The declare construct is used
to set execution directives for a block of code. The syntax
of declare is similar to the syntax
of other flow control constructs:
The directive section allows
the behavior of the declare block to
be set. Currently only one directive is recognized: the ticks directive. (See below for more
information on the
ticks directive)
The statement part of the declare block will be executed -- how it
is executed and what side effects occur during execution may
depend on the directive set in the
directive block.
A tick is an event that occurs for every N low-level statements executed
by the parser within the declare
block. The value for N
is specified using ticks=N within the declare blocks's
directive section.
The event(s) that occur on each tick are specified
using the register_tick_function(). See the
example below for more details. Note that more than one
event can occur for each tick.
Ticks are well suited for debugging, implementing
simple multitasking, backgrounded I/O and many other
tasks.
See also
register_tick_function() and unregister_tick_function().