Nikita Popov 4b497045e0 Move attribute handling into parser
The Lexer now only provides the tokens to the parser, while the
parser is responsible for determining which attributes are placed
on notes. This only needs to be done when the attributes are
actually needed, rather than for all tokens.

This removes the usedAttributes lexer option (and lexer options
entirely). The attributes are now enabled unconditionally. They
have less overhead now, and the need to explicitly enable them for
some use cases (e.g. formatting-preserving printing) doesn't seem
like a good tradeoff anymore.

There are some additional changes to the Lexer interface that
should be done after this, and the docs / upgrading guide haven't
been adjusted yet.
2023-08-13 10:40:21 +02:00
..
2023-07-09 21:18:21 +02:00
2023-08-13 10:40:21 +02:00

What do all those files mean?

  • php.y: PHP 5-8 grammar written in a pseudo language
  • parser.template: A kmyacc parser prototype file for PHP
  • rebuildParsers.php: Preprocesses the grammar and builds the parser using kmyacc

.phpy pseudo language

The .y file is a normal grammar in kmyacc (yacc) style, with some transformations applied to it:

  • Nodes are created using the syntax Name[..., ...]. This is transformed into new Name(..., ..., attributes())
  • Some function-like constructs are resolved (see rebuildParsers.php for a list)

Building the parser

Run php grammar/rebuildParsers.php to rebuild the parsers. Additional options:

  • The KMYACC environment variable can be used to specify an alternative kmyacc binary. By default the phpyacc dev dependency will be used. To use the original kmyacc, you need to compile moriyoshi's fork.
  • The --debug option enables emission of debug symbols and creates the y.output file.
  • The --keep-tmp-grammar option preserves the preprocessed grammar file.