Document parser utils.

doc/utils.md

@@ -66,6 +66,40 @@ most scheme implementations.
 Returns a list containing only elements matching given ```pred?```
 predicate.
 
+### Parser
+
+    (import util-parser)
+
+This module contains common functions for both configuration and
+member file parsers. All functions are UTF-8 aware.
+
+    (parser-preprocess-line line)
+
+* ```line``` - a string with contents of one source line
+
+If the input ```line``` contains the ```#``` character, the rest of
+the line (including this character) is removed.
+
+Any leading and trailing space is removed.
+
+Returns a string representing the preprocessed line.
+
+    (parser-parse-line line)
+
+* ```line``` - preprocessed line (string)
+
+If the ```line``` is empty, returns ```#f```.
+
+If the line contains only one token consisting of non-whitespace
+characters before the first whitespace character (there is no
+whitespace), returns a symbol created by interning the whole
+```line```.
+
+When the ```line``` contains whitespace character(s), it returns a
+pair consisting of symbol created by interning the string of
+non-whitespace characters before the first whitespace character and
+the string with the rest of the line.
+
 ### Set (List)
 
     (import util-set-list)