827bd93b8c
This commit adds a decent first-cut of a lexer for CUE (https://cuelang.org). The main aspects of the language are implemented, but there are likely a number of edge cases not covered, especially when it comes to string interpolation, but this is a sufficiently decent first cut so as to warrant merging into the chroma project rather than first working in a fork. This was tested locally for visual correctness using mkdir -p _examples (command cd ./cmd/chroma; go run . --lexer=cue --html --html-inline-styles) < lexers/testdata/cue.actual > _examples/cue.html and then loading _examples/cue.html in a browser. Closes #857
Chroma lexers
All lexers in Chroma should now be defined in XML unless they require custom code.
Lexer tests
The tests in this directory feed a known input testdata/<name>.actual into the parser for <name> and check
that its output matches <name>.expected.
It is also possible to perform several tests on a same parser <name>, by placing know inputs *.actual into a
directory testdata/<name>/.
Running the tests
Run the tests as normal:
go test ./lexers
Update existing tests
When you add a new test data file (*.actual), you need to regenerate all tests. That's how Chroma creates the *.expected test file based on the corresponding lexer.
To regenerate all tests, type in your terminal:
RECORD=true go test ./lexers
This first sets the RECORD environment variable to true. Then it runs go test on the ./lexers directory of the Chroma project.
(That environment variable tells Chroma it needs to output test data. After running go test ./lexers you can remove or reset that variable.)
Windows users
Windows users will find that the RECORD=true go test ./lexers command fails in both the standard command prompt terminal and in PowerShell.
Instead we have to perform both steps separately:
- Set the
RECORDenvironment variable totrue.- In the regular command prompt window, the
setcommand sets an environment variable for the current session:set RECORD=true. See this page for more. - In PowerShell, you can use the
$env:RECORD = 'true'command for that. See this article for more. - You can also make a persistent environment variable by hand in the Windows computer settings. See this article for how.
- In the regular command prompt window, the
- When the environment variable is set, run
go test ./lexers.
Chroma will now regenerate the test files and print its results to the console window.