Hi I thought out a useful pet project to learn to use the PEG module. Unfortunately I ended up avoiding it because it errors out when it encounters a s-exp. This is what I tried to do: run a command in a pipe returning the contents of all source files of guix (once) parse this large string with PEG create stats on the number of lines with comments etc. This is what I ended up doing: run a multiple commands in a pipe with sed|grep|wc -l-foo returning the numbers I was interested in. avoid PEG print stats. In the process I learned a lot. 1. (get-string-all) does not return a proper string (string? => #f). I dont understand this as the manual says it should return a string. 2. (ice-9 match) only works on lists it seems. 3. (ice-9 peg) returns #f if it encounters a paren. Maybe there is a way to avoid this - in that case it is not documented in the manual (or I could not find it). (see my example in the file attached) 4. Maybe I misunderstood how to use the PEG parser and matching. In that case a working example and a tip would be very welcome :D Any thoughts? -- Cheers Swedebugia