Move each rule implementation into its own file (fixes #83).

lib/md013.js

@@ -0,0 +1,63 @@
+// @ts-check
+
+"use strict";
+
+var shared = require("./shared");
+
+var labelRe = /^\s*\[.*[^\\]]:/;
+
+module.exports = {
+  "names": [ "MD013", "line-length" ],
+  "description": "Line length",
+  "tags": [ "line_length" ],
+  "function": function MD013(params, onError) {
+    var lineLength = params.config.line_length || 80;
+    var codeBlocks = params.config.code_blocks;
+    var includeCodeBlocks = (codeBlocks === undefined) ? true : !!codeBlocks;
+    var tables = params.config.tables;
+    var includeTables = (tables === undefined) ? true : !!tables;
+    var headers = params.config.headers;
+    var includeHeaders = (headers === undefined) ? true : !!headers;
+    var headerLineNumbers = [];
+    if (!includeHeaders) {
+      shared.forEachHeading(params, function forHeading(heading) {
+        headerLineNumbers.push(heading.lineNumber);
+      });
+    }
+    var tokenTypeMap = {
+      "em_open": "e",
+      "em_close": "E",
+      "link_open": "l",
+      "link_close": "L",
+      "strong_open": "s",
+      "strong_close": "S",
+      "text": "T"
+    };
+    var linkOnlyLineNumbers = [];
+    shared.filterTokens(params, "inline", function forToken(token) {
+      var childTokenTypes = "";
+      token.children.forEach(function forChild(child) {
+        if (child.type !== "text" || child.content !== "") {
+          childTokenTypes += tokenTypeMap[child.type] || "x";
+        }
+      });
+      if (/^[es]*lT?L[ES]*$/.test(childTokenTypes)) {
+        linkOnlyLineNumbers.push(token.lineNumber);
+      }
+    });
+    var longLineRe = new RegExp("^(.{" + lineLength + "})(.*\\s.*)$");
+    shared.forEachLine(params,
+      function forLine(line, lineIndex, inCode, onFence, inTable) {
+        var lineNumber = lineIndex + 1;
+        if ((includeCodeBlocks || !inCode) &&
+            (includeTables || !inTable) &&
+            (includeHeaders || (headerLineNumbers.indexOf(lineNumber)) < 0) &&
+            (linkOnlyLineNumbers.indexOf(lineNumber) < 0) &&
+            longLineRe.test(line) &&
+            !labelRe.test(line)) {
+          shared.addErrorDetailIf(onError, lineNumber, lineLength,
+            line.length, null, shared.rangeFromRegExp(line, longLineRe));
+        }
+      });
+  }
+};