摘要：架構分析進行文件數據處理進行視圖的呈現作為客戶端語法解析效果展示讀取形式按照代碼行進行讀取每次讀取到一行就進行遍歷分析關鍵字與特殊符號建立映射關鍵字特殊字符遍歷分析過程代碼注釋匹配當讀到一行中包含的兩個字符時候這時把代碼注釋的標志

Node進行文件數據處理

Vue.js進行視圖的呈現

Electron作為客戶端

按照代碼行進行讀取, 每次讀取到一行就進行遍歷分析

/**
 * 關鍵字
 */
let keyWords = [
  "asm", "auto",
  "bool", "break",
  "case", "catch", "char", "class", "const", "continue", "cin", "cout",
  "default", "delete", "do", "double", "define",
  "else", "enum", "except", "explicit", "extern", "endl",
  "false", "finally", "float", "for", "friend",
  "goto",
  "if", "inline", "int", "include",
  "long",
  "mutable", "main",
  "namespace", "new",
  "operator",
  "private", "protectde", "public", "printf",
  "register", "return",
  "short", "signed", "szieof", "static", "struct", "string", "switch", "std", "scanf",
  "template", "this", "throw", "true", "try", "typedef", "typename",
  "union", "unsigned", "using",
  "virtual", "void",
  "while"
]

/**
 * 特殊字符
 */
let specialWords = [
  ",", ";", "(", ")", "{", "}", "#", "^", "?", ":", ".", "[", "]", "+", "-", "*", "/", "%", "=", ">", "<", "!", "~", "|", "&",
  "&&", "||", "==", ">=", "<=", "!=", "++", "--", "::", "<<", ">>", "+=", "-=", "*=", "/=", "%=", "&=", "^=", "->"
]

keyWords.forEach(word => {
  wordsMap.set(word, "keyWord")
})

specialWords.forEach(word => {
  wordsMap.set(word, "specialWord")
})

代碼注釋匹配

當讀到一行中包含/*的兩個字符時候, 這時把代碼注釋的標志設置為true, 然后一直讀取，知道遇到*/的時候就把標志重新置為false

判斷是否可以構成單詞，成立的條件是不以數字開頭，并且只包含數字, 下劃線, 以及字母, 可以通過正則來/[a-z]|[A-z]|_/匹配

判斷是否為字符串或者字符, 成立條件是以","開頭

判斷是否為數字

判斷是否為特殊字符, 這時就通過建立的映射進行關鍵字查找

判斷空格

代碼解釋

判斷工具函數

//判斷是否是字母與下劃線
function judgeWord(word) {
  let wordPatten = /[a-z]|[A-z]|\_/
  return wordPatten.test(word)
}

//判斷是否為數字
function judgeNumber(number) {
  let numberPatten = /[0-9]/
  return numberPatten.test(number)
}

//判斷是否為特殊字符
function judgeSpecialWord(letter) {
  return wordsMap.get(letter) === "specialWord" ? true : false
}

//判斷是否為關鍵詞
function judgeKeyWord(letter) {
  return wordsMap.get(letter) === "keyWord" ? true : false
}

行分析函數

exports.analysisLine = (line, annotation) => {
  let oneLine = []
  let word = ""
  let i = 0
  let includeFile = false
  while (i < line.length) {
    //注釋代碼的優先級最高，需要先進行判斷
    if (line[i] === "/" && line[i + 1] === "*") {
      word += line[i]
      i++
      annotation = true;
    }
    if (!annotation) {
      //表示不是注釋內容
      if (judgeWord(line[i])) {
        //表示是屬于字母與下劃線
        word += line[i]
        while (i + 1 < line.length && (judgeNumber(line[i + 1]) || judgeWord(line[i + 1]))) {
          i++
          word += line[i]
        }
        if (judgeKeyWord(word)) {
          //判斷單詞是否屬于關鍵詞
          oneLine.push({
            word: word,
            type: "keyWord"
          })
        } else {
          //不為關鍵詞, 則為標識符
          oneLine.push({
            word: word,
            type: "identifier"
          })
        }
        //由于include是屬于頭文件的引入, 需要對頭文件進行特殊處理
        if (word === "include") {
          includeFile = true
        }
        word = ""
        i++
      } else if (line[i] === """) {
        //字符串判斷
        while (i + 1 < line.length && line[i + 1] !== """) {
          word += line[i]
          i++
        }
        word += (line[i] || "" )+ (line[i + 1] || "")
        oneLine.push({
          word: word,
          type: "string"
        })
        word = ""
        i += 2
      } else if (line[i] === """) {
        //字符判斷
        while (i + 1 < line.length && line[i + 1] !== """) {
          word += line[i]
          i++
        }
        word += (line[i] || "" )+ (line[i + 1] || "")
        oneLine.push({
          word: word,
          type: "char"
        })
        word = ""
        i += 2
      } else if (judgeNumber(line[i])) {
        //數字判斷
        word += line[i]
        while (i + 1 < line.length && (judgeNumber(line[i + 1]) || line[i + 1] === ".")) {
          i++
          word += line[i]
        }
        oneLine.push({
          word: word,
          type: "number"
        })
        word = ""
        i++
      } else if (judgeSpecialWord(line[i])) {
        //特殊字符判斷
        if (line[i] === "<" && includeFile) {
          //處理頭文件的引入
          oneLine.push({
            word: line[i],
            type: "specialWord"
          })
          i++
          word += line[i]
          while (i + 1 < line.length && line[i + 1] !== ">") {
            i++
            word += line[i]
          }
          oneLine.push({
            word: word,
            type: "libraryFile"
          })
          word = ""
          i++
        } else {
          //處理//的注釋代碼
          if (line[i] === "/" && line[i + 1] === "/") {
            i++
            while (i + 1 < line.length) {
              i++
              word += line[i]
            }
            oneLine.push({
              word: word,
              type: "Annotations"
            })
            word = ""
            i += 3
          } else {
            word += line[i]
            while (i + 1 < line.length && (judgeSpecialWord(word + line[i + 1]))) {
              i++
              word += line[i]
            }
            oneLine.push({
              word: word,
              type: "specialWord"
            })
            word = ""
            i++
          }
        }
      } else if (line[i] === " ") {
        oneLine.push({
          word: line[i],
          type: "space"
        })
        i++
      }
    } else {
      //表示注釋內容
      while (i + 1 < line.length && (line[i + 1] !== "*" && line[i + 2] !== "/")) {
        word += line[i]
        i++
      }
      word += line[i] + (line[i + 1] || "") + (line[i + 2] || "")
      oneLine.push({
        word: word,
        type: "Annotations"
      })
      annotation = false;
      word = ""
      i += 3
    }
  }
  return oneLine
}

Electron, Vue搭建

具體的搭建過程省略, 可查看源碼或自行查找資料

動態編輯顯示

數據綁定, 使用v-model結合watch進行數據監控, 當數據發生變化的時候重新分析每行數據

二維數組保存分析的數據, 使用二維數組保存分析完的詞法, 保留原生的代碼行

通過v-bind:class對不同類型的詞法進行代碼高亮的簡單呈現

文件的讀取和寫入

使用Electron中引入Node的fs模塊來進行文件讀取寫入處理

使用Electron的Dialog控件選取文件

import Promise from "bluebird"
import electron from "electron"
const {dialog} = electron.remote
const fs = Promise.promisifyAll(require("fs"));

const writePackage = (filePath, data) => {
  return fs.writeFileAsync(filePath, JSON.stringify(data, null, 2)).catch(err => {
    return Promise.reject(err)
  });
}

const readPackage = (filePath) => {
  return fs.readFileAsync(filePath, "utf-8").catch(err => {
    return Promise.reject(err)
  });
}

const openDialog = () => {
  return new Promise((resolve, reject) => {
    dialog.showOpenDialog({
      properties: [
        "openFile",
      ]
    }, (res) => {
      if(!res) {
        return reject("404")
      }
      return resolve(res[0])
    });
  })
}

export default {
  writePackage,
  readPackage,
  openDialog
}

對此, 一個簡單的C++詞法分析就完成了, 過程并不復雜, 只要理解了優先級和并列情況的區分就比較清晰的寫出, 由于
個人匆匆寫完這個程序, 并沒有對js部分的代碼進行優化, 質量過低, 僅供參考