v2.autofix #

`v2.autofix`

Mechanical source-level rewrites driven by the -autofix flag.

Add missing mut: A variable declared with := that is later mutated (x = ..., x += ..., x++, x--, or passed as mut x to a call) is rewritten to mut x := .... Lexical scope is honored, so a shadowed inner x does not affect the outer declaration.

Skipped for declarations in for-init (for i := 0; ... ; i++) where V treats the loop variable as implicitly mutable.

These are mechanical, low-risk rewrites that fit the same style. Listed here so we can pick them up later, not implemented yet.

Remove unused mut: variable declared mut x := ... but never mutated → drop the mut keyword.
Unused imports: import foo with no reference to foo.* in the file → delete the import line.
Unused local variables: x := expr where x is never read → rename to _ (when expr has side effects) or delete the statement (when expr is pure).
Unnecessary unsafe { ... }: unsafe block whose body contains no unsafe operations → unwrap.
Unused function parameters: warn-only today; autofix could prefix with _ to silence the diagnostic.
Snake_case rename: function/variable names in camelCase → rename to snake_case (with cross-file references updated).
Trailing-comma normalization: enforce or strip the trailing comma in multi-line lists according to the project style.
Add ? / ! propagation: when a return value is an Option/Result and the caller ignores it via _ := f(), suggest f()? or f()! based on the enclosing function's return type.
Replace if x != none { x.foo() } with if y := x { y.foo() } for Option chains.
println('${x}') → println(x) when the interpolation has no formatting and the value is already a string.
Drop redundant return at the end of a void function.
Re-order pub / mut modifiers to match the canonical order V fmt uses (pub mut: etc.).

fn run(files []ast.File, file_set &token.FileSet) int

run scans the given files and, when fixes are found, rewrites the corresponding source files in place. Returns the number of edits applied.