Hi Ricardo, On Wed, 20 Feb 2019 16:56:35 +0100 Ricardo Wurmus wrote: > The fixed version is attached. Thanks a lot! It almost works, but it seems not to find the "test_" lines. I've reduced the problem to: scheme@(guile-user)> ,use (ice-9 regex) scheme@(guile-user)> (fold-matches "^void" "blah\nvoid\n" '() cons) $24 = () After reading the documentation, I've revised it to: scheme@(guile-user)> ,use (ice-9 regex) scheme@(guile-user)> (fold-matches "^void" "blah\nvoid\n" '() cons regexp/newline) $25 = () Huh?