Confusing error message "expecting amp"

[DanielEScherzer]

Description

The following code (https://3v4l.org/oMXAL)

<?php

class Demo {
    private (set) mixed $v1;
}

Resulted in this output:

Parse error: syntax error, unexpected token ")", expecting amp in /in/oMXAL on line 4

But I expected this output instead:

Parse error: syntax error, unexpected token ")", expecting ampersand in /in/oMXAL on line 4

(or expecting "&")

Alternatively, for the limited case of wrong asymmetric visibility specification (there shouldn't be a space in private(set)) maybe mention that? But for things other than (set) the amp is still a bit confusing

PHP Version

8.3+

Operating System

No response

[iluuu1994]

amp is used as a placeholder and later replaced with &.

php-src/Zend/zend_language_parser.y

Lines 1721 to 1727 in 7f0d4e3

	/* We used "amp" as a dummy label to avoid a duplicate token literal warning. */
	if (strcmp(toktype, "\"amp\"") == 0) {
	if (yyres) {
	yystpcpy(yyres, "token \"&\"");
	}
	return sizeof("token \"&\"")-1;
	}

However, it assumes that the keyword is always wrapped in "", but clearly that's not the case. We can probably use a more unambiguous marker than amp and then drop the "" assumption.