How to Use ParseResult.Missing or ParseResult.Transformation in Effect Typescript

export const NumberFromString = Schema.transformOrFail(
  // Source schema: accepts any string
  Schema.String,
  // Target schema: expects a number
  Schema.Number,
  {
    // optional but you get better error messages from TypeScript
    strict: true,
    decode: (input, options, ast) => {
      const parsed = parseFloat(input)
      // If parsing fails (NaN), return a ParseError with a custom error
      if (isNaN(parsed)) {
        return ParseResult.fail(
          // Create a Type Mismatch error
          new ParseResult.Type(
            // Provide the schema's abstract syntax tree for context
            ast,
            // Include the problematic input
            input,
            // Optional custom error message
            "Failed to convert string to number"
          )
        )
      }
      return ParseResult.succeed(parsed)
    },
    encode: (input, options, ast) => ParseResult.succeed(input.toString())
  }
)