Class HFilter

Parses haystack filters so they can be validated and converted into different types of queries.

This class serves as the main entry point for working with Haystack Filters in this module.

As well as static methods, this class also utilizes the builder pattern for the instance methods.

Hierarchy

HFilter

Index

Constructors

Properties

_isHFilter node

Methods

eval toFilter eval isHFilter parse toFilter

Constructors

constructor

new HFilter(filter): HFilter
Constructs a new haystack filter from the string.

This will parse the filter string to a node.
Parameters
- filter: string | Node
  
  The haystack filter or an already parsed AST node.
Returns HFilter

Throws
An error if the filter is invalid.
- Defined in src/filter/HFilter.ts:41

Properties

`Readonly` _isHFilter

_isHFilter: true = true

Used for a type guard check.

`Readonly` node

node: Node

The internal parsed node of the current haystack filter.

Methods

eval

eval(context): boolean
Evalulate a node against an object. The object contains properties used in the evaluation.
Parameters
- context: EvalContext
  
  The evaluation context.
Returns boolean
The result of the evaluation.
- Defined in src/filter/HFilter.ts:89

toFilter

toFilter(): string
Generate a Haystack Filter string from a node.

Returns string
The haystack filter.

Throws
An error is thrown if the haystack filter is invalid.
- Defined in src/filter/HFilter.ts:119

`Static` eval

eval(node, context): boolean
Evalulate a node against an object. The object contains properties used in the evaluation.
Parameters
- node: Node
  
  The AST node to evaluate.
- context: EvalContext
  
  The evaluation context.
Returns boolean
The result of the evaluation.
- Defined in src/filter/HFilter.ts:78

`Static` isHFilter

isHFilter(value): value is HFilter
Return true if the value is a haystack filter object.
Parameters
- value: unknown
  
  The value to test.
Returns value is HFilter
True if the value is a haystack filter.
- Defined in src/filter/HFilter.ts:53

`Static` parse

parse(filter): Node
Parse a Haystack Filter and returns it's base AST node.
Parameters
- filter: string
  
  The Haystack Filter to parse.
Returns Node
The base AST node for the haystack filter.

Throws
An error if the haystack filter isn't valid.
- Defined in src/filter/HFilter.ts:64

`Static` toFilter

toFilter(node): string
Generate a Haystack Filter string from a node.
Parameters
- node: Node
  
  The AST node to generate the Haystack Filter string from.
Returns string
The haystack filter.

Throws
An error is thrown if the haystack filter is invalid.
- Defined in src/filter/HFilter.ts:100

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