wrap

Typeoperator
DictionaryLCS
LibraryLiveCode Script
Syntax
<number> wrap <divisor>
Summary

Wrap allows the user to ensure the value of a variable stays within a specified range.

Introduced2.9
OSmac, windows, linux, ios, android
Platformsdesktop, server, mobile
Parameters
NameTypeDescription
number
divisor
Example
repeat with x = 1 to 10
  put item x wrap 3 of "1,2,3" & comma after tOutput
end repeat
-- evaluates to 1,2,3,1,2,3,1,2,3,1

repeat with x=1 to 9
    put item x wrap 2 of "1,2" & comma after tOutput
end repeat
--evaluates to 1,2,1,2,1,2,1,2,1
RelatedOperator: /
Glossary: math operation
Description

The wrap function makes it easy to loop successively over a fixed number of items in a list. When cycling through the items of a list, the divisor parameter specifies which item will cause the cycle to loop back to the beginning of the list. This means that any number outside this range is mapped to a number within it.

For example, if we had 5 wrap 3, the number 5 would be mapped to the number 2 as this is where the iterator would be pointing on the 5th iteration ie. 1, 2, 3, 1, 2 . Therefore 5 wrap 3 is 2.

The mathematical formula implemented by the wrap operator is:

x wraps y        =       ((x-1) mod abs(y)) +1 if (x &gt;= 0)

=      -((x-1) mod abs(y)) +1 if(x &lt; 0)

If a math operation on finite inputs produces a non-finite output, an execution error is thrown. See math operations for more information.