Function ElideSharedStackTraceSuffix

errbase/format_error.go:956–976

ElideSharedStackTraceSuffix removes the suffix of newStack that's already present in prevStack. The function returns true if some entries were elided.

(prevStack, newStack StackTrace)

// present in prevStack. The function returns true if some entries
// were elided.
func ElideSharedStackTraceSuffix(prevStack, newStack StackTrace) (StackTrace, bool) {
	if len(prevStack) == 0 {
		return newStack, false
	}
	if len(newStack) == 0 {
		return newStack, false
	}

	// Skip over the common suffix.
	var i, j int
	for i, j = len(newStack)-1, len(prevStack)-1; i > 0 && j > 0; i, j = i-1, j-1 {
		if newStack[i] != prevStack[j] {
			break
		}
	}
	if i == 0 {
		// Keep at least one entry.
		i = 1
	}
	return newStack[:i], i < len(newStack)-1
}

// StackTrace is the type of the data for a call stack.
// This mirrors the type of the same name in github.com/pkg/errors.