bugGNU Octave - Bugs: bug #60941, Whitespace now causes parse error...


bug #60941: Whitespace now causes parse error for postfix increment / decrement operators

Submitted by:  None
Submitted on:  Mon 19 Jul 2021 03:47:45 PM UTC  
Category:  Interpreter Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Regression
Status:  Confirmed Assigned to:  None
Originator Name:  Originator Email:  -email is unavailable-
Open/Closed:  Open Release:  dev
Operating System:  GNU/Linux

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Fri 20 Aug 2021 09:07:41 PM UTC, comment #4: 

Should we mark this as Won't Fix?  Seems like we had to change the parser to more closely support Matlab command syntax, and this isn't something we have freedom on.

Also, although you could do it before, it's pretty bad from a legibility-of-code perspective not to tie the increment/decrement operators to the variable they are operating on.  Something like

a ++ b

could be interpreted as a postfix increment of variable 'a', a prefix increment of variable 'b', or 'a' plus '+b'.

Rik <rik5>
Project Administrator
Fri 23 Jul 2021 02:35:44 PM UTC, comment #3: 

I'm not sure what the best solution is for both improving Matlab compatibility and continuing to support Octave's extended set of operators.  I've opened a discussion here:


John W. Eaton <jwe>
Project Administrator
Mon 19 Jul 2021 03:55:56 PM UTC, comment #2: 

Possibly related to bug #60882.
CC'ing jwe.

Markus M├╝tzel <mmuetzel>
Project Member
Mon 19 Jul 2021 03:48:26 PM UTC, comment #1: 

Add to say: Octave version is 7.0.0, hg id bc19d9360bac

Mon 19 Jul 2021 03:47:45 PM UTC, original submission:  

This behavior was found while testing something in bug #60920:

octave:1> foo = 0
foo = 0
octave:2> foo ++
error: foo used as variable and later as function
octave:3> foo++
ans = 0
octave:4> foo
foo = 1
octave:5> ++ foo
ans = 2

Apparently inserting a space after a variable when calling a postfix increment or decrement operator now causes a variable/function parse error.



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  • -email is unavailable- added by rik5 (Posted a comment)
  • -email is unavailable- added by jwe (Posted a comment)
  • -email is unavailable- added by mmuetzel (Posted a comment)
  • -email is unavailable- added by mmuetzel

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    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2021-07-19 mmuetzel StatusNone => Confirmed
        Dependencies- => Depends on bugs #60882
        Carbon-Copy- => Added jwe

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