def SplitAllKeep(operand, ):
splitall = util.Proxy()
splitall.subject = (combine.GuardedChoice(
SplitKeep(operand),
congruent.Cons(base.ident,
congruent.Cons(base.ident, project.head * splitall)),
build.List((base.ident, ))))
return splitall
def One(operand):
'''Applies a transformation to exactly one direct subterm of a term.'''
one = util.Proxy()
one.subject = congruent.Subterms(
# FIXME: write a non-recursive implementation
combine.Choice(congruent.Cons(operand, base.ident),
congruent.Cons(base.ident, one)),
base.fail)
return one
def Some(operand):
'''Applies a transformation to as many direct subterms of a term, but at list one.'''
some = util.Proxy()
some.subject = congruent.Subterms(
# FIXME: write a non-recursive implementation
combine.Choice(
congruent.Cons(operand, lists.Map(combine.Try(operand))),
congruent.Cons(base.ident, some),
),
base.fail)
return some
def SplitBefore(operand):
tail = types.term.Term('tail')
return scope.Scope(
(tail, ),
build.List((AtSuffix(
congruent.Cons(operand, base.ident) * match.Var(tail) * build.nil),
build.Var(tail))))
def SplitAfter(operand):
tail = types.term.Term('tail')
return scope.Scope(
(tail, ),
build.List(
(AtSuffix(congruent.Cons(operand,
match.Var(tail) * build.nil)),
build.Var(tail))))
def AtSuffixR(operand):
atsuffix = util.Proxy()
atsuffix.subject = combine.Choice(congruent.Cons(base.ident, atsuffix),
operand)
return atsuffix