Re: Add `ly:undead?' to predicate list. (issue 93660047)

[markpolesky]

Reviewers: dak,

Message:
On 2014/06/01 15:10:59, dak wrote:
> scm/lily.scm:728: (,ly:undead? . "undead object")
> Probably more like an "undead container" as the undead thing (to
survive between
> sessions) is placed inside.

> Won't be helpful information to somebody reading the manual which is
the reason
> I'm somewhat unenthusiastic including it.  On the other hand, there
are lots of
> predicates sharing that deficiency.

I never thought that the tiny predicate docstrings in
lily.scm were so much about documentation; we have
docstrings in lily/*.cc for that (IR 4: "Scheme functions")
-- and those descriptions can be longer if needed for
clarity.

I thought that the docstrings in lily.scm are primarily
there for error reporting:
"wrong type for argument ~a.  Expecting ~a, found ~s"

They have the added benefit of a little clarification in the
Notation appendix "Predefined type predicates", but I
wouldn't want the error reporting to be too wordy.

In either case, if my pretty-print patch goes through, then
the lilypond-exported-predicates alist will also be used to
define (ly-type? x).  I don't know if an undead container
would ever be the default value of some grob property in the
future, but if it were, I wouldn't want it mistakenly
prepended with a single-quote in the IR, which is what could
happen with my other patch if we leave any predicates off of
the list.

- Mark

Description:
Add `ly:undead?' to predicate list.

Please review this at https://codereview.appspot.com/93660047/

Affected files (+1, -0 lines):
  M scm/lily.scm


Index: scm/lily.scm
diff --git a/scm/lily.scm b/scm/lily.scm
index  
5d230d8f7eb9eef7439af897fe2d6418b1a81e46..44f9f62258342c89fde8066b844b1596d94b7709  
100644
--- a/scm/lily.scm
+++ b/scm/lily.scm
@@ -725,6 +725,7 @@ messages into errors.")
     (,ly:stream-event? . "stream event")
     (,ly:translator? . "translator")
     (,ly:translator-group? . "translator group")
+    (,ly:undead? . "undead container")
     (,ly:unpure-pure-container? . "unpure/pure container")
     ))