return x;
};
+ var readOnlyPrefix = makePredicate("! ~ + - void typeof");
+ function statement_to_expression(stat) {
+ if (stat.body instanceof AST_UnaryPrefix && readOnlyPrefix(stat.body.operator)) {
+ return stat.body.expression;
+ } else {
+ return stat.body;
+ }
+ }
+
function tighten_body(statements, compressor) {
var CHANGED, max_iter = 10;
do {
}
} while (CHANGED && max_iter-- > 0);
- if (compressor.option("negate_iife")) {
- negate_iifes(statements, compressor);
- }
-
return statements;
function collapse_single_use_vars(statements, compressor) {
if (seqLength(seq) >= compressor.sequences_limit) {
push_seq();
}
- seq.push(stat.body);
+ seq.push(seq.length > 0 ? statement_to_expression(stat) : stat.body);
} else {
push_seq();
ret.push(stat);
stat.init = cons_seq(stat.init);
}
else if (!stat.init) {
- stat.init = prev.body;
+ stat.init = statement_to_expression(prev);
ret.pop();
}
} catch(ex) {
}, []);
};
- function negate_iifes(statements, compressor) {
- function is_iife_call(node) {
- if (node instanceof AST_Call) {
- return node.expression instanceof AST_Function || is_iife_call(node.expression);
- }
- return false;
- }
-
- statements.forEach(function(stat){
- if (stat instanceof AST_SimpleStatement) {
- stat.body = (function transform(thing) {
- return thing.transform(new TreeTransformer(function(node){
- if (node instanceof AST_New) {
- return node;
- }
- if (is_iife_call(node)) {
- return make_node(AST_UnaryPrefix, node, {
- operator: "!",
- expression: node
- });
- }
- else if (node instanceof AST_Call) {
- node.expression = transform(node.expression);
- }
- else if (node instanceof AST_Seq) {
- node.car = transform(node.car);
- }
- else if (node instanceof AST_Conditional) {
- var expr = transform(node.condition);
- if (expr !== node.condition) {
- // it has been negated, reverse
- node.condition = expr;
- var tmp = node.consequent;
- node.consequent = node.alternative;
- node.alternative = tmp;
- }
- }
- return node;
- }));
- })(stat.body);
- }
- });
- };
-
};
function extract_functions_from_statement_array(statements) {
return ast1.print_to_string().length >
ast2.print_to_string().length
? ast2 : ast1;
- };
+ }
+
+ function best_of_statement(ast1, ast2) {
+ return best_of(make_node(AST_SimpleStatement, ast1, {
+ body: ast1
+ }), make_node(AST_SimpleStatement, ast2, {
+ body: ast2
+ })).body;
+ }
// methods to evaluate a constant expression
(function (def){
operator: "!",
expression: exp
});
- };
+ }
+ function best(orig, alt, first_in_statement) {
+ var negated = basic_negation(orig);
+ if (first_in_statement) {
+ var stat = make_node(AST_SimpleStatement, alt, {
+ body: alt
+ });
+ return best_of(negated, stat) === stat ? alt : negated;
+ }
+ return best_of(negated, alt);
+ }
def(AST_Node, function(){
return basic_negation(this);
});
self.cdr = self.cdr.negate(compressor);
return self;
});
- def(AST_Conditional, function(compressor){
+ def(AST_Conditional, function(compressor, first_in_statement){
var self = this.clone();
self.consequent = self.consequent.negate(compressor);
self.alternative = self.alternative.negate(compressor);
- return best_of(basic_negation(this), self);
+ return best(this, self, first_in_statement);
});
- def(AST_Binary, function(compressor){
+ def(AST_Binary, function(compressor, first_in_statement){
var self = this.clone(), op = this.operator;
if (compressor.option("unsafe_comps")) {
switch (op) {
case "!==": self.operator = "==="; return self;
case "&&":
self.operator = "||";
- self.left = self.left.negate(compressor);
+ self.left = self.left.negate(compressor, first_in_statement);
self.right = self.right.negate(compressor);
- return best_of(basic_negation(this), self);
+ return best(this, self, first_in_statement);
case "||":
self.operator = "&&";
- self.left = self.left.negate(compressor);
+ self.left = self.left.negate(compressor, first_in_statement);
self.right = self.right.negate(compressor);
- return best_of(basic_negation(this), self);
+ return best(this, self, first_in_statement);
}
return basic_negation(this);
});
})(function(node, func){
- node.DEFMETHOD("negate", function(compressor){
- return func.call(this, compressor);
+ node.DEFMETHOD("negate", function(compressor, first_in_statement){
+ return func.call(this, compressor, first_in_statement);
});
});
return make_node(AST_SimpleStatement, self, {
body: make_node(AST_Conditional, self, {
condition : self.condition,
- consequent : self.body.body,
- alternative : self.alternative.body
+ consequent : statement_to_expression(self.body),
+ alternative : statement_to_expression(self.alternative)
})
}).transform(compressor);
}
body: make_node(AST_Binary, self, {
operator : "||",
left : negated,
- right : self.body.body
+ right : statement_to_expression(self.body)
})
}).transform(compressor);
return make_node(AST_SimpleStatement, self, {
body: make_node(AST_Binary, self, {
operator : "&&",
left : self.condition,
- right : self.body.body
+ right : statement_to_expression(self.body)
})
}).transform(compressor);
}
body: make_node(AST_Binary, self, {
operator : "||",
left : self.condition,
- right : self.alternative.body
+ right : statement_to_expression(self.alternative)
})
}).transform(compressor);
}
}
}
}
- return self.evaluate(compressor)[0];
+ if (compressor.option("negate_iife")
+ && compressor.parent() instanceof AST_SimpleStatement
+ && is_iife_call(self)) {
+ return self.negate(compressor, true);
+ }
+ return self;
+
+ function is_iife_call(node) {
+ if (node instanceof AST_Call && !(node instanceof AST_New)) {
+ return node.expression instanceof AST_Function || is_iife_call(node.expression);
+ }
+ return false;
+ }
});
OPT(AST_New, function(self, compressor){
// !!foo ==> foo, if we're in boolean context
return e.expression;
}
+ if (e instanceof AST_Binary) {
+ var statement = first_in_statement(compressor);
+ self = (statement ? best_of_statement : best_of)(self, e.negate(compressor, statement));
+ }
break;
case "typeof":
// typeof always returns a non-empty string, thus it's
}
return make_node(AST_True, self);
}
- if (e instanceof AST_Binary && self.operator == "!") {
- self = best_of(self, e.negate(compressor));
- }
}
return self.evaluate(compressor)[0];
});
if (compressor.option("comparisons") && self.is_boolean()) {
if (!(compressor.parent() instanceof AST_Binary)
|| compressor.parent() instanceof AST_Assign) {
+ var statement = first_in_statement(compressor);
var negated = make_node(AST_UnaryPrefix, self, {
operator: "!",
- expression: self.negate(compressor)
+ expression: self.negate(compressor, statement)
});
- self = best_of(self, negated);
+ self = (statement ? best_of_statement : best_of)(self, negated);
}
if (compressor.option("unsafe_comps")) {
switch (self.operator) {
return maintain_this_binding(compressor.parent(), self, self.alternative);
}
}
- var negated = cond[0].negate(compressor);
- if (best_of(cond[0], negated) === negated) {
+ var statement = first_in_statement(compressor);
+ var negated = cond[0].negate(compressor, statement);
+ if ((statement ? best_of_statement : best_of)(cond[0], negated) === negated) {
self = make_node(AST_Conditional, self, {
condition: negated,
consequent: self.alternative,