Copyright	© Herbert Valerio Riedel 2015-2018
License	GPL-2.0-or-later
Safe Haskell	Safe
Language	Haskell2010

Data.YAML.Event

Description

Event-stream oriented YAML parsing API

Synopsis

parseEvents :: ByteString -> EvStream
type EvStream = [Either (Pos, String) Event]
data Event
- = StreamStart
- | StreamEnd
- | DocumentStart !Bool
- | DocumentEnd !Bool
- | Alias !Anchor
- | Scalar !(Maybe Anchor) !Tag !Style !Text
- | SequenceStart !(Maybe Anchor) !Tag
- | SequenceEnd
- | MappingStart !(Maybe Anchor) !Tag
- | MappingEnd
data Style
- = Plain
- | SingleQuoted
- | DoubleQuoted
- | Literal
- | Folded
data Tag
untagged :: Tag
isUntagged :: Tag -> Bool
tagToText :: Tag -> Maybe Text
mkTag :: String -> Tag
type Anchor = Text
data Pos = Pos {
- posByteOffset :: !Int
- posCharOffset :: !Int
- posLine :: !Int
- posColumn :: !Int
}

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 #
Instance details Defined in Data.YAML.Event Methods (==) :: Event -> Event -> Bool # (/=) :: Event -> Event -> Bool #
Show Event #
Instance details 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 #
Instance details Defined in Data.YAML.Event Methods (==) :: Style -> Style -> Bool # (/=) :: Style -> Style -> Bool #
Ord Style #
Instance details 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 #
Instance details Defined in Data.YAML.Event Methods showsPrec :: Int -> Style -> ShowS # show :: Style -> String # showList :: [Style] -> ShowS #

data Tag #

YAML Tags

Instances

Eq Tag #
Instance details Defined in Data.YAML.Event Methods (==) :: Tag -> Tag -> Bool # (/=) :: Tag -> Tag -> Bool #
Ord Tag #
Instance details 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 #
Instance details 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 #
Instance details Defined in Data.YAML.Event Methods showsPrec :: Int -> Pos -> ShowS # show :: Pos -> String # showList :: [Pos] -> ShowS #