Re: Add regtest for issue 5181 (issue 327470043 by address@hidden)

[dak]

Reviewers: carl.d.sorensen_gmail.com, thomasmorley651,

Message:
On 2017/09/25 21:28:50, thomasmorley651 wrote:
> Very nice, i.e LGTM

> Not sure whether this should be reflected by a reg-test, but currently
there is
> no case in it triggering the warning like:

> warns = {
>    \override NoteHead.color = #red
>    c'1 d'
>    \revert NoteHead.color
> }
> { \warns -1 e' }


Touché.  I was not sure about whether or not the behavior and warning
for << {c'} -1 >> should be retained.  But your case looks pretty bad.
I mean, sure, one could skip backwards over unusable music expressions
as long as their length amounted to zero...  But it seems like
inviting trouble.

> And there are cases which will probably never work, like:

> fails = {
>    d'-\tweak color #red
>       %% with or without \etc
>       \etc
> }

> { \fails -1 e' }

Ugh.  That's another of those "what do you even think \etc is" cases.
Basically you need to come up with a reasonable definition of the
expression

{ ... \etc }

first.  I mean, the syntax does not yet seem taken so that does not
seem impossible but it may still end up being tricky.

> Not sure if we should mention it in the docs at all, or in "Known
> issues and warnings" or elsewhere ...?

So far I think it's more a case of reviewing "Known issues and
warnings" for stuff that is no longer an issue.  I don't think that we
have rigidly defined the limits of where you could place post-events,
but we may have warned people off a few things.


Description:
Add regtest for issue 5181


Also contains:

Define ly:music-error

Please review this at https://codereview.appspot.com/327470043/

Affected files (+67, -0 lines):
  A input/regression/added-post-event-test.ly
  M scm/music-functions.scm


Index: input/regression/added-post-event-test.ly
diff --git a/input/regression/added-post-event-test.ly  
b/input/regression/added-post-event-test.ly
new file mode 100644
index  
0000000000000000000000000000000000000000..8f637438d5a435c1e58eb9fe4c2345cb3e519b32
--- /dev/null
+++ b/input/regression/added-post-event-test.ly
@@ -0,0 +1,63 @@
+\version "2.21.0"
+
+\header {
+
+  texidoc = "This is a test of combining post-events with various
+constructs.  Problems are reported on the stderr of this run; there
+are no images produced."
+
+}
+
+%%%
+%%% Testing utilities
+%%%
+
+testIt =
+#(define-void-function (harmless music) ((boolean?) ly:music?)
+   ;; We check whether there is sequential music with a single
+   ;; expression that has the location of its single element basically
+   ;; at the end of the expression:
+   ;;
+   ;; That's when the expression has been combined immediately at
+   ;; parse time and not in a second sweep
+   (define (contained? m p)
+     (let ((m-loc (ly:input-both-locations (ly:music-property m 'origin)))
+           (p-loc (ly:input-both-locations (ly:music-property p 'origin))))
+       (and (string= (first m-loc) (first p-loc))
+            (= (fourth m-loc) (fourth p-loc))
+            (>= (fifth m-loc) (fifth p-loc)))))
+   (let* ((musl (and (music-is-of-type? music 'sequential-music)
+                     (ly:music-property music 'elements)))
+          (muse (and (pair? musl) (not (pair? (cdr musl))) (car musl)))
+          (badpost (and muse
+                        (find (lambda (m) (not (contained? muse m)))
+                              (extract-typed-music muse 'post-event)))))
+     (cond ((not muse)
+            (ly:music-error music (_ "expected single-element sequential  
expression")))
+           (badpost
+            (if harmless
+                (ly:music-message badpost (_ "late post-event, expected"))
+                (ly:music-warning badpost (_ "late post-event,  
unexpected"))))
+           (else
+            (if harmless
+                (ly:music-warning muse (_ "no late post-event,  
unexpected")))))))
+
+pitch = c'
+note = c'4
+chord = <c' g'>
+lyr = \lyricmode { two words }
+
+\testIt ##t { \note -1 }
+\testIt ##t { $note -1 }
+\testIt ##t { \chord -1 }
+\testIt { { \note -1 } }
+\testIt ##t { { \note -1 } -2 }
+\testIt { < \note -1 g' > -2 }
+\testIt { { \chord -1 } }
+\testIt { $pitch -1 }
+\testIt { c-\single \slurUp ( -1 }
+\testIt ##t { c \single \slurUp ( -1 }
+\testIt ##t \lyricmode { \lyr __ }
+\testIt ##t \lyricmode { \lyr -- }
+
+%% end test.
Index: scm/music-functions.scm
diff --git a/scm/music-functions.scm b/scm/music-functions.scm
index  
5bbd07ea8fae1ade4bffe1067e9d7faf6b213d69..ff62c17c017d285b377b05d77716879cb61a92f7  
100644
--- a/scm/music-functions.scm
+++ b/scm/music-functions.scm
@@ -1087,6 +1087,10 @@ actually fully cloned."
         (apply ly:input-warning ip msg rest)
         (apply ly:warning msg rest))))

+(define-public (ly:music-error music msg . rest)
+  (ly:parser-error (apply format #f msg rest)
+                   (ly:music-property music 'origin)))
+
 (define-public (ly:event-warning event msg . rest)
   (let ((ip (ly:event-property event 'origin)))
     (if (ly:input-location? ip)