arrayiterator Type

The xreflect module provides a new type xreflect~arrayiterator which will allow you to programatically iterate through the entries of a named array. Each arrayiterator variable represents an iteration through the array, from start to end.

You initially associate the arrayiterator with an array by calling the iteratorinit procedure. The iterator has a current position in the array; this will initially be before the first entry. Then every time you call nextvalue, the iterator will advance to the next entry in the array - initially the first, then the second, etc. nextvalue returns true until the iterator reaches the end of the array, when it returns false.

While iterating through the array, you can obtain information about the current entry using the getindices and getvalue functions.

Example

The following example demonstrates iterating through the array and outputting each element, including index values

! Populate our example data-set
public declarations
  myarray:dynamic array(set of integer,set of string) of real
end-declarations
myarray(100,'fred') := 100.1
myarray(100,'jim') := 101.5
myarray(101,'fred') := 215.7

! Iterate through the array entries using the arrayiterator
declarations
  it:arrayiterator
end-declarations
iteratorinit(it, 'myarray')
while (nextvalue(it)) do
  write('myarray(')
  forall (v in it.indices) do
    write(v,',')
  end-do
  writeln(') = ',it.value)
end-do

will output:

myarray(100,fred,) = 100.1
myarray(100,jim,) = 101.5
myarray(101,fred,) = 215.7

Subroutines