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generate an abstract semantic graph from a Shift AST
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/*
* Copyright 2016 Shape Security, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.shapesecurity.shift.semantics;
import com.shapesecurity.functional.F;
import com.shapesecurity.functional.Pair;
import com.shapesecurity.functional.data.Either;
import com.shapesecurity.functional.data.HashTable;
import com.shapesecurity.functional.data.ImmutableList;
import com.shapesecurity.functional.data.Maybe;
import com.shapesecurity.shift.ast.ArrayExpression;
import com.shapesecurity.shift.ast.AssignmentExpression;
import com.shapesecurity.shift.ast.BinaryExpression;
import com.shapesecurity.shift.ast.Binding;
import com.shapesecurity.shift.ast.BindingIdentifier;
import com.shapesecurity.shift.ast.BlockStatement;
import com.shapesecurity.shift.ast.BreakStatement;
import com.shapesecurity.shift.ast.CallExpression;
import com.shapesecurity.shift.ast.CompoundAssignmentExpression;
import com.shapesecurity.shift.ast.ComputedMemberExpression;
import com.shapesecurity.shift.ast.ComputedPropertyName;
import com.shapesecurity.shift.ast.ConditionalExpression;
import com.shapesecurity.shift.ast.ContinueStatement;
import com.shapesecurity.shift.ast.DataProperty;
import com.shapesecurity.shift.ast.DebuggerStatement;
import com.shapesecurity.shift.ast.Directive;
import com.shapesecurity.shift.ast.DoWhileStatement;
import com.shapesecurity.shift.ast.EmptyStatement;
import com.shapesecurity.shift.ast.Expression;
import com.shapesecurity.shift.ast.ExpressionStatement;
import com.shapesecurity.shift.ast.ExpressionSuper;
import com.shapesecurity.shift.ast.ForInStatement;
import com.shapesecurity.shift.ast.ForStatement;
import com.shapesecurity.shift.ast.FormalParameters;
import com.shapesecurity.shift.ast.FunctionBody;
import com.shapesecurity.shift.ast.FunctionDeclaration;
import com.shapesecurity.shift.ast.FunctionExpression;
import com.shapesecurity.shift.ast.Getter;
import com.shapesecurity.shift.ast.IdentifierExpression;
import com.shapesecurity.shift.ast.IfStatement;
import com.shapesecurity.shift.ast.LabeledStatement;
import com.shapesecurity.shift.ast.LiteralBooleanExpression;
import com.shapesecurity.shift.ast.LiteralInfinityExpression;
import com.shapesecurity.shift.ast.LiteralNullExpression;
import com.shapesecurity.shift.ast.LiteralNumericExpression;
import com.shapesecurity.shift.ast.LiteralRegExpExpression;
import com.shapesecurity.shift.ast.LiteralStringExpression;
import com.shapesecurity.shift.ast.MemberExpression;
import com.shapesecurity.shift.ast.Module;
import com.shapesecurity.shift.ast.NewExpression;
import com.shapesecurity.shift.ast.ObjectExpression;
import com.shapesecurity.shift.ast.ObjectProperty;
import com.shapesecurity.shift.ast.PropertyName;
import com.shapesecurity.shift.ast.ReturnStatement;
import com.shapesecurity.shift.ast.Script;
import com.shapesecurity.shift.ast.Setter;
import com.shapesecurity.shift.ast.SpreadElementExpression;
import com.shapesecurity.shift.ast.Statement;
import com.shapesecurity.shift.ast.StaticMemberExpression;
import com.shapesecurity.shift.ast.StaticPropertyName;
import com.shapesecurity.shift.ast.Super;
import com.shapesecurity.shift.ast.SwitchCase;
import com.shapesecurity.shift.ast.SwitchStatementWithDefault;
import com.shapesecurity.shift.ast.ThisExpression;
import com.shapesecurity.shift.ast.ThrowStatement;
import com.shapesecurity.shift.ast.TryCatchStatement;
import com.shapesecurity.shift.ast.TryFinallyStatement;
import com.shapesecurity.shift.ast.UnaryExpression;
import com.shapesecurity.shift.ast.UpdateExpression;
import com.shapesecurity.shift.ast.VariableDeclaration;
import com.shapesecurity.shift.ast.VariableDeclarationExpression;
import com.shapesecurity.shift.ast.VariableDeclarationStatement;
import com.shapesecurity.shift.ast.WhileStatement;
import com.shapesecurity.shift.ast.WithStatement;
import com.shapesecurity.shift.ast.operators.UpdateOperator;
import com.shapesecurity.shift.scope.Declaration;
import com.shapesecurity.shift.scope.GlobalScope;
import com.shapesecurity.shift.scope.Scope;
import com.shapesecurity.shift.scope.ScopeAnalyzer;
import com.shapesecurity.shift.scope.ScopeLookup;
import com.shapesecurity.shift.scope.Variable;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.BinaryOperation;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.BinaryOperator;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.Equality;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.FloatMath;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.In;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.InstanceOf;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.IntMath;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.Logic;
import com.shapesecurity.shift.semantics.asg.BinaryOperation.RelationalComparison;
import com.shapesecurity.shift.semantics.asg.Block;
import com.shapesecurity.shift.semantics.asg.BlockWithValue;
import com.shapesecurity.shift.semantics.asg.Break;
import com.shapesecurity.shift.semantics.asg.BreakTarget;
import com.shapesecurity.shift.semantics.asg.Call;
import com.shapesecurity.shift.semantics.asg.DeleteGlobalProperty;
import com.shapesecurity.shift.semantics.asg.DeleteProperty;
import com.shapesecurity.shift.semantics.asg.GlobalReference;
import com.shapesecurity.shift.semantics.asg.Halt;
import com.shapesecurity.shift.semantics.asg.IfElse;
import com.shapesecurity.shift.semantics.asg.Keys;
import com.shapesecurity.shift.semantics.asg.LiteralBoolean;
import com.shapesecurity.shift.semantics.asg.LiteralEmptyArray;
import com.shapesecurity.shift.semantics.asg.LiteralEmptyObject;
import com.shapesecurity.shift.semantics.asg.LiteralFunction;
import com.shapesecurity.shift.semantics.asg.LiteralInfinity;
import com.shapesecurity.shift.semantics.asg.LiteralNull;
import com.shapesecurity.shift.semantics.asg.LiteralNumber;
import com.shapesecurity.shift.semantics.asg.LiteralRegExp;
import com.shapesecurity.shift.semantics.asg.LiteralString;
import com.shapesecurity.shift.semantics.asg.LiteralUndefined;
import com.shapesecurity.shift.semantics.asg.LocalReference;
import com.shapesecurity.shift.semantics.asg.Loop;
import com.shapesecurity.shift.semantics.asg.MemberAccess;
import com.shapesecurity.shift.semantics.asg.MemberAssignment;
import com.shapesecurity.shift.semantics.asg.MemberAssignmentProperty;
import com.shapesecurity.shift.semantics.asg.MemberDefinition;
import com.shapesecurity.shift.semantics.asg.New;
import com.shapesecurity.shift.semantics.asg.Node;
import com.shapesecurity.shift.semantics.asg.NodeWithValue;
import com.shapesecurity.shift.semantics.asg.RequireObjectCoercible;
import com.shapesecurity.shift.semantics.asg.Return;
import com.shapesecurity.shift.semantics.asg.SwitchStatement;
import com.shapesecurity.shift.semantics.asg.TemporaryReference;
import com.shapesecurity.shift.semantics.asg.This;
import com.shapesecurity.shift.semantics.asg.Throw;
import com.shapesecurity.shift.semantics.asg.TryCatchFinally;
import com.shapesecurity.shift.semantics.asg.TypeCoercionNumber;
import com.shapesecurity.shift.semantics.asg.TypeCoercionString;
import com.shapesecurity.shift.semantics.asg.TypeofGlobal;
import com.shapesecurity.shift.semantics.asg.UnaryOperation.BitwiseNot;
import com.shapesecurity.shift.semantics.asg.UnaryOperation.Negation;
import com.shapesecurity.shift.semantics.asg.UnaryOperation.Not;
import com.shapesecurity.shift.semantics.asg.UnaryOperation.Typeof;
import com.shapesecurity.shift.semantics.asg.UnaryOperation.VoidOp;
import com.shapesecurity.shift.semantics.asg.VariableAssignment;
import com.shapesecurity.shift.semantics.asg.Void;
import com.shapesecurity.shift.semantics.visitor.FinallyJumpReducer;
import org.jetbrains.annotations.NotNull;
import java.util.ArrayList;
public class Explicator {
@NotNull
private final GlobalScope scope;
@NotNull
private final Either program;
@NotNull
private final HashTable> jumpMap;
@NotNull
private final ScopeLookup scopeLookup;
@NotNull
private HashTable>> targets = HashTable.emptyUsingEquality();
// map from AST loops and labelled statement to their corresponding Target nodes. Loops have an outer and an inner, for break and continue respectively.
@NotNull
private ImmutableList> temporaries = ImmutableList.of(ImmutableList.empty());
// Stack of function-local temporaries. Whenever you begin explicating a function, push a new empty list; when you finish, pop it. TODO this is a somewhat hacky way of accomplishing this. It would be better to be intraproceedural or something.
// todo runtime errors for with, direct eval
private Explicator(@NotNull Script script) {
this.program = Either.left(script);
this.scope = ScopeAnalyzer.analyze(script);
this.jumpMap = FinallyJumpReducer.analyze(script);
this.scopeLookup = new ScopeLookup(this.scope);
}
private Explicator(@NotNull Module module) {
this.program = Either.right(module);
this.scope = ScopeAnalyzer.analyze(module);
this.jumpMap = FinallyJumpReducer.analyze(module);
this.scopeLookup = new ScopeLookup(this.scope);
}
@NotNull
public static Semantics deriveSemantics(@NotNull Script script) {
Explicator exp = new Explicator(script);
Node result = exp.explicate();
ImmutableList maybeGlobals = exp.functionVariablesHelper(script);
ImmutableList scriptLocals =
maybeGlobals.filter(x -> !exp.scopeLookup.isGlobal(x)).append(exp.temporaries.maybeHead().fromJust());
ImmutableList scriptVarDecls =
maybeGlobals.filter(x -> exp.scopeLookup.isGlobal(x) && x.declarations.isNotEmpty()).map(x -> x.name);
return new Semantics(result, scriptLocals, scriptVarDecls);
}
@NotNull
public static Semantics deriveSemantics(@NotNull Module module) {
Explicator exp = new Explicator(module);
Node result = exp.explicate();
ImmutableList scriptLocals =
exp.functionVariablesHelper(module)
.filter(x -> !exp.scopeLookup.isGlobal(x))
.append(exp.temporaries.maybeHead().fromJust());
return new Semantics(result, scriptLocals, ImmutableList.empty());
}
private Node explicate() {
return this.program.either(
script -> explicateBody(script.statements, isStrict(script.directives)),
module -> explicateBody(module.items.map(i -> (Statement) i), true)
);
}
private ImmutableList simpleParamsHelper(FormalParameters params) {
assert params.rest.isNothing();
return params.items.map(
b -> scopeLookup.findVariableDeclaredBy((BindingIdentifier) b).fromJust()
);
}
private boolean isStrict(ImmutableList directives) {
return directives.find(d -> d.rawValue.equals("use strict")).isJust();
}
private NodeWithValue variableAssignmentHelper(
Either ref, NodeWithValue rhs, boolean strict
) { // handles const-ness correctly. not to be used with variable or function declarations.
if (ref.isRight()) {
Variable variable = ref.right().fromJust().variable;
if (variable.declarations.exists(decl -> decl.kind == Declaration.Kind.Const || decl.kind == Declaration.Kind.FunctionExpressionName)) { // note that this is an AssignmentExpression or similar, not a VariableDeclaration, so this is *not* the initialization of the variable, i.e., it is certainly an improper write to a constant variable.
assert variable.declarations.length == 1;
// TODO maybe warn about writing to a constant variable?
if (strict || variable.declarations.maybeHead()
.fromJust().kind == Declaration.Kind.Const) { // writing to const variables is always a TypeError, even in strict mode: https://github.com/tc39/test262/pull/430#issuecomment-139423863
return new BlockWithValue(
ImmutableList.of(rhs, new Throw(new New(new GlobalReference("TypeError"), ImmutableList.empty()))),
// TODO throw an actual TypeError, not whatever the global TypeError value happens to be at the moment (it is writable)
new LiteralUndefined()
);
} else {
return rhs; // silently fail to write to function-expression names
}
}
}
return new VariableAssignment(
ref,
rhs,
strict
);
}
// given a FunctionDeclaration or FunctionExpression, find all the variables created in it or its children not crossing function boundaries
// which is to say, all variables which calling this function recursively might shadow
private ImmutableList functionVariablesHelper(@NotNull com.shapesecurity.shift.ast.Node node) {
return scopeLookup.findScopeFor(node).maybe(ImmutableList.empty(), this::functionVariablesHelper);
}
// helper for the above. find variables in the given scope and its descendants, up to function boundaries
// TODO should maybe be a Scope or ScopeLookup method (but probably not)
private ImmutableList functionVariablesHelper(Scope scope) {
ImmutableList initial = ImmutableList.from(new ArrayList<>(scope.variables()));
if (scope.type == Scope.Type.FunctionName) {
assert scope.children.length == 1; // in ES5, anyway...
assert scope.children.maybeHead().fromJust().type == Scope.Type.Function;
return initial.append(this.functionVariablesHelper(scope.children.maybeHead().fromJust()));
}
// this will need to include parameter scope in ES6
return initial.append(scope.children.flatMap(s ->
s.type == Scope.Type.Function || s.type == Scope.Type.FunctionName
? ImmutableList.empty()
: this.functionVariablesHelper(s)
));
}
@NotNull
private Either refHelper(BindingIdentifier bindingIdentifier) {
Variable variable = scopeLookup.findVariableReferencedBy(bindingIdentifier).fromJust();
return scopeLookup.isGlobal(variable) ?
Either.left(new GlobalReference(bindingIdentifier.name)) :
Either.right(new LocalReference(variable));
}
@NotNull
private Either refHelper(IdentifierExpression identifierExpression) {
return scopeLookup.isGlobal(scopeLookup.findVariableReferencedBy(identifierExpression)) ?
Either.left(new GlobalReference(identifierExpression.name)) :
Either.right(new LocalReference(scopeLookup.findVariableReferencedBy(identifierExpression)));
}
@NotNull
private Either refHelper(Variable variable) {
return scopeLookup.isGlobal(variable) ?
Either.left(new GlobalReference(variable.name)) :
Either.right(new LocalReference(variable));
}
// for function, block, caseblock, and script bodies, not arbitrary lists of statements. Performs hoisting.
// TODO ensure that function declarations in switch statements get hoisted to the top of the switch, per 13.12.6 (I think)
@NotNull
private Block explicateBody(ImmutableList statements, boolean strict) {
ImmutableList res = ImmutableList.empty();
// hoist functions
for (Statement s : statements) {
if (s instanceof FunctionDeclaration) {
FunctionDeclaration functionDeclaration = (FunctionDeclaration) s;
Variable variable = scopeLookup.findVariablesForFuncDecl(functionDeclaration).left;
Either ref = refHelper(variable);
Scope myScope = scopeLookup.findScopeFor(functionDeclaration).fromJust();
Maybe name = Maybe.empty();
ImmutableList parameters = simpleParamsHelper(functionDeclaration.params);
res = res.cons(new VariableAssignment(
ref,
explicateGeneralFunction(name, myScope, parameters, functionDeclaration.body, strict),
strict
));
}
}
// then evaluate everything
res = res.reverse().append(statements.map(s -> explicateStatement(s, strict)));
return new Block(res);
}
@NotNull
private LiteralFunction explicateGeneralFunction(
@NotNull Maybe name, @NotNull Scope scope, @NotNull ImmutableList parameters,
@NotNull FunctionBody functionBody, boolean strict
) {
Maybe arguments = Maybe.empty();
if (scope.type == Scope.Type.FunctionName) {
scope = scope.children.maybeHead().fromJust();
}
for (Variable v : scope.variables()) {
if (v.name.equals("arguments")) {
arguments = Maybe.of(v);
break;
}
}
strict = strict || isStrict(functionBody.directives);
this.temporaries = this.temporaries.cons(ImmutableList.empty());
Block body = explicateBody(functionBody.statements, strict);
ImmutableList fnTemporaries = this.temporaries.maybeHead().fromJust();
this.temporaries = this.temporaries.maybeTail().fromJust();
ImmutableList locals = fnTemporaries.append(functionVariablesHelper(scope)); // todo concatlists, I guess
// TODO capture may have duplicate entries: `function g(x){function h(){x+x}}`
ImmutableList captured = scope.through.entries()
.flatMap(p -> p.right.map(r -> r.node.either(
bi -> scopeLookup.findVariableReferencedBy(bi).fromJust(),
scopeLookup::findVariableReferencedBy
)))
.filter(v -> !scopeLookup.isGlobal(v)); // everything needing capture
return new LiteralFunction(name, arguments, parameters, locals, captured, body, strict);
}
@NotNull
private Node explicateStatement(@NotNull Statement statement, boolean strict) {
if (statement instanceof BlockStatement) {
return explicateBody(((BlockStatement) statement).block.statements, strict);
} else if (statement instanceof BreakStatement) {
Pair _break = jumpMap.get(statement).fromJust();
return new Break(targets.get(_break.left).fromJust().left, _break.right);
} else if (statement instanceof ContinueStatement) {
Pair _break = jumpMap.get(statement).fromJust();
return new Break(targets.get(_break.left).fromJust().right.fromJust(), _break.right);
} else if (statement instanceof DebuggerStatement) {
return Void.INSTANCE;
} else if (statement instanceof DoWhileStatement) { // exactly the same as WhileStatement, except that the test is last instead of first
DoWhileStatement doWhileStatement = (DoWhileStatement) statement;
BreakTarget outerTarget = new BreakTarget();
BreakTarget innerTarget = new BreakTarget();
targets = targets.put(statement, new Pair<>(outerTarget, Maybe.of(innerTarget)));
Break breakNode = new Break(outerTarget, 0);
Block body = new Block(ImmutableList.of(
explicateStatement(doWhileStatement.body, strict),
innerTarget,
new IfElse(
explicateExpressionReturningValue(doWhileStatement.test, strict),
new Block(Void.INSTANCE),
new Block(breakNode)
)
));
Loop loop = new Loop(body);
return new Block(ImmutableList.of(loop, outerTarget));
} else if (statement instanceof ExpressionStatement) {
return explicateExpressionDiscardingValue(((ExpressionStatement) statement).expression, strict);
} else if (statement instanceof EmptyStatement) {
return Void.INSTANCE;
} else if (statement instanceof ForInStatement) {
/*
Desugaring:
for(x in o) {
...
}
becomes
__o = o;
__t = keys(__o);
__i = 0;
while(__i < __t.length) {
if(__t[__i] in __o) {
x = __t[__i];
...
}
__i = __i + 1;
}
*/
ForInStatement forInStatement = (ForInStatement) statement;
BreakTarget outerTarget = new BreakTarget();
BreakTarget innerTarget = new BreakTarget();
targets = targets.put(statement, new Pair<>(outerTarget, Maybe.of(innerTarget)));
Break breakNode = new Break(outerTarget, 0);
BindingIdentifier binding;
boolean isDeclaration;
if (forInStatement.left instanceof VariableDeclaration) {
VariableDeclaration variableDeclaration = (VariableDeclaration) forInStatement.left;
assert variableDeclaration.declarators.length == 1; // TODO maybe remove this
// assumes ES5
binding = (BindingIdentifier) variableDeclaration.declarators.maybeHead().fromJust().binding;
isDeclaration = true;
} else if (forInStatement.left instanceof BindingIdentifier) {
binding = (BindingIdentifier) forInStatement.left;
isDeclaration = false;
} else {
throw new UnsupportedOperationException("ES6 not supported: " + forInStatement.left.getClass().getSimpleName());
}
return makeUnvaluedTemporary(object -> makeUnvaluedTemporary(counter -> makeUnvaluedTemporary(keys -> {
Block body = new Block(ImmutableList.of(
new IfElse(
new RelationalComparison(
RelationalComparison.Operator.LessThan,
counter,
new MemberAccess(keys, new LiteralString("length"))
),
new Block(Void.INSTANCE),
new Block(breakNode)
))
.append(ImmutableList.of(
new IfElse(
new In(new MemberAccess(keys, counter), object),
new Block(ImmutableList.of(
isDeclaration ?
new VariableAssignment(refHelper(binding), new MemberAccess(keys, counter), strict) :
variableAssignmentHelper(refHelper(binding), new MemberAccess(keys, counter), strict),
explicateStatement(forInStatement.body, strict)
)),
new Block(Void.INSTANCE)
),
innerTarget,
new VariableAssignment(
counter,
new FloatMath(FloatMath.Operator.Plus, counter, new LiteralNumber(1)),
false
)
)));
Loop loop = new Loop(body);
return new Block(ImmutableList.of(
new VariableAssignment(object, explicateExpressionReturningValue(forInStatement.right, strict), false),
new VariableAssignment(keys, new Keys(object), false),
new VariableAssignment(counter, new LiteralNumber(0), false),
loop,
outerTarget
));
})));
} else if (statement instanceof ForStatement) {
ForStatement forStatement = (ForStatement) statement;
BreakTarget outerTarget = new BreakTarget();
BreakTarget innerTarget = new BreakTarget();
targets = targets.put(statement, new Pair<>(outerTarget, Maybe.of(innerTarget)));
Break breakNode = new Break(outerTarget, 0);
Block body = new Block(forStatement.test.map(t -> ((ImmutableList) ImmutableList.of(
new IfElse(
explicateExpressionReturningValue(t, strict),
new Block(Void.INSTANCE),
new Block(breakNode)
)))).orJust(ImmutableList.empty())
.append(ImmutableList.of(
explicateStatement(forStatement.body, strict),
innerTarget
))
.append(forStatement.update.map(e -> ((ImmutableList) ImmutableList.of((Node) explicateExpressionDiscardingValue(
e,
strict
)))).orJust(ImmutableList.empty())));
Loop loop = new Loop(body);
return new Block(ImmutableList.of(forStatement.init.map(i -> (Node) new Block(ImmutableList.of(
explicateVariableDeclarationExpression(i, strict),
loop
))).orJust(loop), outerTarget));
} else if (statement instanceof FunctionDeclaration) {
// todo maybe warn people about using block-level function declarations.
FunctionDeclaration functionDeclaration = (FunctionDeclaration) statement;
Pair> functionVariables = scopeLookup.findVariablesForFuncDecl(functionDeclaration);
if (functionVariables.right.isJust()) {
// this is from annex B.3.3
return new VariableAssignment(
new LocalReference(functionVariables.right.fromJust()),
new LocalReference(functionVariables.left),
false
);
} else {
return Void.INSTANCE;
}
} else if (statement instanceof IfStatement) {
IfStatement ifStatement = (IfStatement) statement;
NodeWithValue test = explicateExpressionReturningValue(ifStatement.test, strict);
Node consequent = explicateStatement(ifStatement.consequent, strict);
Node alternate = ifStatement.alternate.map(s -> explicateStatement(s, strict)).orJust(Void.INSTANCE);
return new IfElse(test, new Block(consequent), new Block(alternate));
} else if (statement instanceof LabeledStatement) {
LabeledStatement labeledStatement = (LabeledStatement) statement;
BreakTarget target = new BreakTarget();
targets = targets.put(labeledStatement.body, new Pair<>(target, Maybe.empty()));
return new Block(ImmutableList.of(explicateStatement(labeledStatement.body, strict), target));
} else if (statement instanceof ReturnStatement) {
ReturnStatement returnStatement = (ReturnStatement) statement;
return new Return(
returnStatement.expression.map(e -> explicateExpressionReturningValue(e, strict))
);
} else if (statement instanceof com.shapesecurity.shift.ast.SwitchStatement) {
// TODO hoist function declarations. This will require modifying asg SwitchStatements to have a Declarations block of statements, horrifyingly enough. probably also need to fix scope analysis.
com.shapesecurity.shift.ast.SwitchStatement switchStatement = (com.shapesecurity.shift.ast.SwitchStatement) statement;
BreakTarget target = new BreakTarget();
targets = targets.put(statement, new Pair<>(target, Maybe.empty()));
return new Block(ImmutableList.of(
let(
explicateExpressionReturningValue(switchStatement.discriminant, strict),
d -> new Block(new SwitchStatement(
d,
switchStatement.cases.map(c -> explicateSwitchCase(c, strict)),
new Block(ImmutableList.empty()),
ImmutableList.empty()
))
),
target
));
} else if (statement instanceof SwitchStatementWithDefault) {
// TODO hoist function declarations. This will require modifying asg SwitchStatements to have a Declarations block of statements, horrifyingly enough. probably also need to fix scope analysis.
SwitchStatementWithDefault switchStatement = (SwitchStatementWithDefault) statement;
BreakTarget target = new BreakTarget();
targets = targets.put(statement, new Pair<>(target, Maybe.empty()));
return new Block(ImmutableList.of(
let(
explicateExpressionReturningValue(switchStatement.discriminant, strict),
d -> new Block(new SwitchStatement(
d,
switchStatement.preDefaultCases.map(c -> explicateSwitchCase(c, strict)),
new Block(switchStatement.defaultCase.consequent.map(c -> explicateStatement(c, strict))),
switchStatement.postDefaultCases.map(c -> explicateSwitchCase(c, strict))
))
),
target
));
} else if (statement instanceof ThrowStatement) {
ThrowStatement throwStatement = (ThrowStatement) statement;
return new Throw(
explicateExpressionReturningValue(throwStatement.expression, strict)
);
} else if (statement instanceof TryCatchStatement) {
TryCatchStatement tryCatchStatement = (TryCatchStatement) statement;
Variable catchVariable =
scopeLookup.findVariableDeclaredBy((BindingIdentifier) tryCatchStatement.catchClause.binding).fromJust();
return new TryCatchFinally(
explicateBody(tryCatchStatement.body.statements, strict),
Maybe.of(new Pair<>(catchVariable, explicateBody(tryCatchStatement.catchClause.body.statements, strict))),
new Block(ImmutableList.empty())
);
} else if (statement instanceof TryFinallyStatement) {
TryFinallyStatement tryFinallyStatement = (TryFinallyStatement) statement;
Maybe> catchBody = tryFinallyStatement.catchClause.map(c ->
new Pair<>(
scopeLookup.findVariableDeclaredBy((BindingIdentifier) c.binding).fromJust(),
explicateBody(c.body.statements, strict)
)
);
return new TryCatchFinally(
explicateBody(tryFinallyStatement.body.statements, strict),
catchBody,
explicateBody(tryFinallyStatement.finalizer.statements, strict)
);
} else if (statement instanceof VariableDeclarationStatement) {
VariableDeclarationStatement variableDeclarationStatement = (VariableDeclarationStatement) statement;
return explicateVariableDeclaration(variableDeclarationStatement.declaration, strict);
} else if (statement instanceof WhileStatement) {
WhileStatement whileStatement = (WhileStatement) statement;
BreakTarget outerTarget = new BreakTarget();
BreakTarget innerTarget = new BreakTarget();
targets = targets.put(statement, new Pair<>(outerTarget, Maybe.of(innerTarget)));
Break breakNode = new Break(outerTarget, 0);
Block body = new Block(ImmutableList.of(
new IfElse(
explicateExpressionReturningValue(whileStatement.test, strict),
new Block(Void.INSTANCE),
new Block(breakNode)
),
explicateStatement(whileStatement.body, strict),
innerTarget
));
Loop loop = new Loop(body);
return new Block(ImmutableList.of(loop, outerTarget));
} else if (statement instanceof WithStatement) {
return new Halt(); // TODO maybe warn.
}
throw new UnsupportedOperationException("ES6 not supported: " + statement.getClass().getSimpleName());
}
@NotNull
private NodeWithValue explicateExpressionReturningValue(Expression expression, boolean strict) {
return explicateExpression(expression, true, strict);
}
@NotNull
private NodeWithValue explicateExpressionDiscardingValue(Expression expression, boolean strict) {
return explicateExpression(expression, false, strict);
}
// Here, keepValue is just used for statements like i++, to avoid creating unnecessary temporaries.
@NotNull
private NodeWithValue explicateExpression(Expression expression, boolean keepValue, boolean strict) {
if (expression instanceof ArrayExpression) {
ArrayExpression arrayExpression = (ArrayExpression) expression;
if (arrayExpression.elements.exists(Maybe::isNothing)) { // ie, contains hole
return letWithValue(
new LiteralEmptyArray(),
arr -> new BlockWithValue(ImmutableList.cons(
new MemberAssignment(
arr,
new LiteralString("length"),
new LiteralNumber(arrayExpression.elements.length),
false
),
arrayExpression.elements.mapWithIndex((ind, p) -> p.maybe(
Void.INSTANCE,
e -> explicateSpreadElementExpression(arr, ind, e, strict)
))
), arr)
);
} else if (arrayExpression.elements.isEmpty()) {
return new LiteralEmptyArray();
}
return letWithValue(
new LiteralEmptyArray(),
arr -> new BlockWithValue(
arrayExpression.elements.mapWithIndex((ind, p) -> p.map(e -> explicateSpreadElementExpression(
arr,
ind,
e,
strict
))
.orJust(new LiteralUndefined())),
arr
)
);
} else if (expression instanceof AssignmentExpression) {
AssignmentExpression assignmentExpression = (AssignmentExpression) expression;
Binding binding = assignmentExpression.binding;
if (binding instanceof StaticMemberExpression) {
StaticMemberExpression staticMemberExpression = (StaticMemberExpression) binding;
return new MemberAssignment(
explicateExpressionSuper(staticMemberExpression._object, strict),
new LiteralString(staticMemberExpression.property),
explicateExpressionReturningValue(assignmentExpression.expression, strict),
strict
);
} else if (binding instanceof ComputedMemberExpression) {
ComputedMemberExpression computedMemberExpression = (ComputedMemberExpression) binding;
return letWithValue(
// semantics: evaluate obj, evaluate prop, coerce obj to object, coerce prop to string. in that order. TODO find a better way of doing this.
explicateExpressionSuper(computedMemberExpression._object, strict),
objectRef -> letWithValue(
explicateExpressionReturningValue(computedMemberExpression.expression, strict),
fieldRef -> new BlockWithValue(
ImmutableList.of(new RequireObjectCoercible(objectRef)),
letWithValue(
new TypeCoercionString(fieldRef),
prop -> new MemberAssignment(
objectRef,
prop,
explicateExpressionReturningValue(assignmentExpression.expression, strict),
strict
)
)
)
)
);
} else if (binding instanceof BindingIdentifier) {
BindingIdentifier bindingIdentifier = (BindingIdentifier) binding;
Either ref = refHelper(bindingIdentifier);
NodeWithValue rhs = explicateExpressionReturningValue(assignmentExpression.expression, strict);
return variableAssignmentHelper(
ref,
rhs,
strict
);
} else {
throw new UnsupportedOperationException("ES6 not supported: " + binding.getClass().getSimpleName());
}
} else if (expression instanceof BinaryExpression) {
return explicateBinaryExpression((BinaryExpression) expression, strict);
} else if (expression instanceof CallExpression) {
CallExpression c = (CallExpression) expression;
// abort on direct eval. todo maybe warn.
if (c.callee instanceof IdentifierExpression && (((IdentifierExpression) c.callee).name.equals("eval"))) {
return new Halt();
}
ImmutableList arguments =
c.arguments.map(a -> explicateExpressionReturningValue((Expression) a, strict));
if (c.callee instanceof MemberExpression) {
MemberExpression memberExpression = (MemberExpression) c.callee;
// TODO: if memberExpression._object is a Super, we need to actually call it as super.<...>
return letWithValue(
explicateExpressionSuper(memberExpression._object, strict),
contextRef -> new Call(
Maybe.of(contextRef),
memberExpression instanceof StaticMemberExpression
? new MemberAccess(
contextRef,
new LiteralString(((StaticMemberExpression) memberExpression).property)
)
: new MemberAccess(
contextRef,
explicateExpressionReturningValue(
((ComputedMemberExpression) memberExpression).expression,
strict
)
),
arguments
)
);
}
NodeWithValue callee = explicateExpressionSuper(c.callee, strict);
return new Call(Maybe.empty(), callee, arguments);
} else if (expression instanceof CompoundAssignmentExpression) {
return explicateCompoundAssignmentExpression((CompoundAssignmentExpression) expression, strict);
} else if (expression instanceof ComputedMemberExpression) {
ComputedMemberExpression computedMemberExpression = (ComputedMemberExpression) expression;
return new MemberAccess(
explicateExpressionSuper(computedMemberExpression._object, strict),
explicateExpressionReturningValue(computedMemberExpression.expression, strict)
);
} else if (expression instanceof ConditionalExpression) {
ConditionalExpression conditionalExpression = (ConditionalExpression) expression;
return makeTemporary(
// TODO there are several other ways of doing this; the temporary is not necessary if we have proper completion values
ref -> new BlockWithValue(
ImmutableList.of(
new IfElse(
explicateExpressionReturningValue(conditionalExpression.test, strict),
new Block(new VariableAssignment(
ref,
explicateExpressionReturningValue(conditionalExpression.consequent, strict),
false
)),
new Block(new VariableAssignment(
ref,
explicateExpressionReturningValue(conditionalExpression.alternate, strict),
false
))
)),
ref
)
);
} else if (expression instanceof FunctionExpression) {
FunctionExpression functionExpression = (FunctionExpression) expression;
return explicateGeneralFunction(
functionExpression.name.flatMap(scopeLookup::findVariableDeclaredBy),
scopeLookup.findScopeFor(functionExpression).fromJust(),
simpleParamsHelper(functionExpression.params),
functionExpression.body,
strict
);
} else if (expression instanceof StaticMemberExpression) {
StaticMemberExpression staticMemberExpression = (StaticMemberExpression) expression;
return new MemberAccess(
explicateExpressionSuper(staticMemberExpression._object, strict),
new LiteralString(staticMemberExpression.property)
);
} else if (expression instanceof IdentifierExpression) {
IdentifierExpression identifierExpression = (IdentifierExpression) expression;
return Either.extract(refHelper(identifierExpression));
} else if (expression instanceof LiteralBooleanExpression) {
return new LiteralBoolean(((LiteralBooleanExpression) expression).value);
} else if (expression instanceof LiteralInfinityExpression) {
return new LiteralInfinity();
} else if (expression instanceof LiteralNumericExpression) {
return new LiteralNumber(((LiteralNumericExpression) expression).value);
} else if (expression instanceof LiteralNullExpression) {
return new LiteralNull();
} else if (expression instanceof LiteralRegExpExpression) {
LiteralRegExpExpression literalRegExpExpression = (LiteralRegExpExpression) expression;
return new LiteralRegExp(literalRegExpExpression.pattern, literalRegExpExpression.flags);
} else if (expression instanceof LiteralStringExpression) {
return new LiteralString(((LiteralStringExpression) expression).value);
} else if (expression instanceof ObjectExpression) { // TODO this would be faster/better as Object.defineProperties (all at once, instead of one at a time), probably
ObjectExpression objectExpression = (ObjectExpression) expression;
if (objectExpression.properties.isEmpty()) {
return new LiteralEmptyObject();
}
return letWithValue(
new LiteralEmptyObject(),
obj -> new BlockWithValue(
objectExpression.properties.map(p -> explicateObjectProperty(obj, p, strict)),
obj
)
);
} else if (expression instanceof NewExpression) {
NewExpression c = (NewExpression) expression;
ImmutableList arguments =
c.arguments.map(a -> explicateExpressionReturningValue((Expression) a, strict));
NodeWithValue callee = explicateExpressionSuper(c.callee, strict);
return new New(callee, arguments);
} else if (expression instanceof ThisExpression) {
return new This(strict && this.temporaries.length > 1); // temporaries.length > 1 iff we are within a function. global-code `this` is the same in non-strict mode as strict.
} else if (expression instanceof UnaryExpression) {
return explicateUnaryExpression((UnaryExpression) expression, strict);
} else if (expression instanceof UpdateExpression) {
UpdateExpression updateExpression = (UpdateExpression) expression;
if (updateExpression.operand instanceof BindingIdentifier) {
Either binding = refHelper((BindingIdentifier) updateExpression.operand);
NodeWithValue valExpr = new TypeCoercionNumber(Either.extract(binding));
if (keepValue && !updateExpression.isPrefix) {
return letWithValue(
valExpr,
oldVal -> new BlockWithValue(
new Block(variableAssignmentHelper(
binding,
new FloatMath(
updateExpression.operator == UpdateOperator.Increment ? FloatMath.Operator.Plus : FloatMath.Operator.Minus,
oldVal,
new LiteralNumber(1)
),
strict
)),
oldVal
)
);
} else {
return variableAssignmentHelper(
binding,
new FloatMath(
updateExpression.operator == UpdateOperator.Increment ? FloatMath.Operator.Plus : FloatMath.Operator.Minus,
valExpr,
new LiteralNumber(1)
),
strict
);
}
} else {
NodeWithValue _object;
NodeWithValue field;
if (updateExpression.operand instanceof ComputedMemberExpression) {
ComputedMemberExpression computedMemberExpression = (ComputedMemberExpression) updateExpression.operand;
_object = explicateExpressionSuper(computedMemberExpression._object, strict);
field = explicateExpressionReturningValue(computedMemberExpression.expression, strict);
} else if (updateExpression.operand instanceof StaticMemberExpression) {
StaticMemberExpression staticMemberExpression = (StaticMemberExpression) updateExpression.operand;
_object = explicateExpressionSuper(staticMemberExpression._object, strict);
field = new LiteralString(staticMemberExpression.property);
} else {
throw new RuntimeException("Not reached");
}
return letWithValue(
// semantics: evaluate obj, evaluate prop, ensure obj is object, coerce prop to string, coerce obj[prop] to number. in that order. TODO find a better way of doing this.
_object,
objectRef -> letWithValue(
field,
fieldRef -> new BlockWithValue(
ImmutableList.of(new RequireObjectCoercible(objectRef)),
letWithValue(
new TypeCoercionString(fieldRef),
// todo we don't actually need a new temporary for this (here or elsewhere); we can just reuse fieldRef
prop -> (keepValue && !updateExpression.isPrefix) ?
letWithValue(
new TypeCoercionNumber(new MemberAccess(objectRef, prop)),
oldVal -> new BlockWithValue(
ImmutableList.of(new MemberAssignment(
objectRef,
prop,
new FloatMath(
updateExpression.operator == UpdateOperator.Increment ? FloatMath.Operator.Plus : FloatMath.Operator.Minus,
oldVal,
new LiteralNumber(1)
),
strict
)),
oldVal
)
) :
new MemberAssignment(
objectRef,
prop,
new FloatMath(
updateExpression.operator == UpdateOperator.Increment ? FloatMath.Operator.Plus : FloatMath.Operator.Minus,
new TypeCoercionNumber(new MemberAccess(objectRef, prop)),
new LiteralNumber(1)
),
strict
)
)
)
)
);
}
}
throw new UnsupportedOperationException("ES6 not supported: " + expression.getClass().getSimpleName());
}
@NotNull
private Pair explicateSwitchCase(@NotNull SwitchCase switchCase, boolean strict) {
return new Pair<>(
explicateExpressionReturningValue(switchCase.test, strict),
new Block(switchCase.consequent.map(s -> explicateStatement(s, strict)))
);
}
@NotNull
private Node explicateVariableDeclarationExpression(
@NotNull VariableDeclarationExpression variableDeclarationExpression, boolean strict
) {
if (variableDeclarationExpression instanceof VariableDeclaration) {
return explicateVariableDeclaration((VariableDeclaration) variableDeclarationExpression, strict);
} else if (variableDeclarationExpression instanceof Expression) {
return explicateExpressionReturningValue((Expression) variableDeclarationExpression, strict);
} else {
throw new RuntimeException("Not reached");
}
}
@NotNull
private Node explicateVariableDeclaration(@NotNull VariableDeclaration variableDeclaration, boolean strict) {
return new Block(
Maybe.catMaybes(variableDeclaration.declarators.map(d -> d.init.isNothing() ? Maybe.empty() :
Maybe.of(new VariableAssignment(
refHelper((BindingIdentifier) d.binding),
explicateExpressionReturningValue(d.init.fromJust(), strict),
strict
))
))
);
}
@NotNull
private NodeWithValue explicateUnaryExpression(@NotNull UnaryExpression unaryExpression, boolean strict) {
switch (unaryExpression.operator) {
case Plus:
return new TypeCoercionNumber(explicateExpressionReturningValue(unaryExpression.operand, strict));
case Minus:
return new Negation(explicateExpressionReturningValue(unaryExpression.operand, strict));
case LogicalNot:
return new Not(explicateExpressionReturningValue(unaryExpression.operand, strict));
case BitNot:
return new BitwiseNot(explicateExpressionReturningValue(unaryExpression.operand, strict));
case Void:
return new VoidOp(explicateExpressionDiscardingValue(unaryExpression.operand, strict));
case Delete:
if (unaryExpression.operand instanceof IdentifierExpression) {
IdentifierExpression identifierExpression = (IdentifierExpression) unaryExpression.operand;
assert !strict; // In strict mode, this is a syntax error.
if (scopeLookup.isGlobal(scopeLookup.findVariableReferencedBy(identifierExpression))) {
return new DeleteGlobalProperty(identifierExpression.name);
} else {
// No local variables may be deleted.
return new LiteralBoolean(false);
}
} else if (unaryExpression.operand instanceof ComputedMemberExpression) {
ComputedMemberExpression computedMemberExpression = (ComputedMemberExpression) unaryExpression.operand;
return new DeleteProperty(
explicateExpressionSuper(computedMemberExpression._object, strict),
explicateExpressionReturningValue(computedMemberExpression.expression, strict),
strict
);
} else if (unaryExpression.operand instanceof StaticMemberExpression) {
StaticMemberExpression staticMemberExpression = (StaticMemberExpression) unaryExpression.operand;
return new DeleteProperty(
explicateExpressionSuper(staticMemberExpression._object, strict),
new LiteralString(staticMemberExpression.property),
strict
);
} else {
// Deleting anything other than a reference simply evaluates the thing and returns true (for some reason).
return new BlockWithValue(
new Block(explicateExpressionDiscardingValue(unaryExpression.operand, strict)),
new LiteralBoolean(true)
);
}
case Typeof:
// globals not declared by us need special treatment to avoid throwing when nonexistent
if (unaryExpression.operand instanceof IdentifierExpression) {
IdentifierExpression identifierExpression = (IdentifierExpression) unaryExpression.operand;
Variable var = scopeLookup.findVariableReferencedBy(identifierExpression);
if (scopeLookup.isGlobal(var) && var.declarations.isEmpty()) {
return new TypeofGlobal(var.name);
}
// else fall through
}
return new Typeof(explicateExpressionReturningValue(unaryExpression.operand, strict));
}
throw new RuntimeException("Not reached");
}
@NotNull
private NodeWithValue explicateBinaryExpression(@NotNull BinaryExpression binaryExpression, boolean strict) {
NodeWithValue right = explicateExpressionReturningValue(binaryExpression.right, strict);
if (binaryExpression.operator == com.shapesecurity.shift.ast.operators.BinaryOperator.Sequence) { // unlike all other cases, we do not need the RHS.
return new BlockWithValue(
ImmutableList.of(explicateExpressionDiscardingValue(binaryExpression.left, strict)),
right
);
}
NodeWithValue left = explicateExpressionReturningValue(binaryExpression.left, strict);
switch (binaryExpression.operator) {
case Equal:
return new Equality(
Equality.Operator.Eq,
left,
right
);
case NotEqual:
return new Equality(
Equality.Operator.Neq,
left,
right
);
case StrictEqual:
return new Equality(
Equality.Operator.StrictEq,
left,
right
);
case StrictNotEqual:
return new Equality(
Equality.Operator.StrictNeq,
left,
right
);
case LogicalAnd:
return new Logic(
Logic.Operator.And,
left,
right
);
case LogicalOr:
return new Logic(
Logic.Operator.Or,
left,
right
);
case LessThan:
return new RelationalComparison(
RelationalComparison.Operator.LessThan,
left,
right
);
case LessThanEqual:
return new RelationalComparison(
RelationalComparison.Operator.LessThanEqual,
left,
right
);
case GreaterThan:
return new RelationalComparison(
RelationalComparison.Operator.GreaterThan,
left,
right
);
case GreaterThanEqual:
return new RelationalComparison(
RelationalComparison.Operator.GreaterThanEqual,
left,
right
);
case Plus:
return new FloatMath(
FloatMath.Operator.Plus,
left,
right
);
case Minus:
return new FloatMath(
FloatMath.Operator.Minus,
left,
right
);
case Mul:
return new FloatMath(
FloatMath.Operator.Mul,
left,
right
);
case Div:
return new FloatMath(
FloatMath.Operator.Div,
left,
right
);
case Rem:
return new FloatMath(
FloatMath.Operator.Rem,
left,
right
);
case BitwiseAnd:
return new IntMath(
IntMath.Operator.BitwiseAnd,
left,
right
);
case BitwiseOr:
return new IntMath(
IntMath.Operator.BitwiseOr,
left,
right
);
case BitwiseXor:
return new IntMath(
IntMath.Operator.BitwiseXor,
left,
right
);
case Left:
return new IntMath(
IntMath.Operator.LeftShift,
left,
right
);
case Right:
return new IntMath(
IntMath.Operator.RightShift,
left,
right
);
case UnsignedRight:
return new IntMath(
IntMath.Operator.UnsignedRightShift,
left,
right
);
case In:
return new In(
left,
right
);
case Instanceof:
return new InstanceOf(
left,
right
);
}
throw new RuntimeException("Not reached");
}
@NotNull
private NodeWithValue explicateCompoundAssignmentExpression(
@NotNull CompoundAssignmentExpression compoundAssignmentExpression, boolean strict
) {
BinaryOperator operator;
switch (compoundAssignmentExpression.operator) {
case AssignPlus:
operator = FloatMath.Operator.Plus;
break;
case AssignMinus:
operator = FloatMath.Operator.Minus;
break;
case AssignMul:
operator = FloatMath.Operator.Mul;
break;
case AssignDiv:
operator = FloatMath.Operator.Div;
break;
case AssignRem:
operator = FloatMath.Operator.Rem;
break;
case AssignBitAnd:
operator = IntMath.Operator.BitwiseAnd;
break;
case AssignBitOr:
operator = IntMath.Operator.BitwiseOr;
break;
case AssignBitXor:
operator = IntMath.Operator.BitwiseXor;
break;
case AssignLeftShift:
operator = IntMath.Operator.LeftShift;
break;
case AssignRightShift:
operator = IntMath.Operator.RightShift;
break;
case AssignUnsignedRightShift:
operator = IntMath.Operator.UnsignedRightShift;
break;
default:
throw new RuntimeException("Not reached");
}
if (compoundAssignmentExpression.binding instanceof BindingIdentifier) {
Either binding = refHelper((BindingIdentifier) compoundAssignmentExpression.binding);
NodeWithValue reference = Either.extract(binding);
return variableAssignmentHelper(
binding,
BinaryOperation.fromOperator(
operator,
reference,
explicateExpressionReturningValue(compoundAssignmentExpression.expression, strict)
),
strict
);
} else {
NodeWithValue _object;
NodeWithValue field;
NodeWithValue value;
if (compoundAssignmentExpression.binding instanceof ComputedMemberExpression) {
ComputedMemberExpression computedMemberExpression =
(ComputedMemberExpression) compoundAssignmentExpression.binding;
_object = explicateExpressionSuper(computedMemberExpression._object, strict);
field = explicateExpressionReturningValue(computedMemberExpression.expression, strict);
value = explicateExpressionReturningValue(compoundAssignmentExpression.expression, strict);
} else if (compoundAssignmentExpression.binding instanceof StaticMemberExpression) {
StaticMemberExpression staticMemberExpression = (StaticMemberExpression) compoundAssignmentExpression.binding;
_object = explicateExpressionSuper(staticMemberExpression._object, strict);
field = new LiteralString(staticMemberExpression.property);
value = explicateExpressionReturningValue(compoundAssignmentExpression.expression, strict);
} else {
throw new RuntimeException("Not reached");
}
return letWithValue(
// semantics: evaluate obj, evaluate prop, coerce obj to object, coerce prop to string. in that order. TODO find a better way of doing this.
_object,
objectRef -> letWithValue(
field,
fieldRef -> new BlockWithValue(
ImmutableList.of(new RequireObjectCoercible(objectRef)),
letWithValue(
new TypeCoercionString(fieldRef),
prop -> new MemberAssignment(
objectRef,
prop,
BinaryOperation.fromOperator(
operator,
new MemberAccess(objectRef, prop),
value
),
strict
)
)
)
)
);
}
}
@NotNull
private NodeWithValue explicateExpressionSuper(@NotNull ExpressionSuper node, boolean strict) {
return node instanceof Super
? explicateSuper((Super) node)
: explicateExpressionReturningValue((Expression) node, strict);
}
@NotNull
private NodeWithValue explicateSuper(@NotNull Super node) {
throw new UnsupportedOperationException("ES6 not supported: Super");
}
@NotNull
private Node explicateObjectProperty(@NotNull LocalReference ref, @NotNull ObjectProperty objectProperty, boolean strict) {
if (objectProperty instanceof DataProperty) {
DataProperty dataProperty = (DataProperty) objectProperty;
return new MemberDefinition(
ref,
explicatePropertyName(dataProperty.name, strict),
explicateExpressionReturningValue(((DataProperty) objectProperty).expression, strict)
);
} else if (objectProperty instanceof Getter) {
Getter getter = (Getter) objectProperty;
return new MemberDefinition(
ref,
explicatePropertyName(getter.name, strict),
new MemberAssignmentProperty.Getter(explicateGeneralFunction(
Maybe.empty(),
scopeLookup.findScopeFor(getter).fromJust(),
ImmutableList.empty(),
getter.body,
strict
))
);
} else if (objectProperty instanceof Setter) {
Setter setter = (Setter) objectProperty;
return new MemberDefinition(
ref,
explicatePropertyName(setter.name, strict),
new MemberAssignmentProperty.Setter(explicateGeneralFunction(
Maybe.empty(),
scopeLookup.findScopeFor(setter).fromJust(),
scopeLookup.findVariableDeclaredBy((BindingIdentifier) setter.param).toList(),
setter.body,
strict
))
);
}
throw new UnsupportedOperationException("ES6 not supported: " + objectProperty.getClass().getSimpleName());
}
@NotNull
private NodeWithValue explicatePropertyName(@NotNull PropertyName propertyName, boolean strict) {
if (propertyName instanceof ComputedPropertyName) {
// TODO not a part of ES5
return explicateExpressionReturningValue(((ComputedPropertyName) propertyName).expression, strict);
} else if (propertyName instanceof StaticPropertyName) {
return new LiteralString(((StaticPropertyName) propertyName).value);
}
throw new RuntimeException("Not reached");
}
@NotNull
private Node explicateSpreadElementExpression(
@NotNull LocalReference arr, int index, @NotNull SpreadElementExpression spreadElementExpression, boolean strict
) { // TODO assigning every individual element of the array is extremely inefficient
if (spreadElementExpression instanceof Expression) {
return new MemberDefinition(
arr,
new LiteralNumber(index),
explicateExpressionReturningValue((Expression) spreadElementExpression, strict)
); // TODO could be non-strict assignment always
}
throw new UnsupportedOperationException("ES6 not supported: SpreadElement");
}
@NotNull
private NodeWithValue makeTemporary(F withTemporary) {
LocalReference ref = new TemporaryReference();
ImmutableList curTemps = this.temporaries.maybeHead().fromJust().cons(ref.variable);
this.temporaries = this.temporaries.maybeTail().fromJust().cons(curTemps);
return withTemporary.apply(ref);
}
@NotNull
private Node makeUnvaluedTemporary(F withTemporary) { // TODO would be nice to join this with the above
LocalReference ref = new TemporaryReference();
ImmutableList curTemps = this.temporaries.maybeHead().fromJust().cons(ref.variable);
this.temporaries = this.temporaries.maybeTail().fromJust().cons(curTemps);
return withTemporary.apply(ref);
}
@NotNull
private NodeWithValue letWithValue(NodeWithValue value, F function) {
F wrapped =
ref ->
new BlockWithValue(new Block(new VariableAssignment(ref, value, false)), function.apply(ref));
return makeTemporary(wrapped);
}
@NotNull
private Node let(NodeWithValue value, F function) {
return makeUnvaluedTemporary(ref ->
new Block(ImmutableList.of(
new VariableAssignment(ref, value, false),
function.apply(ref)
)));
}
}