Data.YAML.Event

Event-stream oriented YAML parsing API

Documentation

parseEvents :: ByteString -> EvStream

Parse YAML Events from a lazy ByteString.

The input ByteString is expected to have a YAML 1.2 stream using the UTF-8, UTF-16 (LE or BE), or UTF-32 (LE or BE) encodings (which will be auto-detected).

type EvStream = [Either (Pos, String) Event]

Event stream produced by parseEvents

A Left value denotes parsing errors. The event stream ends immediately once a Left value is returned.

data Event

YAML Event Types

The events correspond to the ones from LibYAML

The grammar below defines well-formed streams of Events:

stream   ::= StreamStart document* StreamEnd
document ::= DocumentStart node DocumentEnd
node     ::= Alias
           | Scalar
           | sequence
           | mapping
sequence ::= SequenceStart node* SequenceEnd
mapping  ::= MappingStart (node node)* MappingEnd

Constructors

StreamStart

StreamEnd

DocumentStart !Bool

DocumentEnd !Bool

Alias !Anchor

Scalar !(Maybe Anchor) !Tag !Style !Text

SequenceStart !(Maybe Anchor) !Tag

SequenceEnd

MappingStart !(Maybe Anchor) !Tag

MappingEnd

Instances

Eq Event

Defined in Data.YAML.Event

Methods

(==) :: Event -> Event -> Bool

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

Show Event

Defined in Data.YAML.Event

Methods

showsPrec :: Int -> Event -> ShowS

show :: Event -> String

showList :: [Event] -> ShowS

data Style

Scalar node style

Constructors

Plain

SingleQuoted

DoubleQuoted

Literal

Folded

Instances

Eq Style

Defined in Data.YAML.Event

Methods

(==) :: Style -> Style -> Bool

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

Ord Style

Defined in Data.YAML.Event

Methods

compare :: Style -> Style -> Ordering

(<) :: Style -> Style -> Bool

(<=) :: Style -> Style -> Bool

(>) :: Style -> Style -> Bool

(>=) :: Style -> Style -> Bool

max :: Style -> Style -> Style

min :: Style -> Style -> Style

Show Style

Defined in Data.YAML.Event

Methods

showsPrec :: Int -> Style -> ShowS

show :: Style -> String

showList :: [Style] -> ShowS

data Tag

YAML Tags

Instances

Eq Tag

Defined in Data.YAML.Event

Methods

(==) :: Tag -> Tag -> Bool

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

Ord Tag

Defined in Data.YAML.Event

Methods

compare :: Tag -> Tag -> Ordering

(<) :: Tag -> Tag -> Bool

(<=) :: Tag -> Tag -> Bool

(>) :: Tag -> Tag -> Bool

(>=) :: Tag -> Tag -> Bool

max :: Tag -> Tag -> Tag

min :: Tag -> Tag -> Tag

Show Tag

Defined in Data.YAML.Event

Methods

showsPrec :: Int -> Tag -> ShowS

show :: Tag -> String

showList :: [Tag] -> ShowS

untagged :: Tag

An "untagged" YAML tag

isUntagged :: Tag -> Bool

Equivalent to (== untagged)

tagToText :: Tag -> Maybe Text

Convert Tag to its string representation

Returns Nothing for untagged

mkTag :: String -> Tag

Construct YAML tag

type Anchor = Text

YAML Anchor identifiers

data Pos

Position in parsed YAML source

Constructors

Pos

Fields

• posByteOffset :: !Int

  0-based byte offset

• posCharOffset :: !Int

  0-based character (Unicode code-point) offset

• posLine :: !Int

  1-based line number

• posColumn :: !Int

  0-based character (Unicode code-point) column number

Instances

Show Pos

Defined in Data.YAML.Event

Methods

showsPrec :: Int -> Pos -> ShowS

show :: Pos -> String

showList :: [Pos] -> ShowS