Graphics.Web.Processing.Core.Var

Module exporting Var and ArrayVar type and functions.

Variables

The variable system presented here is actually an artifact to make explicit which values may change over time and which don't. It also guides the user to create variables before use them and do so in a more natural way. Somehow, it tries to be similar to IORefs, while they aren't. Strictly speaking, they do not contain any value, but it will contain a value when processing.js executes the resulting code. To make sure you are doing the right thing, variables are typed, thus forcing you to feed the correct functions with the correct values.

data Var a

Type of variables.

data ArrayVar a

Type of variables storing arrays.

arraySize :: ArrayVar a -> Int

Size of the array.

Functions

varName :: Var a -> Text

Get the name of a variable.

arrayVarName :: ArrayVar a -> Text

Get the name of a variable storing an array.

newVar :: (ProcMonad m, ProcType a) => a -> m Preamble (Var a)

Create a new variable with a starting value.

readVar :: (ProcMonad m, ProcType a) => Var a -> m c a

Read a variable.

writeVar :: (ProcMonad m, ProcType a) => Var a -> a -> m c ()

Write a new value to a variable.

newArrayVar :: (ProcMonad m, ProcType a) => [a] -> m Preamble (ArrayVar a)

Create a new array variable with a starting list of values.

readArrayVar :: (ProcMonad m, Monad (m c), ProcType a) => ArrayVar a -> Proc_Int -> m c a

Read a component of an array variable.

writeArrayVar :: (ProcMonad m, ProcType a) => ArrayVar a -> Proc_Int -> a -> m c ()

Write a component of an array variable.