use crate::T;
use crate::ast::ast::While;
use crate::ast::ast::WhileBody;
use crate::ast::ast::WhileColonDelimitedBody;
use crate::ast::sequence::Sequence;
use crate::error::ParseError;
use crate::parser::Parser;
impl<'input, 'arena> Parser<'input, 'arena> {
pub(crate) fn parse_while(&mut self) -> Result<While<'arena>, ParseError> {
Ok(While {
r#while: self.expect_keyword(T!["while"])?,
left_parenthesis: self.stream.eat_span(T!["("])?,
condition: self.arena.alloc(self.parse_expression()?),
right_parenthesis: self.stream.eat_span(T![")"])?,
body: self.parse_while_body()?,
})
}
fn parse_while_body(&mut self) -> Result<WhileBody<'arena>, ParseError> {
Ok(match self.stream.peek_kind(0)? {
Some(T![":"]) => WhileBody::ColonDelimited(self.parse_while_colon_delimited_body()?),
_ => WhileBody::Statement(self.arena.alloc(self.parse_statement()?)),
})
}
fn parse_while_colon_delimited_body(&mut self) -> Result<WhileColonDelimitedBody<'arena>, ParseError> {
Ok(WhileColonDelimitedBody {
colon: self.stream.eat_span(T![":"])?,
statements: {
let mut statements = self.new_vec();
loop {
if matches!(self.stream.peek_kind(0)?, Some(T!["endwhile"])) {
break;
}
let position_before = self.stream.current_position();
statements.push(self.parse_statement()?);
if self.stream.current_position() == position_before {
if let Ok(Some(token)) = self.stream.lookahead(0) {
self.errors.push(self.stream.unexpected(Some(token), &[]));
let _ = self.stream.consume();
} else {
break;
}
}
}
Sequence::new(statements)
},
end_while: self.expect_keyword(T!["endwhile"])?,
terminator: self.parse_terminator()?,
})
}
}