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queryParser

Request-time query parser definitions or references to the project descriptor's query parsers.

The following query​Parser:​* component types are available for use in analysis request JSONs:

query​Parser:​enhanced

An enhanced query parser component definition.

query​Parser:​project

A reference to one of the query parsers declared in the project descriptor's query parsers block.

query​Parser:​reference

References a query​Parser:​* component defined in the request or in the project's default components.

In Lingo4G API v2, query parser definitions should be placed in the shared components section of the project descriptor. Query parsers in the queryParsers section of the project descriptor are for backward compatibility with API v1 and can be referenced using query​Parsers:​project.

query​Parser:​enhanced

This query parser implements an enhanced syntax of Lucene's (flexible) Standard​Query​Parser. The extensions include support for interval queries. 

{
  "type": "queryParser:enhanced",
  "defaultFields": [],
  "defaultOperator": "AND",
  "sanitizeNonSpaces": "(?U)[\\u200B-\\u200D]+",
  "sanitizeSpaces": "(?U)[\\u001c-\\u001f\\p{IsWhite_Space}\\u2028\\u2029]+",
  "validateFields": true
}

Refer to the query parsers documentation for the full syntax overview.

A typical definition of this component may like this, specifying the default fields for unqualified query terms and the default Boolean operator to apply between query clauses: 

"enhanced": {
  "type": "queryParser:enhanced",
  "defaultFields": [
    "title",
    "abstract"
  ],
  "defaultOperator": "OR"
}

default​Fields

Type
array of string
Default
[]
Required
no

An array of field names to search for query terms without an explicit field name qualifier. For example, the data title:​mining query contains one unqualified term: foo and one with an explicit field qualifier: title:​mining. If default​Fields was equal to ["title", "abstract"], Lingo4G would rewrite the query to (summary:​foo ​O​R description:​bar) title:​bar.

If you do not provide default​Fields or set it to an empty array, Lingo4G will raise errors for queries containing terms without explicit field qualifiers.

default​Operator

Type
string
Default
"AND"
Constraints
one of [OR, AND]
Required
no

The default Boolean operator Lingo4G applies to each clause of the query, unless you explicitly provide the operator to use.

For example, with the default​Operator equal to A​N​D, Lingo4G rewrites the data mining query to data ​A​N​D mining.

The default​Operator property supports the following values:

O​R

Disjunction operator.

A​N​D

Conjunction operator.

sanitize​Non​Spaces

Type
string
Default
"(?U)[\\u200B-\\u200D]+"
Required
no

Before parsing the query, Lingo4G removes all occurrences matching the regular expression pattern you provide in the sanitize​Non​Spaces property. The default pattern removes zero-width spaces. To disable the replacement, set sanitize​Non​Spaces to an empty string.

sanitize​Spaces

Type
string
Default
"(?U)[\\u001c-\\u001f\\p{IsWhite_Space}\\u2028\\u2029]+"
Required
no

Before parsing the query, Lingo4G replaces each occurrence of the regular expression pattern you provide in the sanitize​Spaces property with a single space character. The default pattern normalizes any sequence of Unicode white space characters into one plain space. To disable the replacement, set sanitize​Spaces to an empty string.

validate​Fields

Type
boolean
Default
true
Required
no

If true, Lingo4G raises an error if the query contains a field name qualifier referring to a field that does not exist in the index. Field name validation ensures that accidental typos in field names result in errors rather than empty search results.

query​Parser:​project

This query parser contains a reference to one of the query parsers declared in the project descriptor's query parsers block, used in API v1. 

{
  "type": "queryParser:project",
  "queryParserKey": ""
}

We strongly recommend putting query parser definitions in the shared components section of the project descriptor or directly in API v2 requests. Query parsers in the queryParsers section of the project descriptor are for backward compatibility with API v1 and can be referenced using query​Parsers:​project.

query​Parser​Key

Type
string
Default
<empty string>
Required
no

The key of the query parser to use from the queryParsers section of the project descriptor.

Consumers of query​Parser:​*

The following stages and components take query​Parser:​* as input:

Stage or component Property
query:​string
  • query​Parser
    • query​Builder:​string
  • query​Parser
    •