Text.Yaml.Reference

Implementation of the YAML syntax as defined in http://www.yaml.org. Actually this file contains the parsing framework and includes (using CPP) the actual productions from Reference.bnf.

The parsing framework is fully streaming (generates output tokens "immediately").

Documentation

data Code

Token codes.

Constructors

Bom

BOM, contains "TF8", "TF16LE", "TF32BE", etc.

Text

Content text characters.

Meta

Non-content (meta) text characters.

Break

Separation line break.

LineFeed

Line break normalized to content line feed.

LineFold

Line break folded to content space.

Indicator

Character indicating structure.

White

Separation white space.

Indent

Indentation spaces.

DirectivesEnd

Document start marker.

DocumentEnd

Document end marker.

BeginEscape

Begins escape sequence.

EndEscape

Ends escape sequence.

BeginComment

Begins comment.

EndComment

Ends comment.

BeginDirective

Begins directive.

EndDirective

Ends directive.

BeginTag

Begins tag.

EndTag

Ends tag.

BeginHandle

Begins tag handle.

EndHandle

Ends tag handle.

BeginAnchor

Begins anchor.

EndAnchor

Ends anchor.

BeginProperties

Begins node properties.

EndProperties

Ends node properties.

BeginAlias

Begins alias.

EndAlias

Ends alias.

BeginScalar

Begins scalar content.

EndScalar

Ends scalar content.

BeginSequence

Begins sequence content.

EndSequence

Ends sequence content.

BeginMapping

Begins mapping content.

EndMapping

Ends mapping content.

BeginPair

Begins mapping key:value pair.

EndPair

Ends mapping key:value pair.

BeginNode

Begins complete node.

EndNode

Ends complete node.

BeginDocument

Begins document.

EndDocument

Ends document.

BeginStream

Begins YAML stream.

EndStream

Ends YAML stream.

Error

Parsing error at this point.

Unparsed

Unparsed due to errors (or at end of test).

Detected

Detected parameter (for testing).

Instances

Eq Code

Methods

(==) :: Code -> Code -> Bool

(/=) :: Code -> Code -> Bool

Show Code

show code converts a Code to the one-character YEAST token code char. The list of byte codes is also documented in the yaml2yeast program.

Methods

showsPrec :: Int -> Code -> ShowS

show :: Code -> String

showList :: [Code] -> ShowS

data Token

Parsed token.

Instances

Show Token

show token converts a Token to two YEAST lines: a comment with the position numbers and the actual token line.

Methods

showsPrec :: Int -> Token -> ShowS

show :: Token -> String

showList :: [Token] -> ShowS

type Tokenizer = String -> ByteString -> Bool -> [Token]

Tokenizer converts a (named) input text into a list of Token. Errors are reported as tokens with the Error Code, and the unparsed text following an error may be attached as a final token (if the Bool is True). Note that tokens are available "immediately", allowing for streaming of large YAML files with memory requirements depending only on the YAML nesting level.

yaml :: Tokenizer

yaml name input converts the Unicode input (called name in error messages) to a list of Token according to the YAML spec. This is it!

data Context

Production context.

Instances

Read Context

read context converts a String to a Context. We trust our callers to convert any - characters into _ to allow the built-in lex function to handle the names as single identifiers.

Methods

readsPrec :: Int -> ReadS Context

readList :: ReadS [Context]

readPrec :: ReadPrec Context

readListPrec :: ReadPrec [Context]

Show Context

show context converts a Context to a String.

Methods

showsPrec :: Int -> Context -> ShowS

show :: Context -> String

showList :: [Context] -> ShowS

data Chomp

Chomp method.

Instances

Read Chomp

read chomp converts a String to a Chomp.

Methods

readsPrec :: Int -> ReadS Chomp

readList :: ReadS [Chomp]

readPrec :: ReadPrec Chomp

readListPrec :: ReadPrec [Chomp]

Show Chomp

show chomp converts a Chomp to a String.

Methods

showsPrec :: Int -> Chomp -> ShowS

show :: Chomp -> String

showList :: [Chomp] -> ShowS

tokenizer :: String -> Maybe Tokenizer

tokenizer name converts the production with the specified name to a simple Tokenizer, or Nothing if it isn't known.

tokenizerWithN :: String -> Int -> Maybe Tokenizer

tokenizerWithN name n converts the production (that requires an n argument) with the specified name to a simple Tokenizer, or Nothing if it isn't known.

tokenizerWithC :: String -> Context -> Maybe Tokenizer

tokenizerWithC name c converts the production (that requires a c argument) with the specified name to a simple Tokenizer, or Nothing if it isn't known.

tokenizerWithT :: String -> Chomp -> Maybe Tokenizer

tokenizerWithT name t converts the production (that requires an t argument) with the specified name to a simple Tokenizer, or Nothing if it isn't known.

tokenizerWithNC :: String -> Int -> Context -> Maybe Tokenizer

tokenizerWithNC name n c converts the production (that requires n and c arguments) with the specified name to a simple Tokenizer, or Nothing if it isn't known.

tokenizerWithNT :: String -> Int -> Chomp -> Maybe Tokenizer

tokenizerWithNT name n t converts the production (that requires n and t arguments) with the specified name to a simple Tokenizer, or Nothing if it isn't known.

tokenizerNames :: [String]

tokenizerNames returns the list of all productions (tokenizers).

showTokens :: [Token] -> String

showTokens tokens converts a list of tokens to a multi-line YEAST text.