Read the emphasis, the links and the lone image CommonMark spells (#34)

src/markdown/emit/line-escaping.ts

@@ -1,5 +1,5 @@
 import { backtickRun, closingBacktickRun } from '../backtick-runs.ts'
-import { delimiterFlags, isWordCharacter, matchEmphasis } from '../emphasis-matching.ts'
+import { delimiterFlags, isWordCharacter, matchEmphasis, runLength } from '../emphasis-matching.ts'
 import { backslashEscape, escapesLineClaim, inlineHtmlConstruct, opensBracketedAutolink, opensEmailAutolink, type LinePosition } from '../commonmark-grammar.ts'
 import { opensInlineDirective } from '../directive-attributes.ts'
 import { readEntityReference } from '../entity-references.ts'
@@ -260,13 +260,6 @@ function startsRun(scan: string, index: number, escaped: ReadonlySet<number>): b
   return scan.charAt(index - 1) !== scan.charAt(index)
 }
 
-function runLength(scan: string, index: number): number {
-  const character = scan.charAt(index)
-  let length = 0
-  while (scan.charAt(index + length) === character) length += 1
-  return length
-}
-
 function charAt(text: string, index: number): string {
   return index < 0 ? '' : text.charAt(index)
 }