Java版词法分析器

package myCompiler; import java.util.ArrayList; import java.util.Stack; import java.util.Vector; public class Recursive2 { int CONST = 1; int VAR = 2; int PROCEDURE = 3; int IF = 4; int THEN = 5; int WHILE = 6; int DO = 7; int READ = 8; int WRITE = 9; int BEGIN = 10; int END = 11; int CALL = 12; int ODD = 13; int ADD = 14; int SUB = 15; int MUL = 16; int DIV = 17; int EQU = 18; int NEQ = 19; int LES = 20; int LEQ = 21; int LAG = 22; int GEQ = 23; int DOT = 24; int COM = 25; int SEM = 26; int ASS = 27; int LBR = 28; int RBR = 29; int INT = 30; int ID = 31; int EIN = 32; GetWords getwords; SYM sym; String name; String previous; Stack tbl=new Stack(); Vector alltbls=new Vector(); ArrayList alist; Header hdr; int LEV = -1; int DX; int line; Construct cstruct; Varstruct vstruct; Procstruct pstruct; public Recursive2(String SourceFileName) { getwords = new GetWords(SourceFileName); } ArrayList makeTable(String previous,String name){ Header header=new Header(previous,name); ArrayList arraylist=new ArrayList(); arraylist.add(header); return arraylist; } Construct makeConstruct(String name,int value){ Construct cstruct=new Construct(name,value); return cstruct; } Varstruct makeVarstruct(String name,int level,int adr){ Varstruct vstruct=new Varstruct(name,level,adr); return vstruct; } Procstruct makeProcstruct(String name,int level){ Procstruct pstruct=new Procstruct(name,level); return pstruct; } void adrclear(){ DX=0; } void adrincrease(){ DX++; } void levincrease(){ LEV++; } void levdiscrease(){ LEV--; } void setline(int line){ this.line=line; } public void getword() { getwords.getsym(); sym = getwords.sym; setline(getwords.line); System.out.print(sym.name); System.out.print(" " + sym.code); System.out.println(" "+line); } public void print(Object object) { if (object instanceof Construct) { System.out.println(((Construct) object).name + " " + ((Construct) object).kind + " " + ((Construct) object).value); } else if (object instanceof Varstruct) { System.out.println(((Varstruct) object).name + " " + ((Varstruct) object).kind + " " + ((Varstruct) object).level + " " + ((Varstruct) object).adr); } else if (object instanceof Procstruct) { System.out.println(((Procstruct) object).name + " " + ((Procstruct) object).kind + " " + ((Procstruct) object).level + " " + ((Procstruct) object).adr); } } public static void main(String args[]) { String s = "e:/pl0_1.txt"; Recursive2 rr = new Recursive2(s); rr.getword(); rr.program(); Object object; ArrayList aa; Header h; System.out.println("Name Kind Value/Level Address"); for(int i=0;i<rr.alltbls.size();i++){ aa=(ArrayList) rr.alltbls.get(i); h=(Header) aa.get(0); System.out.println("=========================================="); System.out.println(h.name+" "+h.previous); for (int j=1;j<aa.size();j++){ object=aa.get(j); rr.print(object); } } } public void program() { alist=this.makeTable(null, "program"); tbl.push(alist); alltbls.add(alist); block(); if (sym.code == DOT) { getword(); }else { Error2.error(line,"缺少 ."); } } public void block() { levincrease(); adrclear(); conststatement(); varstatement(); procstatement(); sentence(); } public void conststatement() { if (sym.code == CONST) { getword(); constdefine(); constsuffix(); if (sym.code == SEM) { getword(); } } } public void constdefine() { if (sym.code == ID) { name=sym.name; getword(); if (sym.code == EQU) { getword(); if (sym.code == INT) { cstruct=makeConstruct(name,sym.code); alist=(ArrayList) tbl.pop(); alist.add(cstruct); tbl.push(alist); //constvalue(); getword(); } else Error2.error(line,"缺少整数!"); } else Error2.error(line,"缺少标识符!"); } else Error2.error(line,"多余的CONST!"); } public void constsuffix() { if (sym.code == COM) { getword(); constdefine(); constsuffix(); if (sym.code == SEM) { getword(); } else Error2.error(line,"缺少分号!"); } } public void varstatement() { if (sym.code == VAR) { getword(); if (sym.code == ID) { adrincrease(); vstruct=makeVarstruct(sym.name,LEV,DX); alist=(ArrayList) tbl.pop(); alist.add(vstruct); tbl.push(alist); //varadd(); getword(); identsuffix(); if (sym.code == SEM) getword(); else Error2.error(line,"缺少分号!"); } else Error2.error(line,"多余的VAR"); } } public void identsuffix() { if (sym.code == COM) { getword(); if (sym.code == ID) { //varadd(); adrincrease(); vstruct=makeVarstruct(sym.name,LEV,DX); alist=(ArrayList) tbl.pop(); alist.add(vstruct); tbl.push(alist); getword(); identsuffix(); } else Error2.error(line,"多余的逗号!"); } } public void procstatement() { if (sym.code == PROCEDURE) { prochead(); block(); if (sym.code == SEM) { tbl.pop(); levdiscrease(); getword(); procsuffix(); } else Error2.error(line,"缺少分号!"); } } public void prochead() { if (sym.code == PROCEDURE) { getword(); if (sym.code == ID) { pstruct=this.makeProcstruct(sym.name, LEV); alist=(ArrayList) tbl.pop(); alist.add(pstruct); tbl.push(alist); hdr=(Header) alist.get(0); previous=hdr.name; name=sym.name; alist=this.makeTable(previous, name); tbl.push(alist); alltbls.add(alist); //procadd(); getword(); if (sym.code == SEM) { getword(); } else Error2.error(line,"缺少分号!"); } else Error2.error(line,"缺少过程名称!"); } else Error2.error(line,"缺少过程声明!"); } public void procsuffix() { if (sym.code == PROCEDURE) { prochead(); block(); if (sym.code == SEM) { tbl.pop(); levdiscrease(); getword(); procsuffix(); } else Error2.error(line,"缺少分号!"); } } public void sentence() { if (sym.code == ID) assinsent(); else if (sym.code == IF) ifsent(); else if (sym.code == WHILE) whilesent(); else if (sym.code == CALL) callsent(); else if (sym.code == READ) readsent(); else if (sym.code == WRITE) writesent(); else if (sym.code == BEGIN) complsent(); } public void assinsent() { if (sym.code == ID) { getword(); if (sym.code == ASS) { getword(); express(); } else Error2.error(line,"缺少赋值号!"); } else Error2.error(line,"多余的赋值号!"); } public void ifsent() { if (sym.code == IF) { getword(); condition(); if (sym.code == THEN) { getword(); sentence(); } else Error2.error(line,"缺少then"); } else Error2.error(line,"多余的IF!"); } public void whilesent() { if (sym.code == WHILE) { getword(); condition(); if (sym.code == DO) { getword(); sentence(); } else Error2.error(line,"缺少while!"); } else Error2.error(line,"多余的while!"); } public void callsent() { if (sym.code == CALL) { getword(); if (sym.code == ID) getword(); else Error2.error(line,"call语句缺少参数!"); } else