Name
dict_dec_or_remove — Decrement a counter in a dictionary of counters or deletes it if it becomes zero or negative.
Synopsis
dict_dec_or_remove
(
|
inout dict dictionary , |
| in key any , | |
in
value_decrement
integer
); |
Description
The function checks whether
dict
contains
key
.
If it isn't so then the function checks the datatype of the value associated with the key.
An error 42000 is signalled in case of non-integer value or a negative integer value.
If the value is positive and greater than value_decrement
then value_decrement
is subtracted from it and the result become the new value associated with key
in dict
.
If the value is positive and less than or equal to value_decrement
then key
is removed from dict
.
If key is not in the dictionary then the dictionary remains unchanged.
Informally, the function reverts the effect of
dict_inc_or_add
.
Parameters
dict
Dictionary of counters. The NULL value is equivalent to an empty dictionary.
key
Key of a dictionary item to process.
value decrement
A nonnegative integer (typically 1) that is subtracted from the value associated with
key
.
Return Types
The function returns the changed value associated with the
key
, or zero in any other case.