實(shí)驗(yàn)一識別無符號數(shù)的詞法分析器設(shè)計(jì)實(shí)現(xiàn)

1、學(xué)院：計(jì)算機(jī)學(xué)院班級：學(xué)號：一、實(shí)驗(yàn)?zāi)康呐c要求通過編寫并上機(jī)調(diào)試一個詞法分析程序，掌握在對程序設(shè)計(jì)語言的源程序進(jìn)行掃描的過程中，將其分解成各類單詞的詞法分析方法。二、實(shí)驗(yàn)內(nèi)容選取無符號數(shù)的算術(shù)四則運(yùn)算中的各類單詞為識別對象，要求將其中的各個單詞識別出來。輸入：由無符號數(shù)和+，*，/,（,）構(gòu)成的算術(shù)表達(dá)式，如1.5E+2100。輸出：對識別出的每一單詞均單行輸出其類別碼（無符號數(shù)的值暫不要求計(jì)算）。單詞符號類別碼（CLASS）單詞值（VALUE）無符號數(shù)1數(shù)字值+2無值3無值*4無值/5無值(6無值)7無值如1（對應(yīng)1.5E+2）3(對應(yīng))1(對應(yīng)100)三、程序源代碼：#includeusi

2、ngnamespacestd;#defineM101/最多可輸入的字符數(shù)#defineUNSIGNEDNUMBER1/無符號數(shù)#definePLUS2/加號#defineSUBTRACT3/減號#defineMULTIPLY4/乘號#defineDIVIDE5/除號#defineLEFTBRACKET6/左括號#defineRIGHTBRACKET7/右括號classAccidenceAnalysis/定義詞法分析器類private:chartestStrM,*p;/私有數(shù)據(jù)public:AccidenceAnalysis();/構(gòu)造函數(shù)voidInputStr();/輸入函數(shù)voidOutp

3、ut(inta,char*p1,char*p2);/輸出函數(shù)intIsAcceptantCharacter(char*p);/判斷輸入字符是否屬于字符集intIsOperator(char*p);/判斷字符是否是字符集+,-,*,/,(,)中的字符intIsUnsignedNum(char*p);/判斷字符是否是0-9的整數(shù)voidAbnormityExamine(chara);voidIdentifyOperator(char*p);/識別字符集+,-,*,/,(,)中的字符voidAssortIdentify();/對輸入字符分類識別;AccidenceAnalysis:Accidence

4、Analysis()inti;for(i=0;iM;i+)testStri=0;p=&testStr0;/指針P指向字符數(shù)組首元素voidAccidenceAnalysis:InputStr()coutvvt請按要求輸入您要分析的語句，所輸字符應(yīng)在要求范圍(不超過VVMVV)之內(nèi)，并按回車鍵運(yùn)行：;charch;inti=0;while(ch=cin.get()!=n)testStri=ch;i+;AbnormityExamine(testStr);voidAccidenceAnalysis:AbnormityExamine(chara)intj=0;char*ptr1,*ptr2;ptr1=

5、a;ptr2=a;while(*ptr2!=0)j+;if(!IsAcceptantCharacter(ptr2)coutvvt您輸入的第vvjvv個字符vv*ptr2vv不可以被此程序識別！將被跳過.vvendl;ptr2+;continue;else*ptr1=*ptr2;ptr1+;ptr2+;while(ptr1=ptr2)*ptr1=0;ptr1+;voidAccidenceAnalysis:Output(inta,char*p1,char*p2)coutvvt類別碼：vvavv單詞值：；while(p1=p2)cout*p1；p1+；coutendl；intAccidenceAna

6、lysis:IsOperator(char*p)charch=*p；if(ch=+|ch=-|ch=*|ch=/|ch=(|ch=)return1；elsereturn0；intAccidenceAnalysis:IsUnsignedNum(char*p)charch=*p；if(0=ch&ch=9)return1；elsereturn0；intAccidenceAnalysis:IsAcceptantCharacter(char*p)charch=*p;if(IsOperator(p)|IsUnsignedNum(p)|ch=E|ch=.)return1;elsereturn0;voidAc

7、cidenceAnalysis:IdentifyOperator(char*p)charch=*p;switch(ch)case+:Output(PLUS,p,p);break;case-:Output(SUBTRACT,p,p);break;case*:Output(MULTIPLY,p,p);break;case/:Output(DIVIDE,p,p);break;case(:Output(LEFTBRACKET,p,p);break;case):Output(RIGHTBRACKET,p,p);break;default:break;voidAccidenceAnalysis:Assor

8、tIdentify()while(*p!=0)if(IsOperator(p)IdentifyOperator(p+);continue;elseif(IsUnsignedNum(p)|*p=.)char*p1=p;if(IsUnsignedNum(p)while(IsUnsignedNum(p)p+;if(*p=0)Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseif(*p=E)p+;if(IsUnsignedNum(p)while(IsUnsignedNum(p)p+;Output(UNSIGNEDNUMBER,p1,-p);p+;continue

9、;elseif(*p=+|*p=-)p+;while(IsUnsignedNum(p)p+;Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseif(*p=.)p+;while(IsUnsignedNum(p)p+;if(*p=0)Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseif(*p=E)p+;if(IsUnsignedNum(p)while(IsUnsignedNum(p)p+;Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseif(*p=+|*p=-)p+;whil

10、e(IsUnsignedNum(p)p+;Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseOutput(UNSIGNEDNUMBER,p1,-p);p+;continue;elseOutput(UNSIGNEDNUMBER,p1,-p);p+;continue;if(*p=.)p+;if(IsUnsignedNum(p)p+;while(IsUnsignedNum(p)p+;if(*p=0)Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseif(*p=E)p+;if(IsUnsignedNum(p)while(IsUnsignedNum(p)p+;Output(UNSIGNEDNUMBER,p1,-p);p+;continue;elseif(*p=+|*p=-)p+;while(IsUnsignedNum(p)p+;Output(UNSIGNEDNUMBER,p1,-