: operator is left-associative
#11671
Conversation
Allows chained conversions, like `3.14 : Integer : Text`. I have verified with `parse_all_enso_files.sh` that this doesn't change the interpretation of any of the libs or .enso tests; no one is likely relying on the current behavior.
kazcw
requested review from
farmaazon,
vitvakatu,
Frizi,
JaroslavTulach and
AdRiley
as code owners
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This actually conflicts with a syntax that is covered by unit tests, but not currently used--using I will see if I can reconcile this syntax with chained conversions by adjusting precedence also. |
kazcw
requested review from
jdunkerley,
radeusgd,
GregoryTravis and
marthasharkey
as code owners
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| /// Return the precedence for any operator. | ||
| /// Return the lowest precedence for any operator. | ||
| pub fn min_valid() -> Self { |
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min_valid is relatively cryptic name.
| '*' | '/' | '%' => 16, | ||
| '^' => 17, | ||
| _ => 18, | ||
| '!' => token::Precedence::Not, |
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The use of enum makes the code more readable.
| pub fn min_valid() -> Self { | ||
| Precedence { value: 1 } | ||
| debug_assert_eq!(Precedence::Assignment as u8, Precedence::Min as u8 + 1); |
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An assert that two enum values are next to each other!? Can it be false? Shouldn't it be apparent or a check to verify in a test and not code?
| lhs_section_termination: Some(SectionTermination::Reify), | ||
| is_right_associative: true, |
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I have it! This is the line that changes the behavior! The rests are just refactorings.
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This and the precedence change--: and = both had precedence 2, and now they have different levels in the named level order.
Some simplification enabled by the refactor in #11671. Inspired by review from @JaroslavTulach.
Pull Request Description
Adjust operator parsing to allow chained conversions, like
3.14 : Integer : Text.Change the precedence and associativity of the
:operator, when used as a binary operator in an expression:->(previously they were equal)Important Notes
One previously-reasonable syntax has changed interpretation:
x->x:Typeis no longer a valid way to write a casting function, and would likely result in a type error. There was 1 instance of this syntax in our .enso sources.Checklist
Please ensure that the following checklist has been satisfied before submitting the PR:
Scala,
Java,
TypeScript,
and
Rust
style guides. In case you are using a language not listed above, follow the Rust style guide.
or the Snowflake database integration, a run of the Extra Tests has been scheduled.