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GitHub
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Getting Started
Installation
Thinking in pipelines
Guides
Composition utilities
Maybe — absent values
Result — handling failures
Validation — collecting errors
Deferred — infallible async values
Task — lazy async
RemoteData — loading states
These — inclusive OR
Tuple — typed pairs
Lens — nested updates
Optional — nullable paths
Reader — deferred dependencies
Brand — distinguishing values
Refinement — type predicates
Predicate — boolean checks
Resource — safe acquire-release
State — threading state
Logged — values with logs
Arr — array utilities
Rec — record utilities
Num — number utilities
Str — string utilities
Dict — dictionary utilities
Uniq — unique collection utilities
Appendix
Why this exists
Design & influences
Performance & benchmarks
API Reference
Composition
Functions
and
compose
constant
constFalse
constNull
constTrue
constUndefined
constVoid
converge
curry
curry3
curry4
flip
flow
identity
juxt
memoize
memoizeWeak
not
on
once
or
pipe
tap
uncurry
uncurry3
uncurry4
Core
Namespaces
Deferred
functions
fromPromise
toPromise
Lens
functions
andThen
andThenOptional
get
make
modify
prop
set
toOptional
Logged
functions
ap
chain
make
map
run
tap
tell
Maybe
functions
ap
chain
filter
fold
fromNullable
fromResult
fromUndefined
getOrElse
isNone
isSome
map
match
none
recover
some
tap
toNullable
toResult
toUndefined
Optional
functions
index
andThen
andThenLens
fold
get
getOrElse
make
match
modify
prop
set
Predicate
functions
all
and
any
fromRefinement
not
or
using
Reader
functions
ap
ask
asks
chain
local
map
resolve
run
tap
Refinement
functions
and
compose
make
or
toFilter
toResult
RemoteData
functions
ap
chain
failure
fold
getOrElse
isFailure
isLoading
isNotAsked
isSuccess
loading
map
mapError
match
notAsked
recover
success
tap
toMaybe
toResult
Resource
functions
combine
fromTask
make
use
Result
functions
ap
chain
err
fold
getOrElse
isErr
isOk
map
mapError
match
ok
recover
recoverUnless
tap
toMaybe
tryCatch
State
functions
ap
chain
evaluate
execute
get
gets
map
modify
put
resolve
run
tap
Task
functions
abortable
all
ap
chain
delay
from
map
race
repeat
repeatUntil
resolve
sequential
tap
timeout
TaskMaybe
functions
ap
chain
filter
fold
fromMaybe
fromTask
getOrElse
map
match
none
some
tap
toTaskResult
tryCatch
TaskResult
functions
abortable
chain
err
fold
getOrElse
map
mapError
match
ok
pollUntil
recover
retry
tap
timeout
tryCatch
TaskValidation
functions
ap
fold
fromValidation
getOrElse
invalid
invalidAll
map
match
product
productAll
recover
tap
tryCatch
valid
These
functions
both
chainFirst
chainSecond
first
fold
getFirstOrElse
getSecondOrElse
hasFirst
hasSecond
isBoth
isFirst
isSecond
mapBoth
mapFirst
mapSecond
match
second
swap
tap
Tuple
functions
first
fold
make
mapBoth
mapFirst
mapSecond
second
swap
tap
toArray
Validation
functions
ap
fold
getOrElse
invalid
invalidAll
isInvalid
isValid
map
match
product
productAll
recover
recoverUnless
tap
valid
Type Aliases
Deferred
Err
Failure
Invalid
Lens
Loading
Logged
Maybe
None
NotAsked
Ok
Optional
Predicate
Reader
Refinement
RemoteData
Resource
Result
Some
State
Success
Task
TaskMaybe
TaskResult
TaskValidation
These
TheseBoth
TheseFirst
TheseSecond
Tuple
Valid
Validation
Types
Namespaces
Brand
functions
unwrap
wrap
Type Aliases
Brand
NonEmptyList
Functions
isNonEmptyList
Utils
Namespaces
Arr
functions
chunksOf
drop
dropWhile
every
filter
findFirst
findIndex
findLast
flatMap
flatten
groupBy
head
init
insertAt
intersperse
isNonEmpty
last
map
partition
reduce
removeAt
reverse
scan
sequence
sequenceResult
sequenceTask
sequenceTaskResult
size
some
sortBy
splitAt
tail
take
takeWhile
traverse
traverseResult
traverseTask
traverseTaskResult
uniq
uniqBy
zip
zipWith
Dict
functions
compact
difference
empty
entries
filter
filterWithKey
fromEntries
fromRecord
groupBy
has
insert
intersection
isEmpty
keys
lookup
map
mapWithKey
reduce
reduceWithKey
remove
singleton
size
toRecord
union
upsert
values
Num
functions
add
between
clamp
divide
multiply
parse
range
subtract
Rec
functions
compact
entries
filter
filterWithKey
fromEntries
groupBy
isEmpty
keys
lookup
map
mapKeys
mapWithKey
merge
omit
pick
size
values
Str
functions
endsWith
includes
lines
split
startsWith
toLowerCase
toUpperCase
trim
words
variables
parse
Uniq
functions
difference
empty
filter
fromArray
has
insert
intersection
isEmpty
isSubsetOf
map
reduce
remove
singleton
size
toArray
union
GitHub
npm
none
none
():
None
Defined in:
Core/Maybe.ts:41
Creates a None (empty Maybe).
Returns
Section titled “Returns”
None