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.\" Copyright (c) 2026 Bruce Hill
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.TH List.pairs 3 2026-08-20 "Tomo man-pages"
.SH NAME
List.pairs \- iterate over pairs of elements
.SH LIBRARY
Tomo Standard Library
.SH SYNOPSIS
.nf
.BI List.pairs\ :\ func(list:\ [T]\ ->\ func(a:&T,\ b:&T\ ->\ Bool))
.fi
.SH DESCRIPTION
Returns an iterator that yields each unordered pair of distinct elements exactly once (equivalent to iterating `a` at index `i` and `b` at every later index `j > i`). The iterator yields two values per iteration, so a loop over it binds two variables: `for a, b in list.pairs()`. Mutating the list after making the iterator does not affect what it yields.


.SH ARGUMENTS

.TS
allbox;
lb lb lbx
l l l.
Name	Type	Description
list	[T]	The list whose element pairs will be iterated. 
.TE
.SH RETURN
An iterator function that yields each pair of elements.

.SH EXAMPLES
.EX
assert ["$a$b" for a, b in [1, 2, 3].pairs()] == ["12", "13", "23"]
.EE
.SH SEE ALSO
.BR Tomo-List (3)