Cleaned up the code. added some documentation.

private/git-commands.rkt

@@ -51,24 +51,26 @@
   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.
 (define (std-process-git-result cmd exit-code result output out info)
   (if (= exit-code 0)
-      (if result
-          (begin
-            (git-displ out)
-            #t)
-          (git-error cmd "Error" out))
+      (begin
+        (git-displ (map cadr output))
+        #t)
       (git-error cmd (format "Exitcode <> 0: ~a" exit-code) out)
       )
   )
 
 
+;; 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)
-     (def-proxy-cmd f cmd (λ (args info) args) standard-result))
-    ((_ f cmd pre-code)
-     (def-proxy-cmd f cmd pre-code standard-result))
     ((_ f cmd pre-code process-result)
      (define (f args*)
        (let* ((args (flatten args*))
@@ -79,6 +81,3 @@
              (process-result cmd exit-code result output out info))))))
     )
   )
-
-
-