# HG changeset patch
# User Rik <rik@octave.org>
# Date 1571258959 25200
# Node ID 85ad4689aa05672392c35c617b02eff3155ede8c
# Parent  c3e24c82157f1d2fe27a80164ec522b8516c6a06
Add warning when non-scalar argument presented to ':' range operator.

* NEWS: Announce new warning IDs Octave:colon-nonscalar-argument,
Octave:colon-complex-argument.

* basics.txi: Document that warning Octave:colon-nonscalar-argument is turned
off when --traditional mode is used.

* interpreter.cc (interpreter::maximum_braindamage): Disable
Octave:colon-nonscalar-argument when --traditional used.

* ov.cc (do_colon_op): Check that numel() == 1 for base, limit, and increment,
or call warning_with_id.  Change warning() to warning_with_id call for
Octave:colon-complex-argument.

* warning_ids.m: Document new warning IDs Octave:colon-nonscalar-argument,
Octave:colon-complex-argument.

* edit.m (default_user): Fix code that emitted a colon warning.

diff -r c3e24c82157f -r 85ad4689aa05 NEWS
--- a/NEWS	Wed Oct 16 13:35:08 2019 -0400
+++ b/NEWS	Wed Oct 16 13:49:19 2019 -0700
@@ -24,6 +24,12 @@
   'A-F' instead.  The previous uppercase formats, `E` and `G`, no longer
   control the case of the output.
 
+- New warnings have been added about questionable uses of the colon ':'
+  range operator.  Each has a new warning ID so that it can be disabled
+  if desired.
+    Octave:colon-complex-argument   : when any arg is complex
+    Octave:colon-nonscalar-argument : when any arg is non-scalar
+  
 #### Graphics backend
 
 - Graphic primitives now accept a color property value of `"none"`
diff -r c3e24c82157f -r 85ad4689aa05 doc/interpreter/basics.txi
--- a/doc/interpreter/basics.txi	Wed Oct 16 13:35:08 2019 -0400
+++ b/doc/interpreter/basics.txi	Wed Oct 16 13:49:19 2019 -0700
@@ -267,6 +267,7 @@
 @example
 @group
 Octave:abbreviated-property-match
+Octave:colon-nonscalar-argument
 Octave:data-file-in-path
 Octave:function-name-clash
 Octave:possible-matlab-short-circuit-operator
diff -r c3e24c82157f -r 85ad4689aa05 libinterp/corefcn/interpreter.cc
--- a/libinterp/corefcn/interpreter.cc	Wed Oct 16 13:35:08 2019 -0400
+++ b/libinterp/corefcn/interpreter.cc	Wed Oct 16 13:49:19 2019 -0700
@@ -1606,6 +1606,7 @@
     Fstruct_levels_to_print (octave_value (0));
 
     disable_warning ("Octave:abbreviated-property-match");
+    disable_warning ("Octave:colon-nonscalar-argument");
     disable_warning ("Octave:data-file-in-path");
     disable_warning ("Octave:function-name-clash");
     disable_warning ("Octave:possible-matlab-short-circuit-operator");
diff -r c3e24c82157f -r 85ad4689aa05 libinterp/octave-value/ov.cc
--- a/libinterp/octave-value/ov.cc	Wed Oct 16 13:35:08 2019 -0400
+++ b/libinterp/octave-value/ov.cc	Wed Oct 16 13:49:19 2019 -0700
@@ -2550,9 +2550,15 @@
       bool result_is_str = (base.is_string () && limit.is_string ());
       bool dq_str = (base.is_dq_string () || limit.is_dq_string ());
 
+      if (base.numel () > 1 || limit.numel () > 1
+          || (increment.is_defined () && increment.numel () > 1))
+        warning_with_id ("Octave:colon-nonscalar-argument",
+                         "colon arguments should be scalars");
+
       if (base.iscomplex () || limit.iscomplex ()
           || (increment.is_defined () && increment.iscomplex ()))
-        warning ("imaginary part of complex colon arguments is ignored");
+        warning_with_id ("Octave:colon-complex-argument",
+                         "imaginary part of complex colon arguments is ignored");
 
       Matrix m_base, m_limit, m_increment;
 
diff -r c3e24c82157f -r 85ad4689aa05 scripts/help/warning_ids.m
--- a/scripts/help/warning_ids.m	Wed Oct 16 13:35:08 2019 -0400
+++ b/scripts/help/warning_ids.m	Wed Oct 16 13:49:19 2019 -0700
@@ -140,6 +140,20 @@
 ## By default, the @code{Octave:built-in-variable-assignment} warning is
 ## enabled.
 ##
+## @item Octave:colon-complex-argument
+## If the @code{Octave:colon-complex-argument} warning is enabled, a warning
+## is issued when one of the three arguments to the colon operator (base,
+## increment, limit) is a complex value.  For example, @code{1:3*i} will
+## cause a warning to be emitted.
+## By default, the @code{Octave:colon-complex-argument} warning is enabled.
+##
+## @item Octave:colon-nonscalar-argument
+## If the @code{Octave:colon-nonscalar-argument} warning is enabled, a warning
+## is issued when one of the three arguments to the colon operator (base,
+## increment, limit) is not a scalar.  For example, @code{1:[3, 5]} will
+## cause a warning to be emitted.
+## By default, the @code{Octave:colon-nonscalar-argument} warning is enabled.
+##
 ## @item Octave:data-file-in-path
 ## If the @code{Octave:data-file-in-path} warning is enabled, a warning is
 ## issued when Octave does not find the target of a file operation such as
diff -r c3e24c82157f -r 85ad4689aa05 scripts/miscellaneous/edit.m
--- a/scripts/miscellaneous/edit.m	Wed Oct 16 13:35:08 2019 -0400
+++ b/scripts/miscellaneous/edit.m	Wed Oct 16 13:49:19 2019 -0700
@@ -553,7 +553,7 @@
     retval = ent.gecos;
     pos = strfind (retval, ",");
     if (! isempty (pos))
-      retval = retval(1:pos-1);
+      retval = retval(1:pos(1)-1);
     endif
   else
     retval = ent.name;