Function fromString

repos/effect/packages/effect/src/BigDecimal.ts:1378–1421

(s: string)

 * @see {@link toExponential} for always rendering scientific notation
 *
 * @category converting
 * @since 2.0.0
 */
export const format = (n: BigDecimal): string => {
  const normalized = normalize(n)
  if (Math.abs(normalized.scale) >= 16) {
    return toExponential(normalized)
  }

  const negative = normalized.value < bigint0
  const absolute = negative ? `${normalized.value}`.substring(1) : `${normalized.value}`

  let before: string
  let after: string

  if (normalized.scale >= absolute.length) {
    before = "0"
    after = "0".repeat(normalized.scale - absolute.length) + absolute
  } else {
    const location = absolute.length - normalized.scale
    if (location > absolute.length) {
      const zeros = location - absolute.length
      before = `${absolute}${"0".repeat(zeros)}`
      after = ""
    } else {
      after = absolute.slice(location)
      before = absolute.slice(0, location)
    }
  }

  const complete = after === "" ? before : `${before}.${after}`
  return negative ? `-${complete}` : complete
}

/**
 * Formats a given `BigDecimal` as a `string` in scientific notation.
 *
 * **When to use**
 *
 * Use to render a `BigDecimal` in scientific notation.
 *
 * **Example** (Formatting decimals exponentially)
 *
 * ```ts import.meta.vitest
 * import { BigDecimal } from "effect"
 *
 * BigDecimal.toExponential(BigDecimal.make(123456n, -5)) // => "1.23456e+10"