Repeated

p.. or Repeated[p]

is a pattern object that represents a sequence of one or more expressions, each matching p.

Repeated[p,max]

represents from 1 to max expressions matching p.

Repeated[p,{min,max}]

represents between min and max expressions matching p.

Repeated[p,{n}]

represents exactly n expressions matching p.

Details

• p.. can appear as an argument of any function. It represents any sequence of arguments.
• All the objects in the sequence represented by p.. must match p, but the objects need not be identical.
• The expression p may, but need not, itself be a pattern object.

Examples

open allclose all

Basic Examples(2)

Replace any list of a's by x:

Replace any list of f's with one argument:

Scope(7)

a.. represents a sequence of a's inside any head:

Replace any list of a's with length up to 3:

Replace any list of a's with lengths between 2 and 3:

Replace lists of length exactly 3 elements:

Replace lists with lengths between 0 and 2 elements:

Replace lists with 0 to 3 identical elements:

Require only part of the pattern to be the same throughout the sequence:

Applications(1)

Define a function that takes as an argument any list of pairs:

Properties & Relations(4)

Repeated[p] or p.. is equivalent to Repeated[p,{1,Infinity}]:

Repeated[p,max] is equivalent to Repeated[p,{1,max}]:

Repeated[p] and Repeated[p,max] require at least one repeat:

RepeatedNull[p] and RepeatedNull[p,max] allow zero repeats:

The forms RepeatedNull[p,{min,max}] and Repeated[p,{min,max}] are equivalent:

So are the forms RepeatedNull[p,{n}] and Repeated[p,{n}]:

Possible Issues(2)

Use parentheses or spaces to indicate that 1.. is not 1. followed by a dot:

A repeated named pattern will only match a sequence of identical repeats:

A repeated unnamed pattern can match a sequence of nonidentical elements:

Wolfram Research (1988), Repeated, Wolfram Language function, https://reference.wolfram.com/language/ref/Repeated.html (updated 2007).

Text

Wolfram Research (1988), Repeated, Wolfram Language function, https://reference.wolfram.com/language/ref/Repeated.html (updated 2007).

CMS

Wolfram Language. 1988. "Repeated." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2007. https://reference.wolfram.com/language/ref/Repeated.html.

APA

Wolfram Language. (1988). Repeated. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Repeated.html

BibTeX

@misc{reference.wolfram_2022_repeated, author="Wolfram Research", title="{Repeated}", year="2007", howpublished="\url{https://reference.wolfram.com/language/ref/Repeated.html}", note=[Accessed: 29-May-2023 ]}

BibLaTeX

@online{reference.wolfram_2022_repeated, organization={Wolfram Research}, title={Repeated}, year={2007}, url={https://reference.wolfram.com/language/ref/Repeated.html}, note=[Accessed: 29-May-2023 ]}