From 36a6c7daf0f45353efe860e254aa148b7574b04e Mon Sep 17 00:00:00 2001 From: Bill Glover Date: Sun, 8 Mar 2020 21:36:59 +0000 Subject: Rework Replacer loop to handle escaped braces (#3121) Fixes #3116 * Rework Replacer loop to ignore escaped braces * Add benchmark tests for replacer * Optimise handling of escaped braces * Handle escaped closing braces * Remove additional check for closing brace This commit removes the additional check for input in which the closing brace appears before the opening brace. This check has been removed for performance reasons as it is deemed an unlikely edge case. * Check for escaped closing braces in placeholder name --- replacer.go | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'replacer.go') diff --git a/replacer.go b/replacer.go index aad13e2..8823404 100644 --- a/replacer.go +++ b/replacer.go @@ -125,6 +125,14 @@ func (r *Replacer) replace(input, empty string, // iterate the input to find each placeholder var lastWriteCursor int for i := 0; i < len(input); i++ { + + // check for escaped braces + if i > 0 && input[i-1] == phEscape && (input[i] == phClose || input[i] == phOpen) { + sb.WriteString(input[lastWriteCursor : i-1]) + lastWriteCursor = i + continue + } + if input[i] != phOpen { continue } @@ -135,6 +143,11 @@ func (r *Replacer) replace(input, empty string, continue } + // if necessary look for the first closing brace that is not escaped + for end > 0 && end < len(input)-1 && input[end-1] == phEscape { + end = strings.Index(input[end+1:], string(phClose)) + end + 1 + } + // write the substring from the last cursor to this point sb.WriteString(input[lastWriteCursor:i]) @@ -237,4 +250,4 @@ var nowFunc = time.Now // ReplacerCtxKey is the context key for a replacer. const ReplacerCtxKey CtxKey = "replacer" -const phOpen, phClose = '{', '}' +const phOpen, phClose, phEscape = '{', '}', '\\' -- cgit v1.2.3