Enum Value

Source

pub enum Value {
    Nil,
    Integer(i64),
    Error(String),
    String(String),
    Array(Vec<Value>),
}

Expand description

A wrapper type for a RESP value.

This enum implements the TryFrom trait (TryFrom<&str>), to provide on-the-fly parsing and validation of RESP strings.

§Examples

use io_resp::{
    Node::{self, NIL, SIZE, ARRAY, ERROR, INTEGER, UNKNOWN, SIMPLE_STRING, BULK_STRING},
    Value::{self, Nil, Error, Array, String, Integer},
    Error as VError,
    ValueResult,
};

assert_eq!( // Empty RESP
    "".try_into() as ValueResult,
    Err(VError::Unexpected {node: UNKNOWN, index: 0}));

assert_eq!( // Unterminated number: missing "\r\n"
    ":0".try_into() as ValueResult,
    Err(VError::Unexpected {node: INTEGER, index: 2}));

assert_eq!( // Not enough elements in the array
    "*2\r\n$-1\r\n".try_into() as ValueResult,
    Err(VError::Size {node: ARRAY, index: 9}));

assert_eq!( // Longer bulk string: got more that 2-bytes
    "$2\r\nHello\r\n".try_into() as ValueResult,
    Err(VError::Size {node: BULK_STRING, index: 6}));

assert_eq!( // Sorter bulk string: shorter by 1-byte (capital A acute is 2-bytes)
    "$3\r\nÂ\r\n".try_into() as ValueResult,
    Err(VError::Size {node: BULK_STRING, index: 7}));

// JSON: null
assert_eq!(
    Value::try_from("$-1\r\n"),
    Ok(Nil)
);

// JSON: 10
assert_eq!(
    Value::try_from(":10\r\n"),
    Ok(Integer(10))
);

// JSON: "Nina Simone"
assert_eq!(
    Value::try_from("+Nina Simone\r\n"),
    Ok(String("Nina Simone".into()))
);

// JSON: "Lorem ipsum...\r\nDolor sit amet..."
assert_eq!(
    Value::try_from("$33\r\nLorem ipsum...\r\nDolor sit amet...\r\n"),
    Ok(String("Lorem ipsum...\r\nDolor sit amet...".into()))
);

// JavaScript: [null, 447, new Error("Oh oh!"), "Hourly", "Si vis pacem,\r\npara bellum"]
assert_eq!(
    Value::try_from("*5\r\n$-1\r\n:447\r\n-Oh oh!\r\n+Hourly\r\n$26\r\nSi vis pacem,\r\npara bellum\r\n"),
    Ok(Array(vec![
        Nil,
        Integer(447),
        Error("Oh oh!".into()),
        String("Hourly".into()),
        String("Si vis pacem,\r\npara bellum".into())
    ]))
);

// NOTE: Even recursive arrays - we leave that for you to try out.