What Is Malloy
The apply operator takes one expression and applies it to another. The primary us of apply is to "apply" a value to a partial comparison, but there are a number of other powerful gestures which use this operator.
For an expression matching the pattern x ? expression, the following table outlines the various meanings.
| Expression Type | Expression | Meaning in apply |
|---|---|---|
| partial comparison | x ? > 10 & < 100 |
x > 10 and x < 100 |
| alternate choices | x ? 'A' | 'B' |
x = 'A' or x = 'B' |
| range match | x ? 1 to 10 |
x >= 1 and x < 10 |
| equality | x ? 47 |
x = 47 |
| match | x ? r'ab' |
x ~ r'ab' (this only works when applying a regular expression to a string) |
In addition it is very common to use Time Ranges with the apply operator, which operate similar to the numeric range example above.