Filter expression with length function

Setup

Selector: $[?(@.length() == 4)]

[
  [1,2,3,4,5],
  [1,2,3,4],
  [1,2,3]
]

Results

Other responses

Bash (JSONPath.sh)

[]

C (json-glib)

Not supported

Unable to compile selector `$[?(@.length() == 4)]': Invalid array index definition “?(@.length() == 4)]”

Clojure (json-path) ¹

[]

Cpp (jsoncons)

Not supported

Incorrect number of arguments at line 1 and column 14

Dart (json_path)

Not supported

end of input expected at 1:2

Elixir (ExJsonPath)

Not supported

syntax error before: '('

Elixir (jaxon)

[]

Elixir (warpath) ¹

Not supported

Parser error: Invalid token on line 1, syntax error before: <<"(">>

Erlang (ejsonpath)

Not supported

syntax error before: '('

Golang (github.com-PaesslerAG-jsonpath) ¹

Not supported

parsing error: $[?(@.length() == 4)]	:1:14 - 1:15 unexpected ")" while scanning extensions

Golang (github.com-bhmj-jsonslice) ¹ ³

[
  [
    1,
    2,
    3,
    4
  ]
]

Golang (github.com-ohler55-ojg)

Not supported

Golang (github.com-oliveagle-jsonpath) ¹

[]

Golang (github.com-spyzhov-ajson)

[]

Golang (github.com-vmware-labs-yaml-jsonpath)

Not supported

invalid filter syntax at position 14, following ")"

Haskell (jsonpath)

Not supported

Invalid JSONPath: $[?(@.length() == 4)]
 Error: 1:13:
  |
1 | $[?(@.length() == 4)]
  |             ^
unexpected '('
expecting "!=", "&&", "<=", "==", ">=", "||", '!', ')', '.', '<', '>', '[', or white space

JavaScript (jsonpath)

[]

Java (com.github.jsurfer)

Not supported

org.antlr.v4.runtime.misc.ParseCancellationException

Java (com.jayway.jsonpath) ¹ ³

[
  [
    1,
    2,
    3,
    4
  ]
]

Kotlin (com.nfeld.jsonpathkt) ¹

Not supported

Unexpected char, char=?, index=2

Objective-C (SMJJSONPath) ¹ ³

[
  [
    1,
    2,
    3,
    4
  ]
]

PHP (galbar-jsonpath)

Not supported

Invalid JSONPath error: 'Error in JSONPath near '()''

PHP (remorhaz-jsonpath)

[
  [
    1,
    2,
    3,
    4
  ]
]

PHP (softcreatr-jsonpath)

[]

Python (jsonpath) ²

Not found

jsonpath returned false, this might indicate an error

Python (jsonpath-ng)

Not supported

JsonPathLexerError('Error on line 1, col 2: Unexpected character: ? ')

Python (jsonpath-rw)

Not supported

JsonPathLexerError('Error on line 1, col 2: Unexpected character: ? ')

Python (jsonpath2)

Not supported

line 1:16 extraneous input '=' expecting {'@', '$', 'true', 'false', 'null', '{', '[', STRING, NUMBER}
ValueError("line 1:16 extraneous input '=' expecting {'@', '$', 'true', 'false', 'null', '{', '[', STRING, NUMBER}")

Raku (JSON-Path)

Not supported

Evaluation of embedded Perl 6 code not allowed (construct with :allow-eval)

Ruby (jsonpath)

[
  [
    1,
    2,
    3,
    4,
    5
  ],
  [
    1,
    2,
    3,
    4
  ],
  [
    1,
    2,
    3
  ]
]

Rust (jsonpath)

Not supported

parsing error

Rust (jsonpath_lib)

Not supported

path error: 
$[?(@.length() == 4)]
^^^^^^^^^^^^^

Scala (jsonpath)

Not supported

JPError(end of input expected)

Swift (Sextant)

[
  [
    1,
    2,
    3,
    4
  ]
]

dotNET (Json.NET)

Not supported

Array index expected.

dotNET (JsonCons.JsonPath)

Not supported

Invalid arity calling function 'length', expected 1, found 0

dotNET (JsonPath.Net)

Not supported

Pattern '(@.length(...' not recognized.

dotNET (Manatee.Json)

[
  [
    1,
    2,
    3,
    4
  ]
]

JSON (Path_Reference_Implementation)

Not supported

 --> 1:3
  |
1 | $[?(@.length() == 4)]
  |   ^---
  |
  = expected unionChild, unionArrayIndex, or sliceStart

Proposal (A)

Not supported

x 1:13-1:13 ComparisonOperator
| $[?(@.length() == 4)]
|             ^
| x 1:13-1:13 ScalarOperator
| | $[?(@.length() == 4)]
| |             ^
| o 1:5-1:13 DocumentValue
| | $[?(@.length() == 4)]
| |     ^^^^^^^^
| o 1:5-1:13 UnaryFilterExpression
| | $[?(@.length() == 4)]
| |     ^^^^^^^^
| | x 1:13-1:13 ScalarOperator
| | | $[?(@.length() == 4)]
| | |             ^
| | o 1:5-1:13 DocumentValue
| | | $[?(@.length() == 4)]
| | |     ^^^^^^^^
| | o 1:5-1:13 FilterValue
| | | $[?(@.length() == 4)]
| | |     ^^^^^^^^
| | | 
|/ /  
| | 
|/  
o 1:5-1:13 HigherPrecedenceFilterExpression
| $[?(@.length() == 4)]
|     ^^^^^^^^
x 1:5-1:5 LogicalOr
| $[?(@.length() == 4)]
|     ^
| x 1:13-1:13 ComparisonOperator
| | $[?(@.length() == 4)]
| |             ^
| | x 1:13-1:13 ScalarOperator
| | | $[?(@.length() == 4)]
| | |             ^
| | o 1:5-1:13 DocumentValue
| | | $[?(@.length() == 4)]
| | |     ^^^^^^^^
| | o 1:5-1:13 UnaryFilterExpression
| | | $[?(@.length() == 4)]
| | |     ^^^^^^^^
| | | x 1:13-1:13 ScalarOperator
| | | | $[?(@.length() == 4)]
| | | |             ^
| | | o 1:5-1:13 DocumentValue
| | | | $[?(@.length() == 4)]
| | | |     ^^^^^^^^
| | | o 1:5-1:13 FilterValue
| | | | $[?(@.length() == 4)]
| | | |     ^^^^^^^^
| | | | 
| |/ /  
| | | 
| |/  
| o 1:5-1:13 HigherPrecedenceFilterExpression
| | $[?(@.length() == 4)]
| |     ^^^^^^^^
| x 1:5-1:5 LogicalAnd
| | $[?(@.length() == 4)]
| |     ^
| | x 1:13-1:13 ComparisonOperator
| | | $[?(@.length() == 4)]
| | |             ^
| | | x 1:13-1:13 ScalarOperator
| | | | $[?(@.length() == 4)]
| | | |             ^
| | | o 1:5-1:13 DocumentValue
| | | | $[?(@.length() == 4)]
| | | |     ^^^^^^^^
| | | o 1:5-1:13 UnaryFilterExpression
| | | | $[?(@.length() == 4)]
| | | |     ^^^^^^^^
| | | | x 1:13-1:13 ScalarOperator
| | | | | $[?(@.length() == 4)]
| | | | |             ^
| | | | o 1:5-1:13 DocumentValue
| | | | | $[?(@.length() == 4)]
| | | | |     ^^^^^^^^
| | | | o 1:5-1:13 FilterValue
| | | | | $[?(@.length() == 4)]
| | | | |     ^^^^^^^^
| | | | | 
| | |/ /  
| | | | 
| | |/  
| | o 1:5-1:13 HigherPrecedenceFilterExpression
| | | $[?(@.length() == 4)]
| | |     ^^^^^^^^
| | | 
|/ /  
| | 
|/  
o 1:5-1:13 FilterExpression
| $[?(@.length() == 4)]
|     ^^^^^^^^
x 1:3-1:3 BracketElement
| $[?(@.length() == 4)]
|   ^
x 1:3-1:3 BracketElements
| $[?(@.length() == 4)]
|   ^
x 1:2-1:2 BracketChildren
| $[?(@.length() == 4)]
|  ^
x 1:2-1:2 Operator
| $[?(@.length() == 4)]
|  ^
o 1:1-1:2 Start
  $[?(@.length() == 4)]
  ^

Errors

JavaScript (Goessner) ²

jsonPath: _v.length is not a function: _v.length() == 4

JavaScript (brunerd)

Invocation violation: length()

JavaScript (jsonpath-plus)

jsonPath: _$_v.length is not a function: @.length() == 4

PHP (Goessner) ²

ArgumentCountError

Perl (JSON-Path)

non-safe evaluation, died at main.pl line 11.

Rust (jsonpath_plus)

Error Parsing JSON Path:
$[?(@.length() == 4)]
panic occurred

dotNET (JsonPathLib)

Object has no method 'length'

Footnotes

• ¹ This implementation returns a single value where only one match is possible (instead of an array of a single value).
• ² This implementation returns a specific not found value if no match exists.
• ³ This implementation returns a specific not found value if a query that would regularly return a single match results in no match.