Function diff

packages/effect/src/internal/differ/orPatch.ts:189–227

(
  options: {
    readonly oldValue: Either<Value2, Value>
    readonly newValue: Either<Value2, Value>
    readonly left: Differ<Value, Patch>
    readonly right: Differ<Value2, Patch2>
  }
)

/** @internal */
export const diff = <Value, Value2, Patch, Patch2>(
  options: {
    readonly oldValue: Either<Value2, Value>
    readonly newValue: Either<Value2, Value>
    readonly left: Differ<Value, Patch>
    readonly right: Differ<Value2, Patch2>
  }
): Differ.Or.Patch<Value, Value2, Patch, Patch2> => {
  switch (options.oldValue._tag) {
    case "Left": {
      switch (options.newValue._tag) {
        case "Left": {
          const valuePatch = options.left.diff(options.oldValue.left, options.newValue.left)
          if (Equal.equals(valuePatch, options.left.empty)) {
            return empty()
          }
          return makeUpdateLeft(valuePatch)
        }
        case "Right": {
          return makeSetRight(options.newValue.right)
        }
      }
    }
    case "Right": {
      switch (options.newValue._tag) {
        case "Left": {
          return makeSetLeft(options.newValue.left)
        }
        case "Right": {
          const valuePatch = options.right.diff(options.oldValue.right, options.newValue.right)
          if (Equal.equals(valuePatch, options.right.empty)) {
            return empty()
          }
          return makeUpdateRight(valuePatch)
        }
      }
    }
  }
}

/** @internal */
export const combine = Dual.dual<