On Tue, 22 May 2018 08:01:05 +0200, Christian Gollwitzer wrote: >>> If a block of static data is large enough to start to be ugly, a >>> common approach is to load the data from some other file, in a >>> language which is designed around structured data. [...]
> Thing is, you can do it already now in the script, without modifying the > Python interpreter, by parsing a triple-quoted string. See the examples > right here: http://pyyaml.org/wiki/PyYAMLDocumentation Indeed. But that requires the data be parsed at runtime, and requires either that you use only literals, or that you use some form of string interpolation. Imagine if the only way to write a list in Python was: make_list("[1, 2, 3, %d, 5]" % n) instead of [1, 2, 3, n, 5]. That would be annoying and inefficient. Parsing triple-quoted strings is a second-class solution. While I don't think much of Mikhail's proposed solution (except as a good example of how *not* to design programming syntax) the motivation is interesting: can we come up with a good syntax for table-based data? Many years ago, people got frustrated with having to define dicts like this: d = {'key': value, 'a': 1, 'b': 2, ...} and now the dict constructor allows keywords: d = dict(key=value, a=1, b=2, ...) which covers the very common case of keys being strings and values being either identifiers or numeric literals, but cases where keys and values are both strings, and unlike dict displays {...} the compiler can't build the dict at compile-time. No compile-time optimization for us! And I know I spend a lot of unproductive time editing tables of string constants, making sure all the strings are quoted, etc. I would hope there is a better way. There are a very small number of languages with first-class literal syntax for (e.g.) XML: Kawa https://www.gnu.org/software/kawa/XML-literals.html Racket http://docs.racket-lang.org/xml/ VB.Net https://docs.microsoft.com/en-us/dotnet/visual-basic/programming-guide/ language-features/xml/xml-literals-overview and possibly a few others. But it seems to be a niche feature. There's also table-driven programming: http://wiki.c2.com/?TableOrientedProgramming an old, proven, but undervalued technique. Probably undervalued because it is *too simple for non-programmers to understand*. https://blogs.msdn.microsoft.com/ericlippert/2004/02/24/table-driven- programming/ I can't find any languages which have native data types for building tables. Have I missed any? Given how ubiquitous and useful tables of strings or numbers are, why aren't there simple ways to build such tables without parsing a string at runtime? So there's a great big hole in programming languages here. -- Steve -- https://mail.python.org/mailman/listinfo/python-list
