Terry J. Reedy added the comment: This is 3 related but somewhat distinct proposals.
1. Special handling (normal syntax colorizing) of f-expressions (the grammatical term used at https://docs.python.org/3/reference/lexical_analysis.html#formatted-string-literals). 2. Brace matching within the strings. (For normal strings, this would be nice when the string is to be used as a format string, but there is no way to know how the string will be used.) 3. Normal identifier autocompletion (as opposed to within-string file name autocompletion). I have two types of doubts about #1 1. Should it be done? a. I have not yet used f-strings, so I not know if I would want uncolorized holes within them. b. Do beginners use f-strings? Would they find this more useful than confusing? c. Is this the sort of 'advanced feature' that Guido has said should *not* be copied from other editors? 2. Can it be done sensibly within the limits of IDLE's colorizer. IDLE's colorizer defines a giant regex that joins regexes that match keywords, builtins, comments, and strings (and newlines for synchronization). Each of the latter is a named capturing group that joins alternatives for that group. Keywords and built-in names are recognized when complete. Partial comments and strings are recognized as soon as '#' or an open quote is typed. There is a human-verified test of colorizing that could, I believe, be turned into a unit test of the re matching. This would be needed for approach b. below. The compiled re is used in a ColorDelegator instance that is part of a chain of delegators tied to a text widget. The class code is not documented and I do not understand it well enough to modify it without adding tests. But it was not designed for easy testing. Sidenote: There are DEBUG prints in multiple methods (but not inrecolorize_main). Some messages can come from multiple methods. I should add message to the r...main method and prefix all messages with an indicator of the source so the control flow is easier to follow I see two possible approaches to separately colorizing f-expressions within an f-string. a. Follow the example of 'def' and 'class'. They are recognized as a special case (of builting) and when they occur, a separate 'if' clause and re is used to colorize the following name. The problem with doing this with f-strings is that we want to recursively apply the re...main function to a short substring, and the function is not designed for that. We also want to do this separately for each embedded f-expression. It might work to write a reduced version of recolorize_main as recolorize_fexp. This approach would allow for {} matching once a closing quote is typed, but not identifier autocompletion. b. Do the special-casing by writing special regexes to recognize a null f-string (no embedded f-expression), and beginning, middle, and ending string parts of an f-string. But I don't know if it is possible to write an re that will *only* match null f-strings. That aside, the f-expression would then be treated normally, and autocomplete should just work. {} matching would be harder. Without adding new state variables, I imagine that the end quote of the invalid f"a{b" would be seen as the beginning of a new string. ---------- stage: needs patch -> test needed _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue29287> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
