enhance properties (#2412)

- trim array items only if `side_effects`
- extend to non-identifier properties
This commit is contained in:
Alex Lam S.L
2017-10-29 04:11:26 +08:00
committed by GitHub
parent 31f8209193
commit 8428326ea1
4 changed files with 125 additions and 82 deletions

View File

@@ -4537,59 +4537,72 @@ merge(Compressor.prototype, {
});
OPT(AST_Sub, function(self, compressor){
var expr = self.expression;
var prop = self.property;
if (compressor.option("properties")) {
var prop = self.property;
if (prop instanceof AST_String) {
prop = prop.getValue();
if (is_identifier_string(prop)) {
var key = prop.evaluate(compressor);
if (key !== prop) {
var property = "" + key;
if (is_identifier_string(property)
&& property.length <= prop.print_to_string().length + 1) {
return make_node(AST_Dot, self, {
expression : self.expression,
property : prop
expression: expr,
property: property
}).optimize(compressor);
}
var v = parseFloat(prop);
if (!isNaN(v) && v.toString() == prop) {
self.property = make_node(AST_Number, self.property, {
value: v
});
}
}
if (prop instanceof AST_Number && self.expression instanceof AST_Array) {
prop = prop.getValue();
var elements = self.expression.elements;
if (prop in elements) {
var flatten = true;
var values = [];
for (var i = elements.length; --i > prop;) {
var value = elements[i].drop_side_effect_free(compressor);
if (value) {
values.unshift(value);
if (flatten && value.has_side_effects(compressor)) flatten = false;
}
if (!(prop instanceof AST_Number)) {
var value = parseFloat(property);
if (value.toString() == property) {
prop = self.property = make_node(AST_Number, prop, {
value: value
});
}
var retValue = elements[prop];
retValue = retValue instanceof AST_Hole ? make_node(AST_Undefined, retValue) : retValue;
if (!flatten) values.unshift(retValue);
while (--i >= 0) {
var value = elements[i].drop_side_effect_free(compressor);
if (value) values.unshift(value);
else prop--;
}
if (flatten) {
values.push(retValue);
return make_sequence(self, values).optimize(compressor);
} else return make_node(AST_Sub, self, {
expression: make_node(AST_Array, self.expression, {
elements: values
}),
property: make_node(AST_Number, self.property, {
value: prop
})
});
}
}
}
if (is_lhs(self, compressor.parent())) return self;
if (compressor.option("properties") && key !== prop) {
var node = self.flatten_object(property);
if (node) {
expr = self.expression = node.expression;
prop = self.property = node.property;
}
}
if (compressor.option("properties") && compressor.option("side_effects")
&& prop instanceof AST_Number && expr instanceof AST_Array) {
var index = prop.getValue();
var elements = expr.elements;
if (index in elements) {
var flatten = true;
var values = [];
for (var i = elements.length; --i > index;) {
var value = elements[i].drop_side_effect_free(compressor);
if (value) {
values.unshift(value);
if (flatten && value.has_side_effects(compressor)) flatten = false;
}
}
var retValue = elements[index];
retValue = retValue instanceof AST_Hole ? make_node(AST_Undefined, retValue) : retValue;
if (!flatten) values.unshift(retValue);
while (--i >= 0) {
var value = elements[i].drop_side_effect_free(compressor);
if (value) values.unshift(value);
else index--;
}
if (flatten) {
values.push(retValue);
return make_sequence(self, values).optimize(compressor);
} else return make_node(AST_Sub, self, {
expression: make_node(AST_Array, expr, {
elements: values
}),
property: make_node(AST_Number, prop, {
value: index
})
});
}
}
var ev = self.evaluate(compressor);
if (ev !== self) {
ev = make_node_from_constant(ev, self).optimize(compressor);
@@ -4609,6 +4622,33 @@ merge(Compressor.prototype, {
return result;
});
AST_PropAccess.DEFMETHOD("flatten_object", function(key) {
var expr = this.expression;
if (expr instanceof AST_Object) {
var props = expr.properties;
for (var i = props.length; --i >= 0;) {
var prop = props[i];
if ("" + prop.key == key) {
if (!all(props, function(prop) {
return prop instanceof AST_ObjectKeyVal;
})) break;
var value = prop.value;
if (value instanceof AST_Function && value.contains_this()) break;
return make_node(AST_Sub, this, {
expression: make_node(AST_Array, expr, {
elements: props.map(function(prop) {
return prop.value;
})
}),
property: make_node(AST_Number, this, {
value: i
})
});
}
}
}
});
OPT(AST_Dot, function(self, compressor){
var def = self.resolve_defines(compressor);
if (def) {
@@ -4637,28 +4677,9 @@ merge(Compressor.prototype, {
}
}
if (is_lhs(self, compressor.parent())) return self;
if (compressor.option("properties") && self.expression instanceof AST_Object) {
var props = self.expression.properties;
for (var i = props.length; --i >= 0;) {
var prop = props[i];
if (prop.key === self.property) {
if (!all(props, function(prop) {
return prop instanceof AST_ObjectKeyVal;
})) break;
var value = prop.value;
if (value instanceof AST_Function && value.contains_this()) break;
return make_node(AST_Sub, self, {
expression: make_node(AST_Array, self.expression, {
elements: props.map(function(prop) {
return prop.value;
})
}),
property: make_node(AST_Number, self, {
value: i
})
}).optimize(compressor);
}
}
if (compressor.option("properties")) {
var node = self.flatten_object(self.property);
if (node) return node.optimize(compressor);
}
var ev = self.evaluate(compressor);
if (ev !== self) {