编译原理语法分析(2)

void proc()// → procedure （{,}）;{;} { line++; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; while (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; } else error2(); } } if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \//; {

}

mm++; yufa0.SYM = yufa2[mm].SYM;//下一单词---------->> block(); while (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; proc(); } } else error1();// 缺少; } else error7();//括号不匹配 （右括号少） }

else error8();//左括号缺少

}

else error9();//缺少参数 }

else error10();//procedure错误

void body()// → begin {;}end { if (yufa0.SYM == \ { line++; mm++; yufa0.SYM = yufa2[mm].SYM; statement(); // while ((yufa0.SYM == \ // (yufa0.SYM == \|| (yufa0.SYM == \|| (yufa0.SYM == \|| (yufa0.SYM == \

//

error1();//语句未到最后一条，缺少\while(yufa0.SYM == \{ mm++; yufa0.SYM = yufa2[mm].SYM; statement(); }

if (yufa0.SYM == \{ line ++; mm++; yufa0.SYM = yufa2[mm].SYM; }

else error11();//缺少end与begin匹配 } else error12();//缺少begin }

// → := //语句

// |if then [else ] // |while do // |call [（{,}）] // |

// |read ({，}) // |write ({,}) void statement() { if (yufa0.SYM == \ // → := { line++;

mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; exp(); } else error5();//赋值号错误 }

else if (yufa0.SYM == \{ line++; mm++; yufa0.SYM = yufa2[mm].SYM; lexp(); if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; statement(); if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; statement(); } } else error12();//缺少then }

else if (yufa0.SYM == \{ line++; mm++; yufa0.SYM = yufa2[mm].SYM; lexp(); if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; statement(); } else error13();//缺少do不匹配（while 与do 不匹配） }

else if (yufa0.SYM == \（{,}）] { line++; mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \

}

{

mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \{ mm++; yufa0.SYM = yufa2[mm].SYM; while(yufa0.SYM == \ { mm++;yufa0.SYM = yufa2[mm].SYM; exp(); } if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; } }

else error7();//缺少右括号

// 此处不会报错，[（{,}）]因为表示可有可无的 }

else error14();//调用过程缺少标识符

else if (yufa0.SYM == \，}) { line++; mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; while (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; } else error2();//缺少标示符 } if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; } else error7();//缺少右括号

}

}

}

else error9();//read缺少参数 }

else error8();//缺少左括号

else if (yufa0.SYM == \{ line++; mm++; yufa0.SYM = yufa2[mm].SYM; if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; exp(); while (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; exp(); } if (yufa0.SYM == \ { mm++; yufa0.SYM = yufa2[mm].SYM; } else error7();//缺少右括号 } else error8();//缺少左括号 }

else body();//

// → |odd // → [+|-]{} // → {} //→||() // → =|<>|<|<=|>|>= // → +|- // → *|/

// → l{l|d} （注：l表示字母） // → d{d}

void lexp()// → |odd { if (yufa0.SYM == \ { mm++;