Awesome
yaml-ast-parser
This is a fork of JS-YAML which supports parsing of YAML into AST.
In additional to parsing YAML to AST, it has following features:
- restoration after the errors and reporting errors as a part of AST nodes.
- built-in support for
!include
tag used in RAML
Usage
The type information below is relevant when using TypeScript, if using from JavaScript only the field/method information is relevant.
load
method can be used to load the tree and returns a YAMLNode
.
YAMLNode
YAMLNode
class is an ancestor for all node kinds.
It's kind
field determine node kind, one of Kind
enum:
SCALAR
,MAPPING
,MAP
,SEQ
,ANCHOR_REF
orINCLUDE_REF
.
After node kind is determined, it can be cast to one of the YAMLNode
descendants types:
YAMLScalar
,YAMLMapping
,YamlMap
,YAMLSequence
orYAMLAnchorReference
.
class | important members |
---|---|
YAMLNode | startPosition and endPosition provide node range. |
YAMLScalar | string value field |
YAMLMapping | YAMLScalar key and YAMLNode value fields |
YAMLSequence | YAMLNode[] items field |
YamlMap | YAMLMapping[] mappings field |
YAMLAnchorReference | string referencesAnchor and YAMLNode value |
YAMLScalar
Scalars are one of the three main node types defined by YAML and are effectively leaf nodes.
There are many factors that can influence the type of datum represent in scalar node (context, schema, tag, etc.).
To help inspection of a YAMLScalar
to determine its datatype when a document uses the Core Schema, you can pass the YAMLScalar
to the determineScalarType
function. It will return an enum value indicating null
, bool
, int
, float
, or string
.
Once you know the type, there are also some helper functions to help read the value by passing them the string, value
: parseYamlBoolean
, parseYamlFloat
, and parseYamlInteger
.