oxabl_parser 0.3.1

use oxabl_ast::{
    BooleanLiteral, DecimalLiteral, IntegerLiteral, Literal, Span, StringLiteral, UnknownLiteral,
};
use oxabl_lexer::{Kind, Token, TokenValue};

// pub fn parse_literal(tokens: &mut TokenStream) -> Literal {

// }

pub fn token_to_literal(token: &Token) -> Option<Literal> {
    match (&token.kind, &token.value) {
        (Kind::IntegerLiteral, TokenValue::Integer(v)) => Some(Literal::Integer(IntegerLiteral {
            span: Span {
                start: token.start as u32,
                end: token.end as u32,
            },
            value: *v as i64,
        })),
        (Kind::BigIntLiteral, TokenValue::BigInt(v)) => Some(Literal::Integer(IntegerLiteral {
            span: Span {
                start: token.start as u32,
                end: token.end as u32,
            },
            value: *v,
        })),
        (Kind::DecimalLiteral, TokenValue::Decimal(v)) => Some(Literal::Decimal(DecimalLiteral {
            span: Span {
                start: token.start as u32,
                end: token.end as u32,
            },
            value: *v,
        })),
        (Kind::StringLiteral, TokenValue::String(v)) => Some(Literal::String(StringLiteral {
            span: Span {
                start: token.start as u32,
                end: token.end as u32,
            },
            value: v.to_string(),
        })),
        (Kind::Question, TokenValue::None) => Some(Literal::Unknown(UnknownLiteral {
            span: Span {
                start: token.start as u32,
                end: token.end as u32,
            },
        })),
        (Kind::KwTrue | Kind::KwFalse, TokenValue::Boolean(v)) => {
            Some(Literal::Boolean(BooleanLiteral {
                span: Span {
                    start: token.start as u32,
                    end: token.end as u32,
                },
                value: *v,
            }))
        }
        _ => None,
    }
}

// TODO add a round-trip test to ensure tokens are converted to literals correctly
#[cfg(test)]
mod tests {
    use super::*;
    use oxabl_lexer::tokenize;
    use rust_decimal::Decimal;
    use std::str::FromStr;

    fn assert_integer(
        literal: Literal,
        expected_value: i64,
        expected_start: u32,
        expected_end: u32,
    ) {
        assert_eq!(
            literal,
            Literal::Integer(IntegerLiteral {
                span: Span {
                    start: expected_start,
                    end: expected_end
                },
                value: expected_value
            })
        )
    }

    fn assert_decimal(
        literal: Literal,
        expected_value: Decimal,
        expected_start: u32,
        expected_end: u32,
    ) {
        assert_eq!(
            literal,
            Literal::Decimal(DecimalLiteral {
                span: Span {
                    start: expected_start,
                    end: expected_end
                },
                value: expected_value
            })
        )
    }

    fn assert_string(
        literal: Literal,
        expected_value: String,
        expected_start: u32,
        expected_end: u32,
    ) {
        assert_eq!(
            literal,
            Literal::String(StringLiteral {
                span: Span {
                    start: expected_start,
                    end: expected_end
                },
                value: expected_value
            })
        )
    }

    fn assert_boolean(
        literal: Literal,
        expected_value: bool,
        expected_start: u32,
        expected_end: u32,
    ) {
        assert_eq!(
            literal,
            Literal::Boolean(BooleanLiteral {
                span: Span {
                    start: expected_start,
                    end: expected_end
                },
                value: expected_value
            })
        )
    }

    fn assert_unknown(literal: Literal, expected_start: u32, expected_end: u32) {
        assert_eq!(
            literal,
            Literal::Unknown(UnknownLiteral {
                span: Span {
                    start: expected_start,
                    end: expected_end
                },
            })
        )
    }

    #[test]
    fn integer_literal_from_token() {
        let source = "def var myInt as int no-undo init 4.";
        let tokens = tokenize(source);
        // get the integer literal token
        let token = tokens
            .iter()
            .find(|t| t.kind == Kind::IntegerLiteral)
            .expect("expected an integer literal token");
        // convert to integer literal
        let lit = token_to_literal(token);
        let lit = lit.expect("expected an integer literal span");
        assert_integer(lit, 4, 34, 35);
    }

    #[test]
    fn decimal_literal_from_token() {
        let source = "def var myDec as dec no-undo init 3.14.";
        let tokens = tokenize(source);
        // get the decimal literal token
        let token = tokens
            .iter()
            .find(|t| t.kind == Kind::DecimalLiteral)
            .expect("expected a decimal literal token");
        // convert to decimal literal
        let lit = token_to_literal(token);
        let lit = lit.expect("expected a decimal literal span");
        assert_decimal(lit, Decimal::from_str("3.14").unwrap(), 34, 38);
    }

    #[test]
    fn string_literal_from_token() {
        let source = "def var myStr as char no-undo init 'hello'.";
        let tokens = tokenize(source);
        // get the string literal token
        let token = tokens
            .iter()
            .find(|t| t.kind == Kind::StringLiteral)
            .expect("expected a string literal token");
        // convert to string literal
        let lit = token_to_literal(token);
        let lit = lit.expect("expected a string literal span");
        assert_string(lit, "hello".to_string(), 35, 42);
    }

    #[test]
    fn boolean_literal_from_token() {
        let source = "def var myBool as log no-undo init true.";
        let tokens = tokenize(source);
        // get the boolean literal token
        let token = tokens
            .iter()
            .find(|t| t.kind == Kind::KwTrue)
            .expect("expected a boolean literal token");
        // convert to boolean literal
        let lit = token_to_literal(token);
        let lit = lit.expect("expected a boolean literal span");
        assert_boolean(lit, true, 35, 39);
    }

    #[test]
    fn unknown_literal_from_token() {
        let source = "def var myUnk as int no-undo init ?.";
        let tokens = tokenize(source);
        // get the unknown literal token
        let token = tokens
            .iter()
            .find(|t| t.kind == Kind::Question)
            .expect("expected an unknown literal token");
        // convert to unknown literal
        let lit = token_to_literal(token);
        let lit = lit.expect("expected an unknown literal span");
        assert_unknown(lit, 34, 35);
    }
}