A formatter for the Ceylon programming language.

Command line usage

(If the ceylon format plugin wasn’t installed by default in your distribution, you can add it by cloning the formatter repository and running ant install; alternatively, write ceylon run ceylon.formatter instead of ceylon format.)

To format all Ceylon code in the source and test-source directories:

ceylon format source test-source

To format all Ceylon code in the source directory into the source-formatted directory:

ceylon format source --to source-formatted

To format all Ceylon code in the source and test-source directories into the source-formatted directory:

ceylon format source --and test-source --to source-formatted

(This results in two subdirectories source and test-source of source-formatted.)

You can specify an arbitrary amount of these formatting commands:

ceylon format \
        source --to source-formatted \
        test-source --to test-source-formatted

(The line breaks are only included for clarity and not a part of the command line syntax.)

If no formatting commands are present, the formatter operates in “pipe mode”, reading code from standard input and writing to standard output.

Options

You can specify formatting options using the following syntax:

--optionName=optionValue
# or
--optionName optionValue

For available option names, see ceylon.formatter.options::FormattingOptions. The syntax of optionValue is:

• for Boolean or Integer values, use a Ceylon-style literal (1, true)
• for Range values, use a Ceylon-style range operator x..y
• for ceylon.formatter.options::IndentMode values, see the documentation of ceylon.formatter.options::parseIndentMode
• for Iterable values, list the individual elements, separated by spaces
• for ceylon.formatter.options::LineBreakStrategy, the only valid value is default
• for enumerated types, use the name of one of the object cases (lf, all)

Library usage

Use the format function to format any AST node. This can be a compilation unit (simply speaking, a complete file) or any other node.

If the node was parsed from an existing file, don’t forget to pass the token stream to format ([[format.tokens]]) – without the token stream, the formatter can’t obtain the comments, so they’ll not be present in the formatted file.

To construct ceylon.formatter.options::FormattingOptions, usage of named arguments is highly recommended:

FormattingOptions {
    indentMode = Spaces(8);
    maxLineLength = 80;
}

You can also use ceylon.formatter.options::SparseFormattingOptions and ceylon.formatter.options::combinedOptions to compose several sets of options, like this:

combinedOptions {
    baseOptions = companyWideOptions;
    SparseFormattingOptions {
        indentMode = Spaces(1); // our department has very small screens :-(
    }
}