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c20f20c | 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 | import * as mathmlHandlers from './mathml/index.js'
import { addScriptlevel } from './ooml/index.js'
export function walker(
element,
targetParent,
previousSibling = false,
nextSibling = false,
ancestors = []
) {
if (
!previousSibling &&
['m:deg', 'm:den', 'm:e', 'm:fName', 'm:lim', 'm:num', 'm:sub', 'm:sup'].includes(
targetParent.name
)
) {
// We are walking through the first element within one of the
// elements where an <m:argPr> might occur. The <m:argPr> can specify
// the scriptlevel, but it only makes sense if there is some content.
// The fact that we are here means that there is at least one content item.
// So we will check whether to add the m:rPr.
// For possible parent types, see
// https://docs.microsoft.com/en-us/dotnet/api/documentformat.openxml.math.argumentproperties?view=openxml-2.8.1#remarks
addScriptlevel(targetParent, ancestors)
}
let targetElement
const nameOrType = element.name || element.type
if (mathmlHandlers[nameOrType]) {
targetElement = mathmlHandlers[nameOrType](
element,
targetParent,
previousSibling,
nextSibling,
ancestors
)
} else {
if (nameOrType && nameOrType !== 'root') {
console.warn(`Type not supported: ${nameOrType}`)
}
targetElement = targetParent
}
if (!targetElement) {
// Target element hasn't been assigned, so don't handle children.
return
}
if (element.children?.length) {
ancestors = [...ancestors]
ancestors.unshift(element)
// Track nary body redirect: after a nary operator, redirect subsequent
// siblings into its <m:e> until a relational operator (=, <, >, etc.) is
// encountered. Chains through nested nary operators (e.g. double
// integrals ∫∫).
let naryBodyTarget = null
// Track prescript redirect: after a msubsup with empty base (e.g.
// {}^{14}_{6}C), redirect the next sibling into <m:sPre>'s <m:e>.
let prescriptTarget = null
for (let i = 0; i < element.children.length; i++) {
const child = element.children[i]
if (child.skipInWalker) continue
// A relational/separator <mo> or <mtext> stops the nary redirect so
// that content after the operand stays outside the nary body.
// Examples: ∑ aᵢ = S → operand is aᵢ (stopped by =)
// ∑ aᵢ, bⱼ → operand is aᵢ (stopped by ,)
// ∑ aᵢ \text{ for } i → operand is aᵢ (stopped by mtext)
if (naryBodyTarget) {
if (child.name === 'mo') {
const txt = child.children?.[0]?.data
if (txt && /^[=<>≤≥≠≈≡∼≲≳≪≫∈∉⊂⊃⊆⊇⊄⊅≺≻⪯⪰∝≅≃≍≎∥⊥⊢⊣⊨⊩,;:∣]$/.test(txt)) {
naryBodyTarget = null
}
} else if (child.name === 'mtext') {
naryBodyTarget = null
}
}
const effectiveTarget = prescriptTarget || naryBodyTarget || targetElement
walker(
child,
effectiveTarget,
element.children[i - 1],
element.children[i + 1],
ancestors
)
if (child.isNary) {
// Chain into the new nary's <m:e>
const naryNode = effectiveTarget.children[effectiveTarget.children.length - 1]
naryBodyTarget = naryNode.children[naryNode.children.length - 1]
}
if (child.isPrescript) {
// Redirect next sibling into <m:sPre>'s <m:e>
const preNode = effectiveTarget.children[effectiveTarget.children.length - 1]
prescriptTarget = preNode.children[preNode.children.length - 1]
} else if (prescriptTarget) {
// One element consumed; stop prescript redirect
prescriptTarget = null
}
}
}
}
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