class BasicProcessTreeBuilder(object):
def __init__(self, drivingEngine, exp):
self.drivingEngine = drivingEngine
self.tree = ProcessTree(exp)
# The parts common to the basic and advanced supercompilers.
# If beta `instOf` alpha, we generalize beta by introducing
# a let-expression, in order to make beta the same as alpha
# (modulo variable names).
def loopBack(self, beta, alpha):
subst = matchAgainst(alpha.exp, beta.exp)
bindings = list(subst.items())
bindings.sort()
letExp = Let(alpha.exp, bindings)
self.tree.replaceSubtree(beta, letExp)
# This function applies a driving step to the node's expression,
# and, in general, adds children to the node.
def expandNode(self, beta):
branches = self.drivingEngine.drivingStep(beta.exp)
self.tree.addChildren(beta, branches)
# Basic supercompiler process tree builder
def buildStep(self, beta):
"""
This method is overridden in the advanced version of
the process tree builder.
"""
alpha = beta.findMoreGeneralAncestor()
if alpha:
self.loopBack(beta, alpha)
else:
self.expandNode(beta)
def buildProcessTree(self, k):
# Specifying k = -1 results in an unlimited building loop.
while True:
if k == 0:
break
k -= 1
beta = self.tree.findUnprocessedNode()
if not beta:
break
self.buildStep(beta)
class BasicProcessTreeBuilder(object):
def __init__(self, drivingEngine, exp):
self.drivingEngine = drivingEngine
self.tree = ProcessTree(exp)
# The parts common to the basic and advanced supercompilers.
# If beta `instOf` alpha, we generalize beta by introducing
# a let-expression, in order to make beta the same as alpha
# (modulo variable names).
def loopBack(self, beta, alpha):
subst = matchAgainst(alpha.exp, beta.exp)
bindings = list(subst.items())
bindings.sort()
letExp = Let(alpha.exp, bindings)
self.tree.replaceSubtree(beta, letExp)
# This function applies a driving step to the node's expression,
# and, in general, adds children to the node.
def expandNode(self, beta):
branches = self.drivingEngine.drivingStep(beta.exp)
self.tree.addChildren(beta, branches)
# Basic supercompiler process tree builder
def buildStep(self, beta):
"""
This method is overridden in the advanced version of
the process tree builder.
"""
alpha = beta.findMoreGeneralAncestor()
if alpha:
self.loopBack(beta, alpha)
else:
self.expandNode(beta)
def buildProcessTree(self, k):
# Specifying k = -1 results in an unlimited building loop.
while True:
if k == 0:
break
k -= 1
beta = self.tree.findUnprocessedNode()
if not beta:
break
self.buildStep(beta)
