Add hex number tokenization to R language

src/r.ts

@@ -193,6 +193,7 @@ export const language = <ILanguage>{
 
 		// Recognize positives, negatives, decimals, imaginaries, and scientific notation
 		numbers: [
+			[/0[xX][0-9a-fA-F]+/, 'number.hex'],
 			[/-?(\d*\.)?\d+([eE][+\-]?\d+)?/, 'number']
 		],