[REBOL] Re: Using a Math oper. buried in a variable
From: mumpsoid:gmx at: 2-Apr-2009 15:09
On Thu, 2 Apr 2009, Gregg Irwin wrote:
> Hi Duke,
>
> >>> num1
> mgc> == 5
> >>> num2
> mgc> == 6
> >>> op
> mgc> == *
> >>> do reform [num1 op num2]
> mgc> == 30
> >>>
>
> mgc> Is it OK for me to think that this is a PITA?
>
> Sure, you can think whatever you want. :) How would you like it to
> work, and what is your ultimate goal?
>
> A big part of understanding REBOL is figuring out when evaluation
> occurs, and how values are evaluated.
I can see that...
> I almost never DO strings. 1) it's just non-REBOLish. REBOL is a data
> language, and you can almost always build up expressions to evaluate
> far easier using native types, and 2) it's a risky habit to get into,
> in case, one day, you write something that uses untrusted data.
I agree!
>> about
REBOL/Core 2.7.6.2.5 17-Mar-2008
Copyright 2000-2008 REBOL Technologies. All rights reserved.
REBOL is a trademark of REBOL Technologies. WWW.REBOL.COM
>> op: :*
>> op num1 num2
== 30
>> integer? num1
== true
>> integer? num2
== true
>>
I don't believe that this was issue here.
However, it wa an issue in my little "learning" program:
REBOL [
title: "Calculator Program"
author: "Duke Normandin"
date: 30-March-2009
File: %myCalc.r
version: 1.0.0
]
clrscrn: does [print "^(1B)[2J"]
until [
clrscrn
num1: ask "Enter the 1st number: "
num2: ask "Enter the 2nd number: "
op: ask "Enter an operator [+ - * /]: "
any [
if op = "+" [
print ["The answer is: " ((to-integer num1) + (to-integer num2))]
]
if op = "-" [
print ["The answer is: " ((to-integer num1) - (to-integer num2))]
]
if op = "*" [
print ["The answer is: " ((to-integer num1) * (to-integer num2))]
]
if op = "/" [
print ["The answer is: " ((to-integer num1) / (to-integer num2))]
]
print ["You entered an invalid operator"]
]
confirm "Are you done? Y/N: "
]
--
Duke Normandin
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
