Pipe operator

Returns the field value for a field name

Sets a field of a record and returns the new record.

Like set but wraps the value with a Just.

Like set but doesn't set the value if it's Nothing.

Like modify, but only modifies the value if it's not Nothing.

Plus 1 on record field.

Minus 1 on a record field.

Example:

forEach users \user -> putStrLn (tshow user)

Example: Within HSX

renderUser :: User -> Html
renderUser user = [hsx|<div>User: {user.name}</div>|]

render = [hsx|{forEach users renderUser}|]

Like forEach but with an index, starting at 0

Example: With a Callback

forEachWithIndex users \(index, user) -> putStrLn (tshow index <> ": " <> tshow user)

Example: With a Function

printUser :: (Int, User) -> IO ()
printUser (index, user) = putStrLn (tshow index <> ": " <> tshow user)

forEachWithIndex users printUser

Example: Within HSX

renderUser :: (Int, User) -> Html
renderUser (index, user) = [hsx|<div>User {index}: {user.name}</div>|]

render = [hsx|{forEachWithIndex users renderUser}|]

Parses a text to an int. Returns Nothing on failure.

Example:

>>> textToInt "1337"
Just 1337

>>> textToInt "bad input"
Nothing

Returns True when day is Saturday or Sunday.

Example:

>>> isWeekend $ fromGregorian 2019 10 7
False

>>> isWeekend $ fromGregorian 2020 6 13
True

Returns True when today is Saturday or Sunday.

Example:

do
    todayIsWeekend <- isWeekend
    when todayIsWeekend (putStrLn "It's weekend!")

Debug-print a value during evaluation

Alias for traceShowId

Removes all html tags from a given html text

>>> stripTags "This is <b>Bold</b>"
"This is Bold"

Returns the value of a type level symbol as a text

>>> symbolToText @"hello"
"hello"

>>> symbolToText @(GetTableName User)
"users"

Returns the value of a type level symbol as a bytestring

>>> symbolToByteString @"hello"
"hello"

>>> symbolToByteString @(GetTableName User)
"users"

Used by nonEmpty and isEmptyValue to check for emptyness

Returns a list of all values of an enum type

Given a data structure like this:

data Color = Yellow | Red | Blue deriving (Enum)

You can call allEnumValues to get a list of all colors:

>>> allEnumValues @Color
[Yellow, Red, Blue]

This also works if the enum is defined in the Schema.sql:

CREATE TYPE brokerage_subscription_type AS ENUM ('basic_subscription', 'bronze_subscription', 'silver_subscription', 'gold_subscription');

>>> allEnumValues @BrokerageSubscriptionType
[BasicSubscription, BronzeSubscription, SilverSubscription]