reduce ( ... seq identity quot: ( ... prev elt -- ... next ) -- ... result )

Factor documentation > Factor handbook > The language > Collections > Sequence operations > Sequence combinators

Factor documentation > Factor handbook > The language > Collections > Sequence operations > Sequence combinators

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Vocabulary

sequences

Inputs and outputs

Word description

Combines successive elements of the sequence using a binary operation, and outputs the final result. On the first iteration, the two inputs to the quotation are identity, and the first element of the sequence. On successive iterations, the first input is the result of the previous iteration, and the second input is the corresponding element of the sequence.

Examples

Definition

sequences

Inputs and outputs

seq | a sequence |

identity | an object |

quot | a quotation with stack effect ( ... prev elt -- ... next ) |

result | the final result |

Word description

Combines successive elements of the sequence using a binary operation, and outputs the final result. On the first iteration, the two inputs to the quotation are identity, and the first element of the sequence. On successive iterations, the first input is the result of the previous iteration, and the second input is the corresponding element of the sequence.

Examples

USING: math prettyprint sequences ;
{ 1 5 3 } 0 [ + ] reduce .

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Definition