data.sets

unique values in insertion order: union, intersection, difference

Example results generated on 2026-10-08. Ones using now, today or randomness will differ when you run them: press Run on any example to run it in your browser, after editing it if you like.

types

# set
set(1, 2, 3)

operators

# a | b  union
set(1, 2) | set(2, 3)
# → set(1, 2, 3)
# a & b  intersection
set(1, 2) & set(2, 3)
# → set(2)
# a - b  difference
set(1, 2) - set(2, 3)
# → set(1)
# a ^ b  symmetric difference
set(1, 2) ^ set(2, 3)
# → set(1, 3)
# x in s
2 in set(1, 2)
# → true

holds

# int, str, bool and nil only

pretty

# long: one item per line, indented, items pretty
# short: one line, items short
pretty(set(1500, "a"), "short")
# → "set(1.5K, \"a\")"

Functions

set

set(xs: list|str|set) / set(a?: any, ...): a set of a list’s items (or a string’s characters), or of the arguments

[3, 1, 3, 2].set
# → set(3, 1, 2)
set(1, 2)
"hello" to set
# → set("h", "e", "l", "o")

See also: unique, list

is_subset

is_subset(a: set, b: set): true if every item of a is in b

set(1, 2).is_subset(set(1, 2, 3))
# → true

See also: is_superset

is_superset

is_superset(a: set, b: set): true if a has every item of b

set(1, 2, 3).is_superset(set(1, 5))
# → false

See also: is_subset

is_disjoint

is_disjoint(a: set, b: set): true if a and b share nothing

set(1, 2).is_disjoint(set(3))
# → true

See also: is_subset

add

add(s: set, v: any): add v in place and return the set

set(1).add(2)
# → set(1, 2)

See also: remove, push

remove

remove(s: set, v: any): remove v in place (if there) and return the set

set(1, 2).remove(1)
# → set(2)

See also: add, del

More examples

sets

# distinct words
"the cat and the hat".split.set
# → set("the", "cat", "and", "hat")
# in both
set(1, 2, 3) & set(2, 3, 4)
# → set(2, 3)
# in either, not both
set(1, 2, 3) ^ set(2, 3, 4)
# → set(1, 4)
# order doesn't matter
set(1, 2) == set(2, 1)
# → true