"{ Package: 'stx:goodies/petitparser' }"

PPCompositeParser subclass:#PPArithmeticParser

	instanceVariableNames:'terms addition factors multiplication power primary parentheses

		number'

	classVariableNames:''

	poolDictionaries:''

	category:'PetitTests-Examples'

!

!PPArithmeticParser methodsFor:'accessing'!

start

	^ terms end

! !

!PPArithmeticParser methodsFor:'grammar'!

addition

	^ (factors separatedBy: ($+ asParser / $- asParser) token trim)

		foldLeft: [ :a :op :b | a perform: op value asSymbol with: b ]

!

factors

	^ multiplication / power

!

multiplication

	^ (power separatedBy: ($* asParser / $/ asParser) token trim)

		foldLeft: [ :a :op :b | a perform: op value asSymbol with: b ]

!

number

	^ ($- asParser optional , #digit asParser plus , ($. asParser , #digit asParser plus) optional) token trim ==> [ :token | token value asNumber ]

!

parentheses

	^ $( asParser flatten trim , terms , $) asParser flatten trim ==> #second

!

power

	^ (primary separatedBy: $^ asParser token trim) foldRight: [ :a :op :b | a raisedTo: b ]

!

primary

	^ number / parentheses

!

terms

	^ addition / factors

! !

!PPArithmeticParser class methodsFor:'documentation'!

version_SVN

    ^ '$Id: PPArithmeticParser.st,v 1.2 2012-01-13 11:22:50 cg Exp $'

! !