Make <- less of a signal boost for R

Author: klmr

src/languages/r.js

@@ -202,9 +202,21 @@ export default function(hljs) {
 
       // Operators/punctuation when they're not directly followed by numbers
       {
+        // Avoid false detections of other languages.
         scope: 'operator',
+        relevance: 0,
         match: /<-/
       },
+      {
+        // Relevance boost for the most common assignment form.
+        scope: { 3: 'operator' },
+        match: [
+          IDENT_RE,
+          /\s+/,
+          /<-/,
+          /\s+/
+        ]
+      },
       {
         scope: 'operator',
         variants: [