@dpkit/table/field/types/yearmonth.ts

Data Package implementation in TypeScript.

import type { YearmonthField } from "@dpkit/core"
import { DataType, col } from "nodejs-polars"
import type { Expr } from "nodejs-polars"

// TODO:
// Add more validation:
// - Check the length of the list is 2 (no list.lenghts in polars currently)
// - Check the values are year and month limits
// - Return null instead of list if any of the values are out of range
export function parseYearmonthField(field: YearmonthField, expr?: Expr) {
  expr = expr ?? col(field.name)

  expr = expr.str.split("-").cast(DataType.List(DataType.Int16))

  return expr
}