Hi all, I agree that such stricter management of parameters would be wise .
David ________________________________________ De : dev [dev-boun...@lists.scilab.org] de la part de Stéphane Mottelet [stephane.motte...@utc.fr] Envoyé : vendredi 26 février 2021 15:01 À : List dedicated to the development of Scilab Objet : Re: [Scilab-Dev] [Scilab-users] Variable scope in Scilab Le 26/02/2021 à 14:50, Stéphane Mottelet a écrit : > Hi devs, > > Just after changing the rule in macro.cpp I see this at startup, and I > am laughing out loud ;-) > > Scilab branch-6.1 (Feb 19 2021, 14:37:51) > at line 44 of function mdelete ( > /Users/mottelet/git/scilab_6.1.orig/scilab/modules/fileio/macros/mdelete.sci > line 57 ) > at line 26 of function atomsAUWriteAccess ( > /Users/mottelet/git/scilab_6.1.orig/scilab/modules/atoms/macros/atoms_internals/atomsAUWriteAccess.sci > line 42 ) > at line 11 of function atomsSystemInit ( > /Users/mottelet/git/scilab_6.1.orig/scilab/modules/atoms/macros/atomsSystemInit.sci > line 27 ) > > Wrong number of input arguments. > > --> > > Does it mean that we use the "crappy shortcut" as a feature in Scilab > internals ? of course nobody uses it, my patch waas a little bit rude. We have the right to call macros with less arguments than the number of formal input arguments, hence when inheriting the outer context then there is a complete confusion between the formal parameter name and the same name of a symbol in the outer context. Inheritance should be OK for all symbols BUT formal input parameters. S. > > S. > > Le 26/02/2021 à 14:38, Stéphane Mottelet a écrit : >> Hi all, >> >> In Scilab the scope of variables is quite permissive but even in >> Julia (really strict rules) we can have the following behavior: >> >> function y=f(x) >> y=x+a; >> end >> >> a=1; >> f(2) >> a=2; >> f(3) >> >> -> a=1; >> >> --> f(2) >> ans = >> >> 3. >> >> --> a=2; >> >> --> f(3) >> ans = >> >> 5. >> >> Yesterday afternoon I was my students for a Scilab beginners >> tutorial, and by accident one of them had "x" defined before in the >> main workspace and tried to call f without arguments. I reproduce the >> experiment here by explicitely defining x before the call: >> >> x=1; >> f >> >> --> x=1; >> >> --> f >> ans = >> >> 3. >> >> Allowing the function inner scope to see variables of the outer scope >> is one thing, you may or may not agree this is not the point here, >> but allowing to call f without arguments just because the formal >> input parameter has the same symbol as an outer scope symbol is >> another thing. I knew this was possible even if i never used such a >> feature, but my students were so puzzled by this, particularly those >> who already learned other low-level languages, that I decided to >> propose the suppression of this, that I consider as a serious >> potential source of many bugs. Don't tell me that this would break >> some user code because I frankly have no consideration for this kind >> of crappy shortcut and, sorry if it may sound rude, for programmers >> who use it... >> >> S. >> -- Stéphane Mottelet Ingénieur de recherche EA 4297 Transformations Intégrées de la Matière Renouvelable Département Génie des Procédés Industriels Sorbonne Universités - Université de Technologie de Compiègne CS 60319, 60203 Compiègne cedex Tel : +33(0)344234688 http://www.utc.fr/~mottelet _______________________________________________ dev mailing list dev@lists.scilab.org http://lists.scilab.org/mailman/listinfo/dev _______________________________________________ dev mailing list dev@lists.scilab.org http://lists.scilab.org/mailman/listinfo/dev
