* gate.st
* 
* Implements the class Gate and its subclasses
*
* by Ricardo Szmit
*
* Last update: 03.04.94

Class Gate Object inputs 

Methods Gate 'all'

	new
		inputs <- List new
|
	connect: aGate
		inputs addLast: aGate
|
	numberOfInputs
		^inputs size
|
	trueInputs
		^( inputs select: [ :gate | gate output ] ) size
]

Class And Gate

Methods And 'all'

	output
		^self trueInputs = self numberOfInputs 
]

Class Or Gate

Methods Or 'all'

	output
		^self trueInputs > 0
]

Class Xor Gate

Methods Xor 'all'

	output
		^self trueInputs = 1
]

Class One Gate

Methods One 'all'

	output
		^true
]

Class Zero Gate

Methods Zero 'all'

	output
		^false
]

Class Nand And

Methods Nand 'all'

	output

		^super output not
]

Class Nor Or

Methods Nor 'all'

	output

		^super output not
]

Class Nxor Xor

Methods Nxor 'all'

	output

		^super output not
]