Function unifyModes

analysis/validation.go:1290–1309

unifyModes takes multiple modes definition for the statement and merges them together into a single mode definition per argument. Example: single argument modes [+,+,?] result in ?, but [+,+] results in +.

(modes []ast.Mode)

// unifyModes takes multiple modes definition for the statement and merges them together into a single mode definition per argument.
// Example: single argument modes [+,+,?] result in ?, but [+,+] results in +.
func unifyModes(modes []ast.Mode) ast.Mode {
	if len(modes) == 0 {
		return ast.Mode{}
	}

	var unifiedMode []ast.ArgMode
	for i := 0; i < len(modes[0]); i++ {
		argMode := modes[0][i]

		for _, m := range modes[1:] {
			if argMode != m[i] {
				argMode = ast.ArgModeInputOutput
				break
			}
		}
		unifiedMode = append(unifiedMode, argMode)
	}

	return unifiedMode
}

// While checking a rule, we want to look up possible relation types.
// If we find several applicable ones, we return the feasible ones.