Dot notation with key root literal

Setup

Selector: $.$

{
  "$": "value"
}

Results

Other responses

Bash (JSONPath.sh) 

[]

C (json-glib) 

[
  "value"
]

Clojure (json-path) ¹ 

{
  "$": "value"
}

Cpp (jsoncons) 

[]

Dart (json_path)

Not supported

Instance of 'ParserException': 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: $.$	:1:3 - 1:4 unexpected "$" while scanning JSON select expected Ident, "." or "*"

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

"value"

Golang (github.com-ohler55-ojg)

Not supported

Golang (github.com-spyzhov-ajson) 

[
  {
    "$": "value"
  }
]

Golang (github.com-theory-jsonpath)

Not supported

jsonpath: unexpected '$' at position 3

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

[
  "value"
]

Haskell (jsonpath)

Not supported

Invalid JSONPath: $.$
 Error: 1:3:
  |
1 | $.$
  |   ^
unexpected '$'
expecting '.' or white space

JavaScript (Goessner) ² 

[
  "value"
]

JavaScript (brunerd) 

[
  "value"
]

JavaScript (jsonpath)

Not supported

Parse error on line 1:
$.$
--^
Expecting 'STAR', 'IDENTIFIER', 'SCRIPT_EXPRESSION', 'INTEGER', 'END', got 'DOLLAR'

JavaScript (jsonpath-plus) 

[
  {
    "$": "value"
  }
]

JavaScript (jsonpathly)

Not supported

mismatched input '$' expecting {'*', 'true', 'false', 'null', KEY, SPECIAL_KEY, NUMBER}

Java (com.github.jsurfer)

Not supported

line 1:2 no viable alternative at input '.$'
org.antlr.v4.runtime.misc.ParseCancellationException

Java (com.github.xmljacquard.ajp)

Not supported

Error at char 18 in expression in xsl:sequence/@select on line 20 column 67 of ajp-runner.xslt:
   <failed xmlns:ixml="http://invisiblexml.org/NS"
  ixml:state="failed"><line>1</line><column>2</column><pos>3</pos><unexpected>$</unexpected><permitted>'*', '_', [#80-'퟿[xd7ff]'], ['A'-'Z'; 'a'-'z'], ['𐀀[x10000]'-'􏿯[x10ffef]'], ['[xe000]'-'￯[xffef]']</permitted><could-be-next><in rule="ALPHA"><tokens>['A'-'Z'; 'a'-'z']</tokens></in><in rule="wildcard-selector"><tokens>'*'</tokens></in><in rule="name-first"><tokens>'_', [#80-'퟿[xd7ff]'], ['𐀀[x10000]'-'􏿯[x10ffef]'], ['[xe000]'-'￯[xffef]']</tokens></in></could-be-next><unfinished><open rule="child-segment" start="2" end="2"><input>.</input></open><open rule="jsonpath-query" start="1" end="1"><input>$</input></open></unfinished></failed>
During lazy evaluation of tailCallLoop(ajp:getProcessor(...)) on line 20 of jar:file:./implementations/Java_com.github.xmljacquard.ajp/build/deps/org/xmljacquard/ajp/0.0.7/ajp-0.0.7.jar!/xslt/ajp-runner.xslt
In function ajpr:getProcessor on line 17 column 106 of ajp-runner.xslt:
net.sf.saxon.s9api.SaxonApiException: <failed xmlns:ixml="http://invisiblexml.org/NS" ixml:state="failed"><line>1</line><column>2</column><pos>3</pos><unexpected>$</unexpected><permitted>'*', '_', [#80-'퟿'], ['A'-'Z'; 'a'-'z'], ['𐀀'-'􏿯'], [''-'￯']</permitted><could-be-next><in rule="ALPHA"><tokens>['A'-'Z'; 'a'-'z']</tokens></in><in rule="wildcard-selector"><tokens>'*'</tokens></in><in rule="name-first"><tokens>'_', [#80-'퟿'], ['𐀀'-'􏿯'], [''-'￯']</tokens></in></could-be-next><unfinished><open rule="child-segment" start="2" end="2"><input>.</input></open><open rule="jsonpath-query" start="1" end="1"><input>$</input></open></unfinished></failed>

Java (com.jayway.jsonpath) ¹ ³ 

"value"

Kotlin (com.nfeld.jsonpathkt) ¹ 

"value"

Objective-C (SMJJSONPath) ¹ ³ 

"value"

PHP (Goessner) ² 

[
  "value"
]

PHP (galbar-jsonpath) 

[
  "value"
]

PHP (remorhaz-jsonpath)

Not supported

Error: 'Failed to build AST from JSONPath query: $.$'

PHP (softcreatr-jsonpath)

Not supported

Error: 'Unable to parse token $ in expression: .$'

Python (jsonpath) ² 

[
  "value"
]

Python (jsonpath-ng) 

[
  {
    "$": "value"
  }
]

Python (jsonpath-rw) 

[
  {
    "$": "value"
  }
]

Python (jsonpath2)

Not supported

line 1:2 mismatched input '$' expecting {'*', ID}
ValueError("line 1:2 mismatched input '$' expecting {'*', ID}")

Python (python-jsonpath)

Not supported

JSONPathSyntaxError('expected a shorthand selector')

Raku (JSON-Path)

Not supported

JSON path parse error at position 1

Ruby (jsonpath) 

[
  {
    "$": "value"
  }
]

Rust (jsonpath)

Not supported

parsing error

Rust (jsonpath_lib)

Not supported

path error: 
$.$
^^

Rust (serde_json_path)

Not supported

at position 2, in dot member name, must start with lowercase alpha or '_'

Scala (jsonpath) 

[
  "value"
]

Swift (Sextant) 

[
  "value"
]

dotNET (Json.NET) 

[
  "value"
]

dotNET (JsonCons.JsonPath)

Not supported

Expected unquoted string, or single or double quoted string, or index or '*'

dotNET (JsonPath.Net)

Not supported

Could not find any valid selectors.

dotNET (JsonPathLib) 

[
  "value"
]

dotNET (Manatee.Json)

Not supported

Unrecognized JSON Path element. Path up to error: '$'

Errors

Golang (github.com-oliveagle-jsonpath) ¹ 

expression don't support in filter

JavaScript (json-p3) 

unexpected shorthand selector '$' ('$.$':2)

Perl (JSON-Path) 

Assertion ("$" is not an operator) failed!
 at build/lib/perl5/Carp/Assert.pm line 282, <STDIN> line 3.
	Carp::Assert::assert(...) called at build/lib/perl5/JSON/Path/Evaluator.pm line 215
	JSON::Path::Evaluator::_evaluate(...) called at build/lib/perl5/JSON/Path/Evaluator.pm line 120
	JSON::Path::Evaluator::evaluate(...) called at build/lib/perl5/JSON/Path/Evaluator.pm line 93
	JSON::Path::Evaluator::evaluate_jsonpath(...) called at build/lib/perl5/JSON/Path.pm line 103
	JSON::Path::values(...) called at main.pl line 11

Rust (jsonpath_plus) 

Error Parsing JSON Path:
$.$
panic occurred

Footnotes