nandi.uk
Fork of daniellemaywood.uk/gleam — Wasm codegen work
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2 SPDX-License-Identifier: Apache-2.0
3 SPDX-FileCopyrightText: 2020 The Gleam contributors
4-->
5
6# Changelog
7
8## v1.11.0 - 2025-06-02
9
10### Bug fixes
11
12- Fixed a bug where using a pipe operator on the right-hand side of an `assert`
13 statement would generate invalid code on the JavaScript target.
14 ([Surya Rose](https://github.com/GearsDatapacks))
15
16- Fixed a bug where the build tool would try to run a module whose main
17 function is private.
18 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
19
20- Fixed a bug where the compiler would sometimes warn that an assertion was
21 unnecessary because it only asserted literal values, when that was not the case.
22 ([Surya Rose](https://github.com/GearsDatapacks))
23
24- Fixed a bug where using the "generate function" code action on a function
25 capture would generate an argument named `_capture`, using the internal
26 variable names of the compiler.
27 ([Surya Rose](https://github.com/GearsDatapacks))
28
29- Fixed a bug where the language server would provide completions inside a
30 constant string.
31 ([Surya Rose](https://github.com/GearsDatapacks))
32
33- Fixed a grammatical error in the bit array truncation warning message.
34 ([Louis Pilfold](https://github.com/lpil))
35
36## v1.11.0-rc2 - 2025-05-29
37
38### Compiler
39
40- The format of the `assert` and `let assert` location information has been
41 improved, and the file path of the source module has been added.
42 ([Louis Pilfold](https://github.com/lpil))
43
44### Language server
45
46- When using the "remove `echo`" code action, the language server will also
47 remove any literal expression being printed by `echo` statements. For example
48
49 ```gleam
50 pub fn main() {
51 echo "Before"
52 do_complex_stuff()
53 echo "After"
54 do_something_else()
55 }
56 ```
57
58 Will become:
59
60 ```gleam
61 pub fn main() {
62 do_complex_stuff()
63 do_something_else()
64 }
65 ```
66
67 Making it easier to get rid of debug printing messages once they're no longer
68 needed.
69
70 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
71
72### Bug fixes
73
74- Fixed a bug where type constructors with many fields would not be formatted
75 properly in the generated documentation.
76 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
77
78- Fixed a bug where fields name `x0` in records could cause invalid code to be
79 generated on the JavaScript target.
80 ([Surya Rose](https://github.com/GearsDatapacks))
81
82- Fixed a bug where exceptions on JavaScript could be sometimes missing the
83 function name metadata.
84 ([Louis Pilfold](https://github.com/lpil))
85
86- Fixed a bug where the missing patterns shown for an inexhaustive `case`
87 expression would include constructors of opaque types which were not available
88 in the current module, leading to invalid code.
89 ([Surya Rose](https://github.com/GearsDatapacks))
90
91- Fixed a bug where the language server would offer completions for local
92 variables where the variables were not in scope, leading to invalid code being
93 produced if the completion was followed.
94 ([Surya Rose](https://github.com/GearsDatapacks))
95
96- Fixed a bug where the compiler would crash when compiling `let assert`
97 statements which contained a bit array pattern inside a tuple pattern on the
98 JavaScript target.
99 ([Surya Rose](https://github.com/GearsDatapacks))
100
101- Fixed a bug where a zero-length segment of a bit array would never match
102 in a case expression on the JavaScript target.
103 ([Sakari Bergen](https://github.com/sbergen))
104
105## v1.11.0-rc1 - 2025-05-15
106
107### Compiler
108
109- The compiler can now tell if some branches with bit array patterns are
110 unreachable. For example, the following code:
111
112 ```gleam
113 case payload {
114 <<first_byte, _:bits>> -> first_byte
115 <<1, _:bits>> -> 1
116 _ -> 0
117 }
118 ```
119
120 Will raise the following warning:
121
122 ```
123 warning: Unreachable case clause
124 ┌─ /src/bit_array.gleam:4:5
125 │
126 4 │ <<1, _:bits>> -> 1
127 │ ^^^^^^^^^^^^^^^^^^
128 This case clause cannot be reached as a previous clause matches the same
129 values.
130 Hint: It can be safely removed.
131 ```
132
133 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
134
135- The code generated for pattern matching on the JavaScript target has been
136 improved to be more efficient and perform as little checks as possible.
137 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
138
139- The compiler now raises a warning when it can tell that an int segment
140 with a literal value is going to be truncated. For example, if you wrote this:
141
142 ```gleam
143 <<258>>
144 ```
145
146 The compiler will now warn you:
147
148 ```txt
149 warning: Truncated bit array segment
150 ┌─ /src/main.gleam:4:5
151 │
152 4 │ <<258>>
153 │ ^^^ You can safely replace this with 2
154
155 This segment is 1 byte long, but 258 doesn't fit in that many bytes. It
156 would be truncated by taking its first byte, resulting in the value 2.
157 ```
158
159 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
160
161- The compiler will now include labels in the error message when a `case`
162 expression is inexhaustive. For example, this code:
163
164 ```gleam
165 pub type Person {
166 Person(name: String, age: Int)
167 }
168
169 pub fn classify(person: Person) {
170 case person {
171 Person(name: "John", age: 27) -> todo
172 Person(name: _, age: 42) -> todo
173 }
174 }
175 ```
176
177 Will produces this error:
178
179 ```
180 error: Inexhaustive patterns
181 ┌─ /src/main.gleam:6:3
182 │
183 6 │ ╭ case person {
184 7 │ │ Person(name: "John", age: 27) -> todo
185 8 │ │ Person(name: _, age: 42) -> todo
186 9 │ │ }
187 │ ╰───^
188
189 This case expression does not have a pattern for all possible values. If it
190 is run on one of the values without a pattern then it will crash.
191
192 The missing patterns are:
193
194 Person(name:, age:)
195 ```
196
197 ([Surya Rose](https://github.com/GearsDatapacks))
198
199- The analysis of lists, tuples, negation operators, `panic`, `echo` and `todo`
200 is now fault tolerant, meaning that the compiler will not stop reporting
201 errors as soon as it finds one.
202 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
203
204- The error message for types used with the wrong number of arguments has been
205 improved. For example, this piece of code:
206
207 ```gleam
208 type Wibble(a)
209
210 type Wobble {
211 Wobble(Wibble)
212 }
213 ```
214
215 Produces the following error:
216
217 ```txt
218 error: Incorrect arity
219 ┌─ /src/one/two.gleam:5:10
220 │
221 5 │ Wobble(Wibble)
222 │ ^^^^^^ Expected 1 type argument, got 0
223
224 `Wibble` requires 1 type argument but none where provided.
225 ```
226
227 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
228
229- You can now use the `assert` keyword by itself to test a boolean expression.
230 If the expression evaluates to `False` at runtime, the `assert` statement
231 will cause the program to panic, with information about the expression that
232 was asserted.
233
234 For example:
235
236 ```gleam
237 pub fn ok_error_test() {
238 assert result.is_ok(Ok(10))
239 assert result.is_error(Error("Some error"))
240 assert Ok(1) != Error(1)
241 assert result.is_error(Ok(42)) // panic: Assertion failed
242 }
243 ```
244
245 A custom panic message can also be provided in order to add extra information:
246
247 ```gleam
248 pub fn identity_test() {
249 assert function.identity(True) as "Identity of True should never be False"
250 }
251 ```
252
253 ([Surya Rose](https://github.com/GearsDatapacks))
254
255- The compiler will now emit a warning when the return value of a call to a
256 function without side effects is unused. For example the following code:
257
258 ```gleam
259 pub fn main() {
260 add(1, 2)
261 add(3, 4)
262 }
263 ```
264
265 Will produce the following warning:
266
267 ```
268 warning: Unused value
269 ┌─ /src/main.gleam:4:3
270 │
271 4 │ add(1, 2)
272 │ ^^^^^^^^^ This value is never used
273
274 This expression computes a value without any side effects, but then the
275 value isn't used at all. You might want to assign it to a variable, or
276 delete the expression entirely if it's not needed.
277 ```
278
279 ([Surya Rose](https://github.com/GearsDatapacks))
280
281- The compiler will now generate more efficient code for `let assert` on the
282 Erlang target.
283 ([Surya Rose](https://github.com/GearsDatapacks))
284
285- The compiler will now reject bit array segment patterns whose constant size is
286 zero or negative. Previously a zero or negative sized segment would crash the
287 compiler.
288 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
289
290- The compiler will not generate needless code for unused pattern variables.
291 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
292
293- Function parameters are now fault tolerant, meaning that type-checking can
294 continue to occur if a function references invalid type in its signature.
295 ([Surya Rose](https://github.com/GearsDatapacks))
296
297- The compiler is now fault tolerant when analysing patterns for custom types,
298 meaning it won't stop at the first error it encounters (for example if a
299 constructor is wrong).
300 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
301
302- On the JavaScript target, bit arrays now support UTf-16 and UTF-32 string
303 segments.
304 ([Surya Rose](https://github.com/GearsDatapacks))
305
306- When an import with unqualified types and values is unused the compiler will
307 now raise a single warning for the entire import rather than warning for each
308 individual item.
309 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
310
311### Build tool
312
313- The build tool now supports placing modules in a directory called `dev`,
314 which like `test`, is only for development code.
315 ([Surya Rose](https://github.com/GearsDatapacks))
316
317- There is now a new CLI command, `gleam dev`, which runs the `$PACKAGE_dev`
318 module, for running development entrypoints.
319 ([Surya Rose](https://github.com/GearsDatapacks))
320
321- Updated the Erlang shipment POSIX entrypoint script to add an exec statement
322 so the Erlang process replaces the shell's process and can receive signals
323 when deployed.
324 ([Christopher De Vries](https://github.com/devries))
325
326- The build tool now provides additional information when printing warnings for
327 deprecated environment variables.
328 ([Surya Rose](https://github.com/GearsDatapacks))
329
330- When generating documentation, the build tool now prints type variable using
331 the same names as were used in the code for function signatures. For example,
332 this code:
333
334 ```gleam
335 pub fn from_list(entries: List(#(key, value))) -> Dict(key, value) {
336 ...
337 }
338 ```
339
340 Previously would have been printed as:
341
342 ```gleam
343 pub fn from_list(entries: List(#(a, b))) -> Dict(a, b)
344 ```
345
346 But now is rendered as the following:
347
348 ```gleam
349 pub fn from_list(entries: List(#(key, value))) -> Dict(key, value)
350 ```
351
352 ([Surya Rose](https://github.com/GearsDatapacks))
353
354- When generating documentation, types from other modules are now rendered with
355 their module qualifiers. Hovering over them shows the module name.
356 For example, this code:
357
358 ```gleam
359 import gleam/dynamic/decode
360
361 pub fn something_decoder() -> decode.Decoder(Something) {
362 ...
363 }
364 ```
365
366 Will now generate the following documentation:
367
368 ```gleam
369 pub fn something_decoder() -> decode.Decoder(Something)
370 ```
371
372 And hovering over the `decode.Decoder` text will show the following:
373
374 ```txt
375 gleam/dynamic/decode.{type Decoder}
376 ```
377
378 ([Surya Rose](https://github.com/GearsDatapacks))
379
380- When generating documentation, types in rendered documentation code will now
381 link to their corresponding documentation pages.
382 ([Surya Rose](https://github.com/GearsDatapacks))
383
384- `gleam add` will now emit an error if you try to add a package as a dependency
385 of itself.
386 ([Louis Pilfold](https://github.com/lpil))
387
388- The build tool will now emit an error when compiling a package if the package
389 has a Gleam and Erlang file which would collide.
390 ([Surya Rose](https://github.com/GearsDatapacks))
391
392### Language server
393
394- The code action to add missing labels to functions now also works in patterns:
395
396 ```gleam
397 pub type Person {
398 Person(name: String, age: Int, job: String)
399 }
400
401 pub fn age(person: Person) {
402 let Person(age:) = person
403 age
404 }
405 ```
406
407 Becomes:
408
409 ```gleam
410 pub type Person {
411 Person(name: String, age: Int, job: String)
412 }
413
414 pub fn age(person: Person) {
415 let Person(age:, name:, job:) = person
416 age
417 }
418 ```
419
420 ([Surya Rose](https://github.com/GearsDatapacks))
421
422- The JSON encoding function that the language server code action generates is
423 now named `$TYPENAME_to_json` instead of `encode_$TYPENAME`. This is to remove
424 ambiguity with functions that encode to other formats, and to make the
425 function easier to discover by searching.
426 ([Louis Pilfold](https://github.com/lpil))
427
428- The code action to add missing patterns to a `case` expression now includes
429 labels in the generated patterns. For example:
430
431 ```gleam
432 pub type Person {
433 Person(name: String, age: Int)
434 }
435
436 pub fn classify(person: Person) {
437 case person {
438 Person(name: "John", age: 27) -> todo
439 Person(name: _, age: 42) -> todo
440 }
441 }
442 ```
443
444 Will now become:
445
446 ```gleam
447 pub type Person {
448 Person(name: String, age: Int)
449 }
450
451 pub fn classify(person: Person) {
452 case person {
453 Person(name: "John", age: 27) -> todo
454 Person(name: _, age: 42) -> todo
455 Person(name:, age:) -> todo
456 }
457 }
458 ```
459
460 ([Surya Rose](https://github.com/GearsDatapacks))
461
462- The language server now provides hover, autocomplete and goto definition
463 for constant definitions.
464 ([Surya Rose](https://github.com/GearsDatapacks))
465
466- The "generate function" code action can now choose better names based on the
467 labels and variables used. For example if I write the following code:
468
469 ```gleam
470 pub fn main() -> List(Int) {
471 let list = [1, 2, 3]
472 let number = 1
473 remove(each: number, in: list)
474 //^^^^ This function doesn't exist yet!
475 }
476 ```
477
478 And ask the language server to generate the missing function, the generated
479 code will now look like this:
480
481 ```gleam
482 fn remove(each number: Int, in list: List(Int)) -> List(Int) {
483 todo
484 }
485 ```
486
487 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
488
489- The language server now provides autocomplete suggestions for labels after
490 part of the label has already been typed. For example, in this code:
491
492 ```gleam
493 pub type Person {
494 Person(name: String, number: Int)
495 }
496
497 pub fn main() {
498 Person(n|)
499 }
500 ```
501
502 The language server will provide `name:` and `number:` as autocomplete
503 suggestions.
504
505 ([Surya Rose](https://github.com/GearsDatapacks))
506
507- The language server now provides a code action to automatically generate a new
508 variant from incorrect code:
509
510 ```gleam
511 pub type Msg {
512 ServerSentResponse(Json)
513 }
514
515 pub fn view() -> Element(Msg) {
516 div([], [
517 button([on_click(UserPressedButton)], [text("Press me!")])
518 // ^^^^^^^^^^^^^^^^^ This doesn't exist yet!
519 ])
520 }
521 ```
522
523 Triggering the code action on the `UserPressedButton` will add it to the `Msg`
524 type:
525
526 ```gleam
527 pub type Msg {
528 ServerSentResponse(Json)
529 UserPressedButton
530 }
531 ```
532
533 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
534
535- The language server can now remove unused imported values and types:
536
537 ```gleam
538 import a_module.{type Unused, unused, used}
539
540 pub fn main() {
541 used
542 }
543 ```
544
545 Triggering the code action will remove all unused types and values:
546
547 ```gleam
548 import a_module.{used}
549
550 pub fn main() {
551 used
552 }
553 ```
554
555 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
556
557### Formatter
558
559- Improved the formatting of `echo` when followed by long binary expressions.
560 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
561
562### Installation
563
564- Windows ARM64 pre-built binaries are now provided.
565 ([Jonatan Männchen](https://github.com/maennchen))
566
567### Bug fixes
568
569- Fixed a bug where `case` expressions in custom panic messages would compile
570 to invalid syntax on the JavaScript target.
571 ([Surya Rose](https://github.com/GearsDatapacks))
572
573- Fixed a bug where an underscore after a zero in a number would compile to
574 invalid syntax on the JavaScript target.
575 ([Surya Rose](https://github.com/GearsDatapacks))
576
577- Fixed a bug where the "generate function" code action could generate invalid
578 code when the same variable was passed as an argument twice.
579 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
580
581- Fixed a bug where replacing a Hex dependency with a Git dependency of the
582 same name would cause the build tool to fail.
583 ([Surya Rose](https://github.com/GearsDatapacks))
584
585- Fixed a bug where updating the remote URL of a Git dependency would fail to
586 update the remote in the local dependency, causing a caching issue.
587 ([Surya Rose](https://github.com/GearsDatapacks))
588
589- Fix slightly wrong error message for missing main function in test module.
590 ([Samuel Cristobal](https://github.com/scristobal))
591
592- Fixed a bug where the compiler would not properly warn for unreachable
593 patterns in a `case` expression when the clause matched on multiple
594 alternative patterns.
595 ([Surya Rose](https://github.com/GearsDatapacks))
596
597- Fixed a bug where the language server would generate invalid code for the
598 "fill in missing labels" code action.
599 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
600
601- Fixed a bug where referencing an earlier segment of the bit array in a bit
602 array pattern in a `let assert` assignment would generate invalid code on the
603 Erlang target.
604 ([Surya Rose](https://github.com/GearsDatapacks))
605
606- Fixed instances where the "Extract variable" code action would produce invalid
607 code, most noticeable in code inside `case` clauses and `use` expressions.
608 ([Matias Carlander](https://github.com/matiascr))
609
610- Fixed a bug where the compiler would crash when type-checking code containing
611 an assignment pattern inside a bit-array pattern.
612 ([Surya Rose](https://github.com/GearsDatapacks))
613
614- Fixed a bug where using the pipe operator in the `size` option of a bit array
615 segment would generate invalid code on the Erlang target.
616 ([Surya Rose](https://github.com/GearsDatapacks))
617
618- Fixed a bug where the language server would generate invalid code for the
619 "convert to use" code action, when used on a function call with labelled
620 arguments.
621 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
622
623- Fixed a bug where a reference to an imported external function with a
624 non-alphanumeric module name would compile to invalid syntax on the Erlang
625 target.
626 ([Mathieu Darse](https://github.com/mdarse))
627
628- Fixed a bug where the compiler would not correctly check the size of bit
629 arrays when doing bit array pattern matching on the JavaScript target.
630 ([Giacomo Cavalieri](https://github.com/giacomocavalieri))
631
632- Fixed a bug where using the pipe operator inside a record update would cause
633 the compiler to generate invalid code on the JavaScript target.
634 ([Surya Rose](https://github.com/GearsDatapacks))
635
636- Fixed a bug where some code actions would produce invalid code when a file
637 contained characters that were represented with more than one byte in UTF-8.
638 ([Surya Rose](https://github.com/GearsDatapacks))
639
640- Fixed a bug where LSP ranges would be incorrect when a file contained characters
641 that were represented with more than one byte in UTF-8.
642 ([Surya Rose](https://github.com/GearsDatapacks))
643
644- Only print the user-friendly LSP message when stdin is a terminal to avoid
645 emitting redundant logs.
646 ([Ariel Parker](https://github.com/arielherself))
647
648- Fixed a bug where the language server would wrongly override local variables
649 if they were shadowing an unqualified module function.
650 ([Samuel Cristobal](https://github.com/scristobal))
651
652- Fixed a bug where renaming a local variable which is used in combination with
653 label shorthand syntax would produce invalid code.
654 ([Surya Rose](https://github.com/GearsDatapacks))
655
656- Fixed a bug where the stack would overflow on Windows when type-checking
657 multiple nested `use` expressions.
658 ([Surya Rose](https://github.com/GearsDatapacks))
659
660- Fixed a bug where using a variable from a separate pattern inside a bit array
661 pattern would be allowed but generate invalid Erlang code.
662 ([Surya Rose](https://github.com/GearsDatapacks))
663
664- Fixed a bug where the compiler would crash if duplicate variables were defined
665 in alternative patterns.
666 ([Surya Rose](https://github.com/GearsDatapacks))