Modern Array ForEach

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ForEach

Calls a procedure on every element in order, passing each by reference.

Syntax

ForEach( byref a as Array( of T ), byref f as F )

Notes

• Each element is passed byref, so the function can modify it in place.
• It takes the callable as a generic, not a procedure pointer, which is what lets a capturing lambda work -- a closure object is not a procptr.
• A plain @proc or a non-capturing lambda works too, because calling through a generic parameter is just f( x ) either way.
• for each is the alternative when the body is written inline rather than passed.

Examples

#import "std/containers"
using containers

dim v as Array( of int32 )
for i as int32 = 1 to 3
    v.Push( i )
next

'' A CAPTURING lambda, which a procedure-pointer parameter could not take
dim as int64 total = 0
ForEach( v, sub[ byref total ]( byref x as int32 )
    total += x
end sub )
print total                  '' 6

'' Byref, so it can modify in place
ForEach( v, sub( byref x as int32 ) : x *= 10 : end sub )
print v[ 0 ]                 '' 10

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Library: Array Container
Category: Array
Documented under: Members