def DEL(productions):
newSet = []
#seekAndDestroy throw back in:
# – outlaws all left side of productions such that right side is equal to the outlaw
# – productions the productions without outlaws
outlaws, productions = helper.seekAndDestroy(target='e',
productions=productions)
#add new reformulation of old rules
for outlaw in outlaws:
#consider every production: old + new resulting important when more than one outlaws are in the same prod.
for production in productions + [
e for e in newSet if e not in productions
]:
#if outlaw is present in the right side of a rule
if outlaw in production[right]:
#the rule is rewrited in all combination of it, rewriting "e" rather than outlaw
#this cycle prevent to insert duplicate rules
newSet = newSet + [
e for e in helper.rewrite(outlaw, production)
if e not in newSet
]
#add unchanged rules and return
return newSet + ([
productions[i]
for i in range(len(productions)) if productions[i] not in newSet
])
def DELmakeNewRules(productions):
newSet = []
# menghapus leftside production sehingga hanya tersisa rightside untuk di manipulasi
outlaws, productions = helper.seekAndDestroy(target='e',
productions=productions)
# membuat rules baru
for outlaw in outlaws:
for production in productions + [
e for e in newSet if e not in productions
]:
if outlaw in production[right]:
newSet = newSet + [
e for e in helper.rewrite(outlaw, production)
if e not in newSet
]
# menambahkan rules yang tidak di ubah sebelumnya
return newSet + ([
productions[i]
for i in range(len(productions)) if productions[i] not in newSet
])