Implement filter builtin function
#63
Open
+158
−1
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
friendlymatthew
changed the title
filter builtin function
crates/monty/src/builtins/filter.rs
Outdated
Comment on lines
35
to
64
| let (mut positional, kwargs) = args.into_parts(); | ||
|
|
||
| if !kwargs.is_empty() { | ||
| for (k, v) in kwargs { | ||
| k.drop_with_heap(heap); | ||
| v.drop_with_heap(heap); | ||
| } | ||
|
|
||
| for v in positional { | ||
| v.drop_with_heap(heap); | ||
| } | ||
|
|
||
| return Err(SimpleException::new_msg(ExcType::TypeError, "filter() does not support keyword arguments").into()); | ||
| } | ||
|
|
||
| // Check we have exactly 2 positional arguments | ||
| let positional_len = positional.len(); | ||
| if positional_len != 2 { | ||
| for v in positional { | ||
| v.drop_with_heap(heap); | ||
| } | ||
| return Err(SimpleException::new_msg( | ||
| ExcType::TypeError, | ||
| format!("filter() expected 2 arguments, got {positional_len}"), | ||
| ) | ||
| .into()); | ||
| } | ||
|
|
||
| let function = positional.next().expect("positional must have 2 elements"); | ||
| let iterable = positional.next().expect("positional must have 2 elements"); |
Member
There was a problem hiding this comment.
I think you can use get_one_two_args for this.
Member
Author
There was a problem hiding this comment.
very nice, we can probably update a bunch of other builtin functions like sorted that manually parse args atm
Member
There was a problem hiding this comment.
Yup. Claude can go though and fix them all I guess.
Member
There was a problem hiding this comment.
we also need tests for a non-callable discriminator, like filter(4, [1, 2])
Member
Author
There was a problem hiding this comment.
See crates/monty/test_cases/builtin__filter_not_callable.py
friendlymatthew
force-pushed
the
filter
branch
from
e97204a to
fe37fa4
Compare
friendlymatthew
force-pushed
the
filter
branch
from
fe37fa4 to
7629de6
Compare
samuelcolvin
requested changes
Jan 26, 2026
Member
samuelcolvin
left a comment
samuelcolvin
left a comment
There was a problem hiding this comment.
Looking good, but I forgot we also need support for use defined functions which might require a bit of logic change, look at list.sort for an example.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR implements the
filter()builtin function that filters elements from an iterable based on a predicateNote: the implementation returns a list (following the pattern of other iterator-returning builtins like enumerate() and zip() for simplicyt). Currently, only builtin functions are supported as predicates which matches the existing limitation in
sorted()with thekeyparam