monad-flow.core — com.ichramm/monad-flow 0.0.1

MonadFlow: A library for idiomatic error handling using the Either monad. Functions should return a vector [val error], where val represents a successful result (the Right value), and error represents a failure (the Left value). If no error occurs, val contains the result, and error is nil. Functions not following this convention can be 'lifted' using the lift function.

Either clj protocol

The Either monad interface, representing success (Right) or error (Left).

success? clj

(success? _)

Returns true if this is a Right value, indicating success.

inspect-chain-> clj macro

(inspect-chain-> val body)

Inserts side-effecting operations into a try-chain-> flow for debugging or logging. The value :flow-value is replaced with the current computation value.

Example: (f/try-chain-> 10 (f/inspect-chain-> (println "initial value: " :flow-value)) inc (f/inspect-chain-> (println "intermediate value: " :flow-value)) inc (f/inspect-chain-> (println "not important")) inc (f/inspect-chain-> (println "final value: " :flow-value))) initial value: 10 intermediate value: 11 not important final value: 13 => Right{:value 13}

inspect-chain->> clj macro

(inspect-chain->> body val)

Inserts side-effecting operations into a try-chain->> flow for debugging or logging. The value :flow-value is replaced with the current computation value.

Example: (f/try-chain->> 10 (f/inspect-chain->> (println "initial value: " :flow-value)) inc (f/inspect-chain->> (println "intermediate value: " :flow-value)) inc (f/inspect-chain->> (println "not important")) inc (f/inspect-chain->> (println "final value: " :flow-value))) initial value: 10 intermediate value: 11 not important final value: 13 => .Right{:value 13}

lift clj

(lift f)

(lift f error-fn)

Wraps a function f with error handling, returning a monadic value (Right on success, Left on error). Optionally, customize the error transformation with error-fn.

lift-> clj macro

(lift-> body)

(lift-> val body)

Helper for more readable error handling inside try-chain->. Automatically wraps expressions in a try block and returns a monadic value.

Example: (try-chain-> {:a "a value"} (lift-> :a)) => Right{:value "a value"}

lift->> clj macro

(lift->> body)

(lift->> body val)

Helper for more readable error handling inside try-chain->>. Automatically wraps expressions in a try block and returns a monadic value.

Example: (try-chain->> {:a "a value"} (lift->> :a)) => Right{:value "a value"}

lift-value clj

(lift-value x)

Wraps the plain value x into a monadic (Right, Left) value. If x is nil or a [nil error] pair, it returns a Left with an error message.

try-chain-> clj macro

(try-chain-> expr & forms)

Attempts to thread the expression expr through forms, like ->, but handling errors monadically. Each function must return an Either value or a pair [val error] pair. If an error occurs (Left), it short-circuits the flow.

Example: (try-chain-> 1 (wrap inc)) => Right{:value 2}

(try-chain-> 1 (wrap inc) (wrap #(throw+ (str "error: " %)))) => Left{:error "error: 2"}

try-chain->> clj macro

(try-chain->> expr & forms)

Similar to try-chain->, but uses the ->> threading model. The result of each function is passed as the last argument to the next form. Returns either a Right (success) or Left (error).

Example: (try-chain->> 1 (wrap inc) (wrap #(throw+ (str "error: " %)))) => Left{:error "error: 2"}

wrap clj

(wrap f)

(wrap f error-fn)

Alias for lift