@thi.ng/parse/prims/anchor.js

Purely functional parser combinators & AST generation for generic inputs

import { ALPHA_NUM } from "@thi.ng/strings/groups";
const anchor = (fn) => ({ reader, state }) => fn(reader.prev(state), state.done ? null : reader.read(state));
const inputStart = (ctx) => ctx.reader.prev(ctx.state) == null;
const inputEnd = ({ reader, state }) => state.done || reader.read(state) === void 0;
const lineStart = (ctx) => {
  const l = ctx.reader.prev(ctx.state);
  return l == null || l === "\n" || l === "\r";
};
const lineEnd = ({ reader, state }) => {
  let c;
  return state.done || (c = reader.read(state)) === "\n" || c === "\r";
};
const wordBoundaryP = (prev, next) => {
  return prev ? next ? ALPHA_NUM[prev] && !ALPHA_NUM[next] : ALPHA_NUM[prev] : next ? ALPHA_NUM[next] : false;
};
const wordBoundary = anchor(wordBoundaryP);
export {
  anchor,
  inputEnd,
  inputStart,
  lineEnd,
  lineStart,
  wordBoundary,
  wordBoundaryP
};