6.2.12. Tuple sections

TupleSections

Since:

6.12

Status:

Included in GHC2021

Allow the use of tuple section syntax

The TupleSections extension enables partially applied tuple constructors. For example, the following program

(, True)

is considered to be an alternative notation for the more unwieldy alternative

\x -> (x, True)

You can omit any combination of arguments to the tuple, as in the following

(, "I", , , "Love", , 1337)

which translates to

\a b c d -> (a, "I", b, c, "Love", d, 1337)

If you have unboxed tuples enabled, tuple sections will also be available for them, like so

(# , True #)

Because there is no unboxed unit tuple, the following expression

(# #)

continues to stand for the unboxed singleton tuple data constructor.