Document the command-line module.

README.md

@@ -87,6 +87,37 @@ implemented anyway to not require any external dependencies.
 
 ### Command Line parsing
 
+Generic syntax-based implementation of command-line options parsing
+with focus on generated help and ergonomic binding of option
+arguments.
+
+    (command-line print-help (opt (args ...) help body ...) ...)
+
+* ```print-help``` - identifier binding for the help printing procedure
+* ```opt``` - command-line option name as identifier (unquoted symbol)
+* ```args ...``` - optional arguments of given option
+* ```help``` - help string for this option
+* ```body ...``` - expressions to be evaluated upon option match
+
+Parses command-line arguments based on the specification given. If
+evaluated inside ```csi``` script, only options and arguments after
+the ```--``` meta-option are parsed. If evaluated inside compiled
+binary, all arguments are parsed as usual.
+
+Each option is represented by the ```opt``` option identifier
+(unquoted symbol), optional arguments ```args``` which become bound in
+the option specification ```body ...``` expressions, help string and
+the actual expressions to be evaluated when the option (and possibly
+its arguments) match.
+
+If an option is encountered on the command-line and not enough
+arguments (according to the option specification) are provided for it,
+an exception is raised.
+
+Within any of the ```body ...``` expressions the ```print-help```
+procedure can be used to print the options, their argument names and
+help strings in a nice, human-readable format.
+
 ### Dictionary
 
 Simple key/value dictionary with most operations implemented in linear

command-line.scm

@@ -27,10 +27,12 @@
 
 (module
  command-line
- (command-line
+ (
+  command-line
   command-line:parse-command-line
   command-line:print-options
-  command-line-tests!)
+  command-line-tests!
+  )
 
  (import scheme
 	 (chicken base)
@@ -119,8 +121,6 @@
  ;; Syntax for expanding various types of options.
  (define-syntax make-option
    (syntax-rules ()
-     ((_ opt help proc)
-      (list (symbol->string 'opt) help proc))
      ((_ opt (args ...) help body ...)
       (list (symbol->string 'opt)
 	    help