说明讲稿aiken编译器slralex parsing 0 slides original08-slr14m16s 0.pdfVIP

SLRParsing

•LR(0)Parsing:Assume

–stackcontainsa

–nextinputist

–DFAoninputaterminatesinstates

•ReducebyXbif

–scontainsitemXb.

•Shiftif

–scontainsitemXb.tw

–equivalenttosayingshasatransitionlabeledt

AlexAiken

SLRParsing

•LR(0)hasareduce/reduceconflictif:

–Anystatehastworeduceitems:

–Xb.andYw.

•LR(0)hasashift/reduceconflictif:

–Anystatehasareduceitemandashiftitem:

–Xb.andYw.td

AlexAiken

SParsing

ET+.E

E.TEET+E.

TE.T+E

S’E.ET.+T.(E)

(

ETET.+EintT.int*TT(.E)

Tint.*TT.int(E.T

S’.EintTint.intT

E.T+E

E.Tint*Tint*T.E

E.T+ETint*.TT.(E)

T

T(E.)T.int*T

T.(E)T.(E)

)