在新行拆分，除非在双引号内

Question

更新

澄清一下，我特意寻找一个正则表达式：

在换行符处拆分...除非换行符在双引号内。

如果换行符在双引号内，它将：

1. 忽略双引号内的换行符
2. 结果中不包含外部双引号
3. 将任何双双引号 ("") 转换为外部双引号内的单引号

---

我有一个看起来像这样的数据网格。

复制粘贴后的文本如下：

Data        
Data    Data    
Data    Data    Data
Data    Data    Data"
Data    Data    "Da
ta"
Data    Data    "Da
ta"""
Data    Data    Data""
Data    Data    """Da
ta"""
Data    Data    """Da

ta"""

生成的文本有点奇怪，因为单元格的换行inside会导致一些奇怪的行为：

1. 单元格的内容被双引号括起来
2. 该单元格内的任何现有双引号都将转换为双双引号 ("")。

我希望能够将该文本粘贴到 textarea 中，然后在 HTML 表格中重新创建原始网格，即使提到了不可靠的行为。

我已经找到并稍微修改了this 代码，我认为这很接近，但我认为 RegEx 不太正确，所以我还在this 答案中添加了 RegEx 作为选项（我'已注释掉，因为它会导致“内存不足”异常：

function splitOnNewlineExceptInDoubleQuotes(string) {
    //The parenthesis in the regex creates a captured group within the quotes
    var myRegexp = /[^\n"]+|"([^"]*)"/gim;
    //var myRegexp = /(\n)(?=(?:[^\"]|\"[^\"]*\")*$)/m;
    var myString = string
    var myArray = [];

    do {
        //Each call to exec returns the next regex match as an array
        var match = myRegexp.exec(myString);
        if (match != null)
        {
            //Index 1 in the array is the captured group if it exists
            //Index 0 is the matched text, which we use if no captured group exists
            myArray.push(match[1] ? match[1] : match[0]);
        }
    } while (match != null);

    return myArray
}

所以，我认为这可以通过正则表达式（而不是完整的状态机）来实现，但我不太确定该怎么做。

Answer 1

虽然假设可以使用极其复杂的正则表达式来定义您的解析器（我什至不相信这种语法是可能的），但使用解析器生成器将更容易和更易于维护以更易读的格式定义你的语法。

使用PEG.js，可以为明文Excel表格格式定义如下简单语法：

Table
  = row: Row '\n' table: Table { return [row, ...table] }
  / row: Row { return [row] }

Row
  = cell: Cell '\t' row: Row { return [cell, ...row] }
  / cell: Cell { return [cell] }

Cell
  = '"' value: Value '"' { return value }
  / $ [^\t\n]*

Value
  = escaped: $ Escaped
  { return escaped.replace(/""/g, '"') }

Escaped
  = multiline: $ ([^"\t]+ / '""')+
  & { return multiline.includes('\n') }

这是一个包含您输入的演示：

window.excelTableParser=function(){"use strict";function n(r,t,e,u){this.message=r,this.r=t,this.t=e,this.e=u,this.name="SyntaxError","function"==typeof Error.captureStackTrace&&Error.captureStackTrace(this,n)}return function(n,r){function t(){this.constructor=n}t.prototype=r.prototype,n.prototype=new t}(n,Error),n.u=function(n,r){var t={o:function(n){return'"'+u(n.i)+'"'},f:function(n){var r,t="";for(r=0;r<n.c.length;r++)t+=n.c[r]instanceof Array?o(n.c[r][0])+"-"+o(n.c[r][1]):o(n.c[r]);return"["+(n.s?"^":"")+t+"]"},a:function(n){return"any character"},l:function(n){return"end of input"},x:function(n){return n.description}};function e(n){return n.charCodeAt(0).toString(16).toUpperCase()}function u(n){return n.replace(/\\/g,"\\\\").replace(/"/g,'\\"').replace(/\0/g,"\\0").replace(/\t/g,"\\t").replace(/\n/g,"\\n").replace(/\r/g,"\\r").replace(/[\x00-\x0F]/g,function(n){return"\\x0"+e(n)}).replace(/[\x10-\x1F\x7F-\x9F]/g,function(n){return"\\x"+e(n)})}function o(n){return n.replace(/\\/g,"\\\\").replace(/\]/g,"\\]").replace(/\^/g,"\\^").replace(/-/g,"\\-").replace(/\0/g,"\\0").replace(/\t/g,"\\t").replace(/\n/g,"\\n").replace(/\r/g,"\\r").replace(/[\x00-\x0F]/g,function(n){return"\\x0"+e(n)}).replace(/[\x10-\x1F\x7F-\x9F]/g,function(n){return"\\x"+e(n)})}return"Expected "+function(n){var r,e,u,o=new Array(n.length);for(r=0;r<n.length;r++)o[r]=(u=n[r],t[u.g](u));if(o.sort(),o.length>0){for(r=1,e=1;r<o.length;r++)o[r-1]!==o[r]&&(o[e]=o[r],e++);o.length=e}switch(o.length){case 1:return o[0];case 2:return o[0]+" or "+o[1];default:return o.slice(0,-1).join(", ")+", or "+o[o.length-1]}}(n)+" but "+function(n){return n?'"'+u(n)+'"':"end of input"}(r)+" found."},{v:n,parse:function(r,t){t=void 0!==t?t:{};var e,u={},o={d:I},i=I,f="\n",c=q("\n",!1),s=function(n,r){return[n,...r]},a=function(n){return[n]},l="\t",x=q("\t",!1),g=function(n,r){return[n,...r]},v=function(n){return[n]},d='"',h=q('"',!1),p=function(n){return n},y=/^[^\t\n]/,w=z(["\t","\n"],!0,!1),F=function(n){return n.replace(/""/g,'"')},E=/^[^"\t]/,m=z(['"',"\t"],!0,!1),P='""',C=q('""',!1),b=function(n){return n.includes("\n")},A=0,S=[{h:1,p:1}],R=0,T=[],j=0,k={};if("startRule"in t){if(!(t.y in o))throw new Error("Can't start parsing from rule \""+t.y+'".');i=o[t.y]}function q(n,r){return{g:"literal",i:n,ignoreCase:r}}function z(n,r,t){return{g:"class",c:n,s:r,ignoreCase:t}}function B(n){var t,e=S[n];if(e)return e;for(t=n-1;!S[t];)t--;for(e={h:(e=S[t]).h,p:e.p};t<n;)10===r.charCodeAt(t)?(e.h++,e.p=1):e.p++,t++;return S[n]=e,e}function D(n,r){var t=B(n),e=B(r);return{w:{F:n,h:t.h,p:t.p},l:{F:r,h:e.h,p:e.p}}}function G(n){A<R||(A>R&&(R=A,T=[]),T.push(n))}function H(r,t,e){return new n(n.u(r,t),r,t,e)}function I(){var n,t,e,o,i=5*A+0,l=k[i];return l?(A=l.m,l.P):(n=A,(t=J())!==u?(10===r.charCodeAt(A)?(e=f,A++):(e=u,0===j&&G(c)),e!==u&&(o=I())!==u?n=t=s(t,o):(A=n,n=u)):(A=n,n=u),n===u&&(n=A,(t=J())!==u&&(t=a(t)),n=t),k[i]={m:A,P:n},n)}function J(){var n,t,e,o,i=5*A+1,f=k[i];return f?(A=f.m,f.P):(n=A,(t=K())!==u?(9===r.charCodeAt(A)?(e=l,A++):(e=u,0===j&&G(x)),e!==u&&(o=J())!==u?n=t=g(t,o):(A=n,n=u)):(A=n,n=u),n===u&&(n=A,(t=K())!==u&&(t=v(t)),n=t),k[i]={m:A,P:n},n)}function K(){var n,t,e,o,i=5*A+2,f=k[i];if(f)return A=f.m,f.P;if(n=A,34===r.charCodeAt(A)?(t=d,A++):(t=u,0===j&&G(h)),t!==u&&(e=function(){var n,t,e,o=5*A+3,i=k[o];return i?(A=i.m,i.P):(n=A,t=A,(t=(e=function(){var n,t,e,o,i,f=5*A+4,c=k[f];if(c)return A=c.m,c.P;if(n=A,t=A,e=[],o=[],E.test(r.charAt(A))?(i=r.charAt(A),A++):(i=u,0===j&&G(m)),i!==u)for(;i!==u;)o.push(i),E.test(r.charAt(A))?(i=r.charAt(A),A++):(i=u,0===j&&G(m));else o=u;if(o===u&&(r.substr(A,2)===P?(o=P,A+=2):(o=u,0===j&&G(C))),o!==u)for(;o!==u;){if(e.push(o),o=[],E.test(r.charAt(A))?(i=r.charAt(A),A++):(i=u,0===j&&G(m)),i!==u)for(;i!==u;)o.push(i),E.test(r.charAt(A))?(i=r.charAt(A),A++):(i=u,0===j&&G(m));else o=u;o===u&&(r.substr(A,2)===P?(o=P,A+=2):(o=u,0===j&&G(C)))}else e=u;return(t=e!==u?r.substring(t,A):e)!==u&&(e=(e=b(t))?void 0:u)!==u?n=t=[t,e]:(A=n,n=u),k[f]={m:A,P:n},n}())!==u?r.substring(t,A):e)!==u&&(t=F(t)),n=t,k[o]={m:A,P:n},n)}())!==u?(34===r.charCodeAt(A)?(o=d,A++):(o=u,0===j&&G(h)),o!==u?n=t=p(e):(A=n,n=u)):(A=n,n=u),n===u){for(n=A,t=[],y.test(r.charAt(A))?(e=r.charAt(A),A++):(e=u,0===j&&G(w));e!==u;)t.push(e),y.test(r.charAt(A))?(e=r.charAt(A),A++):(e=u,0===j&&G(w));n=t!==u?r.substring(n,A):t}return k[i]={m:A,P:n},n}if((e=i())!==u&&A===r.length)return e;throw e!==u&&A<r.length&&G({g:"end"}),H(T,R<r.length?r.charAt(R):null,R<r.length?D(R,R+1):D(R,R))}}}();
console.log(excelTableParser.parse(`Data		
Data	Data	
Data	Data	Data
Data	Data	Data"
Data	Data	"Da
ta"
Data	Data	"Da
ta"""
Data	Data	Data""
Data	Data	"""Da
ta"""
Data	Data	"""Da

ta"""`));

Answer 2

这是一个正则表达式解决方案，它将文本拆分为单元格（包括带有换行符的单元格）。它不会处理所有的复杂性，但现在可以更容易地解析，因为您可以单独处理每个单元格。

警告：正如 Patrick Roberts 在 cmets 中指出的那样，这仅适用于仅在最后一列中找到多行单元格的情况。

const input = `Data		
Data	Data	
Data	Data	Data
Data	Data	Data"
Data	Data	"Da
ta"
Data	Data	"Da
ta"""
Data	Data	Data""
Data	Data	"""Da
ta"""
Data	Data	"""Da

ta"""`;

const s = (input + '\n')
  .replace(/(("[^"]*")*)\n/g, '$1\r')
  .trim('\r');
const cells = s
  .split('\r')
  .map(row => row.split('\t'));

console.log(cells);

Answer 3

我无法想出一个健壮的正则表达式解决方案，但这里有一个可行的解决方案。

注意：我稍微更改了输入以测试不在最后一列中的多行单元格。

const input = `Data		
Data	Data	
"Da
ta"	Data	Data
Data	Data	Data"
Data	Data	"Da
ta"
Data	Data	"Da
ta"""
Data	Data	Data""
Data	Data	"""Da
ta"""
Data	Data	"""Da

ta"""`;

const columnCount = (input.split('\n')[0].match(/\t/g) || []).length + 1;

//parse input into cells and undo wonkiness
const parts = input.split(/[\t\n]/);
const cells = [];
let next = '';
for (let part of parts) {
  next += part + '\n';
  const quoteCount = (next.match(/"/g) || []).length;
  if (!next.startsWith('"') || quoteCount % 2 === 0) {
    let cell = next.trim('\n');
    if (cell.startsWith('"') && cell.endsWith('"')) {
      cell = cell.replace(/^"([^]*)"$/, '$1');
      cell = cell.replace(/""/g, '"');
    }
    cells.push(cell);
    next = '';
  }
}

//rearrange cells into rows
const rows = [];
let row = [];
for (let cell of cells) {
  row.push(cell);
  if (row.length === columnCount) {
    rows.push(row);
    row = [];
  }
}

//display results in table
const tableElem = document.getElementById('table');
for (let row of rows) {
  let trElem = document.createElement('tr');
  for (let cell of row) {
    let tdElem = document.createElement('td');
    tdElem.innerHTML = cell.replace('\n', '<br/>');
    trElem.appendChild(tdElem);
  }
  tableElem.appendChild(trElem);
}

<style>
    table, th, td {
      border: 1px solid black;
      border-collapse: collapse;
      padding: 2px;
    }
  </style>
  <table id="table"></table>

Answer 4

解析所有数据

这是一个正则表达式，它将匹配源中的每个组件，一个一个地匹配到编号的捕获组中：

1. 制表符分隔符
2. 行尾/新行
3. 引用数据
4. 未引用的数据

这将同时处理单行数据或所有行。 还处理 CLRF (\r\n) 和 RF (\n) 行尾。

表达式

/(?:(\t)|(\r?\n)|"((?:[^"]+|"")*)"|([^\t\r\n]+))/

可视化

示例用法

这里我们使用捕获的组来指示要做什么。

这会在控制台中输出一个行数组。

var str =
  'Data		' + "\r\n" +
  'Data	Data	' + "\r\n" +
  'Data	Data	Data' + "\r\n" +
  'Data	Data	Data"' + "\r\n" +
  'Data	Data	"Da' + "\r\n" +
  'ta"' + "\r\n" +
  'Data	Data	"Da' + "\r\n" +
  'ta"""' + "\r\n" +
  'Data	Data	Data""' + "\r\n" +
  'Data	Data	"""Da' + "\r\n" +
  'ta"""' + "\r\n" +
  'Data	Data	"""Da' + "\r\n" +
  '' + "\r\n" +
  'ta"""';



var myregexp = /(?:(\t)|(\r?\n)|"((?:[^"]+|"")*)"|([^\t\r\n]+))/ig;
var match = myregexp.exec(str);
var emptyRow = [];
var row = emptyRow.slice();
var rows = [];
var prevTab = false;
while (match != null) {
  if (match[4]) {
    // Unquoted data
    row.push(match[4]);
    prevTab = false;
  } else if (match[3]) {
    // Quoted data (replace escaped double quotes with single)
    row.push(match[3].replace(/""/g, "'"));
    prevTab = false;
  } else if (match[1]) {
    // Tab seperator
    if (prevTab) {
      // Two tabs means empty data
      row.push('');
    }
    prevTab = true;
  } else if (match[2]) {
    // End of the row
    if (prevTab) {
      // Previously had a tab, so include the empty data
      row.push('');
    }
    prevTab = false;
    rows.push(row);
    
    // Here we are ensuring the new empty row doesn't reference the old one.
    row = emptyRow.slice();
  }
  match = myregexp.exec(str);
}

// Handles missing new line at end of string
if (row.length) {
  if (prevTab) {
    // Previously had a tab, so include the empty data
    row.push('');
  }
  rows.push(row);
}

console.log('rows', rows);

注释正则表达式

// (?:(\t)|(\r?\n)|"((?:[^"]+|"")*)"|([^\t\r\n]+))
// 
// Options: Case insensitive; ^$ don’t match at line breaks
// 
// Match the regular expression below «(?:(\t)|(\r?\n)|"((?:[^"]+|"")*)"|([^\t\r\n]+))»
//    Match this alternative (attempting the next alternative only if this one fails) «(\t)»
//       Match the regex below and capture its match into backreference number 1 «(\t)»
//          Match the tab character «\t»
//    Or match this alternative (attempting the next alternative only if this one fails) «(\r?\n)»
//       Match the regex below and capture its match into backreference number 2 «(\r?\n)»
//          Match the carriage return character «\r?»
//             Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
//          Match the line feed character «\n»
//    Or match this alternative (attempting the next alternative only if this one fails) «"((?:[^"]+|"")*)"»
//       Match the character “"” literally «"»
//       Match the regex below and capture its match into backreference number 3 «((?:[^"]+|"")*)»
//          Match the regular expression below «(?:[^"]+|"")*»
//             Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
//             Match this alternative (attempting the next alternative only if this one fails) «[^"]+»
//                Match any character that is NOT a “"” «[^"]+»
//                   Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
//             Or match this alternative (the entire group fails if this one fails to match) «""»
//                Match the character string “""” literally «""»
//       Match the character “"” literally «"»
//    Or match this alternative (the entire group fails if this one fails to match) «([^\t\r\n]+)»
//       Match the regex below and capture its match into backreference number 4 «([^\t\r\n]+)»
//          Match any single character NOT present in the list below «[^\t\r\n]+»
//             Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
//             The tab character «\t»
//             The carriage return character «\r»
//             The line feed character «\n»