File size: 2,884 Bytes
f56a29b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 | import { getNary, getNaryTarget } from '../ooml/index.js'
import { walker } from '../walker.js'
export function msub(element, targetParent, previousSibling, nextSibling, ancestors) {
// Subscript
if (element.children.length !== 2) {
// treat as mrow
return targetParent
}
ancestors = [...ancestors]
ancestors.unshift(element)
const base = element.children[0]
const subscript = element.children[1]
let topTarget
//
// m:nAry
//
// Conditions:
// 1. base text must be nary operator
// 2. no accents
const naryChar = getNary(base)
if (
naryChar &&
element.attribs?.accent?.toLowerCase() !== 'true' &&
element.attribs?.accentunder?.toLowerCase() !== 'true'
) {
topTarget = getNaryTarget(naryChar, element, 'subSup', false, true)
element.isNary = true
} else {
// Check for empty base → prescript pattern (LaTeX {}_{sub}X)
const isEmptyBase = base.name === 'mrow' && (!base.children || base.children.length === 0)
if (isEmptyBase) {
topTarget = {
type: 'tag',
name: 'm:sPre',
attribs: {},
children: [
{
type: 'tag',
name: 'm:sPrePr',
attribs: {},
children: [
{
type: 'tag',
name: 'm:ctrlPr',
attribs: {},
children: []
}
]
}
]
}
element.isPrescript = true
} else {
const baseTarget = {
name: 'm:e',
type: 'tag',
attribs: {},
children: []
}
walker(base, baseTarget, false, false, ancestors)
topTarget = {
type: 'tag',
name: 'm:sSub',
attribs: {},
children: [
{
type: 'tag',
name: 'm:sSubPr',
attribs: {},
children: [
{
type: 'tag',
name: 'm:ctrlPr',
attribs: {},
children: []
}
]
},
baseTarget
]
}
}
}
const subscriptTarget = {
name: 'm:sub',
type: 'tag',
attribs: {},
children: []
}
walker(subscript, subscriptTarget, false, false, ancestors)
topTarget.children.push(subscriptTarget)
if (element.isNary) {
topTarget.children.push({ type: 'tag', name: 'm:sup', attribs: {}, children: [] })
topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] })
}
// For prescript, add empty m:sup and m:e (base filled by walker redirect)
if (element.isPrescript) {
topTarget.children.push({ type: 'tag', name: 'm:sup', attribs: {}, children: [] })
topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] })
}
targetParent.children.push(topTarget)
// Don't iterate over children in the usual way.
}
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