CompoundCondition

CompoundConditon allow conditions to be combined into more complex logical statements. The logical operators allowed are or, and, and not.

or/and operators

or & and operators require >= 2 operands to be specified.

Let's take a look at this abbreviated condition example:

import { conditions } from '@nucypher/taco';

const conditionA = ...
const conditionB = ...

const aAndB = new conditions.compound.CompoundCondition({
  operator: 'and',
  operands: [conditionA, conditionB],
});

Here, we define two conditions conditionA and conditionB, and combine them into a single condition using and operator. So now, our new condition will "trigger" only when both conditionA and conditionB "trigger".

We can use two or more conditions when using and and or operators:

const allMustPass = new conditions.compound.CompoundCondition({
  operator: 'and',
  operands: [conditionA, conditionB, ..., conditionX],
});

const anyOneMustPass = new conditions.compound.CompoundCondition({
  operator: 'or',
  operands: [conditionA, conditionB, ..., conditionX],
});

Alternatively, we can use CompoundCondition.or and CompoundCondition.and short-hand methods

const allMustMatch = new conditions.compound.CompoundCondition.and([
    conditionA, conditionB, ..., conditionX],
]);

const atLeastOneMustMatch = new conditions.compound.CompoundCondition.or([
    conditionA, conditionB, ..., conditionX],
]);

not operator

The not operator only allows one operand.

For example:

import { conditions } from '@nucypher/taco';

const conditionA = ...

const notA = new conditions.compound.CompoundCondition({
  operator: 'not',
  operands: [conditionA],
});

Nested Combinations

CompoundCondition objects can be nested on itself i.e. you can create compound conditions of compound conditions.

For example:

import { conditions } from '@nucypher/taco';

const conditionA = ...
const conditionB = ...
const conditionC = ...
const conditionD = ...
const conditionE = ...

const cOrD = new conditions.compound.CompoundCondition({
  operator: 'or',
  operands: [conditionC, conditionD],
});

const notE = new conditions.compound.CompoundCondition({
  operator: 'not',
  operands: [conditionE],
});

// conditionA AND conditionB AND cOrD AND notE
overallCondition = new conditions.compound.CompoundCondition({
  operator: 'and',
  operands: [conditionA, conditionB, cOrD, notE],
});

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