NONE
Represents the absence of a value in the Maybe type.
SOME
Wraps a value in the Maybe type.
SOME 5 == (0 5)
SOME b#hello == (0 b#hello)
SOME [] == (0 [])
maybeCase
Pattern matches on a Maybe value, providing cases for NONE and SOME.
maybeCase NONE 0 inc == 0
maybeCase (SOME 5) 0 inc == 6
maybeCase (SOME b#a) b#none id == b#a
maybe
Alias for maybeCase. Pattern matches on a Maybe value.
maybe 0 inc NONE == 0
maybe 0 inc (SOME 5) == 6
maybe b#none id (SOME b#a) == b#a
fromSome
Extracts the value from a SOME, or returns a default for NONE.
fromSome 0 (SOME 5) == 5
fromSome 0 NONE == 0
fromSome b#a (SOME b#b) == b#b
unpackSome
Extracts the value from a SOME, or crashes for NONE.
unpackSome (SOME 5) == 5
unpackSome (SOME b#a) == b#a
unpackSome NONE ; crashes with "Unexpected NONE"
isSome
Checks if a Maybe value is SOME.
isSome (SOME 5) == 1
isSome (SOME []) == 1
isSome NONE == 0
isNone
Checks if a Maybe value is NONE.
isNone NONE == 1
isNone (SOME 5) == 0
isNone (SOME []) == 0
fmapMaybe
Applies a function to the value inside a SOME, or returns NONE.
fmapMaybe (SOME 5) inc == (0 6)
fmapMaybe (SOME b#b) (barWeld b#a) == (0 b#ab)
fmapMaybe NONE inc == NONE
maybeGuard
Returns NONE if the condition is false, otherwise returns the Maybe value.
maybeGuard TRUE (SOME 5) == (0 5)
maybeGuard FALSE (SOME 5) == NONE
maybeGuard TRUE NONE == NONE
maybeGuardNot
Returns NONE if the condition is true, otherwise returns the Maybe value.
maybeGuardNot FALSE (SOME 5) == (0 5)
maybeGuardNot TRUE (SOME 5) == NONE
maybeGuardNot FALSE NONE == NONE
