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