Boa 0.10.0

Boa is a Javascript lexer, parser and Just-in-Time compiler written in Rust. Currently, it has support for some of the language.
Documentation 
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//! Block statement parsing.
//!
//! More information:
//!  - [MDN documentation][mdn]
//!  - [ECMAScript specification][spec]
//!
//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/block
//! [spec]: https://tc39.es/ecma262/#sec-block

#[cfg(test)]
mod tests;

use super::StatementList;

use crate::syntax::lexer::TokenKind;
use crate::{
    profiler::BoaProfiler,
    syntax::{
        ast::{node, Punctuator},
        parser::{AllowAwait, AllowReturn, AllowYield, Cursor, ParseError, TokenParser},
    },
};

use std::io::Read;

/// A `BlockStatement` is equivalent to a `Block`.
///
/// More information:
///  - [ECMAScript specification][spec]
///
/// [spec]: https://tc39.es/ecma262/#prod-BlockStatement
pub(super) type BlockStatement = Block;

/// Variable declaration list parsing.
///
/// More information:
///  - [MDN documentation][mdn]
///  - [ECMAScript specification][spec]
///
/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/block
/// [spec]: https://tc39.es/ecma262/#prod-Block
#[derive(Debug, Clone, Copy)]
pub(super) struct Block {
    allow_yield: AllowYield,
    allow_await: AllowAwait,
    allow_return: AllowReturn,
}

impl Block {
    /// Creates a new `Block` parser.
    pub(super) fn new<Y, A, R>(allow_yield: Y, allow_await: A, allow_return: R) -> Self
    where
        Y: Into<AllowYield>,
        A: Into<AllowAwait>,
        R: Into<AllowReturn>,
    {
        Self {
            allow_yield: allow_yield.into(),
            allow_await: allow_await.into(),
            allow_return: allow_return.into(),
        }
    }
}

impl<R> TokenParser<R> for Block
where
    R: Read,
{
    type Output = node::Block;

    fn parse(self, cursor: &mut Cursor<R>) -> Result<Self::Output, ParseError> {
        let _timer = BoaProfiler::global().start_event("Block", "Parsing");
        cursor.expect(Punctuator::OpenBlock, "block")?;
        if let Some(tk) = cursor.peek(0)? {
            if tk.kind() == &TokenKind::Punctuator(Punctuator::CloseBlock) {
                cursor.next()?.expect("} token vanished");
                return Ok(node::Block::from(vec![]));
            }
        }

        let statement_list =
            StatementList::new(self.allow_yield, self.allow_await, self.allow_return, true)
                .parse(cursor)
                .map(node::Block::from)?;
        cursor.expect(Punctuator::CloseBlock, "block")?;

        Ok(statement_list)
    }
}