Formatter

Part of m2-ls, and also a standalone m2-fmt.

It fixes spacing, derives indentation from the syntax tree and wraps long lines where the syntax allows. It doesn’t change what your code does: dropping redundant parentheses and such is left to quick fixes.

f=x->(if x>0 then 1 else 2)        -- before
f = x -> (if x > 0 then 1 else 2)  -- after

In the editor, just use “format document”. On the command line:

m2-fmt file.m2            # in place
m2-fmt --check file.m2    # exit 1 if not formatted, handy in CI
m2-fmt --stdout file.m2   # print instead of writing

Files with syntax errors are left alone.

Knobs

Under m2-ls.formatting (or --config settings.json for m2-fmt):

• indent, useTabs: default to your editor’s settings, 4 spaces on the CLI
• softLineWidth / hardLineWidth: preferred and maximum line width, 78 / 90
• controlFlowLayout: compact, multiline or multilineCompactElse (default)
• compactFactorOperators: 2*x instead of 2 * x
• breakAfterSemicolon: new line after every ;