6.12 Bold and Italic (太字・斜体)

Synopsis

太字 (bold / ゴシック) and 斜体 (italic) mark a run for emphasis as a change of weight or slant, rather than the dots or lines of bouten (§6.2). The two form one family with a 太字/斜体 split, parallel to the 点/線 split of bouten.

Notation

Three forms produce emphasis. Unlike bouten the particle is は (not に), and the family has both a bare inline range and a ここから/ここで block range.

Forward reference — quote the target; the emphasis applies to the most recent preceding occurrence (§7.5):
```
作者附記［＃「作者附記」は太字］
序文［＃「序文」は斜体］
```

Inline range — a bare opener and matching closer wrap the run directly, within a line. This is the most common form in the corpus:

emphasis-range = directive 1*element directive   ; ［＃太字］ … ［＃太字終わり］

本文［＃太字］註［＃太字終わり］。
値は［＃斜体］ｅ［＃斜体終わり］である。

Block range — the ここから/ここで…終わり form wraps one or more whole paragraphs; the opener sits on its own line:
```
［＃ここから太字］
強調する段落。
［＃ここで太字終わり］
```

Parameters

weight — 太字 (bold) or 斜体 (italic). The weight is what pairing checks for the range forms (§7.2): a 太字 opener pairs with a 太字 closer.
target — for the forward-reference form, the single quoted run to emphasise. The form names exactly one target; a multi-quote body (「A」「B」は太字) is not a recognised emphasis shape and degrades (§6.14).

Semantics

The forward-reference form resolves its target by the look-back rule of §7.5 and yields an emphasis node over that run. It is an inline construct.
The inline range form pairs opener and closer by weight (§7.1) and is an inline construct (§7.3): in the corpus it never spans a line, and rendering does not introduce block structure. It yields a container node (weight-tagged bold / italic) over the enclosed content.
The block range form pairs the same way but is a block construct: it wraps the enclosed paragraphs in a weight-tagged container node.
Reference rendering (§8): the inline forms are <b class="aozora-futoji">…</b> (太字) and <i class="aozora-shatai">…</i> (斜体) — presentational elements distinct from the <em> of bouten, so the two families never collide on one tag. The block form is a block container, <div class="aozora-container aozora-container-futoji">…</div> (resp. aozora-container-shatai), so the wrapped paragraphs nest validly.
Serialization (§7.6) reconstructs the source form — the は forward reference (including a redundant preceding target copy), the bare inline range, or the ここから/ここで block range — byte-exact.

Error conditions

Weight mismatch (range) — a 太字 opener closed by a 斜体 closer, or vice-versa, raises mismatched-container-close (error); the run is keyed to the opener's weight (recovery).
Unclosed range — an opener with no closer is handled per unclosed-bracket.
Target with no referent (forward reference) — a は太字 / は斜体 directive whose quoted target does not occur in the preceding text has no earlier run to emphasise, so the quoted target is itself the styled run: a self-contained forward reference, rendered <b> / <i>. ゴシック体 is a first-class gothic construct (§6.6), distinct from 太字 — the corpus uses them in disjoint works and gothic is a typeface family, not a bold weight — so the parser preserves its spelling and never folds it to 太字; serialization reconstructs ［＃「X」はゴシック体／太字／斜体］ byte-exact (§7.6). The vanishing ゴチック variant degrades (§6.14) with a lint suggesting ゴシック体. (Contrast the multi-quote body above, which is still unrecognised and degrades, §6.14.)

Conformance vectors

bold_inline, italic_inline, bold_block, italic_block, bold_forward, italic_forward, emphasis_mixed, bold_forward_no_referent, italic_forward_no_referent, bold_forward_gothic_no_referent (under conformance/vectors/).

Keyboard shortcuts