haskell-session-choose-target - choose REPL target

Fix initial commit

 - selection moved to `(interactive)` part
 - functionality embeded in function `haskell-session-change-target`
 - cabal target enumeration function moved to `haskell-cabal.el`
 - `-mapcar` replaced with another function

Fix failed tests

Author: vlatkoB

doc/haskell-mode.texi

@@ -601,32 +601,24 @@ TODO/WRITEME
 @findex haskell-session-change-target
 @vindex haskell-interactive-mode-hook
 
-With @code{haskell-session-change-target} you can change the section
-(defined in project's @file{.cabal} file) the interactive REPL session is
-started with.
+With @code{haskell-session-change-target} you can change the target for
+REPL session.
 
-After the session is started, you can switch the target for
+
+After REPL session started, in @code{haskell-interactive-mode} buffer invoke the
+@code{haskell-session-change-target} and select from available targets for
 
 @cindex testing
 - Testing
 
-In @code{haskell-interactive-mode} buffer invoke the
-@code{haskell-session-change-target} and enter the name of the test you
-wish to perform, i.e. ``test''.
-Answer ``yes'' to restart the session.
-
 @cindex benchmarking
 - Benchmark
 
-In @code{haskell-interactive-mode} buffer invoke the  @code{haskell-session-change-target}
-and enter the name of the benchmark you wish to perform, i.e. ``bench''.
-Answer ``yes'' to restart the session.
-
 - Executable
 
-In @code{haskell-interactive-mode} buffer invoke the  @code{haskell-session-change-target}
-and enter the name of the executable you wish to work with.
-Answer ``yes'' to restart the session.
+- Library
+
+Answer ``yes'' to restart the session and run your tests, benchmarks, executables.
 
 
 TODO/WRITEME

haskell-cabal.el

@@ -444,6 +444,25 @@ OTHER-WINDOW use `find-file-other-window'."
 (defun haskell-cabal-section-data-start-column (section)
   (plist-get section :data-start-column))
 
+(defun haskell-cabal-enum-targets ()
+  "Enumerate targets from .cabal file."
+  (defvar haskell-cabal-source-bearing-sections)
+  (let ((cabal-file (haskell-cabal-find-file)))
+    (when (and cabal-file (file-readable-p cabal-file))
+      (with-temp-buffer
+	(insert-file-contents cabal-file)
+	(let* ((targets (mapcar (lambda (arg) (haskell-cabal--all-instances arg))
+				haskell-cabal-source-bearing-sections)))
+	  (apply #'append targets))))))
+
+(defun haskell-cabal--all-instances (target)
+  "Return list of all instances of TARGET section."
+  (goto-char (point-min))
+  (let (matches)
+    (while (re-search-forward (concat target " +\\([[:word:]-]+\\)") nil t)
+      (push (match-string 1) matches))
+    (sort matches 'string<)))
+
 (defmacro haskell-cabal-with-subsection (subsection replace &rest funs)
   "Copy subsection data into a temporary buffer, save indentation
 and execute FORMS

haskell-commands.el

@@ -773,7 +773,8 @@ inferior GHCi process."
 ;;;###autoload
 (defun haskell-session-change-target (target)
   "Set the build TARGET for cabal REPL."
-  (interactive "sNew build target:")
+  (interactive
+   (list (completing-read "New build target:" (haskell-cabal-enum-targets))))
   (let* ((session haskell-session)
          (old-target (haskell-session-get session 'target)))
     (when session