Tested (and fixed) `map-lines()`. It works now.

Fortune for cl-utils's current commit: Small blessing − 小吉

flan-utils.lisp

@@ -138,12 +138,12 @@ To use a custom line reader function, set `read-line' to a function that takes a
 To stop on a specific line, `continue' can be set to a function that receives the line string; and if `nil' is returned from that function, the iteration stops.
 The default behaviour (with `mapper' being `mapcar' and `applicator' being `list') works just like `mapcar'(). To emulate the behaviour of functions like `mapcan'(), set `applicator' to `nconc'(); then set `mapper' to `maplist'() for `mapcon'() behaviour."
 					;(with-open-file (stream location :direction :input)
-    (let ((filter-single-line (switch ignore
+    (let ((filter-single-line (cond
 				;; Specific `ignore' values
-				(:blank (lambda (line) (> (length line) 0)))
-				(:whitespace-only (lambda (line) (not (cl-ppcre:scan "^\s*$" line))))
-				;; Otherwise, the ignore function
-				ignore)))
+				((eql ignore :blank) (lambda (line) (> (length line) 0)))
+				((eql ignore :whitespace-only) (lambda (line) (not (cl-ppcre:scan "^\\s*$" line))))
+				;; Otherwise, the ignore function (or pass all, if nil)
+				(t (or ignore (lambda (--n) (declare (ignore --n)) t))))))
       (apply applicator ; apply `applicator' to the result of each iteration in `mapper'.
 	     (funcall mapper func ; call the mapping function with `func' and the list of transformed and filtered lines
 		      (mapcan (lambda (n) (when n (list n))) ; outputs a list of the lines
@@ -156,8 +156,7 @@ The default behaviour (with `mapper' being `mapcar' and `applicator' being `list
     (let ((stream (gensym)))
       `(with-open-file (,stream ,location :direction :input)
 	 ,(cons 'map-lines (append `(,stream ,func) kvs)))))
-  ;TODO: test map-lines -- (map-file-lines "file" #'identity :applicator #'nconc :ignore :blank)
-  
+
   (defun mapcan-lines (stream func &rest kvs &key &allow-other-keys)
     "See `map-lines'(): Uses `nconc'() as the applicator and `mapcar'() as the mapper, which produces an output you'd expect from `mapcan'() The other key arguments can be specified according to the signature of `map-lines'()."
     (apply #'map-lines (append (list stream func :applicator #'nconc :mapper #'mapcar) kvs)))