json
json
JavaScript Object Notation (JSON)
Description
JSON is a structured data-type within Murex. It is the standard format for all structured data within Murex however other formats such as YAML, TOML and CSV are equally first class citizens.
Examples
Example JSON document taken from Wikipedia
{
"firstName": "John",
"lastName": "Smith",
"isAlive": true,
"age": 27,
"address": {
"streetAddress": "21 2nd Street",
"city": "New York",
"state": "NY",
"postalCode": "10021-3100"
},
"phoneNumbers": [
{
"type": "home",
"number": "212 555-1234"
},
{
"type": "office",
"number": "646 555-4567"
},
{
"type": "mobile",
"number": "123 456-7890"
}
],
"children": [],
"spouse": null
}
Detail
Tips when writing JSON inside for loops
One of the drawbacks (or maybe advantages, depending on your perspective) of JSON is that parsers generally expect a complete file for processing in that the JSON specification requires closing tags for every opening tag. This means it's not always suitable for streaming. For example
» ja [1..3] -> foreach i { out ({ "$i": $i }) }
{ "1": 1 }
{ "2": 2 }
{ "3": 3 }
What does this even mean and how can you build a JSON file up sequentially?
One answer if to write the output in a streaming file format and convert back to JSON
» ja [1..3] -> foreach i { out (- "$i": $i) }
- "1": 1
- "2": 2
- "3": 3
» ja [1..3] -> foreach i { out (- "$i": $i) } -> cast yaml -> format json
[
{
"1": 1
},
{
"2": 2
},
{
"3": 3
}
]
What if I'm returning an object rather than writing one?
The problem with building JSON structures from existing structures is that you can quickly end up with invalid JSON due to the specifications strict use of commas.
For example in the code below, each item block is it's own object and there are no [ ... ]
encapsulating them to denote it is an array of objects, nor are the objects terminated by a comma.
» config -> [ shell ] -> formap k v { $v -> alter /Foo Bar }
{
"Data-Type": "bool",
"Default": true,
"Description": "Display the interactive shell's hint text helper. Please note, even when this is disabled, it will still appear when used for regexp searches and other readline-specific functions",
"Dynamic": false,
"Foo": "Bar",
"Global": true,
"Value": true
}
{
"Data-Type": "block",
"Default": "{ progress $PID }",
"Description": "Murex function to execute when an `exec` process is stopped",
"Dynamic": false,
"Foo": "Bar",
"Global": true,
"Value": "{ progress $PID }"
}
{
"Data-Type": "bool",
"Default": true,
"Description": "ANSI escape sequences in Murex builtins to highlight syntax errors, history completions, {SGR} variables, etc",
"Dynamic": false,
"Foo": "Bar",
"Global": true,
"Value": true
}
...
Luckily JSON also has it's own streaming format: JSON lines (jsonl
). We can cast
this output as jsonl
then format
it back into valid JSON:
» config -> [ shell ] -> formap k v { $v -> alter /Foo Bar } -> cast jsonl -> format json
[
{
"Data-Type": "bool",
"Default": true,
"Description": "Write shell history (interactive shell) to disk",
"Dynamic": false,
"Foo": "Bar",
"Global": true,
"Value": true
},
{
"Data-Type": "int",
"Default": 4,
"Description": "Maximum number of lines with auto-completion suggestions to display",
"Dynamic": false,
"Foo": "Bar",
"Global": true,
"Value": "6"
},
{
"Data-Type": "bool",
"Default": true,
"Description": "Display some status information about the stop process when ctrl+z is pressed (conceptually similar to ctrl+t / SIGINFO on some BSDs)",
"Dynamic": false,
"Foo": "Bar",
"Global": true,
"Value": true
},
...
foreach
will automatically cast it's output as jsonl
if it's STDIN type is json
» ja: [Tom,Dick,Sally] -> foreach: name { out Hello $name }
Hello Tom
Hello Dick
Hello Sally
» ja [Tom,Dick,Sally] -> foreach name { out Hello $name } -> debug -> [[ /Data-Type/Murex ]]
jsonl
» ja: [Tom,Dick,Sally] -> foreach: name { out Hello $name } -> format: json
[
"Hello Tom",
"Hello Dick",
"Hello Sally"
]
Default Associations
- Extension:
json
- MIME:
application/json
- MIME:
application/x-json
- MIME:
text/json
- MIME:
text/x-json
Supported Hooks
Marshal()
Writes minified JSON when no TTY detected and human readable JSON when stdout is a TTYReadArray()
Works with JSON arrays. Maps are converted into arraysReadArrayWithType()
Works with JSON arrays. Maps are converted into arrays. Elements data-type in Murex mirrors the JSON type of the elementReadIndex()
Works against all properties in JSONReadMap()
Works with JSON mapsReadNotIndex()
Works against all properties in JSONUnmarshal()
SupportedWriteArray()
Works with JSON arrays
See Also
Marshal()
(type): Converts structured memory into a structured file format (eg for stdio)ReadArray()
(type): Read from a data type one array element at a timeReadArrayWithType()
(type): Read from a data type one array element at a time and return the elements contents and data typeReadIndex()
(type): Data type handler for the index,[
, builtinReadMap()
(type): Treat data type as a key/value structure and read its contentsReadNotIndex()
(type): Data type handler for the bang-prefixed index,![
, builtinUnmarshal()
(type): Converts a structured file format into structured memoryWriteArray()
(type): Write a data type, one array element at a time[[
(element): Outputs an element from a nested structure[
(index): Outputs an element from an array, map or tablecast
: Alters the data type of the previous function without altering it's outputformat
: Reformat one data-type into another data-typehcl
: HashiCorp Configuration Language (HCL)jsonc
: Concatenated JSONjsonl
: JSON Lineslang.ArrayTemplate()
(template API): Unmarshals a data type into a Go struct and returns the results as an arraylang.ArrayWithTypeTemplate()
(template API): Unmarshals a data type into a Go struct and returns the results as an array with data type includedopen
: Open a file with a preferred handlerpretty
: Prettifies JSON to make it human readableruntime
: Returns runtime information on the internal state of Murextoml
: Tom's Obvious, Minimal Language (TOML)yaml
: YAML Ain't Markup Language (YAML)- mxjson: Murex-flavoured JSON (deprecated)