Relation:function

Define a custom function you can use in expressions.

function name (was (parameter (, parameter...)))

limitedinstructionlist

set result expression

end function

parameter: any valid name

limitedinstructionlist: set, if, while

result: the last value of this variable is returned. It is always of type text.

Using the sample relation films.csv .

function even (y) if y mod 2 = 0 set result = 1 else set result = 0 end if end function read "films.csv" extend iseven = even(year)

film	director	year	iseven
A bout de souffle	Godard	1960	1
Tirez sur le pianiste	Truffaut	1960	1
Cléo de 5 à 7	Varda	1962	1
Jules et Jim	Truffaut	1962	1
Pierrot le fou	Godard	1965	0
Week-End	Godard	1967	0
Die verlorene Ehre der Katharina Blum	von Trotta	1975	0
Der starke Ferdinand	Kluge	1976	1
Sans toi ni loi	Varda	1985	0

Use functions when you are limited with expression or you want to reuse complicated expressions.

Functions cannot act directly on a relation. They deal with text and numbers and return text.

There is no return instruction. The last value set for result is returned.

Variable scope: Functions see only variables passed by parameters.