Formatting

Mew has one formatter, and it is the same code whether it runs in an editor or on the command line. There is nothing to configure.

What it decides

The formatter decides indentation and the spacing between tokens. It does not decide what goes on which line, so a line break you wrote is a line break it keeps.

// Before
pub type Point{
pub field x:i32;
}

// After
pub type Point {
    pub field x: i32;
}

Runs of blank lines collapse to one, and a file that has any content at all ends with a single newline.

Running it

mew fmt                # every .mew file under the current directory
mew fmt src            # or under a directory you name
mew fmt main.mew       # or a single file
mew fmt --check .      # report what is unformatted, write nothing, exit 1

--check is what a build runs. Mew's own build uses it to hold the sample programs to the style the formatter produces.

Why it is safe to run

The formatter lexes its own output and compares it token by token against the input. If anything differs it returns the original unchanged, so a formatting rule cannot drop or reorder code.