tryhard command

tryhard is a very basic tool to list and rewrite try candidate statements. It operates on a file-by-file basis and does not type-check the code; potential statements are recognized and rewritten purely based on pattern matching, with the very real possibility of false positives. Use utmost caution when using the rewrite feature (-r flag) and have a backup as needed.

Given a file, it operates on that file; given a directory, it operates on all .go files in that directory, recursively. Files starting with a period are ignored.

tryhard considers each top-level function with a last result of named type error, which may or may not be the predefined type error. Inside these functions tryhard considers assignments of the form

	v1, v2, ..., vn, err = f() // can also be :=

followed by an if statement of the form

	if err != nil {
		return ..., err
	}

or if statements with an init expression matching the above assignment. The error variable must be called err, which may or may not be of type error or correspond to the result error. The return statement must contain one or more return expressions, with all but the last one denoting a zero value of sorts (a zero number literal, an empty string, an empty composite literal, etc.). The last result must be the identifier err.

CAUTION: If the rewrite flag (-r) is specified, the file is updated in place! Make sure you can revert to the original.

Function literals (closures) are currently ignored.

Usage:

	tryhard [flags] [path ...]

The flags are:

	-l
		list positions of potential `try` candidate statements
	-r
		rewrite potential `try` candidate statements to use `try`

If no -l is provided, tryhard reports the number of potential candidates found.