Match characters: match_characters

Syntax

match_characters ( op , pattern )

Input parameters

op	the dataset to be checked
pattern	the regular expression to check the Data Set or the Component against

Examples of valid syntaxes

match_characters(ds1, "[abc]+\d\d")
ds1 [ calc m1 := match_characters(ds1, "[abc]+\d\d") ]

Semantics for scalar operations

match_characters returns TRUE if op matches the regular expression regexp, FALSE otherwise.

The string regexp is an Extended Regular Expression as described in the POSIX standard. Different implementations of VTL may implement different versions of the POSIX standard therefore it is possible that match_characters may behave in slightly different ways.

Input parameters type

op

dataset {measure<string> _}
| component<string>
| string

pattern

component<string>
| string

Result type

result

dataset { measure<boolean> bool_var }
| component<boolean>
| boolean

Additional Constraints

If op is a Data Set then it has exactly one measure.

pattern is a POSIX regular expression.

Behaviour

The operator has the typical behaviour of the “Operators changing the data type” (see the section “Typical behaviours of the ML Operators”).

Examples

Given the operand dataset DS_1:

Input DS_1 (see structure)

Id_1	Id_2	Id_3	Id_4	Me_1
G	Total	Percentage	Total	AX123
R	Total	Percentage	Total	AX2J5

Example 1

DS_r:=match_characters(DS_1, "[:alpha:]{2}[:digit:]{3}");

results in (see structure):

DS_r
Id_1	Id_2	Id_3	Id_4	bool_var
G	Total	Percentage	Total	True
R	Total	Percentage	Total	False