Data.YAML.Event

Event-stream oriented YAML parsing and serializing API

Tutorial

Data.YAML module provides us with API which allow us to interact with YAML data at the cost of some presentation details. In contrast, this module provide us with API which gives us access to a other significant details like ScalarStyles, NodeStyles, Comments, etc.

Parsing YAML Documents

Suppose you want to parse this YAML Document while preserving its format and comments

# Home runs
hr:  65
# Runs Batted In
rbi: 147

then you might want to use the function parseEvents.

The following is a reference implementation of a function using parseEvents. It takes a YAML document as input and prints the parsed YAML Events.

import Data.YAML.Event
import qualified Data.ByteString.Lazy as BS.L

printEvents :: BS.L.ByteString -> IO ()
printEvents input =
  forM_ (parseEvents input) $ ev -> case ev of
    Left _ -> error "Failed to parse"
    Right event -> print (eEvent event)

When we pass the above mentioned YAML document to the function printEvents it outputs the following:

StreamStart
DocumentStart NoDirEndMarker
MappingStart Nothing Nothing Block
Comment " Home runs"
Scalar Nothing Nothing Plain "hr"
Scalar Nothing Nothing Plain "65"
Comment " Runs Batted In"
Scalar Nothing Nothing Plain "rbi"
Scalar Nothing Nothing Plain "147"
MappingEnd
DocumentEnd False
StreamEnd

Notice that now we have all the necessary details in the form of Events.

We can now write simple functions to work with this data without losing any more details.

parseEvents :: ByteString -> EvStream

Parse YAML Events from a lazy ByteString.

The parsed Events allow us to round-trip at the event-level while preserving many features and presentation details like Comments,ScalarStyle,NodeStyle, Anchors, Directives marker along with YAML document version, Chomping Indicator,Indentation Indicator (IndentOfs) ,ordering, etc. It does not preserve non-content white spaces.

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).

Serializing Events to YAML Character Stream

Now, suppose we want to generate back the YAML document after playing with the Event-stream, then you might want to use writeEvents.

The following function takes a YAML document as a input and dumps it back to STDOUT after a round-trip.

import Data.YAML.Event
import qualified Data.YAML.Token as YT
import qualified Data.ByteString.Lazy as BS.L

yaml2yaml :: BS.L.ByteString -> IO ()
yaml2yaml input = case sequence $ parseEvents input of
    Left _ -> error "Parsing Failure!"
    Right events -> do
      BS.L.hPutStr stdout (writeEvents YT.UTF8 (map eEvent events))
      hFlush stdout

Let this be the sample document passed to the above function

# This is a Directives Marker
---
# All Comments are preserved
date    : 2019-07-12
bill-to : # Anchor represents a map node
   &id001
    address:
        lines: # This a Block Scalar with Keep chomping Indicator and IndentAuto Indentant indicator
                |+ # Extra Indentation (non-content white space) will not be preserved
                      Vijay
                      IIT Hyderabad


        # Trailing newlines are a preserved here as they are a part of the Scalar node
        country    : India
ship-to  : # This is an Alias
           *id001
# Key is a Scalar and Value is a Sequence
Other Details:
          total: $ 3000
          # Tags are also preserved
          Online Payment: !!bool True
          product:
              - Item1
              # This comment is inside a Sequence
              - Item2
...
# DocumentEnd True
# StreamEnd

This function outputs the following

# This is a Directives Marker
---
# All Comments are preserved
date: 2019-07-12
bill-to: # Anchor represents a map node
  &id001
  address:
    lines: # This a Block Scalar with Keep chomping Indicator and IndentAuto Indentant indicator
      # Extra Indentation (non-content white space) will not be preserved
      |+
      Vijay
      IIT Hyderabad


    # Trailing newlines are a preserved here as they are a part of the Scalar node
    country: India
ship-to: # This is an Alias
  *id001
# Key is a Scalar and Value is a Sequence
Other Details:
  total: $ 3000
  # Tags are also preserved
  Online Payment: !!bool True
  product:
  - Item1
  # This comment is inside a Sequence
  - Item2
...
# DocumentEnd True
# StreamEnd

writeEvents :: Encoding -> [Event] -> ByteString

Serialise Events using specified UTF encoding to a lazy ByteString

NOTE: This function is only well-defined for valid Event streams

Since: 0.2.0.0

writeEventsText :: [Event] -> Text

Serialise Events to lazy Text

NOTE: This function is only well-defined for valid Event streams

Since: 0.2.0.0

How to comment your yaml document for best results

Round-tripping at event-level will preserve all the comments and their relative position in the YAML-document but still, we lose some information like the exact indentation and the position at which the comments were present previously. This information sometimes can be quite important for human-perception of comments. Below are some guildlines, so that you can avoid ambiguities.

1) Always try to start your comment in a newline. This step will avoid most of the ambiguities.

2) Comments automaticly get indented according to the level in which they are present. For example,

Input YAML-document

# Level 0
- a
# Level 0
- - a
# Level 1
  - a
  - - a
# Level 2
    - a

After a round-trip looks like

# Level 0
- a
# Level 0
- - a
  # Level 1
  - a
  - - a
    # Level 2
    - a

3) Comments immediately after a Scalar node, start from a newline. So avoid commenting just after a scalar ends, as it may lead to some ambiguity. For example,

Input YAML-document

- scalar # After scalar
- random  : scalar # After scalar
  key: 1
# not after scalar
- random  : scalar
  key: 1
- random  : # not after scalar
            scalar
  # not after scalar
  key: 1

After a round-trip looks like

- scalar
# After scalar
- random: scalar
  # After scalar
  key: 1
  # not after scalar
- random: scalar
  key: 1
- random: # not after scalar
    scalar
  # not after scalar
  key: 1

4) Similarly in flow-style, avoid commenting immediately after a comma (,) seperator. Comments immediately after a comma (,) seperator will start from a new line

Input YAML-document

{
    # comment 0
    Name: Vijay # comment 1
    ,
    # comment 2
    age: 19, # comment 3
    # comment 4
    country: India # comment 5
}

After a round-trip looks like

{
  # comment 0
  Name: Vijay,
  # comment 1
  # comment 2
  age: 19,
  # comment 3
  # comment 4
  country: India,
  # comment 5
}

5) Avoid commenting in between syntatical elements. For example,

Input YAML-document

? # Complex key starts
  [
     a,
     b
  ]
 # Complex key ends
: # Complex Value starts
  ? # Complex key starts
    [
       a,
       b
    ]
    # Complex key ends
  : # Simple value
    a
  # Complex value ends

After a round-trip looks like

? # Complex key starts
  [
     a,
     b
 ]
: # Complex key ends
  # Complex Value starts

  ? # Complex key starts
    [
       a,
       b
   ]
  : # Complex key ends
    # Simple value
    a
  # Complex value ends

The above two YAML-documents, after parsing produce the same Event-stream.

So, these are some limitation of this Format-preserving YAML processor.

Event-stream Internals

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

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
           | Comment
           | sequence
           | mapping
sequence ::= SequenceStart node* SequenceEnd
mapping  ::= MappingStart (node node)* MappingEnd

Since: 0.2.0

Constructors

StreamStart

StreamEnd

DocumentStart !Directives

DocumentEnd !Bool

Comment !Text

Alias !Anchor

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

SequenceStart !(Maybe Anchor) !Tag !NodeStyle

SequenceEnd

MappingStart !(Maybe Anchor) !Tag !NodeStyle

MappingEnd

Instances

Eq Event

Defined in Data.YAML.Event.Internal

Methods

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

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

Show Event

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> Event -> ShowS

show :: Event -> String

showList :: [Event] -> ShowS

Generic Event

Defined in Data.YAML.Event.Internal

Associated Types

type Rep Event :: Type -> Type

Methods

from :: Event -> Rep Event x

to :: Rep Event x -> Event

NFData Event

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: Event -> ()

type Rep Event

Defined in Data.YAML.Event.Internal

type Rep Event = D1 ('MetaData "Event" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (((C1 ('MetaCons "StreamStart" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "StreamEnd" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "DocumentStart" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Directives)) :+: (C1 ('MetaCons "DocumentEnd" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Bool)) :+: C1 ('MetaCons "Comment" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Text))))) :+: ((C1 ('MetaCons "Alias" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Anchor)) :+: (C1 ('MetaCons "Scalar" 'PrefixI 'False) ((S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Maybe Anchor)) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Tag)) :*: (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ScalarStyle) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Text))) :+: C1 ('MetaCons "SequenceStart" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Maybe Anchor)) :*: (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Tag) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 NodeStyle))))) :+: (C1 ('MetaCons "SequenceEnd" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "MappingStart" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Maybe Anchor)) :*: (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Tag) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 NodeStyle))) :+: C1 ('MetaCons "MappingEnd" 'PrefixI 'False) (U1 :: Type -> Type)))))

data EvPos

Event with corresponding Pos in YAML stream

Since: 0.2.0

Constructors

EvPos

Fields

• eEvent :: !Event
• ePos :: !Pos

Instances

Eq EvPos

Defined in Data.YAML.Event.Internal

Methods

(==) :: EvPos -> EvPos -> Bool

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

Show EvPos

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> EvPos -> ShowS

show :: EvPos -> String

showList :: [EvPos] -> ShowS

Generic EvPos

Defined in Data.YAML.Event.Internal

Associated Types

type Rep EvPos :: Type -> Type

Methods

from :: EvPos -> Rep EvPos x

to :: Rep EvPos x -> EvPos

NFData EvPos

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: EvPos -> ()

type Rep EvPos

Defined in Data.YAML.Event.Internal

type Rep EvPos = D1 ('MetaData "EvPos" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (C1 ('MetaCons "EvPos" 'PrefixI 'True) (S1 ('MetaSel ('Just "eEvent") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Event) :*: S1 ('MetaSel ('Just "ePos") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Pos)))

data Directives

Encodes document %YAML directives and the directives end-marker

Since: 0.2.0

Constructors

NoDirEndMarker

no directives and also no --- marker

DirEndMarkerNoVersion

--- marker present, but no explicit %YAML directive present

DirEndMarkerVersion !Word

--- marker present, as well as a %YAML 1.mi version directive; the minor version mi is stored in the Word field.

Instances

Eq Directives

Defined in Data.YAML.Event.Internal

Methods

(==) :: Directives -> Directives -> Bool

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

Show Directives

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> Directives -> ShowS

show :: Directives -> String

showList :: [Directives] -> ShowS

Generic Directives

Defined in Data.YAML.Event.Internal

Associated Types

type Rep Directives :: Type -> Type

Methods

from :: Directives -> Rep Directives x

to :: Rep Directives x -> Directives

NFData Directives

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: Directives -> ()

type Rep Directives

Defined in Data.YAML.Event.Internal

type Rep Directives = D1 ('MetaData "Directives" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (C1 ('MetaCons "NoDirEndMarker" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "DirEndMarkerNoVersion" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DirEndMarkerVersion" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Word))))

data ScalarStyle

Scalar-specific node style

This can be considered a more granular superset of NodeStyle. See also scalarNodeStyle.

Since: 0.2.0

Constructors

Plain

SingleQuoted

DoubleQuoted

Literal !Chomp !IndentOfs

Folded !Chomp !IndentOfs

Instances

Eq ScalarStyle

Defined in Data.YAML.Event.Internal

Methods

(==) :: ScalarStyle -> ScalarStyle -> Bool

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

Ord ScalarStyle

Defined in Data.YAML.Event.Internal

Methods

compare :: ScalarStyle -> ScalarStyle -> Ordering

(<) :: ScalarStyle -> ScalarStyle -> Bool

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

(>) :: ScalarStyle -> ScalarStyle -> Bool

(>=) :: ScalarStyle -> ScalarStyle -> Bool

max :: ScalarStyle -> ScalarStyle -> ScalarStyle

min :: ScalarStyle -> ScalarStyle -> ScalarStyle

Show ScalarStyle

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> ScalarStyle -> ShowS

show :: ScalarStyle -> String

showList :: [ScalarStyle] -> ShowS

Generic ScalarStyle

Defined in Data.YAML.Event.Internal

Associated Types

type Rep ScalarStyle :: Type -> Type

Methods

from :: ScalarStyle -> Rep ScalarStyle x

to :: Rep ScalarStyle x -> ScalarStyle

NFData ScalarStyle

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: ScalarStyle -> ()

type Rep ScalarStyle

Defined in Data.YAML.Event.Internal

type Rep ScalarStyle = D1 ('MetaData "ScalarStyle" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) ((C1 ('MetaCons "Plain" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "SingleQuoted" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "DoubleQuoted" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "Literal" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Chomp) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 IndentOfs)) :+: C1 ('MetaCons "Folded" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Chomp) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 IndentOfs)))))

data NodeStyle

Node style

Since: 0.2.0

Constructors

Flow

Block

Instances

Eq NodeStyle

Defined in Data.YAML.Event.Internal

Methods

(==) :: NodeStyle -> NodeStyle -> Bool

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

Ord NodeStyle

Defined in Data.YAML.Event.Internal

Methods

compare :: NodeStyle -> NodeStyle -> Ordering

(<) :: NodeStyle -> NodeStyle -> Bool

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

(>) :: NodeStyle -> NodeStyle -> Bool

(>=) :: NodeStyle -> NodeStyle -> Bool

max :: NodeStyle -> NodeStyle -> NodeStyle

min :: NodeStyle -> NodeStyle -> NodeStyle

Show NodeStyle

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> NodeStyle -> ShowS

show :: NodeStyle -> String

showList :: [NodeStyle] -> ShowS

Generic NodeStyle

Defined in Data.YAML.Event.Internal

Associated Types

type Rep NodeStyle :: Type -> Type

Methods

from :: NodeStyle -> Rep NodeStyle x

to :: Rep NodeStyle x -> NodeStyle

NFData NodeStyle

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: NodeStyle -> ()

type Rep NodeStyle

Defined in Data.YAML.Event.Internal

type Rep NodeStyle = D1 ('MetaData "NodeStyle" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (C1 ('MetaCons "Flow" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Block" 'PrefixI 'False) (U1 :: Type -> Type))

data Chomp

Block Chomping Indicator

Since: 0.2.0

Constructors

Strip

Remove all trailing line breaks and shows the presence of - chomping indicator.

Clip

Keep first trailing line break; this also the default behavior used if no explicit chomping indicator is specified.

Keep

Keep all trailing line breaks and shows the presence of + chomping indicator.

Instances

Eq Chomp

Defined in Data.YAML.Event.Internal

Methods

(==) :: Chomp -> Chomp -> Bool

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

Ord Chomp

Defined in Data.YAML.Event.Internal

Methods

compare :: Chomp -> Chomp -> Ordering

(<) :: Chomp -> Chomp -> Bool

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

(>) :: Chomp -> Chomp -> Bool

(>=) :: Chomp -> Chomp -> Bool

max :: Chomp -> Chomp -> Chomp

min :: Chomp -> Chomp -> Chomp

Show Chomp

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> Chomp -> ShowS

show :: Chomp -> String

showList :: [Chomp] -> ShowS

Generic Chomp

Defined in Data.YAML.Event.Internal

Associated Types

type Rep Chomp :: Type -> Type

Methods

from :: Chomp -> Rep Chomp x

to :: Rep Chomp x -> Chomp

NFData Chomp

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: Chomp -> ()

type Rep Chomp

Defined in Data.YAML.Event.Internal

type Rep Chomp = D1 ('MetaData "Chomp" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (C1 ('MetaCons "Strip" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "Clip" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Keep" 'PrefixI 'False) (U1 :: Type -> Type)))

data IndentOfs

Block Indentation Indicator

IndentAuto is the special case for auto Block Indentation Indicator

Since: 0.2.0

Constructors

IndentAuto

IndentOfs1

IndentOfs2

IndentOfs3

IndentOfs4

IndentOfs5

IndentOfs6

IndentOfs7

IndentOfs8

IndentOfs9

Instances

Enum IndentOfs

Defined in Data.YAML.Event.Internal

Methods

succ :: IndentOfs -> IndentOfs

pred :: IndentOfs -> IndentOfs

toEnum :: Int -> IndentOfs

fromEnum :: IndentOfs -> Int

enumFrom :: IndentOfs -> [IndentOfs]

enumFromThen :: IndentOfs -> IndentOfs -> [IndentOfs]

enumFromTo :: IndentOfs -> IndentOfs -> [IndentOfs]

enumFromThenTo :: IndentOfs -> IndentOfs -> IndentOfs -> [IndentOfs]

Eq IndentOfs

Defined in Data.YAML.Event.Internal

Methods

(==) :: IndentOfs -> IndentOfs -> Bool

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

Ord IndentOfs

Defined in Data.YAML.Event.Internal

Methods

compare :: IndentOfs -> IndentOfs -> Ordering

(<) :: IndentOfs -> IndentOfs -> Bool

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

(>) :: IndentOfs -> IndentOfs -> Bool

(>=) :: IndentOfs -> IndentOfs -> Bool

max :: IndentOfs -> IndentOfs -> IndentOfs

min :: IndentOfs -> IndentOfs -> IndentOfs

Show IndentOfs

Defined in Data.YAML.Event.Internal

Methods

showsPrec :: Int -> IndentOfs -> ShowS

show :: IndentOfs -> String

showList :: [IndentOfs] -> ShowS

Generic IndentOfs

Defined in Data.YAML.Event.Internal

Associated Types

type Rep IndentOfs :: Type -> Type

Methods

from :: IndentOfs -> Rep IndentOfs x

to :: Rep IndentOfs x -> IndentOfs

NFData IndentOfs

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: IndentOfs -> ()

type Rep IndentOfs

Defined in Data.YAML.Event.Internal

type Rep IndentOfs = D1 ('MetaData "IndentOfs" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (((C1 ('MetaCons "IndentAuto" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "IndentOfs1" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "IndentOfs2" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "IndentOfs3" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "IndentOfs4" 'PrefixI 'False) (U1 :: Type -> Type)))) :+: ((C1 ('MetaCons "IndentOfs5" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "IndentOfs6" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "IndentOfs7" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "IndentOfs8" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "IndentOfs9" 'PrefixI 'False) (U1 :: Type -> Type)))))

data Tag

YAML Tags

Instances

Eq Tag

Defined in Data.YAML.Event.Internal

Methods

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

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

Ord Tag

Defined in Data.YAML.Event.Internal

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.Internal

Methods

showsPrec :: Int -> Tag -> ShowS

show :: Tag -> String

showList :: [Tag] -> ShowS

Generic Tag

Defined in Data.YAML.Event.Internal

Associated Types

type Rep Tag :: Type -> Type

Methods

from :: Tag -> Rep Tag x

to :: Rep Tag x -> Tag

NFData Tag

Since: 0.2.0

Defined in Data.YAML.Event.Internal

Methods

rnf :: Tag -> ()

type Rep Tag

Defined in Data.YAML.Event.Internal

type Rep Tag = D1 ('MetaData "Tag" "Data.YAML.Event.Internal" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'True) (C1 ('MetaCons "Tag" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Maybe Text))))

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

See also prettyPosWithSource.

NOTE: if posCharOffset is negative the Pos value doesn't refer to a proper location; this may be emitted in corner cases when no proper location can be inferred.

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

Eq Pos

Defined in Data.YAML.Pos

Methods

(==) :: Pos -> Pos -> Bool

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

Show Pos

Defined in Data.YAML.Pos

Methods

showsPrec :: Int -> Pos -> ShowS

show :: Pos -> String

showList :: [Pos] -> ShowS

Generic Pos

Defined in Data.YAML.Pos

Associated Types

type Rep Pos :: Type -> Type

Methods

from :: Pos -> Rep Pos x

to :: Rep Pos x -> Pos

NFData Pos

Since: 0.2.0

Defined in Data.YAML.Pos

Methods

rnf :: Pos -> ()

type Rep Pos

Defined in Data.YAML.Pos

type Rep Pos = D1 ('MetaData "Pos" "Data.YAML.Pos" "HsYAML-0.2.1.1-DyP0T3Y4esA6hxhTdWEB4a" 'False) (C1 ('MetaCons "Pos" 'PrefixI 'True) ((S1 ('MetaSel ('Just "posByteOffset") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Int) :*: S1 ('MetaSel ('Just "posCharOffset") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Int)) :*: (S1 ('MetaSel ('Just "posLine") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Int) :*: S1 ('MetaSel ('Just "posColumn") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Int))))