Read the block nodes back, and stop a marker change splitting a list

src/markdown/pipe-table-syntax.ts

@@ -0,0 +1,48 @@
+import type { ConvertFault } from '../result.ts'
+import { backslashEscape, claimsPipeLine, trimSpace } from './commonmark-grammar.ts'
+
+const alignmentCell = /^:-+:?$|^-+:$/
+const delimiterCell = /^-+$/
+
+export function isPipeAlignment(cell: string): boolean {
+  return alignmentCell.test(cell)
+}
+
+export function isPipeDelimiter(cell: string): boolean {
+  return delimiterCell.test(cell)
+}
+
+export function malformedPipeTable(message: string): ConvertFault {
+  return { code: 'malformed-pipe-table', message }
+}
+
+// spec/flavour.md, Tables: the cells of a claimed row, the closing `|` the spelling writes optional here.
+export function pipeCells(line: string): string[] | undefined {
+  if (!claimsPipeLine(line)) return undefined
+  const row = line.replace(/[ \t]+$/, '')
+  const cells: string[] = []
+  let start = 1
+  let index = 1
+  while (index < row.length) {
+    if (backslashEscape(row, index) !== undefined) {
+      index += 2
+      continue
+    }
+    if (row.charAt(index) === '|') {
+      cells.push(trimSpace(row.slice(start, index)))
+      start = index + 1
+    }
+    index += 1
+  }
+  cells.push(trimSpace(row.slice(start)))
+  if (cells.length > 1 && cells.at(-1) === '') cells.pop()
+  return cells
+}
+
+export function spellPipeDelimiter(columns: number): string {
+  return spellPipeRow(Array.from({ length: columns }, () => '---'))
+}
+
+export function spellPipeRow(cells: readonly string[]): string {
+  return `| ${cells.join(' | ')} |`
+}