Learning Perl on Win32 Systems

The redo Statement

The third way you can jump around in a looping block is with redo. This construct causes a jump to the beginning of the current block (without reevaluating the control expression), like so:

            while (somecondition) {
		# redo comes here
		something;
		something;
		something;
		if (somecondition) {
			somestuff;
			somestuff;
			redo;
		}
		morething;
		morething;
		morething;
}

Once again, the if block doesn’t count—just the looping blocks.

With redo, last, and a naked block, you can make an infinite loop that exits out of the middle, like so:

{
		startstuff;
		startstuff;
		startstuff;
		if (somecondition) {
			last;
		}
		laterstuff;
		laterstuff;
		laterstuff;
		redo;
}

This logic would be appropriate for a while-like loop that needed to have some part of the loop executed as initialization before the first test. (In a later section entitled “Expression Modifiers,” we’ll show you how to write that if statement with fewer punctuation characters.)