module", "assert", "switch",
"while", "catch", "throw", "scope", "break", "super", "class", "false", "mixin", "super", "macro",
"auto", // provided as an alias for var right now, may change later
"null", "else", "true", "eval", "goto", "enum", "case", "cast",
"var", "for", "try", "new",
"if", "do",
];
private enum string[] symbols = [
"//", "/*", "/+",
"&&", "||",
"+=", "-=", "*=", "/=", "~=", "==", "<=", ">=","!=",
"&=", "|=", "^=",
"..",
".",",",";",":",
"[", "]", "{", "}", "(", ")",
"&", "|", "^",
"+", "-", "*", "/", "=", "<", ">","~","!",
];
// we need reference semantics on this all the time
class TokenStream(TextStream) {
TextStream textStream;
string text;
int lineNumber = 1;
string scriptFilename;
void advance(ptrdiff_t size) {
foreach(i; 0 .. size) {
if(text.empty)
break;
if(text[0] == '\n')
lineNumber ++;
text = text[1 .. $];
// text.popFront(); // don't want this because it pops too much trying to do its own UTF-8, which we already handled!
}
}
this(TextStream ts, string fn) {
textStream = ts;
scriptFilename = fn;
text = textStream.front;
popFront;
}
ScriptToken next;
// FIXME: might be worth changing this so i can peek far enough ahead to do () => expr lambdas.
ScriptToken peek;
bool peeked;
void pushFront(ScriptToken f) {
peek = f;
peeked = true;
}
ScriptToken front() {
if(peeked)
return peek;
else
return next;
}
bool empty() {
advanceSkips();
return text.length == 0 && textStream.empty && !peeked;
}
int skipNext;
void advanceSkips() {
if(skipNext) {
skipNext--;
popFront();
}
}
void popFront() {
if(peeked) {
peeked = false;
return;
}
assert(!empty);
mainLoop:
while(text.length) {
ScriptToken token;
token.lineNumber = lineNumber;
token.scriptFilename = scriptFilename;
if(text[0] == ' ' || text[0] == '\t' || text[0] == '\n') {
advance(1);
continue;
} else if(text[0] >= '0' && text[0] <= '9') {
int pos;
bool sawDot;
while(pos < text.length && ((text[pos] >= '0' && text[pos] <= '9') || text[pos] == '.')) {
if(text[pos] == '.') {
if(sawDot)
break;
else
sawDot = true;
}
pos++;
}
if(text[pos - 1] == '.') {
// This is something like "1.x", which is *not* a floating literal; it is UFCS on an int
sawDot = false;
pos --;
}
token.type = sawDot ? ScriptToken.Type.float_number : ScriptToken.Type.int_number;
token.str = text[0 .. pos];
advance(pos);
} else if((text[0] >= 'a' && text[0] <= 'z') || (text[0] == '_') || (text[0] >= 'A' && text[0] <= 'Z') || text[0] == '$') {
bool found = false;
foreach(keyword; keywords)
if(text.length >= keyword.length && text[0 .. keyword.length] == keyword &&
// making sure this isn't an identifier that starts with a keyword
(text.length == keyword.length || !(
(
(text[keyword.length] >= '0' && text[keyword.length] <= '9') ||
(text[keyword.length] >= 'a' && text[keyword.length] <= 'z') ||
(text[keyword.length] == '_') ||
(text[keyword.length] >= 'A' && text[keyword.length] <= 'Z')
)
)))
{
found = true;
if(keyword == "__FILE__") {
token.type = ScriptToken.Type.string;
token.str = to!string(token.scriptFilename);
token.wasSpecial = keyword;
} else if(keyword == "__LINE__") {
token.type = ScriptToken.Type.int_number;
token.str = to!string(token.lineNumber);
token.wasSpecial = keyword;
} else {
token.type = ScriptToken.Type.keyword;
// auto is done as an alias to var in the lexer just so D habits work there too
if(keyword == "auto") {
token.str = "var";
token.wasSpecial = keyword;
} else
token.str = keyword;
}
advance(keyword.length);
break;
}
if(!found) {
token.type = ScriptToken.Type.identifier;
int pos;
if(text[0] == '$')
pos++;
while(pos < text.length
&& ((text[pos] >= 'a' && text[pos] <= 'z') ||
(text[pos] == '_') ||
(text[pos] >= 'A' && text[pos] <= 'Z') ||
(text[pos] >= '0' && text[pos] <= '9')))
{
pos++;
}
token.str = text[0 .. pos];
advance(pos);
}
} else if(text[0] == '"' || text[0] == '\'' || text[0] == '`' ||
// Also supporting double curly quoted strings: “foo” which nest. This is the utf 8 coding:
(text.length >= 3 && text[0] == 0xe2 && text[1] == 0x80 && text[2] == 0x9c))
{
char end = text[0]; // support single quote and double quote strings the same
int openCurlyQuoteCount = (end == 0xe2) ? 1 : 0;
bool escapingAllowed = end != '`'; // `` strings are raw, they don't support escapes. the others do.
token.type = ScriptToken.Type.string;
int pos = openCurlyQuoteCount ? 3 : 1; // skip the opening dchar
int started = pos;
bool escaped = false;
bool mustCopy = false;
bool atEnd() {
if(openCurlyQuoteCount) {
if(openCurlyQuoteCount == 1)
return (pos + 3 <= text.length && text[pos] == 0xe2 && text[pos+1] == 0x80 && text[pos+2] == 0x9d); // ”
else // greater than one means we nest
return false;
} else
return text[pos] == end;
}
while(pos < text.length && (escaped || !atEnd())) {
if(escaped) {
mustCopy = true;
escaped = false;
} else {
if(text[pos] == '\\' && escapingAllowed)
escaped = true;
if(openCurlyQuoteCount) {
// also need to count curly quotes to support nesting
if(pos + 3 <= text.length && text[pos+0] == 0xe2 && text[pos+1] == 0x80 && text[pos+2] == 0x9c) // “
openCurlyQuoteCount++;
if(pos + 3 <= text.length && text[pos+0] == 0xe2 && text[pos+1] == 0x80 && text[pos+2] == 0x9d) // ”
openCurlyQuoteCount--;
}
}
pos++;
}
if(mustCopy) {
// there must be something escaped in there, so we need
// to copy it and properly handle those cases
string copy;
copy.reserve(pos + 4);
escaped = false;
foreach(dchar ch; text[started .. pos]) {
if(escaped)
escaped = false;
else if(ch == '\\') {
escaped = true;
continue;
}
copy ~= ch;
}
token.str = copy;
} else {
token.str = text[started .. pos];
}
advance(pos + ((end == 0xe2) ? 3 : 1)); // skip the closing " too
} else {
// let's check all symbols
bool found = false;
foreach(symbol; symbols)
if(text.length >= symbol.length && text[0 .. symbol.length] == symbol) {
if(symbol == "//") {
// one line comment
int pos = 0;
while(pos < text.length && text[pos] != '\n')
pos++;
advance(pos);
continue mainLoop;
} else if(symbol == "/*") {
int pos = 0;
while(pos + 1 < text.length && text[pos..pos+2] != "*/")
pos++;
if(pos + 1 == text.length)
throw new ScriptCompileException("unclosed /* */ comment", lineNumber);
advance(pos + 2);
continue mainLoop;
} else if(symbol == "/+") {
// FIXME: nesting comment
}
found = true;
token.type = ScriptToken.Type.symbol;
token.str = symbol;
advance(symbol.length);
break;
}
if(!found) {
// FIXME: make sure this gives a valid utf-8 sequence
throw new ScriptCompileException("unknown token " ~ text[0], lineNumber);
}
}
next = token;
return;
}
textStream.popFront();
if(!textStream.empty()) {
text = textStream.front;
goto mainLoop;
}
return;
}
}
TokenStream!TextStream lexScript(TextStream)(TextStream textStream, string scriptFilename) if(is(ElementType!TextStream == string)) {
return new TokenStream!TextStream(textStream, scriptFilename);
}
class MacroPrototype : PrototypeObject {
var func;
// macros are basically functions that get special treatment for their arguments
// they are passed as AST objects instead of interpreted
// calling an AST object will interpret it in the script
this(var func) {
this.func = func;
this._properties["opCall"] = (var _this, var[] args) {
return func.apply(_this, args);
};
}
}
alias helper(alias T) = T;
// alternative to virtual function for converting the expression objects to script objects
void addChildElementsOfExpressionToScriptExpressionObject(ClassInfo c, Expression _thisin, PrototypeObject sc, ref var obj) {
foreach(itemName; __traits(allMembers, mixin(__MODULE__)))
static if(__traits(compiles, __traits(getMember, mixin(__MODULE__), itemName))) {
alias Class = helper!(__traits(getMember, mixin(__MODULE__), itemName));
static if(is(Class : Expression)) if(c == typeid(Class)) {
auto _this = cast(Class) _thisin;
foreach(memberName; __traits(allMembers, Class)) {
alias member = helper!(__traits(getMember, Class, memberName));
static if(is(typeof(member) : Expression)) {
auto lol = __traits(getMember, _this, memberName);
if(lol is null)
obj[memberName] = null;
else
obj[memberName] = lol.toScriptExpressionObject(sc);
}
static if(is(typeof(member) : Expression[])) {
obj[memberName] = var.emptyArray;
foreach(m; __traits(getMember, _this, memberName))
if(m !is null)
obj[memberName] ~= m.toScriptExpressionObject(sc);
else
obj[memberName] ~= null;
}
static if(is(typeof(member) : string) || is(typeof(member) : long) || is(typeof(member) : real) || is(typeof(member) : bool)) {
obj[memberName] = __traits(getMember, _this, memberName);
}
}
}
}
}
struct InterpretResult {
var value;
PrototypeObject sc;
enum FlowControl { Normal, Return, Continue, Break, Goto }
FlowControl flowControl;
string flowControlDetails; // which label
}
class Expression {
abstract InterpretResult interpret(PrototypeObject sc);
// this returns an AST object that can be inspected and possibly altered
// by the script. Calling the returned object will interpret the object in
// the original scope passed
var toScriptExpressionObject(PrototypeObject sc) {
var obj = var.emptyObject;
obj["type"] = typeid(this).name;
obj["toSourceCode"] = (var _this, var[] args) {
Expression e = this;
// FIXME: if they changed the properties in the
// script, we should update them here too.
return var(e.toString());
};
obj["opCall"] = (var _this, var[] args) {
Expression e = this;
// FIXME: if they changed the properties in the
// script, we should update them here too.
return e.interpret(sc).value;
};
// adding structure is going to be a little bit magical
// I could have done this with a virtual function, but I'm lazy.
addChildElementsOfExpressionToScriptExpressionObject(typeid(this), this, sc, obj);
return obj;
}
}
class MixinExpression : Expression {
Expression e1;
this(Expression e1) {
this.e1 = e1;
}
override string toString() { return "mixin(" ~ e1.toString() ~ ")"; }
override InterpretResult interpret(PrototypeObject sc) {
return InterpretResult(.interpret(e1.interpret(sc).value.get!string ~ ";", sc), sc);
}
}
class StringLiteralExpression : Expression {
string literal;
override string toString() {
import std.string : replace;
return `"` ~ literal.replace("\\", "\\\\").replace("\"", "\\\"") ~ "\"";
}
this(string s) {
char[] unescaped;
int lastPos;
bool changed = false;
bool inEscape = false;
foreach(pos, char c; s) {
if(c == '\\') {
if(!changed) {
changed = true;
unescaped.reserve(s.length);
}
unescaped ~= s[lastPos .. pos];
inEscape = true;
continue;
}
if(inEscape) {
lastPos = cast(int) pos + 1;
inEscape = false;
switch(c) {
case 'n':
unescaped ~= '\n';
break;
case 't':
unescaped ~= '\t';
break;
case '\\':
unescaped ~= '\\';
break;
default: throw new ScriptCompileException("literal escape unknown " ~ c, 0, null, 0);
}
}
}
if(changed)
literal = cast(string) unescaped;
else
literal = s;
}
override InterpretResult interpret(PrototypeObject sc) {
return InterpretResult(var(literal), sc);
}
}
class BoolLiteralExpression : Expression {
bool literal;
this(string l) {
literal = to!bool(l);
}
override string toString() { return to!string(literal); }
override InterpretResult interpret(PrototypeObject sc) {
return InterpretResult(var(literal), sc);
}
}
class IntLiteralExpression : Expression {
long literal;
this(string s) {
literal = to!long(s);
}
override string toString() { return to!string(literal); }
override InterpretResult interpret(PrototypeObject sc) {
return InterpretResult(var(literal), sc);
}
}
class FloatLiteralExpression : Expression {
this(string s) {
literal = to!real(s);
}
real literal;
override string toString() { return to!string(literal); }
override InterpretResult interpret(PrototypeObject sc) {
return InterpretResult(var(literal), sc);
}
}
class NullLiteralExpression : Expression {
this() {}
override string toString() { return "null"; }
override InterpretResult interpret(PrototypeObject sc) {
var n;
return InterpretResult(n, sc);
}
}
class ArrayLiteralExpression : Expression {
this() {}
override string toString() {
string s = "[";
foreach(i, ele; elements) {
if(i) s ~= ", ";
s ~= ele.toString();
}
s ~= "]";
return s;
}
Expression[] elements;
override InterpretResult interpret(PrototypeObject sc) {
var n = var.emptyArray;
foreach(i, element; elements)
n[i] = element.interpret(sc).value;
return InterpretResult(n, sc);
}
}
class ObjectLiteralExpression : Expression {
Expression[string] elements;
override string toString() {
string s = "json!q{";
bool first = true;
foreach(k, e; elements) {
if(first)
first = false;
else
s ~= ", ";
s ~= "\"" ~ k ~ "\":"; // FIXME: escape if needed
s ~= e.toString();
}
s ~= "}";
return s;
}
PrototypeObject backing;
this(PrototypeObject backing = null) {
this.backing = backing;
}
override InterpretResult interpret(PrototypeObject sc) {
var n;
if(backing is null)
n = var.emptyObject;
else
n._object = backing;
foreach(k, v; elements)
n[k] = v.interpret(sc).value;
return InterpretResult(n, sc);
}
}
class FunctionLiteralExpression : Expression {
this() {
// we want this to not be null at all when we're interpreting since it is used as a comparison for a magic operation
if(DefaultArgumentDummyObject is null)
DefaultArgumentDummyObject = new PrototypeObject();
}
this(VariableDeclaration args, Expression bod, PrototypeObject lexicalScope = null) {
this();
this.arguments = args;
this.functionBody = bod;
this.lexicalScope = lexicalScope;
}
override string toString() {
string s = (isMacro ? "macro" : "function") ~ " (";
s ~= arguments.toString();
s ~= ") ";
s ~= functionBody.toString();
return s;
}
/*
function identifier (arg list) expression
so
var e = function foo() 10; // valid
var e = function foo() { return 10; } // also valid
// the return value is just the last expression's result that was evaluated
// to return void, be sure to do a "return;" at the end of the function
*/
VariableDeclaration arguments;
Expression functionBody; // can be a ScopeExpression btw
PrototypeObject lexicalScope;
bool isMacro;
override InterpretResult interpret(PrototypeObject sc) {
assert(DefaultArgumentDummyObject !is null);
var v;
v._function = (var _this, var[] args) {
auto argumentsScope = new PrototypeObject();
PrototypeObject scToUse;
if(lexicalScope is null)
scToUse = sc;
else {
scToUse = lexicalScope;
scToUse._secondary = sc;
}
argumentsScope.prototype = scToUse;
argumentsScope._getMember("this", false, false) = _this;
argumentsScope._getMember("_arguments", false, false) = args;
argumentsScope._getMember("_thisfunc", false, false) = v;
if(arguments)
foreach(i, identifier; arguments.identifiers) {
argumentsScope._getMember(identifier, false, false); // create it in this scope...
if(i < args.length && !(args[i].payloadType() == var.Type.Object && args[i]._payload._object is DefaultArgumentDummyObject))
argumentsScope._getMember(identifier, false, true) = args[i];
else
if(arguments.initializers[i] !is null)
argumentsScope._getMember(identifier, false, true) = arguments.initializers[i].interpret(sc).value;
}
if(functionBody !is null)
return functionBody.interpret(argumentsScope).value;
else {
assert(0);
}
};
if(isMacro) {
var n = var.emptyObject;
n._object = new MacroPrototype(v);
v = n;
}
return InterpretResult(v, sc);
}
}
class CastExpression : Expression {
string type;
Expression e1;
override string toString() {
return "cast(" ~ type ~ ") " ~ e1.toString();
}
override InterpretResult interpret(PrototypeObject sc) {
var n = e1.interpret(sc).value;
foreach(possibleType; CtList!("int", "long", "float", "double", "real", "char", "dchar", "string", "int[]", "string[]", "float[]")) {
if(type == possibleType)
n = mixin("cast(" ~ possibleType ~ ") n");
}
return InterpretResult(n, sc);
}
}
class VariableDeclaration : Expression {
string[] identifiers;
Expression[] initializers;
this() {}
override string toString() {
string s = "";
foreach(i, ident; identifiers) {
if(i)
s ~= ", ";
s ~= "var " ~ ident;
if(initializers[i] !is null)
s ~= " = " ~ initializers[i].toString();
}
return s;
}
override InterpretResult interpret(PrototypeObject sc) {
var n;
foreach(i, identifier; identifiers) {
n = sc._getMember(identifier, false, false);
auto initializer = initializers[i];
if(initializer) {
n = initializer.interpret(sc).value;
sc._getMember(identifier, false, false) = n;
}
}
return InterpretResult(n, sc);
}
}
template CtList(T...) { alias CtList = T; }
class BinaryExpression : Expression {
string op;
Expression e1;
Expression e2;
override string toString() {
return e1.toString() ~ " " ~ op ~ " " ~ e2.toString();
}
this(string op, Expression e1, Expression e2) {
this.op = op;
this.e1 = e1;
this.e2 = e2;
}
override InterpretResult interpret(PrototypeObject sc) {
var left = e1.interpret(sc).value;
var right = e2.interpret(sc).value;
//writeln(left, " "~op~" ", right);
var n;
foreach(ctOp; CtList!("+", "-", "*", "/", "==", "!=", "<=", ">=", ">", "<", "~", "&&", "||", "&", "|", "^"))
if(ctOp == op) {
n = mixin("left "~ctOp~" right");
}
return InterpretResult(n, sc);
}
}
class OpAssignExpression : Expression {
string op;
Expression e1;
Expression e2;
this(string op, Expression e1, Expression e2) {
this.op = op;
this.e1 = e1;
this.e2 = e2;
}
override string toString() {
return e1.toString() ~ " " ~ op ~ "= " ~ e2.toString();
}
override InterpretResult interpret(PrototypeObject sc) {
auto v = cast(VariableExpression) e1;
if(v is null)
throw new ScriptRuntimeException("not an lvalue", 0 /* FIXME */);
var right = e2.interpret(sc).value;
//writeln(left, " "~op~"= ", right);
var n;
foreach(ctOp; CtList!("+=", "-=", "*=", "/=", "~=", "&=", "|=", "^="))
if(ctOp[0..1] == op)
n = mixin("v.getVar(sc) "~ctOp~" right");
// FIXME: ensure the variable is updated in scope too
return InterpretResult(n, sc);
}
}
class AssignExpression : Expression {
Expression e1;
Expression e2;
bool suppressOverloading;
this(Expression e1, Expression e2, bool suppressOverloading = false) {
this.e1 = e1;
this.e2 = e2;
this.suppressOverloading = suppressOverloading;
}
override string toString() { return e1.toString() ~ " = " ~ e2.toString(); }
override InterpretResult interpret(PrototypeObject sc) {
auto v = cast(VariableExpression) e1;
if(v is null)
throw new ScriptRuntimeException("not an lvalue", 0 /* FIXME */);
auto ret = v.setVar(sc, e2.interpret(sc).value, false, suppressOverloading);
return InterpretResult(ret, sc);
}
}
class UnaryExpression : Expression {
string op;
Expression e;
// FIXME
override InterpretResult interpret(PrototypeObject sc) {
return InterpretResult();
}
}
class VariableExpression : Expression {
string identifier;
this(string identifier) {
this.identifier = identifier;
}
override string toString() {
return identifier;
}
ref var getVar(PrototypeObject sc, bool recurse = true) {
return sc._getMember(identifier, true /* FIXME: recurse?? */, true);
}
ref var setVar(PrototypeObject sc, var t, bool recurse = true, bool suppressOverloading = false) {
return sc._setMember(identifier, t, true /* FIXME: recurse?? */, true, suppressOverloading);
}