> Just FYI, some background on keywords that start with a number... > > The reader docs (http://clojure.org/reader) states that symbols (and keywords > follow symbols in these rules) must "begin with a non-numeric character".
Thanks, Alex. The REPL-y and sjacket issues cited the Clojure issues in Jira and I looked through them. There seems to be an assumption in the discussion I've seen that the current description of keywords at http://clojure.org/reader means that the characters *after* the leading colon in a keyword have to follow the rules for a symbol. I think another reasonable way to interpret the description of keywords is that the spelling of a keyword *including the leading colon* has to follow the rules for a symbol -- with the obvious exception that a symbol's spelling *cannot* begin with a colon. Since a colon is always non-numeric, keywords *always* pass the "begins with a non-numeric character" test. When I looked in the past at what it takes to parse a token in Clojure, I concluded that the syntax of numbers vs. non-numbers (including the syntax for numbers with a radix component) was chosen such that a token represents a number if and only if it has a leading numeric character. I've always interpreted the "no leading numeric character" rule for the spelling of symbols (and keywords, including the leading colon) as in support of that simple distinction. More generally, the reader can classify a token by its leading character, or leading 2 characters in the case of a leading #. I don't see a similarly compelling reason to disallow numeric characters immediately after the leading colon in a keyword. --Steve -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
