Re: Interpretation of wrog use of Operators
- To: mathgroup at smc.vnet.net
- Subject: [mg21351] Re: Interpretation of wrog use of Operators
- From: Tobias Oed <tobias at physics.odu.edu>
- Date: Tue, 28 Dec 1999 00:49:37 -0500 (EST)
- Organization: Old Dominion University
- References: <8471gd$n81@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Drago Ganic wrote: > > Hi !! > > I believe that the functions SyntaxQ and SyntaxLength shouldn't return an error message like they do when we use super-, sub-, over- or underscripts with an operator. > > In[27]:= SyntaxQ [ "\!\(x\[CirclePlus]\_n y\)" ] > > Syntax::"sntxi": "Incomplete expression; more input is needed.\!\(\"\"\)" > > Out[27]= False > > In[27]:= SyntaxLength [ "\!\(x\[CirclePlus]\_n y\)" ] > > Syntax::"sntxi": "Incomplete expression; more input is needed.\!\(\"\"\)" > > Out[28]=31 > > It seems that Mathematica has the problem to interpret the expression > > SubscriptBox["\[CirclePlus]", n_ ] > > where instead of \[CirclePlus] can be any operator name. > > Of course this input is syntactically incorrect, but why the error message when I _just ask_ > if it is correct. > > In the example of The Mathematica Book 2.8.13 > > SyntaxLength["1 + 2 + "] > > we don't get the error message. I think Mathematica is here inconsistent. > > I also don't know how to interpret the return value of the SyntaxLength function because I can't see the FullForm ? > > Any comments.... > > Greetings, > Drago Ganic, Croatia You can switch the message off by issuing a Off[SyntaxQ::sntxi] but you are right, Mathematica's behaviour seems not to be consistent between the two examples. cheers Tobias