commit | 64e00b78820a7032be83683adcf3aeb29d6a2727 | [log] [tgz] |
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author | Carmi Grushko <carmi@fb.com> | Thu May 14 08:37:33 2020 -0700 |
committer | Facebook GitHub Bot <facebook-github-bot@users.noreply.github.com> | Thu May 14 08:39:29 2020 -0700 |
tree | 0ce842fb8fde1733318f8f679af2488b2f595294 | |
parent | c8b7b31f77d786f4c2b3ab622a1b93cea6561831 [diff] |
Drop redundant semicolons Summary: dropRedundantElements is a hack that tries to detect a necessary semicolon; it would be much better to use https://github.com/Kotlin/grammar-tools, which would return `SEMICOLON` for necessary semicolons, and `semi` for optional ones. However, it's marked experimental, and the README says it could sometimes diverge from kotlin-compiler. So for now, I went with looking at ASTs of necessary semicolons and manually checking if that's the case in the code as well. I used the grammar definition (https://github.com/Kotlin/kotlin-spec/blob/master/grammar/src/main/antlr/KotlinParser.g4) to code the rules for a semicolon to be necessary. This fixes https://github.com/facebookincubator/ktfmt/issues/38 Reviewed By: strulovich Differential Revision: D21544559 fbshipit-source-id: 2b40be467dbcba833284859983d60c2afde0b6e7
ktfmt
is a program that pretty-prints (formats) Kotlin code, based on google-java-format.
Note that ktfmt
still has some rough edges which we're constantly working on fixing.
The minimum supported runtime version is JDK 11, released September 2018.
Before Formatting | Formatted by ktfmt |
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For comparison, the same code formatted by ktlint
and IntelliJ:
Formatted by ktlint | Formatted by IntelliJ |
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Download the formatter and run it with:
java -jar /path/to/ktfmt-<VERSION>-jar-with-dependencies.jar [--dropbox-style] [files...]
--dropbox-style
makes ktfmt
use a block indent of 4 spaces instead of 2. See below for details.
Note: There is no configurability as to the formatter's algorithm for formatting (apart from --dropbox-format
). This is a deliberate design decision to unify our code formatting on a single format.
ktfmt
vs ktlint
vs IntelliJktfmt
uses google-java-format's underlying engine, and as such, many items on google-java-format's FAQ apply to ktfmt
as well.
In particular,
ktfmt
ignores most existing formatting. It respects existing newlines in some places, but in general, its output is determinstic and is independent of the input code.ktfmt
exposes no configuration options that govern formatting behavior. See https://github.com/google/google-java-format/wiki/FAQ#i-just-need-to-configure-it-a-bit-differently-how for the rationale.These two properties make ktfmt
a good fit in large Kotlin code bases, where consistency is very important.
We created ktfmt
because ktlint
and IntelliJ sometime fail to produce nice-looking code that fits in 100 columns, as can be seen in the Demo section.
ktfmt
uses a 2-space indent; why not 4? any way to change that?Two reasons -
However, we do offer an escape-hatch for projects that absolutely cannot make the move to ktfmt
because of 2-space: the --dropbox-style
flag changes block indents to 4-space.
pom.xml
in IntelliJ. Choose “Open as a Project”FormatterKtTest.kt
.mvn install
java -jar core/target/ktfmt-<VERSION>-jar-with-dependencies.jar
See RELEASING.md.
Apache License 2.0