Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

**APD constants**
Constant	Value	Description
`FUNCTION_TRACE` (integer)	1
`ARGS_TRACE` (integer)	2
`ASSIGNMENT_TRACE` (integer)	4
`STATEMENT_TRACE` (integer)	8
`MEMORY_TRACE` (integer)	16
`TIMING_TRACE` (integer)	32
`SUMMARY_TRACE` (integer)	64
`ERROR_TRACE` (integer)	128
`PROF_TRACE` (integer)	256
`APD_VERSION` (string)	example: 1.0.2-dev