@pretextbook/ptxast

TypeScript type definitions for the PreTeXt Abstract Syntax Tree (ptxast).

ptxast is a strongly-typed AST representation for PreTeXt documents, following the unist / xast ecosystem patterns.

Design

Each significant PreTeXt element (<theorem>, <section>, <p>, <m>, etc.) has its own TypeScript interface with typed children and attributes, rather than using a generic Element with a string name field. This gives you IDE autocompletion and compile-time checks across the entire PreTeXt vocabulary.

Node type values match PreTeXt XML tag names exactly ("theorem", "section", "p", etc.).

Usage

import type { PtxRoot, Section, Theorem, P } from "@pretextbook/ptxast";
import {
  section,
  theorem,
  proof,
  p,
  text,
  m,
  statement,
} from "@pretextbook/ptxast";
import { isPtxNode, isTheorem, isSection } from "@pretextbook/ptxast";

// Build a tree with typed factory functions
const tree = section(
  [
    theorem(
      [
        statement([p([text("For a right triangle: "), m("a^2 + b^2 = c^2")])]),
        proof([p([text("Left as an exercise.")])]),
      ],
      { "xml:id": "thm-pythagoras" },
    ),
  ],
  { "xml:id": "sec-geometry" },
);

// Narrow with type guards
if (isSection(tree)) {
  for (const child of tree.children) {
    if (isTheorem(child)) {
      console.log("Found a theorem:", child.attributes?.["xml:id"]);
    }
  }
}

Content Model

| Union | Description | | -------------------- | ---------------------------------------------------- | | PtxInlineContent | Text, emphasis, math (<m>), cross-refs, code, etc. | | PtxBlockContent | Paragraphs, lists, display math, all environments | | PtxDivisionContent | Chapters, sections, subsections, appendices | | PtxContent | Everything — the full union |

Building

npm run build -w @pretextbook/ptxast

Testing

npm run test -w @pretextbook/ptxast