CAML

CAML Ain't Markup Language

What does CAML do?

Caml simply adds a layer of conditional logic when deserialising a YAML file.

CAML expressions

CAML supports basic logical expressions, which can be resolved by passing in an instance of IMatcher, such as the built in ConfigurableMatcher.

CAML API

Literals

The simplest expressions are literals. A literal is a string which will be evaluated to true or false by the IMatcher instance at runtime.

- monday
    workday: true
- tuesday
    workday: true
- wednesday
    workday: true
- thursday
    workday: true
- friday
    workday: true
- saturday
    workday: false
- sunday
    workday: false

Default

The default expression is a special literal which will always evaluate to true, this is useful to reduce verbosity in a yaml file

- default
    workday: true
- saturday
    workday: false
- sunday
    workday: false

Functions

Functions can be used to pass one or more values to the IMatcher at runtime

- day(monday, tuesday, wednesday, thursday, friday)
    workday: true
- day(saturday, sunday)
    workday: false

Operators

Logical operators can be used to combine expressions

NOT

The NOT operator ! will negate the result of the expression it is applied to.

note if ! is the first character in an expression, the expression will need to be defined using yaml quotation format.

- "!day(saturday, sunday)"
    workday: true

AND

The AND operator & will evaluate true if both expressions evaluate to true. Otherwise, the result is false.

The operation is conditional, so the second expression will not be evaluated if the first expression evaluates to false.

OR

The OR operator | will evaluate true if either expressions evaluate to true. Otherwise, the result is false.

The operation is conditional, so the second expression will not be evaluated if the first expression evaluates to true.

XOR

The XOR operator ^ will evaluate true if exactly one expression evaluates to true. Otherwise, the result is false.

The operation is not conditional, so the both expressions will be evaluated.

Expression Groups

Expressions can be grouped by surrounding them in parentheses. This allows more flexibility when combining expressions

- (monday | tuesday) & !day(thursday)