Parsley.Internal.Backend.Machine.Types.Coins

This module exposes Coins and the relevant operations. These are used by constant input analysis to side-step unnecessary length checks and character reads (in the case of lookahead).

Since: 1.5.0.0

Documentation

data Coins

Packages together the known input that can be consumed after a length-check with the number of characters that can be rewound on a lookahead backtrack.

Since: 1.5.0.0

Constructors

Coins

Fields

• willConsume :: !Int

  The number of tokens we know must be consumed along the path to succeed.

• willCache :: !Int
• knownPreds :: !(Maybe CharPred)

Instances

Show Coins

Defined in Parsley.Internal.Backend.Machine.Types.Coins

Methods

showsPrec :: Int -> Coins -> ShowS

show :: Coins -> String

showList :: [Coins] -> ShowS

minCoins :: Coins -> Coins -> Coins

Takes the pairwise min of two Coins values.

Since: 1.5.0.0

plus1 :: CharPred -> Coins -> Coins

Adds 1 to all the Coins values.

Since: 1.5.0.0

minus :: Coins -> Int -> Coins

Since: 1.5.0.0

canReclaim :: Coins -> Int

pattern Zero :: Coins

Makes a Coins value of 0.

Since: 1.5.0.0

one :: CharPred -> Coins

items :: Int -> Coins