When finding or extracting text in EPUB/KEPUB DOM trees, inline
formatting elements like <em>, <strong>, <i>, <b>, <span>, etc. should
not break text continuity. A reader sees 'Vokalia and Consonantia' as
one phrase regardless of the <em> wrappers around each word.
Add inline formatting element set and helper functions:
- isInlineFormatting: checks if an element is an inline phrasing element
- collectInlineText: flattens text across formatting elements within
a block-level parent, returning segments that map back to original
text nodes
- findBlockParent: walks up from a text node to find the nearest
block-level ancestor (used to scope text collection)
- findTextAcrossInlineElements: fallback for findTextInNode that
concatenates text within each block element (transparently crossing
formatting elements) and maps match positions back to actual nodes
- collectBlockElements: gathers all block-level elements containing text
The key invariant: text collection NEVER crosses block-level element
boundaries (<p>, <div>, <h1>-<h6>, <li>, etc.) to avoid concatenating
text from different paragraphs.
The findTextInNode function now tries single-text-node matching first
(fast path, unchanged), then falls back to cross-element matching only
when needed. This preserves performance for the common case.
john-okeefe
3a54dda5c5