The following is now allowed:
o =
a: 1
b: 2
"#{'c'}": 3
"#{'d'}": 4
e: 5
"#{'f'}": 6
g: 7
It compiles to:
o = (
obj = {
a: 1,
b: 2
},
obj["" + 'c'] = 3,
obj["" + 'd'] = 4,
obj.e = 5,
obj["" + 'f'] = 6,
obj.g = 7,
obj
);
- Closes#3039. Empty interpolations in object keys are now _supposed_ to be
allowed.
- Closes#1131. No need to improve error messages for attempted key
interpolation anymore.
- Implementing this required fixing the following bug: `("" + a): 1` used to
error out on the colon, saying "unexpected colon". But really, it is the
attempted object key that is unexpected. Now the error is on the opening
parenthesis instead.
- However, the above fix broke some error message tests for regexes. The easiest
way to fix this was to make a seemingly unrelated change: The error messages
for unexpected identifiers, numbers, strings and regexes now say for example
'unexpected string' instead of 'unexpected """some #{really long} string"""'.
In other words, the tag _name_ is used instead of the tag _value_.
This was way easier to implement, and is more helpful to the user. Using the
tag value is good for operators, reserved words and the like, but not for
tokens which can contain any text. For example, 'unexpected identifier' is
better than 'unexpected expected' (if a variable called 'expected' was used
erraneously).
- While writing tests for the above point I found a few minor bugs with string
locations which have been fixed.
Since zaach/jison commit 3548861b, `parser.lexer` is never modified anymore (a
copy of it is made, and that copy is modified instead). CoffeeScript itself
modifies `parser.lexer` and then accesses those modifications in the custom
`parser.yy.parseError` function, but that of course does not work anymore. This
commit puts the data that `parser.yy.parseError` needs directly on the `parser`
so that it is not lost.
Supersedes #3603. Fixes#3608 and zaach/jison#243.
Any variables generated by CoffeeScript are now made sure to be named to
something not present in the source code being compiled. This way you can no
longer interfere with them, either on purpose or by mistake. (#1500, #1574)
For example, `({a}, _arg) ->` now compiles correctly. (#1574)
As opposed to the somewhat complex implementations discussed in #1500, this
commit takes a very simple approach by saving all used variables names using a
single pass over the token stream. Any generated variables are then made sure
not to exist in that list.
`(@a) -> a` used to be equivalent to `(@a) -> @a`, but now throws a runtime
`ReferenceError` instead (unless `a` exists in an upper scope of course). (#3318)
`(@a) ->` used to compile to `(function(a) { this.a = a; })`. Now it compiles to
`(function(_at_a) { this.a = _at_a; })`. (But you cannot access `_at_a` either,
of course.)
Because of the above, `(@a, a) ->` is now valid; `@a` and `a` are not duplicate
parameters.
Duplicate this-parameters with a reserved word, such as `(@case, @case) ->`,
used to compile but now throws, just like regular duplicate parameters.
- Fix#3394: Unclosed single-quoted strings (both regular ones and heredocs)
used to pass through the lexer, causing a parsing error later, while
double-quoted strings caused an error already in the lexing phase. Now both
single and double-quoted unclosed strings error out in the lexer (which is the
more logical option) with consistent error messages. This also fixes the last
comment by @satyr in #3301.
- Similar to the above, unclosed heregexes also used to pass through the lexer
and not error until in the parsing phase, which resulted in confusing error
messages. This has been fixed, too.
- Fix#3348, by adding passing tests.
- Fix#3529: If a string starts with an interpolation, an empty string is no
longer emitted before the interpolation (unless it is needed to coerce the
interpolation into a string).
- Block comments cannot contain `*/`. Now the error message also shows exactly
where the offending `*/`. This improvement might seem unrelated, but I had to
touch that code anyway to refactor string and regex related code, and the
change was very trivial. Moreover, it's consistent with the next two points.
- Regexes cannot start with `*`. Now the error message also shows exactly where
the offending `*` is. (It might actually not be exatly at the start in
heregexes.) It is a very minor improvement, but it was trivial to add.
- Octal escapes in strings are forbidden in CoffeeScript (just like in
JavaScript strict mode). However, this used to be the case only for regular
strings. Now they are also forbidden in heredocs. Moreover, the errors now
point at the offending octal escape.
- Invalid regex flags are no longer allowed. This includes repeated modifiers
and unknown ones. Moreover, invalid modifiers do not stop a heregex from
being matched, which results in better error messages.
- Fix#3621: `///a#{1}///` compiles to `RegExp("a" + 1)`. So does
`RegExp("a#{1}")`. Still, those two code snippets used to generate different
tokens, which is a bit weird, but more importantly causes problems for
coffeelint (see clutchski/coffeelint#340). This required lots of tests in
test/location.coffee to be updated. Note that some updates to those tests are
unrelated to this point; some have been updated to be more consistent (I
discovered this because the refactored code happened to be seemingly more
correct).
- Regular regex literals used to erraneously allow newlines to be escaped,
causing invalid JavaScript output. This has been fixed.
- Heregexes may now be completely empty (`//////`), instead of erroring out with
a confusing message.
- Fix#2388: Heredocs and heregexes used to be lexed simply, which meant that
you couldn't nest a heredoc within a heredoc (double-quoted, that is) or a
heregex inside a heregex.
- Fix#2321: If you used division inside interpolation and then a slash later in
the string containing that interpolation, the division slash and the latter
slash was erraneously matched as a regex. This has been fixed.
- Indentation inside interpolations in heredocs no longer affect how much
indentation is removed from each line of the heredoc (which is more
intuitive).
- Whitespace is now correctly trimmed from the start and end of strings in a few
edge cases.
- Last but not least, the lexing of interpolated strings now seems to be more
efficient. For a regular double-quoted string, we used to use a custom
function to find the end of it (taking interpolations and interpolations
within interpolations etc. into account). Then we used to re-find the
interpolations and recursively lex their contents. In effect, the same string
was processed twice, or even more in the case of deeper nesting of
interpolations. Now the same string is processed just once.
- Code duplication between regular strings, heredocs, regular regexes and
heregexes has been reduced.
- The above two points should result in more easily read code, too.
In V8, the `stack` property of errors contains a prelude and then the
stack trace. The contents of the prelude depends on whether the error
has a message or not.
If the error has _not_ got a message, the prelude contains the name of the
error and a newline.
If the error _has_ got a message, the prelude contains the name of the
error, a colon, a space, the message and a newline.
In other words, the prelude consists of `error.toString() + "\n"`
Before, coffee-script’s patched stack traces worked exactly like that,
except that it _always_ added a colon and a space after the name of the
error.
This fix is important because it allows for easy and consistent
consumption of the stack trace only:
`stack = error.stack[error.toString().length..]`
This solves two potential problems when it comes to forking:
1) Forking will now work correctly even when `coffee` is not installed
globally.
2) Forking when using a locally installed version of `coffee` will fork
using that version, and not fallback to a globally installed version.
Fixes#2957
Instead of throwing the syntax errors with their source file location and needing to then catch them and call a `prettyErrorMessage` function in order to get the formatted error message, now syntax errors know how to pretty-print themselves (their `toString` method gets overridden).
An intermediate `catch` & re-`throw` is needed at the level of `CoffeeScript.compile` and friends. But the benefit of this approach is that now libraries that use the `CoffeeScript` object directly don't need to bother catching the possible compilation errors and calling a special function in order to get the nice error messages; they can just print the error itself (or let it bubble up) and the error will know how to pretty-print itself.
