langley / jsonparsers

A simple project that illustrates the progression from a permissive json parser to a restrictive one that will only accept a strongly defined json object

What's Here

This project shows how to build a "strict json parser" that insures the input is of the required type before transforming it to gson objects. It started from code illustrated here: http://www.artima.com/pins1ed/combinator-parsing.html

Each of the parsers included extends the basic example, see the table of Scala Files below which explains each step of the progression.

The project is a simple SBT project created using the following steps:

1. g8 typesafehub/scala-sbt
2. adding the project/plugins.sbt containing the eclipse plugin.

Note the eclipse plugin allows you to use the "eclipse" command in sbt to create the eclipse project support.

Scala Files

Name	Illustrates
FirstJsonParser.scala	This is the first example from the url above
SecondJsonParser.scala	This is the second example from the url above
ThirdJsonParser.scala	Adds support for transforming the input json into json objects defined by the google gson library.
FourthJsonParser.scala	Moves the parser from generically parsing json into one that is specifically looking for an address book and finding it, transforms it into gson objects.
FifthJsonParser.scala	Shows what you need to do to report failures and react to them.

Data Files

Name	Used for
addressBook.json	the canonical json from the url example
a.json	basically the same as addrBook.json
aFail.json	an address book that is valid json but not a valid address book.
b.json	a VERY simple json object
bFail.json	a VERY simple BROKEN json object, not valid json