32 lines
1.1 KiB
TypeScript
32 lines
1.1 KiB
TypeScript
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import * as A from '../prelude/array';
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import * as S from '../prelude/string';
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import { MfmForest, MfmTree } from './parser';
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import { createTree, createLeaf } from '../prelude/tree';
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function isEmptyTextTree(t: MfmTree): boolean {
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return t.node.type == 'text' && t.node.props.text === '';
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}
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function concatTextTrees(ts: MfmForest): MfmTree {
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return createLeaf({ type: 'text', props: { text: S.concat(ts.map(x => x.node.props.text)) } });
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}
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function concatIfTextTrees(ts: MfmForest): MfmForest {
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return ts[0].node.type === 'text' ? [concatTextTrees(ts)] : ts;
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}
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function concatConsecutiveTextTrees(ts: MfmForest): MfmForest {
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const us = A.concat(A.groupOn(t => t.node.type, ts).map(concatIfTextTrees));
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return us.map(t => createTree(t.node, concatConsecutiveTextTrees(t.children)));
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}
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function removeEmptyTextNodes(ts: MfmForest): MfmForest {
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return ts
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.filter(t => !isEmptyTextTree(t))
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.map(t => createTree(t.node, removeEmptyTextNodes(t.children)));
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}
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export function normalize(ts: MfmForest): MfmForest {
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return removeEmptyTextNodes(concatConsecutiveTextTrees(ts));
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}
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