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.