wse

This function enforces ThingsDB to create a change.

When using a stored closure which requires a change it might not be possible for ThingsDB to detect the change requirement before evaluation the query. In this case it is required to use wse() to enforce a change.

Function wse() might both wrap a statement and be called without arguments.

Since version 1.10.1 it is possible to write f(..)! instead of wse(f(..)) making the function call obsolete.

This function generates a change.

Function

wse([statement])

Arguments

Argument	Type	Description
statement	any (optional)	Statement or block to wrap.

Return value

Return value of the given statement or nil.

Example

This code shows an example usage for wse():

// Suppose we have a closure with side-effects
.take_license = || .licenses -= 1;

// And we have some initial licenses
.licenses = 99;

Here we need wse() to enforce a change:

// Without wse() no change would be created and thus this would raise an error
wse(.take_license());

// Return the number of licenses left
.licenses;

Return value in JSON format

Or, we could also use the shorter (..)! syntax:

// The `!` after the function tells ThingsDB to use wse(..)
.take_license()!;

// Return the number of licenses left
.licenses;

Return value in JSON format