lecteur at zogotounga.net
Mon Jun 30 16:36:52 UTC 2008
from the class comment of AMB, in the attached sar
(coming soon to a SqueakMap near you):
this is the "ambigous", "nondeterminist", "angelic" operator aka amb
... more seriously described as a declarative control flow statement
able to enumerate over finite domains all values that make a program
terminate. it uses continuations to walk the tree of possible tuples,
backtracking when the program fails.
the amazing thing is the simplicity of the code: four short or very
short methods on the instance side, the class side methods only
providing syntactic sugar.
and it can do incredible things such as:
AMB assert: [:string :n :char | (string occurrencesOf: char) = n]
over: #('maman' 'barbapapa' 'guiliguili' 'arthur' 'chtulu')
and: #(2 4 1)
and: #($m $b $a $i $u)
see AMBTest for more magic.
I would have been unable to implement this by myself ! this is a port of
the code by Dorai Sitaram which is the reference documentation for amb:
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