On Sun, Sep 25, 2016 at 01:50:51PM -0700, Dupéron Georges wrote:
If I understand you well, the intended use of your nested delimiters can be
more or less described as syntactic sugar for #reader, with auto-detection of
where the string ends:
(filter foo?
(python-ish-list-comprehend
«thing for x in sqlish(«select * from foo») where some_pred(x)»))
could be rewritten as:
(filter foo?
#reader"python-ish-list-comprehend.rkt" thing for x in #reader"sqlish.rkt" select *
from foo<READER 2 STOPS HERE> where some_pred(x)<READER 1 STOPS HERE>
That seems like a very reasonable way of looking at it I it.
Here is a little step through of what my rash macro does:
(define pwd-var "pwd")
(rash «ls $(rash/trim «dirname $(rash/trim «$pwd-var»)»)»)
;; after one step of expansion, this looks something like this:
(rash-line-parse 'ls (rash/trim «dirname $(rash/trim «$pwd-var»)»))
;; rash-line-parse would expand to (run-pipeline ...) or (begin ...) if
;; there were multiple lines, but if we pretend that the inner macro
;; would expand first, it would be
(rash-line-parse 'ls (<surrounding-stuff-that-differentiates-rash/out-from-rash>
(rash-line-parse 'dirname (rash/trim «$pwd-var»))))
;; then
(rash-line-parse 'ls (<surrounding-stuff>
(rash-line-parse 'dirname
(<surrounding-stuff>
;; the $ in rash keeps pwd-var from
being quoted
(rash-line-parse pwd-var)))))
So each rash macro reads another layer of string (each one needing a $
due to the syntax specifics of the rash language), but nested strings
will still become strings after applying the reader again, while other
things will become symbols, s-expressions... So you could also use \"
and \\" instead of «», «» is just nicer.
So it is very much like your #reader example above.
William
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