简易编译器

上传者：gujianwise 2019-04-05 11:02:33上传 RAR文件 120.16KB 热度 37次

C#简易编译器 namespace 编译 { public class Grammar { List tokens; List symbles; public string error = ""; int i = 0; public Grammar(Morphology m) { tokens = m.tokens; symbles = m.symbles; Dispose(); } private void Next() { if (i < tokens.Count - 1) { i++; } } private void Before() { if (i > 0) { i--; } } #region 主要函数 private void Dispose() { if (tokens[i].Code == 12)//含有program { Next(); if (tokens[i].Code == 18)//是标识符 { //执行程序体 Next(); ProBody(); } else { error = "该程序program缺少方法名"; } } else { error = "该程序缺少关键字：program"; } } #endregion #region 程序体 private void ProBody() { if (tokens[i].Code == 16) { Next(); VarDef(); } else if (tokens[i].Code == 2) { Next(); ComSent(); } else { error = "程序体缺少var或begin"; } } #endregion #region 变量定义 private void VarDef() { if (IsIdlist()) { Next(); if (tokens[i].Code == 29)//： { Next(); if (tokens[i].Code == 9 || tokens[i].Code == 3 || tokens[i].Code == 13)//integer,bool,real { int j = i; j = j - 2; symbles[tokens[j].Addr].Type = tokens[i].Code; j--; while (tokens[j].Code == 28) { j--; symbles[tokens[j].Addr].Type = tokens[i].Code; } Next(); if (tokens[i].Code == 30) { Next(); if (tokens[i].Code == 2) { Next(); ComSent(); } else { VarDef(); } } else { error = "变量定义后面缺少；"; } } else { error = "变量定义缺少类型或类型定义错误"; return; } } else { error = "var后面缺少冒号"; } } else { error = "变量定义标识符出错"; } } #endregion #region 判断是不是标识符表 private bool IsIdlist() { if (tokens[i].Code == 18) { Next(); if (tokens[i].Code == 28)//, { Next(); return IsIdlist(); } else { Before(); return true; } } else { return false; } } #endregion #region 复合句 private void ComSent() { SentList(); if (error == "") { if (tokens[i].Code == 6) { return; } else { error = "复合句末尾缺少end"; } } } #endregion #region 语句表 private void SentList() { ExecSent(); if (error == "") { Next(); if (tokens[i].Code == 30) { Next(); SentList(); } } } #endregion #region 执行句 private void ExecSent() { if (tokens[i].Code == 18) { Next(); AssiSent(); } else if (tokens[i].Code == 2 || tokens[i].Code == 8 || tokens[i].Code == 17) { StructSent(); } else { Before(); } } #endregion #region 赋值句 private void AssiSent() { if (tokens[i].Code == 31)//:= { Next(); Expression(); } else { error = "赋值句变量后缺少：="; } } #endregion #region 表达式 private void Expression() { if (tokens[i].Code == 7 || tokens[i].Code == 15 || (tokens[i].Addr != -1 && symbles[tokens[i].Addr].Type == 3)) { BoolExp(); } else { AritExp(); } } #endregion #region 布尔表达式 private void BoolExp() { BoolItem(); if (error == "") { Next(); if (tokens[i].Code == 11) { Next(); BoolExp(); } else { Before(); } } else { return; } } #endregion #region 布尔项 private void BoolItem() { BoolFactor(); if (error == "") { Next(); if (tokens[i].Code == 1) { Next(); BoolItem(); } else { Before(); } } } #endregion #region 布尔因子 private void BoolFactor() { if (tokens[i].Code == 10) { Next(); BoolFactor(); } else { BoolValue(); } } #endregion #region 布尔量 private void BoolValue() { if (tokens[i].Code == 15 || tokens[i].Code == 7) { return; } else if (tokens[i].Code == 18) { Next(); if (tokens[i].Code == 34 || tokens[i].Code == 33 || tokens[i].Code == 32 || tokens[i].Code == 37 || tokens[i].Code == 36 || tokens[i].Code == 35) { Next(); if (tokens[i].Code == 18) { } else { error = "关系运算符后缺少标识符"; } } else { Before(); } } else if (tokens[i].Code == 21) { BoolExp(); //? if (tokens[i].Code == 22) { return; } else { error = "布尔量中的布尔表达式缺少一个）"; } } else { error = "布尔量出错"; } } #endregion #region 算数表达式 private void AritExp() { Item(); if (error == "") { Next(); if (tokens[i].Code == 23 || tokens[i].Code == 24) { Next(); AritExp(); } else { Before(); return; } } else { return; } } #endregion #region 项 private void Item() { Factor(); if (error == "") { Next(); if (tokens[i].Code == 25 || tokens[i].Code == 26) { Next(); Item(); } else { Before(); return; } } else { return; } } #endregion #region 因子 private void Factor() { if (tokens[i].Code == 21) { Next(); AritExp(); Next(); if (tokens[i].Code == 22) { return; } else { error = "因子中算数表达式缺少）"; } } else { CalQua(); } } #endregion #region 算数量 private void CalQua() { if (tokens[i].Code == 18 || tokens[i].Code == 19 || tokens[i].Code == 20) { return; } else { error = "算数量出错"; } } #endregion #region 结构句 private void StructSent() { if (tokens[i].Code == 2) { Next(); ComSent(); } else if (tokens[i].Code == 8) { Next(); IfSent(); } else if (tokens[i].Code == 17) { Next(); WhileSent(); } } #endregion #region if语句 private void IfSent() { BoolExp(); if (error == "") { Next(); if (tokens[i].Code == 14) { Next(); ExecSent(); Next(); if (tokens[i].Code == 5) { Next(); ExecSent(); } else { Before(); return; } } else { error = "if...then语句缺少then"; } } else { error = "if语句布尔表达式出错"; } } #endregion #region while语句 private void WhileSent() { BoolExp(); if (error == "") { Next(); if (tokens[i].Code == 4) { Next(); ExecSent(); } else { error = "while语句缺少do"; } } } #endregion } } private void Next() { if (i < tokens.Count - 1) { i++; } } private void Before() { if (i > 0) { i--; } } #region 主要函数 private void Dispose() { if (tokens[i].Code == 12)//含有program { Next(); if (tokens[i].Code == 18)//是标识符 { //执行程序体 Next(); ProBody(); } else { error = "该程序program缺少方法名"; } } else { error = "该程序缺少关键字：program"; } } #endregion #region 程序体 private void ProBody() { if (tokens[i].Code == 16) { Next(); VarDef(); } else if (tokens[i].Code == 2) { Next(); ComSent(); } else { error = "程序体缺少var或begin"; } } #endregion #region 变量定义 private void VarDef() { if (IsIdlist()) { Next(); if (tokens[i].Code == 29)//： { Next(); if (tokens[i].Code == 9 || tokens[i].Code == 3 || tokens[i].Code == 13)//integer,bool,real { int j = i; j = j - 2; symbles[tokens[j].Addr].Type = tokens[i].Code; j--; while (tokens[j].Code == 28) { j--; symbles[tokens[j].Addr].Type = tokens[i].Code; } Next(); if (tokens[i].Code == 30) { Next(); if (tokens[i].Code == 2) { Next(); ComSent(); } else { VarDef(); } } else { error = "变量定义后面缺少；"; } } else { error = "变量定义缺少类型或类型定义错误"; return; } } else { error = "var后面缺少冒号"; } } else { error = "变量定义标识符出错"; } } #endregion #region 判断是不是标识符表 private bool IsIdlist() { if (tokens[i].Code == 18) { Next(); if (tokens[i].Code == 28)//, { Next(); return IsIdlist(); } else { Before(); return true; } } else { return false; } } #endregion #region 复合句 private void ComSent() { SentList(); if (error == "") { if (tokens[i].Code == 6) { return; } else { error = "复合句末尾缺少end"; } } } #endregion #region 语句表 private void SentList() { ExecSent(); if (error == "") { Next(); if (tokens[i].Code == 30) { Next(); SentList(); } } } #endregion #region 执行句 private void ExecSent() { if (tokens[i].Code == 18) { Next(); AssiSent(); } else if (tokens[i].Code == 2 || tokens[i].Code == 8 || tokens[i].Code == 17) { StructSent(); } else { Before(); } } #endregion #region 赋值句 private void AssiSent() { if (tokens[i].Code == 31)//:= { Next(); Expression(); } else { error = "赋值句变量后缺少：="; } } #endregion #region 表达式 private void Expression() { if (tokens[i].Code == 7 || tokens[i].Code == 15 || (tokens[i].Addr != -1 && symbles[tokens[i].Addr].Type == 3)) { BoolExp(); } else { AritExp(); } } #endregion #region 布尔表达式 private void BoolExp() { BoolItem(); if (error == "") { Next(); if (tokens[i].Code == 11) { Next(); BoolExp(); } else { Before(); } } else { return; } } #endregion #region 布尔项 private void BoolItem() { BoolFactor(); if (error == "") { Next(); if (tokens[i].Code == 1) { Next(); BoolItem(); } else { Before(); } } } #endregion #region 布尔因子 private void BoolFactor() { if (tokens[i].Code == 10) { Next(); BoolFactor(); } else { BoolValue(); } } #endregion #region 布尔量 private void BoolValue() { if (tokens[i].Code == 15 || tokens[i].Code == 7) { return; } else if (tokens[i].Code == 18) { Next(); if (tokens[i].Code == 34 || tokens[i].Code == 33 || tokens[i].Code == 32 || tokens[i].Code == 37 || tokens[i].Code == 36 || tokens[i].Code == 35) { Next(); if (tokens[i].Code == 18) { } else { error = "关系运算符后缺少标识符"; } } else { Before(); } } else if (tokens[i].Code == 21) { BoolExp(); //? if (tokens[i].Code == 22) { return; } else { error = "布尔量中的布尔表达式缺少一个）"; } } else { error = "布尔量出错"; } } #endregion #region 算数表达式 private void AritExp() { Item(); if (error == "") { Next(); if (tokens[i].Code == 23 || tokens[i].Code == 24) { Next(); AritExp(); } else { Before(); return; } } else { return; } } #endregion #region 项 private void Item() { Factor(); if (error == "") { Next(); if (tokens[i].Code == 25 || tokens[i].Code == 26) { Next(); Item(); } else { Before(); return; } } else { return; } } #endregion #region 因子 private void Factor() { if (tokens[i].Code == 21) { Next(); AritExp(); Next(); if (tokens[i].Code == 22) { return; } else { error = "因子中算数表达式缺少）"; } } else { CalQua(); } } #endregion #region 算数量 private void CalQua() { if (tokens[i].Code == 18 || tokens[i].Code == 19 || tokens[i].Code == 20) { return; } else { error = "算数量出错"; } } #endregion #region 结构句 private void StructSent() { if (tokens[i].Code == 2) { Next(); ComSent(); } else if (tokens[i].Code == 8) { Next(); IfSent(); } else if (tokens[i].Code == 17) { Next(); WhileSent(); } } #endregion #region if语句 private void IfSent() { BoolExp(); if (error == "") { Next(); if (tokens[i].Code == 14) { Next(); ExecSent(); Next(); if (tokens[i].Code == 5) { Next(); ExecSent(); } else { Before(); return; } } else { error = "if...then语句缺少then"; } } else { error = "if语句布尔表达式出错"; } } #endregion #region while语句 private void WhileSent() { BoolExp(); if (error == "") { Next(); if (tokens[i].Code == 4) { Next(); ExecSent(); } else { error = "while语句缺少do"; } } } #endregion } }

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