Documentation added and extended git log / git diif

private/git-commands.rkt

@@ -12,6 +12,12 @@
          )
 
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; goal   : Determine whether a Git option occurs in an argument list.
+; pre    : args is a list and opt is a symbol, string or regular expression.
+; post   : args has only been inspected.
+; result : The match result, or #f when the option is absent.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (define (has-git-arg? args opt)
   (let ((cmp (cond ((symbol? opt) (λ (x) (eq? x opt)))
                    ((string? opt) (λ (x) (string=? (format "~a" x) opt)))
@@ -28,6 +34,13 @@
           (f args)
           (error 'has-git-arg? "args must be a list of arguments")))))
 
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; goal   : Check that mandatory Git options and their arguments are present.
+; pre    : flags contains (option argument-count error-message) items.
+; post   : Missing options have raised an exception.
+; result : args when every mandatory option is present.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (define (check-git-args cmd args flags)
   (for-each
    (λ (opt)
@@ -51,10 +64,12 @@
   args)
 
 
-;; goal: Process the standard result of a Git command.
-;; pre: exit-code and out belong to the completed Git command.
-;; post: Successful output has been displayed or a Git exception has been raised.
-;; result: #t when exit-code is zero.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; goal   : Process the standard result of a Git command.
+; pre    : exit-code and out belong to the completed Git command.
+; post   : Successful output has been displayed or a Git exception has been raised.
+; result : #t when exit-code is zero.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (define (std-process-git-result cmd exit-code result output out info)
   (if (= exit-code 0)
       (begin
@@ -65,10 +80,12 @@
   )
 
 
-;; goal: Define the internal proxy for a Git command.
-;; pre: pre-code and process-result accept the command proxy arguments.
-;; post: The proxy invokes Git without standard input and processes its result.
-;; result: A procedure named f accepting a list of Git arguments.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; goal   : Define the internal proxy for a Git command.
+; pre    : pre-code and process-result accept the command proxy arguments.
+; post   : The proxy invokes Git without standard input and processes its result.
+; result : A procedure named f accepting a list of Git arguments.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (define-syntax def-git-cmd-proxy
   (syntax-rules ()
     ((_ f cmd pre-code process-result)