[Pharo-project] Parsing Smalltalk Array/Object Literals

Oct. 20, 2012

      Hi,

I took Igor's initial code and created a new project:

	http://smalltalkhub.com/#!/~SvenVanCaekenberghe/ObjectLiterals/

and I added ObjectLiteralParser to convert any Character Stream or String into a Smalltalk Literal Array and eventually into an Object.

This proof of concept moves the ObjectLiteral format/notation away from the Smalltalk compiler and will help us discuss more concretely the actual details of the specification (which is still not 100% finished).

I also added 12 unit tests and cleaned up the code and comments.

Please have a look at the code.

This is one of the tests:

ObjectLiteralParserTests>>#testMixed1
	| input output |
	input := ' 
		#(Array 
			1 
			foo 
			#''foo-#bar'' 
			true 
			false 
			nil 
			3.14159 
			-100 
			''string'' 
			(#OrderedCollection 7 8 9) 
			#(Set 10) 
			(Dictionary 
				x 1 
				y 2) )  '.
	 output := { 
		1. 
		#foo. 
		#'foo-#bar'. 
		true. 
		false. 
		nil. 
		3.14159. 
		-100. 
		'string'. 
		OrderedCollection withAll: #(7 8 9). 
		Set with: 10. 
		Dictionary newFromPairs: #(x 1 y 2 ). }.
	self assert: (self parserOn: input) nextObjectLiteral equals: output

I like this format, its simplicity and elegance is appealing, it offers distinctive advantages in the Smalltalk context while its slight readability disadvantage is acceptable. Like any format it is a compromise and a tradeoff, but a rather good one.  

Regards,

Sven

--
Sven Van Caekenberghe
http://stfx.eu
Smalltalk is the Red Pill