Typed Value Creation
AMPS includes functions for explicitly constructing constant values of various types. As stated in AMPS Data Types, AMPS operators and functions will automatically convert values to compatible types, but these functions can be used for explicit typing, value construction, and type casting.
FALSE_VALUE
FALSE_VALUE
FALSE_VALUE()
Returns a boolean false value. This function is most useful for constructing values in message types that have a distinct type for boolean values. In the AMPS expression language, false is equivalent to a literal 0.
Parameters
None.
Returns
A boolean false value.
TRUE_VALUE
TRUE_VALUE
TRUE_VALUE()
Returns a boolean true value. This function is most useful for constructing values in message types that have a distinct type for boolean values. In the AMPS expression language, true is typically represented with a literal 1.
Parameters
None.
Returns
A boolean true value.
NAN_VALUE
CHAR_VALUE
CHAR_VALUE
CHAR_VALUE(integer)
Returns the character (byte) for the integer provided (0-255). This function is most useful for constructing values in message types that have a distinct type for char values.
In the AMPS expression language, a single character value is equivalent to a string constructed with an escape, and constructing a string literal is more efficient. That is, '\x01' is more efficient in a filter or field construction than CHAR_VALUE(1). However, to construct a character based on a field, use CHAR_VALUE.
Parameters
integer: An integer between 0 and 255.
Returns
The character corresponding to the integer. If integer is less than 0 or greater than 255, '?' is returned.