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Haxe

/*
* Copyright (C)2008-2017 Haxe Foundation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
package hscript;
import hscript.Expr;
enum VarMode {
Defined;
ForceSync;
}
class Async {
var definedVars : Array<{ n : String, prev : Null<VarMode> }>;
var vars : Map<String,VarMode>;
var currentFun : String;
var currentLoop : Expr;
var currentBreak : Expr -> Expr;
var uid = 0;
public var asyncIdents : Map<String,Bool>;
static var nullExpr : Expr = #if hscriptPos { e : null, pmin : 0, pmax : 0, origin : "<null>", line : 0 } #else null #end;
static var nullId = mk(EIdent("null"), nullExpr);
inline static function expr( e : Expr ) {
return #if hscriptPos e.e #else e #end;
}
inline static function mk( e, inf : Expr ) : Expr {
return #if hscriptPos { e : e, pmin : inf.pmin, pmax : inf.pmax, origin : inf.origin, line : inf.line } #else e #end;
}
/**
Convert a script into asynchronous one.
- calls such as foo(a,b,c) are translated to a_foo(function(r) ...rest, a,b,c) where r is the result value
- object access such obj.bar(a,b,c) are translated to obj.a_bar(function(r) ...rest, a, b, c)
- @async expr will execute the expression but continue without waiting for it to finish
- @split [ e1, e2, e3 ] is transformed to split(function(_) ...rest, [e1, e2, e3]) which
should execute asynchronously all expressions - until they return - before continuing the execution
- for(i in v) block; loops are translated to the following:
var _i = makeIterator(v);
function _loop() {
if( !_i.hasNext() ) return;
var v = _i.next();
block(function(_) _loop());
}
_loop()
- while loops are translated similar to for loops
- break and continue are correctly handled
- you can use @sync <expr> to disable async transformation in some code parts (for performance reason)
- a few expressions are still not supported (complex calls, try/catch, and a few others)
In these examples ...rest represents the continuation of execution of the script after the expression
**/
public static function toAsync( e : Expr, topLevelSync = false ) {
var a = new Async();
return a.build(e, topLevelSync);
}
public dynamic function getTopLevelEnd() {
return ignore();
}
public function build( e : Expr, topLevelSync = false ) {
if( topLevelSync ) {
return buildSync(e,null);
} else {
var end = getTopLevelEnd();
return toCps(e, end, end);
}
}
function defineVar( v : String, mode ) {
definedVars.push({ n : v, prev : vars.get(v) });
vars.set(v, mode);
}
function lookupFunctions( el : Array<Expr> ) {
for( e in el )
switch( expr(e) ) {
case EFunction(_, _, name, _) if( name != null ): defineVar(name, Defined);
case EMeta("sync",_,expr(_) => EFunction(_,_,name,_)) if( name != null ): defineVar(name, ForceSync);
default:
}
}
function buildSync( e : Expr, exit : Expr ) : Expr {
switch( expr(e) ) {
case EFunction(_,_,name,_):
if( name != null )
return toCps(e, null, null);
return e;
case EBlock(el):
var v = saveVars();
lookupFunctions(el);
var e = block([for(e in el) buildSync(e,exit)], e);
restoreVars(v);
return e;
case EMeta("async", _, e):
return toCps(e, ignore(), ignore());
case EMeta("sync", args, ef = expr(_) => EFunction(fargs, body, name, ret)):
return mk(EMeta("sync",args,mk(EFunction(fargs, buildSync(body,null), name, ret),ef)),e);
case EBreak if( currentBreak != null ):
return currentBreak(e);
case EContinue if( currentLoop != null ):
return block([retNull(currentLoop, e), mk(EReturn(),e)],e);
case EFor(_), EWhile(_):
var oldLoop = currentLoop, oldBreak = currentBreak;
currentLoop = null;
currentBreak = null;
e = Tools.map(e, buildSync.bind(_, exit));
currentLoop = oldLoop;
currentBreak = oldBreak;
return e;
case EReturn(eret) if( exit != null ):
return block([eret == null ? retNull(exit, e) : call(exit,[eret], e), mk(EReturn(),e)], e);
default:
return Tools.map(e, buildSync.bind(_, exit));
}
}
public function new() {
vars = new Map();
definedVars = [];
}
function ignore(?e) : Expr {
var inf = e == null ? nullExpr : e;
return fun("_", block(e == null ? [] : [e],inf));
}
inline function ident(str, e) {
return mk(EIdent(str), e);
}
inline function fun(arg:String, e, ?name) {
return mk(EFunction([{ name : arg, t : null }], e, name), e);
}
inline function funs(arg:Array<String>, e, ?name) {
return mk(EFunction([for( a in arg ) { name : a, t : null }], e, name), e);
}
inline function block(arr:Array<Expr>, e) {
if( arr.length == 1 && expr(arr[0]).match(EBlock(_)) )
return arr[0];
return mk(EBlock(arr), e);
}
inline function field(e, f, inf) {
return mk(EField(e, f), inf);
}
inline function binop(op, e1, e2, inf) {
return mk(EBinop(op, e1, e2), inf);
}
inline function call(e, args, inf) {
return mk(ECall(e, args), inf);
}
function retNull(e:Expr,?pos) : Expr {
switch( expr(e) ) {
case EFunction([{name:"_"}], e, _, _): return e;
default:
}
return call(e, [nullId], pos == null ? e : pos);
}
function makeCall( ecall, args : Array<Expr>, rest : Expr, exit, sync = false ) {
var names = [for( i in 0...args.length ) "_a"+uid++];
var rargs = [for( i in 0...args.length ) ident(names[i],ecall)];
if( !sync )
rargs.unshift(rest);
var rest = mk(sync ? ECall(rest,[call(ecall, rargs,ecall)]) : ECall(ecall, rargs), ecall);
var i = args.length - 1;
while( i >= 0 ) {
rest = toCps(args[i], fun(names[i], rest), exit);
i--;
}
return rest;
}
var syncFlag : Bool;
function isSync( e : Expr ) {
syncFlag = true;
checkSync(e);
return syncFlag;
}
inline function isAsyncIdent( id : String ) {
return asyncIdents == null || asyncIdents.exists(id);
}
function checkSync( e : Expr ) {
if( !syncFlag )
return;
switch( expr(e) ) {
case ECall(expr(_) => EIdent(i),_) if( isAsyncIdent(i) || vars.get(i) == Defined ):
syncFlag = false;
case ECall(expr(_) => EField(_,i),_) if( isAsyncIdent(i) ):
syncFlag = false;
case EFunction(_,_,name,_) if( name != null ):
syncFlag = false;
case EMeta("sync" | "async", _, _):
// isolated from the sync part
default:
Tools.iter(e, checkSync);
}
}
function saveVars() {
return definedVars.length;
}
function restoreVars(k) {
while( definedVars.length > k ) {
var v = definedVars.pop();
if( v.prev == null ) vars.remove(v.n) else vars.set(v.n, v.prev);
}
}
public function toCps( e : Expr, rest : Expr, exit : Expr ) : Expr {
if( isSync(e) )
return call(rest, [buildSync(e, exit)],e);
switch( expr(e) ) {
case EBlock(el):
var el = el.copy();
var vold = saveVars();
lookupFunctions(el);
while( el.length > 0 ) {
var e = toCps(el.pop(), rest, exit);
rest = ignore(e);
}
restoreVars(vold);
return retNull(rest);
case EFunction(args, body, name, t):
var vold = saveVars();
if( name != null )
defineVar(name, Defined);
for( a in args )
defineVar(a.name, Defined);
args.unshift( { name : "_onEnd", t : null } );
var frest = ident("_onEnd",e);
var oldFun = currentFun;
currentFun = name;
var body = toCps(body, frest, frest);
var f = mk(EFunction(args, body, name, t),e);
restoreVars(vold);
return rest == null ? f : call(rest, [f],e);
case EParent(e):
return mk(EParent(toCps(e, rest, exit)),e);
case EMeta("sync", _, e):
return call(rest,[buildSync(e,exit)],e);
case EMeta("async", _, e):
var nothing = ignore();
return block([toCps(e,nothing,nothing),retNull(rest)],e);
case EMeta("split", _, e):
var args = switch( expr(e) ) { case EArrayDecl(el): el; default: throw "@split expression should be an array"; };
var args = [for( a in args ) fun("_rest", toCps(block([a],a), ident("_rest",a), exit))];
return call(ident("split",e), [rest, mk(EArrayDecl(args),e)],e);
case ECall(expr(_) => EIdent(i), args):
var mode = vars.get(i);
return makeCall( ident( mode != null ? i : "a_" + i,e) , args, rest, exit, mode == ForceSync);
case ECall(expr(_) => EField(e, f), args):
return makeCall(field(e,"a_"+f,e), args, rest, exit);
case EFor(v, eit, eloop):
var id = ++uid;
var it = ident("_i" + id,e);
var oldLoop = currentLoop, oldBreak = currentBreak;
var loop = ident("_loop" + id,e);
currentLoop = loop;
currentBreak = function(inf) return block([retNull(rest, inf), mk(EReturn(),inf)], inf);
var efor = block([
mk(EVar("_i" + id, call(ident("makeIterator",eit),[eit],eit)),eit),
fun("_", block([
mk(EIf(mk(EUnop("!", true, call( field(it, "hasNext", it), [], it)),it), currentBreak(it)),it),
mk(EVar(v, call(field(it, "next",it), [], it)), it),
toCps(eloop, loop, exit),
], it),"_loop" + id),
retNull(loop, e),
], e);
currentLoop = oldLoop;
currentBreak = oldBreak;
return efor;
case EUnop(op = "!", prefix, eop):
return toCps(eop, fun("_r",call(rest, [mk(EUnop(op, prefix, ident("_r",e)),e)], e)), exit);
case EBinop(op, e1, e2):
switch( op ) {
case "=", "+=", "-=", "/=", "*=", "%=", "&=", "|=", "^=":
switch( expr(e1) ) {
case EIdent(_):
var id = "_r" + uid++;
return toCps(e2, fun(id, call(rest, [binop(op, e1, ident(id,e1),e1)], e1)), exit);
case EField(ef1, f):
var id1 = "_r" + uid++;
var id2 = "_r" + uid++;
return toCps(ef1, fun(id1, toCps(e2, fun(id2, call(rest, [binop(op, field(ident(id1, e1), f, ef1), ident(id2, e2), e)], e)), exit)), exit);
case EArray(earr, eindex):
var idArr = "_r" + uid++;
var idIndex = "_r" + uid++;
var idVal = "_r" + uid++;
return toCps(earr,fun(idArr, toCps(eindex, fun(idIndex, toCps(e2,
fun(idVal, call(rest, [binop(op, mk(EArray(ident(idArr,earr), ident(idIndex,eindex)),e1), ident(idVal,e1), e)], e))
, exit)), exit)),exit);
default:
throw "assert " + e1;
}
case "||":
var id1 = "_r" + uid++;
var id2 = "_r" + uid++;
return toCps(e1, fun(id1, mk(EIf(binop("==", ident(id1,e1), ident("true",e1), e1),call(rest,[ident("true",e1)],e1),toCps(e2, rest, exit)),e)), exit);
case "&&":
var id1 = "_r" + uid++;
var id2 = "_r" + uid++;
return toCps(e1, fun(id1, mk(EIf(binop("!=", ident(id1,e1), ident("true",e1), e1),call(rest,[ident("false",e1)],e1),toCps(e2, rest, exit)),e)), exit);
default:
var id1 = "_r" + uid++;
var id2 = "_r" + uid++;
return toCps(e1, fun(id1, toCps(e2, fun(id2, call(rest, [binop(op, ident(id1,e1), ident(id2,e2), e)], e)), exit)), exit);
}
case EIf(cond, e1, e2), ETernary(cond, e1, e2):
return toCps(cond, fun("_c", mk(EIf(ident("_c",cond), toCps(e1, rest, exit), e2 == null ? retNull(rest) : toCps(e2, rest, exit)),e)), exit);
case EWhile(cond, ewh):
var id = ++uid;
var loop = ident("_loop" + id, cond);
var oldLoop = currentLoop, oldBreak = currentBreak;
currentLoop = loop;
currentBreak = function(e) return block([retNull(rest,e), mk(EReturn(),e)],e);
var ewhile = block([
fun("_r",
toCps(cond, fun("_c", mk(EIf(ident("_c", cond), toCps(ewh, loop, exit), retNull(rest,cond)),cond)), exit)
, "_loop"+id),
retNull(loop, cond),
],e);
currentLoop = oldLoop;
currentBreak = oldBreak;
return ewhile;
case EReturn(eret):
return eret == null ? retNull(exit, e) : toCps(eret, exit, exit);
case EObject(fields):
var id = "_o" + uid++;
var rest = call(rest, [ident(id,e)], e);
fields.reverse();
for( f in fields )
rest = toCps(f.e, fun("_r", block([
binop("=", mk(EField(ident(id,f.e), f.name),f.e), ident("_r",f.e), f.e),
rest,
],f.e)),exit);
return block([
mk(EVar(id, mk(EObject([]),e)),e),
rest,
],e);
case EArrayDecl(el):
var id = "_a" + uid++;
var rest = call(rest, [ident(id,e)], e);
var i = el.length - 1;
while( i >= 0 ) {
var e = el[i];
rest = toCps(e, fun("_r", block([
binop("=", mk(EArray(ident(id,e), mk(EConst(CInt(i)),e)),e), ident("_r",e), e),
rest,
],e)), exit);
i--;
}
return block([
mk(EVar(id, mk(EArrayDecl([]),e)),e),
rest,
],e);
case EArray(earr, eindex):
var id1 = "_r" + uid++;
var id2 = "_r" + uid++;
return toCps(earr, fun(id1, toCps(eindex, fun(id2, call(rest, [mk(EArray(ident(id1,e), ident(id2,e)),e)], e)), exit)), exit);
case EVar(v, t, ev):
if( ev == null )
return block([e, retNull(rest, e)], e);
return block([
mk(EVar(v, t),e),
toCps(ev, fun("_r", block([binop("=", ident(v,e), ident("_r",e), e), retNull(rest,e)], e)), exit),
],e);
case EConst(_), EIdent(_), EUnop(_), EField(_):
return call(rest, [e], e);
case ENew(cl, args):
var names = [for( i in 0...args.length ) "_a"+uid++];
var rargs = [for( i in 0...args.length ) ident(names[i], args[i])];
var rest = call(rest,[mk(ENew(cl, rargs),e)],e);
var i = args.length - 1;
while( i >= 0 ) {
rest = toCps(args[i], fun(names[i], rest), exit);
i--;
}
return rest;
case EBreak:
if( currentBreak == null ) throw "Break outside loop";
return currentBreak(e);
case EContinue:
if( currentLoop == null ) throw "Continue outside loop";
return block([retNull(currentLoop, e), mk(EReturn(),e)], e);
case ESwitch(v, cases, def):
var cases = [for( c in cases ) { values : c.values, expr : toCps(c.expr, rest, exit) } ];
return toCps(v, mk(EFunction([ { name : "_c", t : null } ], mk(ESwitch(ident("_c",v), cases, def == null ? retNull(rest) : toCps(def, rest, exit)),e)),e), exit );
case EThrow(v):
return toCps(v, mk(EFunction([ { name : "_v", t : null } ], mk(EThrow(v),v)), v), exit);
case EMeta(name,_,e) if( name.charCodeAt(0) == ":".code ): // ignore custom ":" metadata
return toCps(e, rest, exit);
//case EDoWhile(_), ETry(_), ECall(_):
default:
throw "Unsupported async expression " + Printer.toString(e);
}
}
}
class AsyncInterp extends Interp {
public function setContext( api : Dynamic ) {
var funs = new Array();
for( v in variables.keys() )
if( Reflect.isFunction(variables.get(v)) )
funs.push({ v : v, obj : null });
variables.set("split", split);
variables.set("makeIterator", makeIterator);
var c = Type.getClass(api);
for( f in (c == null ? Reflect.fields(api) : Type.getInstanceFields(c)) ) {
var fv = Reflect.field(api, f);
if( !Reflect.isFunction(fv) ) continue;
if( f.charCodeAt(0) == "_".code ) f = f.substr(1);
variables.set(f, fv);
// create the async wrapper if doesn't exists
if( f.substr(0, 2) != "a_" )
funs.push({ v : f, obj : api });
}
for( v in funs ) {
if( variables.exists("a_" + v.v) ) continue;
var fv : Dynamic = variables.get(v.v);
var obj = v.obj;
variables.set("a_" + v.v, Reflect.makeVarArgs(function(args:Array<Dynamic>) {
var onEnd = args.shift();
onEnd(Reflect.callMethod(obj, fv, args));
}));
}
}
public function hasMethod( name : String ) {
var v = variables.get(name);
return v != null && Reflect.isFunction(v);
}
public function callValue( value : Dynamic, args : Array<Dynamic>, ?onResult : Dynamic -> Void, ?vthis : {} ) {
var oldThis = variables.get("this");
if( vthis != null )
variables.set("this", vthis);
if( onResult == null )
onResult = function(_) {};
args.unshift(onResult);
Reflect.callMethod(null, value, args);
variables.set("this", oldThis);
}
public function callAsync( id : String, args, ?onResult, ?vthis : {} ) {
var v = variables.get(id);
if( v == null )
throw "Missing function " + id + "()";
callValue(v, args, onResult, vthis);
}
function split( rest : Dynamic -> Void, args : Array<Dynamic> ) {
if( args.length == 0 )
rest(null);
else {
var count = args.length;
function next(_) {
if( --count == 0 ) rest(null);
}
for( a in args )
a(next);
}
}
override function fcall( o : Dynamic, f : String, args : Array<Dynamic> ) : Dynamic {
var m = Reflect.field(o, f);
if( m == null ) {
if( f.substr(0, 2) == "a_" ) {
m = Reflect.field(o, f.substr(2));
// fallback on sync version
if( m != null ) {
var onEnd = args.shift();
onEnd(call(o, m, args));
return null;
}
// fallback on generic script
m = Reflect.field(o, "scriptCall");
if( m != null ) {
call(o, m, [args.shift(), f.substr(2), args]);
return null;
}
} else {
// fallback on generic script
m = Reflect.field(o, "scriptCall");
if( m != null ) {
var result : Dynamic = null;
call(o, m, [function(r) result = r, f, args]);
return result;
}
}
error(ECustom(o + " has no method " + f));
}
return call(o, m, args);
}
}