A couple of functions for trimming strings. I need these because, for example, I generate the output filename based on the document type and number, and this goes wrong if they were specified with their end-tags omitted, so that the string has returns or the like within it.
Given a list of characters, return the list with leading whitespace characters removed
This function requires that input-whitespace? work. This is
true in OpenJade but not in Jade 1.2.1 (see notes at
<http://www.jclark.com/jade/#limitations>). In that case,
the char-property whitespace test has to be replaced by the
brute-force version:
(not (or (equal? firstchar #\space)
(equal? firstchar #\ )
(equal? firstchar #\
)))
However this doesn't appear to work within openjade, for some reason
I don't fully undertand, to do with parentheses and ampersands, I think.