reduce index by inlining Hangul Jamo Extended-B range (#109)

* reduce index by inlining Hangul Jamo Extended-B range

* changeset

Author: cometkim

.changeset/afraid-spies-beg.md

@@ -0,0 +1,6 @@
+---
+"unicode-segmenter": patch
+---
+
+Inlining more Hangul ranges (Hangul Jamo Extended-B) to reduce index memory usage (8.5KB -> 7.4KB)
+Slightly improved the bundle size as well.

README.md

@@ -215,7 +215,7 @@ Since [Hermes doesn't support the `Intl.Segmenter` API](https://github.com/faceb
 
 | Name                         | Unicode® | ESM? |   Size    | Size (min) | Size (min+gzip) | Size (min+br) | Size (min+zstd) |
 |------------------------------|----------|------|----------:|-----------:|----------------:|--------------:|----------------:|
-| `unicode-segmenter/grapheme` |   16.0.0 |   ✔️ |    11,272 |      6,846 |           3,449 |         2,803 |           3,564 |
+| `unicode-segmenter/grapheme` |   16.0.0 |   ✔️ |    10,937 |      6,743 |           3,401 |         2,770 |           3,520 |
 | `graphemer`                  |   15.0.0 |   ✖️ ️|   410,435 |     95,104 |          15,752 |        10,660 |          15,911 |
 | `grapheme-splitter`          |   10.0.0 |   ✖️ |   122,254 |     23,682 |           7,852 |         4,802 |           6,753 |
 | `@formatjs/intl-segmenter`*  |   15.0.0 |   ✖️ |   603,510 |    369,673 |          72,273 |        49,530 |          68,027 |
@@ -231,7 +231,7 @@ Since [Hermes doesn't support the `Intl.Segmenter` API](https://github.com/faceb
 
 | Name                         | Bytecode size | Bytecode size (gzip)* |
 |------------------------------|--------------:|----------------------:|
-| `unicode-segmenter/grapheme` |        20,619 |                11,619 |
+| `unicode-segmenter/grapheme` |        20,446 |                11,561 |
 | `graphemer`                  |       134,089 |                31,766 |
 | `grapheme-splitter`          |        63,946 |                19,162 |
 

scripts/unicode.js

@@ -854,6 +854,10 @@ let graphemeTableOptimized = graphemeTable.filter(([from, to, cat]) => {
   if (from >= 0xAC00 && to <= 0xD7A3 && (cat === 'LV' || cat === 'LVT')) {
     return false;
   }
+  // Hangul Jamo Extended-B: 0xD7B0-0xD7FF (inlined in cat())
+  if (from >= 0xD7B0 && to <= 0xD7FF) {
+    return false;
+  }
   // Private Use fast path: 0xE000-0xFDFF (inlined in cat())
   if (from >= 0xE000 && to < 0xFE00) {
     return false;

src/_grapheme_data.js

@@ -100,6 +100,6 @@ export const GraphemeCategory = {
  */
 export const grapheme_ranges = decodeUnicodeData(
   /** @type {UnicodeDataEncoding} */
-  (',9,a,,b,1,d,,e,h,3j,w,4p,,4t,,4u,,lc,33,w3,6,13l,18,14v,,14x,1,150,1,153,,16o,5,174,a,17g,,18r,k,19s,,1cm,6,1ct,,1cv,5,1d3,1,1d6,3,1e7,,1e9,,1f4,q,1ie,a,1kb,8,1kt,,1li,3,1ln,8,1lx,2,1m1,4,1nd,2,1ow,1,1p3,8,1qi,n,1r6,,1r7,v,1s3,,1tm,,1tn,,1to,,1tq,2,1tt,7,1u1,3,1u5,,1u6,1,1u9,6,1uq,1,1vl,,1vm,1,1x8,,1xa,,1xb,1,1xd,3,1xj,1,1xn,1,1xp,,1xz,,1ya,1,1z2,,1z5,1,1z7,,20s,,20u,2,20x,1,213,1,217,2,21d,,228,1,22d,,22p,1,22r,,24c,,24e,2,24h,4,24n,1,24p,,24r,1,24t,,25e,1,262,5,269,,26a,1,27w,,27y,1,280,,281,3,287,1,28b,1,28d,,28l,2,28y,1,29u,,2bi,,2bj,,2bk,,2bl,1,2bq,2,2bu,2,2bx,,2c7,,2dc,,2dd,2,2dg,,2f0,,2f2,2,2f5,3,2fa,2,2fe,3,2fp,1,2g2,1,2gx,,2gy,1,2ik,,2im,,2in,1,2ip,,2iq,,2ir,1,2iu,2,2iy,3,2j9,1,2jm,1,2k3,,2kg,1,2ki,1,2m3,1,2m6,,2m7,1,2m9,3,2me,2,2mi,2,2ml,,2mm,,2mv,,2n6,1,2o1,,2o2,1,2q2,,2q7,,2q8,1,2qa,2,2qe,,2qg,6,2qn,,2r6,1,2sx,,2sz,,2t0,6,2tj,7,2wh,,2wj,,2wk,8,2x4,6,2zc,1,305,,307,,309,,30e,1,31t,d,327,,328,4,32e,1,32l,a,32x,z,346,,371,3,375,,376,5,37d,1,37f,1,37h,1,386,1,388,1,38e,2,38x,3,39e,,39g,,39h,1,39p,,3a5,,3cw,2n,3fk,1z,3hk,2f,3tp,2,4k2,3,4ky,2,4lu,1,4mq,1,4ok,1,4om,,4on,6,4ou,7,4p2,,4p3,1,4p5,a,4pp,,4qz,2,4r2,,4r3,,4ud,1,4vd,,4yo,2,4yr,3,4yv,1,4yx,2,4z4,1,4z6,,4z7,5,4zd,2,55j,1,55l,1,55n,,579,,57a,,57b,,57c,6,57k,,57m,,57p,7,57x,5,583,9,58f,,59s,u,5c0,3,5c4,,5dg,9,5dq,3,5du,2,5ez,8,5fk,1,5fm,,5gh,,5gi,3,5gm,1,5go,5,5ie,,5if,,5ig,1,5ii,2,5il,,5im,,5in,4,5k4,7,5kc,7,5kk,1,5km,1,5ow,2,5p0,c,5pd,,5pe,6,5pp,,5pw,,5pz,,5q0,1,5vk,1r,6bv,,6bw,,6bx,,6by,1,6co,6,6d8,,6dl,,6e8,f,6hc,w,6jm,,6k9,,6ms,5,6nd,1,6xm,1,6y0,,70o,,72n,,73d,a,73s,2,79e,,7fu,1,7g6,,7gg,,7i3,3,7i8,5,7if,b,7is,35,7m8,39,7pk,a,7pw,,7py,,7q5,,7q9,,7qg,,7qr,1,7r8,,7rb,,7rg,,7ri,,7rn,2,7rr,,7s3,4,7th,2,7tt,,7u8,,7un,,850,1,8hx,2,8ij,1,8k0,,8k5,,8vj,2,8zj,,928,v,wvj,3,wvo,9,wwu,1,wz4,1,x6q,,x6u,,x6z,,x7n,1,x7p,1,x7r,,x7w,,xa8,1,xbo,f,xc4,1,xcw,h,xdr,,xeu,7,xfr,a,xg2,,xg3,,xgg,s,xhc,2,xhf,,xir,,xis,1,xiu,3,xiy,1,xj0,1,xj2,1,xj4,,xk5,,xm1,5,xm7,1,xm9,1,xmb,1,xmd,1,xmr,,xn0,,xn1,,xoc,,xps,,xpu,2,xpz,1,xq6,1,xq9,,xrf,,xrg,1,xri,1,xrp,,xrq,,xyb,1,xyd,,xye,1,xyg,,xyh,1,xyk,,xyl,,16ls,m,16mj,1c,1e68,f,1e74,f,1edb,,1ehq,1,1ek0,b,1eyl,,1f4w,,1f92,4,1gjl,2,1gjp,1,1gjw,3,1gl4,2,1glb,,1gpx,1,1h5w,3,1h7t,4,1hgr,1,1hj0,3,1hl2,a,1hmq,3,1hq8,,1hq9,,1hqa,,1hrs,e,1htc,,1htf,1,1htr,2,1htu,,1hv4,2,1hv7,3,1hvb,1,1hvd,1,1hvh,,1hvm,,1hvx,,1hxc,2,1hyf,4,1hyk,,1hyl,7,1hz9,1,1i0j,,1i0w,1,1i0y,,1i2b,2,1i2e,8,1i2n,,1i2o,,1i2q,1,1i2x,3,1i32,,1i33,,1i5o,2,1i5r,2,1i5u,1,1i5w,3,1i66,,1i69,,1ian,,1iao,2,1iar,7,1ibk,1,1ibm,1,1id7,1,1ida,,1idb,,1idc,,1idd,3,1idj,1,1idn,1,1idp,,1idz,,1iea,1,1iee,6,1ieo,4,1igo,,1igp,1,1igr,5,1igy,,1ih1,,1ih3,2,1ih6,,1ih8,1,1iha,2,1ihd,,1ihe,,1iht,1,1ik5,2,1ik8,7,1ikg,1,1iki,2,1ikl,,1ikm,,1ila,,1ink,,1inl,1,1inn,5,1int,,1inu,,1inv,1,1inx,,1iny,,1inz,1,1io1,,1io2,1,1iun,,1iuo,1,1iuq,3,1iuw,3,1iv0,1,1iv2,,1iv3,1,1ivw,1,1iy8,2,1iyb,7,1iyj,1,1iyl,,1iym,,1iyn,1,1j1n,,1j1o,,1j1p,,1j1q,1,1j1s,7,1j4t,,1j4u,,1j4v,,1j4y,3,1j52,,1j53,4,1jcc,2,1jcf,8,1jco,,1jcp,1,1jjk,,1jjl,4,1jjr,1,1jjv,3,1jjz,,1jk0,,1jk1,,1jk2,,1jk3,,1jo1,2,1jo4,3,1joa,1,1joc,3,1jog,,1jok,,1jpd,9,1jqr,5,1jqx,,1jqy,,1jqz,3,1jrb,,1jrl,5,1jrr,1,1jrt,2,1jt0,5,1jt6,c,1jtj,,1jtk,1,1k4v,,1k4w,6,1k54,5,1k5a,,1k5b,,1k7m,l,1k89,,1k8a,6,1k8h,,1k8i,1,1k8k,,1k8l,1,1kc1,5,1kca,,1kcc,1,1kcf,6,1kcm,,1kcn,,1kei,4,1keo,1,1ker,1,1ket,,1keu,,1kev,,1koj,1,1kol,1,1kow,1,1koy,,1koz,,1kqc,1,1kqe,4,1kqm,1,1kqo,2,1kre,,1ovk,f,1ow0,,1ow7,e,1xr2,b,1xre,2,1xrh,2,1zow,4,1zqo,6,206b,,206f,3,20jz,,20k1,1i,20lr,3,20o4,,20og,1,2ftp,1,2fts,3,2jgg,19,2jhs,m,2jxh,4,2jxp,5,2jxv,7,2jy3,7,2jyd,6,2jze,3,2k3m,2,2lmo,1i,2lob,1d,2lpx,,2lqc,,2lqz,4,2lr5,e,2mtc,6,2mtk,g,2mu3,6,2mub,1,2mue,4,2mxb,,2n1s,6,2nce,,2ne4,3,2nsc,3,2nzi,1,2ok0,6,2on8,6,2pz4,73,2q6l,2,2q7j,,2q98,5,2q9q,1,2qa6,,2qa9,9,2qb1,1k,2qcm,p,2qdd,e,2qe2,,2qen,,2qeq,8,2qf0,3,2qfd,c1,2qrf,4,2qrk,8t,2r0m,7d,2r9c,3j,2rg4,b,2rit,16,2rkc,3,2rm0,7,2rmi,5,2rns,7,2rou,29,2rrg,1a,2rss,9,2rt3,c8,2scg,sd,jny8,v,jnz4,2n,jo1s,3j,jo5c,6n,joc0,2rz'),
-  '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',
+  (',9,a,,b,1,d,,e,h,3j,w,4p,,4t,,4u,,lc,33,w3,6,13l,18,14v,,14x,1,150,1,153,,16o,5,174,a,17g,,18r,k,19s,,1cm,6,1ct,,1cv,5,1d3,1,1d6,3,1e7,,1e9,,1f4,q,1ie,a,1kb,8,1kt,,1li,3,1ln,8,1lx,2,1m1,4,1nd,2,1ow,1,1p3,8,1qi,n,1r6,,1r7,v,1s3,,1tm,,1tn,,1to,,1tq,2,1tt,7,1u1,3,1u5,,1u6,1,1u9,6,1uq,1,1vl,,1vm,1,1x8,,1xa,,1xb,1,1xd,3,1xj,1,1xn,1,1xp,,1xz,,1ya,1,1z2,,1z5,1,1z7,,20s,,20u,2,20x,1,213,1,217,2,21d,,228,1,22d,,22p,1,22r,,24c,,24e,2,24h,4,24n,1,24p,,24r,1,24t,,25e,1,262,5,269,,26a,1,27w,,27y,1,280,,281,3,287,1,28b,1,28d,,28l,2,28y,1,29u,,2bi,,2bj,,2bk,,2bl,1,2bq,2,2bu,2,2bx,,2c7,,2dc,,2dd,2,2dg,,2f0,,2f2,2,2f5,3,2fa,2,2fe,3,2fp,1,2g2,1,2gx,,2gy,1,2ik,,2im,,2in,1,2ip,,2iq,,2ir,1,2iu,2,2iy,3,2j9,1,2jm,1,2k3,,2kg,1,2ki,1,2m3,1,2m6,,2m7,1,2m9,3,2me,2,2mi,2,2ml,,2mm,,2mv,,2n6,1,2o1,,2o2,1,2q2,,2q7,,2q8,1,2qa,2,2qe,,2qg,6,2qn,,2r6,1,2sx,,2sz,,2t0,6,2tj,7,2wh,,2wj,,2wk,8,2x4,6,2zc,1,305,,307,,309,,30e,1,31t,d,327,,328,4,32e,1,32l,a,32x,z,346,,371,3,375,,376,5,37d,1,37f,1,37h,1,386,1,388,1,38e,2,38x,3,39e,,39g,,39h,1,39p,,3a5,,3cw,2n,3fk,1z,3hk,2f,3tp,2,4k2,3,4ky,2,4lu,1,4mq,1,4ok,1,4om,,4on,6,4ou,7,4p2,,4p3,1,4p5,a,4pp,,4qz,2,4r2,,4r3,,4ud,1,4vd,,4yo,2,4yr,3,4yv,1,4yx,2,4z4,1,4z6,,4z7,5,4zd,2,55j,1,55l,1,55n,,579,,57a,,57b,,57c,6,57k,,57m,,57p,7,57x,5,583,9,58f,,59s,u,5c0,3,5c4,,5dg,9,5dq,3,5du,2,5ez,8,5fk,1,5fm,,5gh,,5gi,3,5gm,1,5go,5,5ie,,5if,,5ig,1,5ii,2,5il,,5im,,5in,4,5k4,7,5kc,7,5kk,1,5km,1,5ow,2,5p0,c,5pd,,5pe,6,5pp,,5pw,,5pz,,5q0,1,5vk,1r,6bv,,6bw,,6bx,,6by,1,6co,6,6d8,,6dl,,6e8,f,6hc,w,6jm,,6k9,,6ms,5,6nd,1,6xm,1,6y0,,70o,,72n,,73d,a,73s,2,79e,,7fu,1,7g6,,7gg,,7i3,3,7i8,5,7if,b,7is,35,7m8,39,7pk,a,7pw,,7py,,7q5,,7q9,,7qg,,7qr,1,7r8,,7rb,,7rg,,7ri,,7rn,2,7rr,,7s3,4,7th,2,7tt,,7u8,,7un,,850,1,8hx,2,8ij,1,8k0,,8k5,,8vj,2,8zj,,928,v,wvj,3,wvo,9,wwu,1,wz4,1,x6q,,x6u,,x6z,,x7n,1,x7p,1,x7r,,x7w,,xa8,1,xbo,f,xc4,1,xcw,h,xdr,,xeu,7,xfr,a,xg2,,xg3,,xgg,s,xhc,2,xhf,,xir,,xis,1,xiu,3,xiy,1,xj0,1,xj2,1,xj4,,xk5,,xm1,5,xm7,1,xm9,1,xmb,1,xmd,1,xmr,,xn0,,xn1,,xoc,,xps,,xpu,2,xpz,1,xq6,1,xq9,,xrf,,xrg,1,xri,1,xrp,,xrq,,xyb,1,xyd,,xye,1,xyg,,xyh,1,xyk,,xyl,,1e68,f,1e74,f,1edb,,1ehq,1,1ek0,b,1eyl,,1f4w,,1f92,4,1gjl,2,1gjp,1,1gjw,3,1gl4,2,1glb,,1gpx,1,1h5w,3,1h7t,4,1hgr,1,1hj0,3,1hl2,a,1hmq,3,1hq8,,1hq9,,1hqa,,1hrs,e,1htc,,1htf,1,1htr,2,1htu,,1hv4,2,1hv7,3,1hvb,1,1hvd,1,1hvh,,1hvm,,1hvx,,1hxc,2,1hyf,4,1hyk,,1hyl,7,1hz9,1,1i0j,,1i0w,1,1i0y,,1i2b,2,1i2e,8,1i2n,,1i2o,,1i2q,1,1i2x,3,1i32,,1i33,,1i5o,2,1i5r,2,1i5u,1,1i5w,3,1i66,,1i69,,1ian,,1iao,2,1iar,7,1ibk,1,1ibm,1,1id7,1,1ida,,1idb,,1idc,,1idd,3,1idj,1,1idn,1,1idp,,1idz,,1iea,1,1iee,6,1ieo,4,1igo,,1igp,1,1igr,5,1igy,,1ih1,,1ih3,2,1ih6,,1ih8,1,1iha,2,1ihd,,1ihe,,1iht,1,1ik5,2,1ik8,7,1ikg,1,1iki,2,1ikl,,1ikm,,1ila,,1ink,,1inl,1,1inn,5,1int,,1inu,,1inv,1,1inx,,1iny,,1inz,1,1io1,,1io2,1,1iun,,1iuo,1,1iuq,3,1iuw,3,1iv0,1,1iv2,,1iv3,1,1ivw,1,1iy8,2,1iyb,7,1iyj,1,1iyl,,1iym,,1iyn,1,1j1n,,1j1o,,1j1p,,1j1q,1,1j1s,7,1j4t,,1j4u,,1j4v,,1j4y,3,1j52,,1j53,4,1jcc,2,1jcf,8,1jco,,1jcp,1,1jjk,,1jjl,4,1jjr,1,1jjv,3,1jjz,,1jk0,,1jk1,,1jk2,,1jk3,,1jo1,2,1jo4,3,1joa,1,1joc,3,1jog,,1jok,,1jpd,9,1jqr,5,1jqx,,1jqy,,1jqz,3,1jrb,,1jrl,5,1jrr,1,1jrt,2,1jt0,5,1jt6,c,1jtj,,1jtk,1,1k4v,,1k4w,6,1k54,5,1k5a,,1k5b,,1k7m,l,1k89,,1k8a,6,1k8h,,1k8i,1,1k8k,,1k8l,1,1kc1,5,1kca,,1kcc,1,1kcf,6,1kcm,,1kcn,,1kei,4,1keo,1,1ker,1,1ket,,1keu,,1kev,,1koj,1,1kol,1,1kow,1,1koy,,1koz,,1kqc,1,1kqe,4,1kqm,1,1kqo,2,1kre,,1ovk,f,1ow0,,1ow7,e,1xr2,b,1xre,2,1xrh,2,1zow,4,1zqo,6,206b,,206f,3,20jz,,20k1,1i,20lr,3,20o4,,20og,1,2ftp,1,2fts,3,2jgg,19,2jhs,m,2jxh,4,2jxp,5,2jxv,7,2jy3,7,2jyd,6,2jze,3,2k3m,2,2lmo,1i,2lob,1d,2lpx,,2lqc,,2lqz,4,2lr5,e,2mtc,6,2mtk,g,2mu3,6,2mub,1,2mue,4,2mxb,,2n1s,6,2nce,,2ne4,3,2nsc,3,2nzi,1,2ok0,6,2on8,6,2pz4,73,2q6l,2,2q7j,,2q98,5,2q9q,1,2qa6,,2qa9,9,2qb1,1k,2qcm,p,2qdd,e,2qe2,,2qen,,2qeq,8,2qf0,3,2qfd,c1,2qrf,4,2qrk,8t,2r0m,7d,2r9c,3j,2rg4,b,2rit,16,2rkc,3,2rm0,7,2rmi,5,2rns,7,2rou,29,2rrg,1a,2rss,9,2rt3,c8,2scg,sd,jny8,v,jnz4,2n,jo1s,3j,jo5c,6n,joc0,2rz'),
+  '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',
 );

src/grapheme.js

@@ -195,6 +195,7 @@ export function* splitGraphemes(text) {
 // Memory and code size optimization: Skip regions that can be easily inlined
 // - 0x3000-0x9FFF (CJK): 28,672 codepoints, only 12 non-Any ranges
 // - 0xAC00-0xD7A3 (Hangul syllables): 11,172 codepoints, LV or LVT computed at runtime
+// - 0xD7A4-0xD7FF (Hangul Jamo Extended-B): 92 codepoints, only 2 non-Any ranges
 // - 0xE000-0xFDFF (Private Use): 7,680 codepoints, only 1 non-Any range
 // - 0xFE00-0xFFFF (Specials): 512 codepoints -> very rare and small, binary search fallback
 // 
@@ -205,32 +206,28 @@ export function* splitGraphemes(text) {
 // Indexed category segments (4-bit packed, 2 categories per byte):
 // - SEG0: 0x0080-0x2FFF (12,160 codepoints -> 6,080 bytes)
 // - SEG1: 0xA000-0xABFF (3,072 codepoints -> 1,536 bytes)
-// - SEG2: 0xD7A4-0xDFFF (2,140 codepoints -> 1,070 bytes)
-// 
-// Total index size: 8,686 bytes (~8.5KB)
+//
+// Total index size: 7,616 bytes (~7.4KB)
 const SEG0 = new Uint8Array(6080), SEG0_MIN = 0x0080, SEG0_MAX = 0x2FFF;
 const SEG1 = new Uint8Array(1536), SEG1_MIN = 0xA000, SEG1_MAX = 0xABFF;
-const SEG2 = new Uint8Array(1070), SEG2_MIN = 0xD7A4, SEG2_MAX = 0xDFFF;
 const SEG_CURSOR = (() => {
   let cursor = 0;
   while (true) {
     let [start, end, cat] = grapheme_ranges[cursor];
-    if (start > SEG2_MAX) break;
+    if (start > SEG1_MAX) break;
     cursor++;
 
     // Skip inlined ranges
-    if (end < SEG0_MIN || (start > SEG0_MAX && end < SEG1_MIN) || (start > SEG1_MAX && end < SEG2_MIN)) continue;
+    if (end < SEG0_MIN || (start > SEG0_MAX && end < SEG1_MIN)) continue;
 
     for (let cp = start; cp <= end; cp++) {
       let /** @type {Uint8Array} */ seg, idx = 0;
 
       if (cp <= SEG0_MAX) {
         seg = SEG0; idx = (cp - SEG0_MIN) >> 1;
-      } else if (cp <= SEG1_MAX) {
+      } else {
         seg = SEG1; idx = (cp - SEG1_MIN) >> 1;
-      } else if (cp >= SEG2_MIN) {
-        seg = SEG2; idx = (cp - SEG2_MIN) >> 1;
-      } else continue;
+      }
 
       seg[idx] = cp & 1
         ? (seg[idx] & 0x0F) | (cat << 4)
@@ -277,13 +274,13 @@ function cat(cp) {
     return /** @type {GraphemeCategoryNum} */ (cp & 1 ? byte >> 4 : byte & 0x0F);
   }
   // Hangul syllables path: 0xAC00-0xD7A3
-  if (cp < SEG2_MIN) {
+  if (cp <= 0xD7A3) {
     return (cp - 0xAC00) % 28 === 0 ? 7 : 8; // LV : LVT
   }
-  // Index Segment 2: 0xD7A4-0xDFFF
-  if (cp <= SEG2_MAX) {
-    let byte = SEG2[(cp - SEG2_MIN) >> 1];
-    return /** @type {GraphemeCategoryNum} */ (cp & 1 ? byte >> 4 : byte & 0x0F);
+  // Hangul Jamo Extended-B path: 0xD7A4-0xD7FF
+  if (cp <= 0xD7FF) {
+    if (cp <= 0xD7C6) return cp >= 0xD7B0 ? 13 : 0; // V
+    return cp >= 0xD7CB ? 12 : 0; // T
   }
   // Private Use fast path: 0xE000-0xFDFF
   if (cp < 0xFE00) {