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/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

pub mod ast;
mod parser {
    include!(concat!(env!("OUT_DIR"), "/parser.rs"));
}

pub use lalrpop_util::ParseError;

pub use crate::parser::Token;

pub struct Parser {}

impl Parser {
    pub fn parse(input: &str) -> Result<ast::Expression, ParseError<usize, Token, &str>> {
        Ok(*parser::ExpressionParser::new().parse(input)?)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ast::{Expression, OpCode};

    #[test]
    fn literal() {
        assert_eq!(Parser::parse("1"), Ok(Expression::Number(1.0)));
    }

    #[test]
    fn binary_expression() {
        assert_eq!(
            Parser::parse("1+2"),
            Ok(Expression::BinaryOperation {
                operation: OpCode::Add,
                left: Box::new(Expression::Number(1.0)),
                right: Box::new(Expression::Number(2.0)),
            }),
        );
    }

    #[test]
    fn binary_expression_whitespace() {
        assert_eq!(Parser::parse("1  +     2 "), Parser::parse("1+2"),);
    }

    #[test]
    fn transform_simple_no_args() {
        let exp = "'T_T'|lower";
        let parsed = Parser::parse(exp).unwrap();
        assert_eq!(
            parsed,
            Expression::Transform {
                name: "lower".to_string(),
                subject: Box::new(Expression::String("T_T".to_string())),
                args: None
            }
        );
    }

    #[test]
    fn transform_multiple_args() {
        let exp = "'John Doe'|split(' ')";
        let parsed = Parser::parse(exp).unwrap();
        assert_eq!(
            parsed,
            Expression::Transform {
                name: "split".to_string(),
                subject: Box::new(Expression::String("John Doe".to_string())),
                args: Some(vec![Box::new(Expression::String(" ".to_string()))])
            }
        );
    }

    #[test]
    fn trasform_way_too_many_args() {
        let exp = "123456|math(12, 35, 100, 31, 90)";
        let parsed = Parser::parse(exp).unwrap();
        assert_eq!(
            parsed,
            Expression::Transform {
                name: "math".to_string(),
                subject: Box::new(Expression::Number(123_456f64)),
                args: Some(vec![
                    Box::new(Expression::Number(12f64)),
                    Box::new(Expression::Number(35f64)),
                    Box::new(Expression::Number(100f64)),
                    Box::new(Expression::Number(31f64)),
                    Box::new(Expression::Number(90f64)),
                ])
            }
        );
    }
}