Alphanumerics

[adryan]

G'day, all

Great to see more postings in the NWP Macros Forum. Here's another!

First, how can a Macro determine whether a response to a Prompt Input command is an integer or a letter of the alphabet?

Next, how does one increment a letter of the alphabet (eg, get a variable to step through a set of consecutive letters, beginning with a specified letter)?

Finally, what is the correct syntax for the following sample while expression, where x, y are previously declared variables?

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while ((x is not equal to 3) and (y is not equal to "z"))

Cheers,
Adrian

[phspaelti]

Hello Adrian,

First, how can a Macro determine whether a response to a Prompt Input command is an integer or a letter of the alphabet?

The easiest way to do this kind of thing in Nisus is with Find:

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$prompt = Prompt Input
if $prompt.find('[A-Z]','Ei')
prompt "It's a letter"
elsif $prompt.find('\d','E')
prompt "It's a number"
end

In my example here the find will return @true if there is at least one letter in whatever the user types at the prompt. If you want to be sure the input is something more specific -- such as only a single letter -- you can write a more specific find expression.
Note that the result of the Prompt command will always be a text string, even if it consists of numerals, If you want to do calculations with the number you can cast it to an integer, but usually the calculation should work even without that.

Next, how does one increment a letter of the alphabet (eg, get a variable to step through a set of consecutive letters, beginning with a specified letter)?

You'll have to turn numbers into characters using the character code:

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for $code = 65 to 90
$let = Text.newWithCharacter($code)
prompt $let
end

You can get the code for a specified letter with:

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$code = $letter.codepoint(0)

The "0" is the index of the character for which you want to know the code. So "0" means the first character of the string in the variable $letter.
So if $letter contains the string "1", you will get the code "49". I hope that makes sense.

Finally, what is the correct syntax for the following sample while expression, where x, y are previously declared variables?

Code: Select all

while ((x is not equal to 3) and (y is not equal to "z"))

Basically as you have written it, or more precisely:

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while (($x != 3) && ($y != "z"))

Note that in this case Nisus will treat $x as a number, and $y as a string, but it hardly matters in this case.