How do I format all EK9 source files in my project?

← Code Formatting · Ref: Q623

Use the -F flag (uppercase) to format all EK9 source files in the project at once.

BASIC USAGE

  ek9 -F myproject.ek9

This discovers all .ek9 files referenced by the project and formats each one to canonical style. Every file must be parseable for this to succeed.

DIFFERENCE FROM -f
- ek9 -f myfile.ek9 formats a single named file.
- ek9 -F myproject.ek9 formats all files in the project.
Both require the files to parse successfully first.

TYPICAL WORKFLOW

After cloning a project or pulling changes:

  ek9 -F myproject.ek9

This ensures your entire codebase follows the canonical format before you start editing.

After a code review or merge:

  ek9 -F myproject.ek9

This normalises any formatting differences introduced during the merge.

IDEMPOTENCY

Running -F on an already-formatted project produces no changes. This makes it safe to run in CI to verify that all files are correctly formatted.

See Q622 for formatting a single file. See Q624 for force-formatting unparseable files. See Q625 for why EK9 enforces a standard format. See Q626 for integrating formatting into your workflow.

Example

defines module qa.codeformatting.allfiles

  defines function

    <?-
      Multiple functions representing a multi-file project.
      After ek9 -F, every file follows the same format.
    -?>
    add() as pure
      ->
        left as Integer
        right as Integer
      <-
        result as Integer: left + right

    multiply() as pure
      ->
        left as Integer
        right as Integer
      <-
        result as Integer: left * right

  defines program

    FormatAllDemo()
      stdout <- Stdout()

      sum <- add(3, 4)
      product <- multiply(3, 4)

      stdout.println(`Sum: ${sum}`)
      stdout.println(`Product: ${product}`)

Common mistakes

E50001 — Removing the variable declaration means later references to the variable become unresolved, triggering E50001. See ek9 -h E50001 for details.

Incorrect:

add(3, 4)

Correct:

sum <- add(3, 4)

E50060 — Integer has no toString() method; convert with the $ prefix operator ($product) or use string interpolation. See ek9 -h E50060 for details.

Incorrect:

stdout.println(product.toString())

Correct:

stdout.println(`Product: ${product}`)

Coming from another language?

Go: gofmt ./... formats all Go files in directory tree. Rust: cargo fmt formats all crate sources. Python: black . formats all Python files in directory. Java: google-java-format with glob patterns (manual setup). JavaScript: prettier --write . (external tool). EK9: ek9 -F formats all project sources in one command, built into the compiler.

Keywords: project, format, style, normalise, indent, bulk, all, canonical, files, F