Question about checks for min and max values

[Nancy Palmquist]

Christopher Yerry wrote:
>>>You think "" eq "0" is bad? You should have heard me when I first 
>>>discovered
>>>that "abcdefg" eq "abc"  !
>>>But even that is perfectly OK and logical and useful (actually _very_
>>>useful) and doesn't get in the way or cause any problems as long as you 
>>>know
>>>about it.
>>
>>It may be useful, but I continue to assert that it is neither logical,
>>nor OK.
>>
>>The semantics of "=" are *very* well defined in the discipline of
>>programming language design, and language designers override them at
>>their peril.  Spelling it differently (ie: "eq") doesn't *really* get
>>you off the hook.
>>
>>IMHO.
> 
> 
>>Didn't Nancy once point out that in truth, filepro was around before most of 
>>these other languages and there was no such standard at the time fp was 
>>created, and in fact filepro's behavior adheres to the standards of basic 
>>math and logic which were worked out looooong before annnnnnny programming 
>>language? And it's most current programming languages that deviate?
> 
> 
> I don't know what Nancy Said (Although I doubt she said this). I have been coding since the early
> 70's (1973 Digital pdp8 os/8 with massive a 128k that filled a cabinet). And we used "=". filePro
> was out in the trs80's in 1976 - 1977 ? That date is after 1973, (OS/8 Basic (ITT Teletypes),
> FORTRAN, (pascal and COBOL -IBM 36 on punch cards!!!)). These all had "=". C (and B )had ":=" or
> "==" - still does; C# retained this too.  So the "That's how it used to be doesn't fly".
> 
> Additionally filePro was written in "C" or "B" as far as I have been told. That standard is "==".


Just because filePro is written in C does not require the syntax of 
filePro to be "C like".  The user interface for filePro which determined 
the syntax and implementation of the language was determined by the 
filePro development team.

As I recall the first release of the IF:/THEN: version of filePro, it 
only allowed "eq, gt, ge, lt, le" relational operands on the IF line of 
a statement.  The "=" sign was reserved for the assignment function on a 
THEN: line.

This thread has wandered far from the first postings that were 
discussing the difference between "Equivalence" and "Equals" and the use 
of the "eq" and "=" symbols.

The fact that == or any other function available in C was around or not 
at the time is not relevant.  FilePro determined how it would act and 
use these symbols.  This was defined by the filePro application and 
presented to the end user as such.  When I typed "5 eq ab" on an IF 
line, filePro parsed that and made the determined interpretation of that 
statement resulting in a TRUE or FALSE.  The rules for this were clearly 
defined by filePro.

I think this has turned in to a comparison of languages and none of this 
is important to how these functions are defined to behave IN FILEPRO.

In the last 25 years, computer languages have developed and added much 
nuance to logic and functions to enhance what can be done.  All to make 
things clearer and easier to program.  The early version of filePro had 
10 commands, but the logic to determine the relationship between 
expressions has not change one bit.

The rules were taken from mathematics and they remain consistent and 
correct.  Just because other languages have added meaning or used the 
symbols differently for relationships does not make filePro wrong.  As I 
see it, they added meaning to some symbols to offer more levels of 
comparison.

Filepro added the COMPARE() function, that will compare two strings and 
will be true only if length and case are the same. This is what some are 
trying to make the "eq" operand determine.

Mathematics is a set of rules.  Once the rules are determined and 
accepted, the mathematics can be developed to determine other "truths".

Computer languages are the same, filePro defined the rules and 
assumptions, you build your programming from there.  I realize some 
programmers would prefer to have the rules determined by other languages 
or systems, but that does not change the fact that filepro has already 
defined the rules, long ago, that would be basic to filePro.  I find 
them to work well and don't see how they seem to offend so many.  I 
don't see any conflict with mathematical standards of logic for 
equivalence and equality.

Well I have made my argument.  I do not suggest that any other language 
is incorrect or that any person posting is wrong.  We are just seeing 
the rules a little differently.  I apologized for the rant.  Can't help 
myself today.

Have an "equivalently" fabulous day.

Nancy





-- 
Nancy Palmquist 		MOS & filePro Training Available
Virtual Software Systems	Web Based Training and Consulting	
PHONE: (412) 835-9417		   Web site:  http://www.vss3.com