* Output interpolated strings as template literals.
* Update comments to use Markdown, so the annotated source reads well; remove TODOs per @lydell’s explanations
Rather than compiling splats to arrays built using `Array#concat`, splats
are now compiled directly to ES2015 splats, e.g.
f foo, arguments..., bar
[ foo, arguments..., bar ]
Which used to be compiled to:
f.apply(null, [foo].concat(slice.call(arguments), [bar]));
[foo].concat(slice.call(arguments), [bar]);
Is now compiled to:
f(foo, ...arguments, bar);
[ foo, ...arguments, bar ];
* Eliminate wrapper around “bound” (arrow) functions; output `=>` for such functions
* Remove irrelevant (and breaking) tests
* Minor cleanup
* When a function parameter is a splat (i.e., it uses the ES2015 rest parameter syntax) output that parameter as ES2015
* Rearrange function parameters when one of the parameters is a splat and isn’t the last parameter (very WIP)
* Handle params like `@param`, adding assignment expressions for them when they appear; ensure splat parameter is last
* Add parameter names (not a text like `'\nValue IdentifierLiteral: a'`) to the scope, so that parameters can’t be deleted; move body-related lines together; more explanation of what’s going on
* For parameters with a default value, correctly add the parameter name to the function scope
* Handle expansions in function parameters: when an expansion is found, set the parameters to only be the original parameters left of the expansion, then an `...args` parameter; and in the function body define variables for the parameters to the right of the expansion, including setting default values
* Handle splat parameters the same way we handle expansions: if a splat parameter is found, it becomes the last parameter in the function definition, and all following parameters get declared in the function body. Fix the splat/rest parameter values after the post-splat parameters have been extracted from it. Clean up `Code.compileNode` so that we loop through the parameters only once, and we create all expressions using calls like `new IdentifierLiteral` rather than `@makeCode`.
* Fix parameter name when a parameter is a splat attached to `this` (e.g. `@param...`)
* Rather than assigning post-splat parameters based on index, use slice; passes test “Functions with splats being called with too few arguments”
* Dial back our w00t indentation
* Better parsing of parameter names (WIP)
* Refactor processing of splat/expansion parameters
* Fix assignment of default parameters for parameters that come after a splat
* Better check for whether a param is attached to `this`
* More understandable variable names
* For parameters after a splat or expansion, assign them similar to the 1.x destructuring method of using `arguments`, except only concern ourselves with the post-splat parameters instead of all parameters; and use the splat/expansion parameter name, since `arguments` in ES fat arrow functions refers to the parent function’s `arguments` rather than the fat arrow function’s arguments/parameters
* Don’t add unnamed parameters (like `[]` as a parameter) to the function scope
* Disallow multiple splat/expansion parameters in function definitions; disallow lone expansion parameters
* Fix `this` params not getting assigned if the parameter is after a splat parameter
* Allow names of function parameters attached to `this` to be reserved words
* Always add a statement to the function body defining a variable with its default value, if it has one, if the variable `== null`; this covers the case when ES doesn’t apply the default value when `null` is passed in as a value, but CoffeeScript expects `null` and `undefined` to act interchangeably
* Aftermath of having both `undefined` and `null` trigger the use of default values for parameters with default values
* More careful parsing of destructured parameters
* Fall back to processing destructured parameters in the function body, to account for `this` or default values within destructured objects
* Clean up comments
* Restore new bare function test, minus the arrow function part of it
* Test that bound/arrow functions aren’t overwriting the `arguments` object, which should refer to the parent scope’s `arguments` (like `this`)
* Follow ES2015 spec for parameter default values: `null` gets assigned as as `null`, not the default value
* Mimic ES default parameters behavior for parameters after a splat or expansion parameter
* Bound functions cannot be generators: remove no-longer-relevant test, add check to throw error if `yield` appears inside a bound (arrow) function
* Error for bound generator functions should underline the `yield`
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.
