Re: Checking to see if a string is a letter

[deuteros <deuteros@xrs.net>]

On Tue 03 Apr 2012 01:15:27a, Jeffrey Carter
<spam.jrcarter.not@spam.not.acm.org> wrote in
news:jle13q$ale$1@tornado.tornevall.net: 

> What do you mean by "contains a single letter"?

I mean the string contains a single letter and nothing more. For example:

a  - Legal
A  - Legal
aa - Illegal
a1 - Illegal

> It will probably also help to explain the problem that gives rise to
> this sub-problem, as context is always helpful in knowing how to answer.

I'm writing an interpreter for a very simple language grammar. The language 
only has an integer data type and the identifier is only a single letter (not 
case sensitive).

My program takes a text file, breakes it up into lexemes, and stores each 
lexeme in a vector. If the parser finds a single letter that hasn't been 
handled by some other function then it knows it needs to call a function to 
perform a variable assignment.