CalamityCommands

CalamityCommands commands This module exports the DSL and core types for using commands

Documentation

module CalamityCommands.Context

module CalamityCommands.Dsl

module CalamityCommands.Error

module CalamityCommands.Handler

module CalamityCommands.Utils

module CalamityCommands.ParsePrefix

module CalamityCommands.Help

Parameter parsers

data KleenePlusConcat (a :: Type)

A parser that consumes one or more of a then concatenates them together.

KleenePlusConcat Text therefore consumes all remaining input.

Instances

(Semigroup (ParserResult a), ParameterParser a c r) => ParameterParser (KleenePlusConcat a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleenePlusConcat a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleenePlusConcat a))

ParameterParser (KleenePlusConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleenePlusConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text0

parse :: Sem (ParserEffs c r) (ParserResult (KleenePlusConcat Text))

ParameterParser (KleenePlusConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleenePlusConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleenePlusConcat Text))

type ParserResult (KleenePlusConcat a)

Defined in CalamityCommands.Parser

type ParserResult (KleenePlusConcat a) = ParserResult a

type ParserResult (KleenePlusConcat Text)

Defined in CalamityCommands.Parser

type ParserResult (KleenePlusConcat Text) = ParserResult Text

type ParserResult (KleenePlusConcat Text)

Defined in CalamityCommands.Parser

type ParserResult (KleenePlusConcat Text) = ParserResult Text

data KleeneStarConcat (a :: Type)

A parser that consumes zero or more of a then concatenates them together.

KleeneStarConcat Text therefore consumes all remaining input.

Instances

(Monoid (ParserResult a), ParameterParser a c r) => ParameterParser (KleeneStarConcat a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleeneStarConcat a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleeneStarConcat a))

ParameterParser (KleeneStarConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleeneStarConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text0

parse :: Sem (ParserEffs c r) (ParserResult (KleeneStarConcat Text))

ParameterParser (KleeneStarConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleeneStarConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleeneStarConcat Text))

type ParserResult (KleeneStarConcat a)

Defined in CalamityCommands.Parser

type ParserResult (KleeneStarConcat a) = ParserResult a

type ParserResult (KleeneStarConcat Text)

Defined in CalamityCommands.Parser

type ParserResult (KleeneStarConcat Text) = ParserResult Text

type ParserResult (KleeneStarConcat Text)

Defined in CalamityCommands.Parser

type ParserResult (KleeneStarConcat Text) = ParserResult Text

data Named (s :: Symbol) (a :: Type)

A named parameter, used to attach the name s to a type in the command's help output

Instances

(KnownSymbol s, ParameterParser a c r) => ParameterParser (Named s a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (Named s a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (Named s a))

type ParserResult (Named s a)

Defined in CalamityCommands.Parser

type ParserResult (Named s a) = ParserResult a

class Typeable a => ParameterParser (a :: Type) c r where

A typeclass for things that can be parsed as parameters to commands.

Any type that is an instance of ParamerParser can be used in the type level parameter ps of command, buildCommand, etc.

Minimal complete definition

parameterDescription, parse

Associated Types

type ParserResult a

type ParserResult a = a

Methods

parameterInfo :: ParameterInfo

default parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult a)

Instances

ParameterParser Float c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Float

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult Float)

ParameterParser Int c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Int

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult Int)

ParameterParser Integer c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Integer

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult Integer)

ParameterParser Natural c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Natural

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult Natural)

ParameterParser Word c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Word

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult Word)

ParameterParser () c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult ()

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult ())

ParameterParser Text c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Text

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text0

parse :: Sem (ParserEffs c r) (ParserResult Text)

ParameterParser Text c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult Text

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult Text)

ParameterParser a c r => ParameterParser [a] c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult [a]

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult [a])

ParameterParser a c r => ParameterParser (Maybe a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (Maybe a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (Maybe a))

(ParameterParser a c r, Typeable a) => ParameterParser (NonEmpty a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (NonEmpty a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (NonEmpty a))

(Semigroup (ParserResult a), ParameterParser a c r) => ParameterParser (KleenePlusConcat a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleenePlusConcat a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleenePlusConcat a))

ParameterParser (KleenePlusConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleenePlusConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text0

parse :: Sem (ParserEffs c r) (ParserResult (KleenePlusConcat Text))

ParameterParser (KleenePlusConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleenePlusConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleenePlusConcat Text))

(Monoid (ParserResult a), ParameterParser a c r) => ParameterParser (KleeneStarConcat a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleeneStarConcat a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleeneStarConcat a))

ParameterParser (KleeneStarConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleeneStarConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text0

parse :: Sem (ParserEffs c r) (ParserResult (KleeneStarConcat Text))

ParameterParser (KleeneStarConcat Text) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (KleeneStarConcat Text)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (KleeneStarConcat Text))

(ParameterParser a c r, ParameterParser b c r) => ParameterParser (Either a b) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (Either a b)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (Either a b))

(ParameterParser a c r, ParameterParser b c r) => ParameterParser (a, b) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (a, b)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (a, b))

(KnownSymbol s, ParameterParser a c r) => ParameterParser (Named s a) c r

Defined in CalamityCommands.Parser

Associated Types

type ParserResult (Named s a)

Methods

parameterInfo :: ParameterInfo

parameterDescription :: Text

parse :: Sem (ParserEffs c r) (ParserResult (Named s a))

Commands

This module provides abstractions for writing declarative commands, that support grouping, pre-invokation checks, and automatic argument parsing by using a type level list of parameter types.

A DSL is provided in CalamityCommands.Dsl for constructing commands declaratively.

You can implement ParameterParser for your own types to allow them to be used in the parameter list of commands.

A default help command is provided in CalamityCommands.Help which can be added just by using helpCommand inside the command declaration DSL.

Commands are parameterised over three types:

• m, the base monad of the command processor. This is used because all commands and checks run in their base monad in the current implementation, as a result, all commands will run with the monadic state remaining the same as when they were created. In the future this design decision may be revised to remove this constraint. For pure commands this may be Identity and for IO commands this may be IO.
• c, the context that is provided to each command invokation. The default context: BasicContext stores the prefix, command, and unparsed parameters to the command. The context in use is decided by the interpreter for ConstructContext.
• a, the result of a command invokation, for commands performing IO actions this is usually just ().

Examples

Make a command handler, we don't actually use the context and therefore this handler is generic over the context used:

h' :: CommandContext Identity c (Either Text Int) => CommandHandler Identity c (Either Text Int)
h' = runIdentity . runFinal $ do
  (h, _) <- buildCommands $ do
    command @'[Int, Int] "add" $ ctx a b -> pure $ Right (a + b)
    command @'[Int, Int] "mul" $ ctx a b -> pure $ Right (a * b)
    helpCommand (pure . Left)
  pure h

To use the commands we need to provide the interpreters for ConstructContext and ParsePrefix, the default provided ones are being used here: useBasicContext which makes ctx ~ BasicContext, and useConstantPrefix "!" which treats any input starting with ! as a command.

The processCommands function can then be used to parse and invoke commands, since commands are generic over the monad they run in we use runIdentity . runFinal . embedToFinal to have the commands interpreted purely.

This function r takes an input string such as "!add 1 2", and then looks up the invoked command and runs it, returning the result.

r :: Text -> Maybe (Either
                    (CmdInvokeFailReason (BasicContext Identity (Either Text Int)))
                    (BasicContext Identity (Either Text Int), Either Text Int))
r = runIdentity . runFinal . embedToFinal . useBasicContext . useConstantPrefix "!" . processCommands h'

Then to display the result of processing the command nicely, we can use a something like this function, which prints the result of a command if one was invoked successfully, and prints the error nicely if not.

rm :: Text -> IO ()
rm s = case r s of
            Just (Right (_, Right r)) ->
            print r

            Just (Right (_, Left h)) ->
            putStrLn h

            Just (Left (CommandInvokeError _ (ParseError t r))) ->
            putStrLn ("Parsing parameter " <> t <> " failed with reason: " <> r)

             _ -> pure ()

>>> rm "!add 1 1"
2

>>> rm "!add blah 1"
 Parsing parameter :Int failed with reason: 1:2:
   |
 1 |  blah 1
   |  ^
 unexpected 'b'
 expecting '+', '-', integer, or white space

>>> rm "!help"
```
The following commands exist:
- mul :Int, :Int
- help :[Text]
- add :Int, :Int
```

>>> rm "!help add"
Help for command `add`:
```
Usage: !add :Int, :Int
This command or group has no help.
```