util

JSON

The json APIs provide basic serialization between Fantom and Javascript Object Notation (JSON). Refer to json.org for more information about JSON.

JSON types are mapped to Fantom types as follows:

JSON     Fantom
------   --------
object   Str:Obj?
array    Obj?[]
string   Str
number   Int or Float
true     Bool
false    Bool
null     null

In addition when writing Fantom objects the following is supported:

Simples are written as a JSON string
Serializables are written as JSON objects with each non-static, non-transient field being written as a key/val pair

Writing simples or serializables do not "roundtrip". For example if you write a Date it is written and will be read back as a normal string.

Writing is accomplised via JsonOutStream. To write to standard out:

map := ["key":"value", "intKey":123]
JsonOutStream(Env.cur.out).writeJson(map)

You can also use the writeToStr as a convenience to write to an in-memory string.

Reading JSON is accomplised via JsonInStream which takes raw JSON from a stream and produces of the core JSON types. For example:

str := """{"k1":"v1", "k2":3.4159, "k3":[1,2,3], "k4": {"m1":true, "m2":null}}"""
Str:Obj? data := JsonInStream(str.in).readJson
data["k1"]  =>  v1

AbstractMain	AbstractMain provides conveniences for writing the main routine of an app.
BoolArray
CsvInStream	CsvInStream is used to read delimiter-separated values as specified by RFC 4180.
CsvOutStream	CsvOutStream is used to write delimiter-separated values as specified by RFC 4180.
FileLogger	FileLogger appends Str log entries to a file.
FloatArray
IntArray
JVal	JSON Object
Macro	Macro provides a way to replace macro expressions within a pattern using a pluggable implementation for the macro resolution.
Random	Random provides different implementation of random number generators with more flexibility than the methods available in sys.
Unit	Unit models a unit of measurement.

Arg	Facet for annotating an `AbstractMain` argument field.
Opt	Facet for annotating an `AbstractMain` option field.