Class Operation

constructor

• new Operation(): Operation

• Returns Operation

baseLength

operations

targetLength

addDelete

• addDelete(n): this

• Adds a delete operation to the operation.

  Parameters

  • n: number

    The number of characters to delete.

  Returns this

  The updated operation.

addInsert

• addInsert(str): this

• Adds an insert operation to the operation.

  Parameters

  • str: string

    The string to insert.

  Returns this

  The updated operation.

addRetain

• addRetain(n): this

• Adds a retain operation to the operation.

  Parameters

  • n: number

    The number of characters to retain.

  Returns this

  The updated operation.

apply

• apply(doc): string

• Applies the operation to a document.

  Parameters

  • doc: string

    The document to apply the operation to.

  Returns string

  The modified document.

  Throws

  If the operation's base length is not equal to the document's length.

  Throws

  If the operation's target length is not equal to the document's length.

invert

• invert(doc): Operation

• Returns the inverse of this that apply(apply(doc, this), inverse) === doc. Note that the argument doc should be original doc, not the result of apply(doc, this).

  Parameters

  • doc: string

    The original document.

  Returns Operation

  The inverse of this.

Staticcompose

• compose(a, b): Operation

• Returns a merged Operation equal to a + b. Formally, apply(apply(doc, a), b) = apply(doc, compose(a, b)).

  a and b should be sequential operations, not concurrent.

  Parameters

  • a: Operation

    The first Operation.
  • b: Operation

    The second Operation.

  Returns Operation

  The merged Operation.

StaticfromBasicOperations

• fromBasicOperations(ops): Operation

• Creates an Operation object from an array of BasicOperation objects.

  Parameters

  • ops: BasicOperation[]

    An array of BasicOperation objects.

  Returns Operation

  The created Operation object.

Statictransform

• transform(a, b): [Operation, Operation]

• Takes two operations a and b that happened concurrently and produces two operations a' and b' such that apply(apply(doc, a), b') = apply(apply(doc, b), a').

  a and b should be concurrent operations, not sequential.

  This function is commutative, i.e. transform(a, b) === transform(b, a).reverse().

  Parameters

  • a: Operation

    One of the operations.
  • b: Operation

    The other operation.

  Returns [Operation, Operation]

  The transformed operations [a', b'].