:: [a]

Epsilon, the empty word (or list) (ε) = [] (U+3B5, GREEK SMALL LETTER EPSILON)

Look up the previous accumulation

runAccum w look = return (w, w)
runAccum w (look >>= continuation) = runAccum w (continuation w)

Fail the current branch, and prevent backtracking within the nearest enclosing call (if any). Contrast with empty, which fails the current branch but allows backtracking.

cutfail >>= k = cutfail

cutfail <|> m = cutfail

Abort the computation. empty annihilates >>=:

empty >>= k = empty

Retrieve the environment value.

runReader a (ask >>= k) = runReader a (k a)

Get the current state value.

runState a (get >>= k) = runState a (k a)

Lifted version of exitFailure.

>>> exitFailure
*** Exception: ExitFailure 1

Lifted version of exitSuccess.

>>> exitSuccess
*** Exception: ExitSuccess

Lifted version of "System.Exit.exitFailure". @since 0.1.9.0.

Lifted version of "System.Exit.exitSuccess". @since 0.1.9.0.

Lifted version of exitFailure.

Lifted version of exitSuccess.

Use this function when the daemon should terminate normally. It logs a message, and exits with status 0.

O(1) The empty vector.

O(1) Empty vector

Example for a linear equation: Setup a differential equation for y with

y   t = (exp (-t)) * (sin t)
y'  t = -(exp (-t)) * (sin t) + (exp (-t)) * (cos t)
y'' t = -2 * (exp (-t)) * (cos t)

Thus the differential equation

y'' = -2 * (y' + y)

holds. The following function generates a power series for exp (-t) * sin t by solving the differential equation.