B9.Content.AST

B9 produces not only VM-Images but also text documents such as configuration files required by virtual machines. This module is about creating and merging files containing parsable syntactic structures, such as most configuration files do.

Imagine you would want to create a cloud-init 'user-data' file from a set of 'user-data' snippets which each are valid 'user-data' files in yaml syntax and e.g. a write_files section. Now the goal is, for b9 to be able to merge these snippets into one, such that all writefiles sections are combined into a single writefile section. Another example is OTP/Erlang sys.config files. This type class is the greatest commonon denominator of types describing a syntax that can be parsed, concatenated e.g. like in the above example and rendered. The actual concatenation operation is the append from Monoid, i.e. like monoid but without the need for an empty element.

Documentation

class Semigroup a => ConcatableSyntax a where

Types of values that can be parsedrendered fromto ByteStrings. This class is used as basis for the ASTish class.

Minimal complete definition

decodeSyntax, encodeSyntax

Methods

decodeSyntax :: FilePath -> ByteString -> Either String a

encodeSyntax :: a -> ByteString

Instances

ConcatableSyntax ByteString

Methods

decodeSyntax :: FilePath -> ByteString -> Either String ByteString

encodeSyntax :: ByteString -> ByteString

ConcatableSyntax ErlangPropList

Methods

decodeSyntax :: FilePath -> ByteString -> Either String ErlangPropList

encodeSyntax :: ErlangPropList -> ByteString

ConcatableSyntax YamlObject

Methods

decodeSyntax :: FilePath -> ByteString -> Either String YamlObject

encodeSyntax :: YamlObject -> ByteString

class ConcatableSyntax a => ASTish a where

Types of values that describe content, that can be created from an AST.

Minimal complete definition

fromAST

Methods

fromAST :: CanRender c => AST c a -> ReaderT Environment B9 a

Instances

ASTish ErlangPropList

Methods

fromAST :: CanRender c => AST c ErlangPropList -> ReaderT * Environment B9 ErlangPropList

ASTish YamlObject

Methods

fromAST :: CanRender c => AST c YamlObject -> ReaderT * Environment B9 YamlObject

data AST c a

Describe how to create structured content that has a tree-like syntactic structure, e.g. yaml, JSON and erlang-proplists. The first parameter defines a context into which the AST is embeded, e.g. B9.Content.Generator.Content'. The second parameter defines a specifix syntax, e.g ErlangPropList that the AST value generates.

Constructors

ASTObj [(String, AST c a)]

Create an object similar to a Json object.

ASTArr [AST c a]

An array.

ASTMerge [AST c a]

Merge the nested elements, this is a very powerful tool that allows to combine

ASTEmbed c

ASTString String

ASTParse SourceFile

AST a

Instances

(Eq a, Eq c) => Eq (AST c a)

Methods

(==) :: AST c a -> AST c a -> Bool

(/=) :: AST c a -> AST c a -> Bool

(Data a, Data c) => Data (AST c a)

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> AST c a -> c (AST c a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (AST c a)

toConstr :: AST c a -> Constr

dataTypeOf :: AST c a -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c (AST c a))

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (AST c a))

gmapT :: (forall b. Data b => b -> b) -> AST c a -> AST c a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> AST c a -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> AST c a -> r

gmapQ :: (forall d. Data d => d -> u) -> AST c a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> AST c a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> AST c a -> m (AST c a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> AST c a -> m (AST c a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> AST c a -> m (AST c a)

(Read a, Read c) => Read (AST c a)

Methods

readsPrec :: Int -> ReadS (AST c a)

readList :: ReadS [AST c a]

readPrec :: ReadPrec (AST c a)

readListPrec :: ReadPrec [AST c a]

(Show a, Show c) => Show (AST c a)

Methods

showsPrec :: Int -> AST c a -> ShowS

show :: AST c a -> String

showList :: [AST c a] -> ShowS

Generic (AST c a)

Associated Types

type Rep (AST c a) :: * -> *

Methods

from :: AST c a -> Rep (AST c a) x

to :: Rep (AST c a) x -> AST c a

(Arbitrary c, Arbitrary a) => Arbitrary (AST c a)

Methods

arbitrary :: Gen (AST c a)

shrink :: AST c a -> [AST c a]

(Hashable c, Hashable a) => Hashable (AST c a)

Methods

hashWithSalt :: Int -> AST c a -> Int

hash :: AST c a -> Int

(Binary c, Binary a) => Binary (AST c a)

Methods

put :: AST c a -> Put

get :: Get (AST c a)

putList :: [AST c a] -> Put

(NFData c, NFData a) => NFData (AST c a)

Methods

rnf :: AST c a -> ()

type Rep (AST c a)

type Rep (AST c a) = D1 (MetaData "AST" "B9.Content.AST" "b9-0.5.32-IlQbw2aTGzAFvDb4eHOttA" False) ((:+:) ((:+:) (C1 (MetaCons "ASTObj" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [(String, AST c a)]))) ((:+:) (C1 (MetaCons "ASTArr" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [AST c a]))) (C1 (MetaCons "ASTMerge" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [AST c a]))))) ((:+:) ((:+:) (C1 (MetaCons "ASTEmbed" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 c))) (C1 (MetaCons "ASTString" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 String)))) ((:+:) (C1 (MetaCons "ASTParse" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 SourceFile))) (C1 (MetaCons "AST" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a))))))

class CanRender c where

Types of values that can be rendered into a ByteString

Minimal complete definition

render

Methods

render :: c -> ReaderT Environment B9 ByteString

Instances

CanRender Content

Methods

render :: Content -> ReaderT * Environment B9 ByteString