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use crate::types::*;
use crate::syntax::{SyntaxParser, SyntaxParserTrait};
use crate::syntax::unary::UnaryParser;
use alloc::rc::Rc;
pub struct ModuloParser;
pub struct MultiplyDivideParser;
pub struct AddSubtractParser;
impl SyntaxParserTrait for ModuloParser {
fn parse(parser: &mut SyntaxParser) -> AstResult {
parse_binary::<MultiplyDivideParser>(parser, &['%'])
}
}
impl SyntaxParserTrait for MultiplyDivideParser {
fn parse(parser: &mut SyntaxParser) -> AstResult {
parse_binary::<UnaryParser>(parser, &['*', '/'])
}
}
impl SyntaxParserTrait for AddSubtractParser {
fn parse(parser: &mut SyntaxParser) -> AstResult {
parse_binary::<ModuloParser>(parser, &['+', '-'])
}
}
pub fn parse_binary<T: SyntaxParserTrait>(parser: &mut SyntaxParser, operators: &[char]) -> AstResult {
let mut left_expr = T::parse(parser)?;
if let SmartCalcAstType::None = left_expr {
return Ok(left_expr)
}
loop {
let index_backup = parser.get_index();
if let Some(operator) = parser.match_operator(operators) {
loop {
let right_expr = T::parse(parser);
match right_expr {
Ok(SmartCalcAstType::None) => (),
Ok(_) => {
left_expr = SmartCalcAstType::Binary {
left: Rc::new(left_expr),
operator,
right: Rc::new(right_expr.unwrap())
};
break;
},
Err(_) => return right_expr
};
}
}
else {
parser.set_index(index_backup);
break;
}
}
Ok(left_expr)
}
