Answer the review: one shape predicate, and the readable spellings give way

src/markdown-pipe-table.ts

@@ -1,4 +1,5 @@
 import type { AdfNode } from './adf-document.ts'
+import { carriesOnly } from './adf-document.ts'
 import { tryPipeCell } from './markdown-inline.ts'
 import type { ConvertErrorPath } from './result.ts'
 
@@ -23,16 +24,16 @@ export function tryPipeTable(node: AdfNode, path: ConvertErrorPath): string | un
 function pipeRows(node: AdfNode): AdfNode[][] | undefined {
   const rows = node.content ?? []
   const columns = (rows[0]?.content ?? []).length
-  if (!isPlain(node) || columns === 0) return undefined
+  if (!carriesOnly(node, []) || columns === 0) return undefined
   const grid: AdfNode[][] = []
   for (const [index, row] of rows.entries()) {
     const cells = row.content ?? []
-    if (row.type !== 'tableRow' || !isPlain(row) || cells.length !== columns) return undefined
+    if (row.type !== 'tableRow' || !carriesOnly(row, []) || cells.length !== columns) return undefined
     const wanted = index === 0 ? 'tableHeader' : 'tableCell'
     const paragraphs: AdfNode[] = []
     for (const cell of cells) {
       const paragraph = plainParagraph(cell)
-      if (paragraph === undefined || cell.type !== wanted || !isPlain(cell)) return undefined
+      if (paragraph === undefined || cell.type !== wanted || !carriesOnly(cell, [])) return undefined
       paragraphs.push(paragraph)
     }
     grid.push(paragraphs)
@@ -40,13 +41,9 @@ function pipeRows(node: AdfNode): AdfNode[][] | undefined {
   return grid
 }
 
-function isPlain(node: AdfNode): boolean {
-  return Object.keys(node.attrs ?? {}).length === 0 && (node.marks ?? []).length === 0 && node.text === undefined
-}
-
 function plainParagraph(cell: AdfNode): AdfNode | undefined {
   const content = cell.content ?? []
   const paragraph = content[0]
-  if (paragraph === undefined || content.length !== 1 || paragraph.type !== 'paragraph' || !isPlain(paragraph)) return undefined
+  if (paragraph === undefined || content.length !== 1 || paragraph.type !== 'paragraph' || !carriesOnly(paragraph, [])) return undefined
   return paragraph
 }