surrealpatch/lib/src/sql/limit.rs
2022-02-22 14:16:50 +00:00

51 lines
1.2 KiB
Rust

use crate::sql::comment::shouldbespace;
use crate::sql::common::take_usize;
use crate::sql::error::IResult;
use nom::bytes::complete::tag_no_case;
use nom::combinator::opt;
use nom::sequence::tuple;
use serde::{Deserialize, Serialize};
use std::fmt;
#[derive(Clone, Debug, Default, Eq, PartialEq, PartialOrd, Serialize, Deserialize)]
pub struct Limit(pub usize);
impl fmt::Display for Limit {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "LIMIT {}", self.0)
}
}
pub fn limit(i: &str) -> IResult<&str, Limit> {
let (i, _) = tag_no_case("LIMIT")(i)?;
let (i, _) = opt(tuple((shouldbespace, tag_no_case("BY"))))(i)?;
let (i, _) = shouldbespace(i)?;
let (i, v) = take_usize(i)?;
Ok((i, Limit(v)))
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn limit_statement() {
let sql = "LIMIT 100";
let res = limit(sql);
assert!(res.is_ok());
let out = res.unwrap().1;
assert_eq!(out, Limit(100));
assert_eq!("LIMIT 100", format!("{}", out));
}
#[test]
fn limit_statement_by() {
let sql = "LIMIT BY 100";
let res = limit(sql);
assert!(res.is_ok());
let out = res.unwrap().1;
assert_eq!(out, Limit(100));
assert_eq!("LIMIT 100", format!("{}", out));
}
}