go-twig/tokenizer.go

package twig

// Processes whitespace control modifiers in the template
// Applies whitespace trimming to adjacent text tokens based on the token types
// This is called after tokenization to handle the whitespace around trimming tokens
func processWhitespaceControl(tokens []Token) []Token {
	if len(tokens) == 0 {
		return tokens
	}

	// Modify tokens in-place to avoid allocation
	// This works because we're only changing token values, not adding/removing tokens

	// Process each token to apply whitespace trimming
	for i := 0; i < len(tokens); i++ {
		token := tokens[i]

		// Handle opening tags that trim whitespace before them
		if token.Type == TOKEN_VAR_START_TRIM || token.Type == TOKEN_BLOCK_START_TRIM {
			// If there's a text token before this, trim its trailing whitespace
			if i > 0 && tokens[i-1].Type == TOKEN_TEXT {
				tokens[i-1].Value = trimTrailingWhitespace(tokens[i-1].Value)
			}
		}

		// Handle closing tags that trim whitespace after them
		if token.Type == TOKEN_VAR_END_TRIM || token.Type == TOKEN_BLOCK_END_TRIM {
			// If there's a text token after this, trim its leading whitespace
			if i+1 < len(tokens) && tokens[i+1].Type == TOKEN_TEXT {
				tokens[i+1].Value = trimLeadingWhitespace(tokens[i+1].Value)
			}
		}
	}

	return tokens
}