scyllax-parser 0.1.8-alpha

//! A parser for CQL queries
//! See the source code and tests for examples of usage (for now).
pub mod common;
pub mod delete;
pub mod select;
pub mod r#where;

pub use common::{Column, Value, Variable};
pub use delete::DeleteQuery;
pub use r#where::{ComparisonOperator, WhereClause};
pub use select::SelectQuery;

use nom::{error::Error, Err, IResult};

/// Represents a query
/// ```rust
/// use scyllax_parser::{Column, Query, SelectQuery};
///
/// let query = Query::try_from("select id, name from person");
/// assert_eq!(
///     query,
///     Ok(Query::Select(SelectQuery {
///         table: "person".to_string(),
///         columns: vec![
///             Column::Identifier("id".to_string()),
///             Column::Identifier("name".to_string()),
///         ],
///         condition: vec![],
///         limit: None,
///     }))
/// );
/// ```
#[derive(Debug, PartialEq)]
pub enum Query {
    /// A select query
    Select(SelectQuery),
    /// A delete query
    Delete(DeleteQuery),
}

fn parse_query(input: &str) -> IResult<&str, Query> {
    nom::branch::alt((
        nom::combinator::map(select::parse_select, Query::Select),
        nom::combinator::map(delete::parse_delete, Query::Delete),
    ))(input)
}

impl<'a> TryFrom<&'a str> for Query {
    type Error = Err<Error<&'a str>>;

    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
        Ok(parse_query(value)?.1)
    }
}