Parenthetic | A Lisp-style language whose programs

You can get them into the right order by forcing log_midpipe to evaluate x first.

This should work for real examples where the long running code is part of the x in sleep and not a separate call beforehand since Sys.sleep doesn't need any parts of x evaluated.

You might use a pattern to recurse the first sub pattern matching balanced parenthesis and then use the SKIP FAIL. After the alternation you can still use the capture group, which will be group 2 and the values will be kept due to the PREG_SPLIT_DELIM_CAPTURE flag.

To remove the empty entries, you can add the PREG_SPLIT_NO_EMPTY flag.

In order to be able to match an arbitrary amount of anything (be it parentheses, operators, list items etc.) you need recursion (EBNF also features repetition operators that can be used instead of recursion in some cases, but not for constructs that need to be matched like parentheses).

For well-matched parentheses, the proper production is simply:

Use

You are searching for substring matches from a whitelist of lowercase terms, but you are checking for them in a capitalized string.

This may be the test you're looking for:

I would store the raw regular expression.

The additional escape character is not actually part of the regex. It's there for JS to process the string correctly, because \ has a special meaning. You need to specify it when writing the string as "hardcoded" text. In fact, it would also be needed in the PHP side, if you were to use the same assignment technique in PHP, you would write it with the escape backslash:

If we can assume that the title element has no element children but solely plain text and you have an XSLT 2 or 3 processor as mentioning ends-with suggests you can match on the text node in the element and process it with xsl:analyze-string:

Great catch!

I wouldn't look at this as actual bug, but it is a lack of documentation. Possibly there has to be an error/warning message raised when preprocessor is callable and lowercase=True.

FYI, lower casing happens in the default preprocessor function here. Hence, when you override the preprocessor with a callable, the lower casing would not happen.

I have raised this issue here.

You may add a second alternative to the lookbehind and use [^()]+ or [^()]*[^()\s] to match the names up to the first (: