The ECMAScript spec defines multiple equality operations which are used
all over the spec; this patch introduces them. Of course, the two
primary equality operations are AbtractEquals ('==') and StrictEquals
('==='), which have been renamed to 'abstract_eq' and 'strict_eq' in
this patch.
In support of the two operations mentioned above, the following have
also been added: SameValue, SameValueZero, and SameValueNonNumeric.
These are important to have, because they are used elsewhere in the spec
aside from the two primary equality comparisons.
"[Function.length is] the number of formal parameters. This number
excludes the rest parameter and only includes parameters before
the first one with a default value." - MDN
Console methods are now Value(void) functions.
JavaScript functions in the JavaScript ConsoleObject are now implemented
as simple wrappers around Console methods.
This will make it possible for LibJS users to easily override the
default behaviour of JS console functions (even their return value!)
once we add a way to override Console behaviour.
Adds the ability for function arguments to have default values. This
works for standard functions as well as arrow functions. Default values
are not printed in a <function>.toString() call, as nodes cannot print
their source string representation.
A ConsoleMessage is a struct cointaining:
* AK::String text; represents the text of the message sent
to the console.
* ConsoleMessageKind kind; represents the kind of JS `console` function
from which the message was sent.
Now, Javascript `console` functions only send a ConsoleMessage to the
Interpreter's Console instead of printing text directly to stdout.
The Console then stores the recived ConsoleMessage in
Console::m_messages; the Console does not print to stdout by default.
You can set Console::on_new_message to a void(ConsoleMessage&); this
function will get call everytime a new message is added to the Console's
messages and can be used, for example, to print ConsoleMessages to
stdout or to color the output based on the kind of ConsoleMessage.
In this patch, I also:
* Re-implement all the previously implemented functions in the
JavaScript ConsoleObject, as wrappers around Console functions
that add new message to the Console.
* Implement console.clear() like so:
- m_messages get cleared;
- a new_message with kind set ConsoleMessageKind::Clear gets added
to m_messages, its text is an empty AK::String;
* Give credit to linusg in Console.cpp since I used his
console.trace() algorithm in Console::trace().
I think that having this abstration will help us in the implementation
of a browser console or a JS debugger. We could also add more MetaData
to ConsoleMessage, e.g. Object IDs of the arguments passed to console
functions in order to make hyperlinks, Timestamps, ecc.; which could be
interesting to see.
This will also help in implementing a `/bin/js` option to make, for
example, return a ConsoleMessageWrapper to console functions instead of
undefined. This will be useful to make tests for functions like
console.count() and console.countClear(). :^)
I.e. they don't require the |this| value to be a string object and
"can be transferred to other kinds of objects for use as a method" as
the spec describes it.
This commit introduces a way to get an object's own properties in the
correct order. The "correct order" for JS object properties is first all
array-like index properties (numeric keys) sorted by insertion order,
followed by all string properties sorted by insertion order.
Objects also now print correctly in the repl! Before this commit:
courage ~/js-tests $ js
> ({ foo: 1, bar: 2, baz: 3 })
{ bar: 2, foo: 1, baz: 3 }
After:
courage ~/js-tests $ js
> ({ foo: 1, bar: 2, baz: 3 })
{ foo: 1, bar: 2, baz: 3 }
Now that Array.prototype.join() is producing the correct results we
can remove the separate code path for arrays in Value::to_number()
and treat them like all other objects - using to_primitive() with
number as the preferred type and then calling to_number() on the
result.
This is how the spec descibes it.
This also means we don't crash anymore when trying to coerce
[<empty>] to a number - it now does the following:
[<empty>] - to string - "" - to number - 0
[<empty>, <empty>] - to string - "," - to number - NaN
Currently we would create an empty array of size 0 and appening results
of the callback function while skipping empty values.
This is incorrect, we should be initializing a full array of the correct
size beforehand and then inserting the results while still skipping
empty values.
Wrong: new Array(5).map(() => {}) // []
Right: new Array(5).map(() => {}) // [<empty> * 5]
This patch teaches UpdateExpression how to use a Reference. Some other
changes were necessary to keep tests working:
A Reference can now also refer to a local or global variable. This is
not fully aligned with the spec since we don't have a Record concept.