ezno_parser/

block.rs

use derive_enum_from_into::EnumFrom;
use iterator_endiate::EndiateIteratorExt;
use tokenizer_lib::{sized_tokens::TokenReaderWithTokenEnds, Token};
use visitable_derive::Visitable;

use super::{ASTNode, Span, TSXToken, TokenReader};
use crate::{
	declarations::{export::Exportable, ExportDeclaration},
	derive_ASTNode, expect_semi_colon,
	marker::MARKER,
	Declaration, Decorated, Marker, ParseOptions, ParseResult, Statement, TSXKeyword, VisitOptions,
	Visitable,
};

#[apply(derive_ASTNode)]
#[derive(Debug, Clone, PartialEq, Visitable, get_field_by_type::GetFieldByType, EnumFrom)]
#[get_field_by_type_target(Span)]
#[visit_self(under = statement)]
pub enum StatementOrDeclaration {
	Statement(Statement),
	Declaration(Declaration),
	/// For bundling,
	Imported {
		moved: Box<StatementOrDeclaration>,
		/// from the import statement
		originally: Span,
		from: source_map::SourceId,
	},
	/// TODO under cfg
	#[cfg_attr(feature = "self-rust-tokenize", self_tokenize_field(0))]
	Marker(#[visit_skip_field] Marker<Statement>, Span),
}

impl StatementOrDeclaration {
	pub(crate) fn requires_semi_colon(&self) -> bool {
		// TODO maybe more?
		match self {
			Self::Statement(stmt) => stmt.requires_semi_colon(),
			Self::Declaration(dec) => matches!(
				dec,
				Declaration::Variable(..)
					| Declaration::Export(Decorated {
						on: ExportDeclaration::Default { .. }
							| ExportDeclaration::Item {
								exported: Exportable::ImportAll { .. }
									| Exportable::ImportParts { .. }
									| Exportable::Parts { .. },
								..
							},
						..
					}) | Declaration::Import(..)
					| Declaration::TypeAlias(..)
			),
			Self::Imported { moved, .. } => moved.requires_semi_colon(),
			Self::Marker(..) => false,
		}
	}
}

impl ASTNode for StatementOrDeclaration {
	fn get_position(&self) -> Span {
		*get_field_by_type::GetFieldByType::get(self)
	}

	fn from_reader(
		reader: &mut impl TokenReader<TSXToken, crate::TokenStart>,
		state: &mut crate::ParsingState,
		options: &ParseOptions,
	) -> ParseResult<Self> {
		// Exclusively for generator
		if options.interpolation_points
			&& matches!(reader.peek(), Some(Token(TSXToken::Identifier(i), _)) if i == MARKER)
		{
			let Token(_, position) = reader.next().unwrap();
			let marker_id = state.new_partial_point_marker(position);
			return Ok(Self::Marker(marker_id, position.with_length(0)));
		}

		if Declaration::is_declaration_start(reader, options) {
			let dec = Declaration::from_reader(reader, state, options)?;
			// TODO nested blocks? Interfaces...?
			Ok(StatementOrDeclaration::Declaration(dec))
		} else {
			if let Some(Token(TSXToken::Keyword(TSXKeyword::Enum | TSXKeyword::Type), _)) =
				reader.peek()
			{
				if reader.peek_n(1).map_or(false, |t| !t.0.is_symbol()) {
					return Ok(StatementOrDeclaration::Declaration(Declaration::from_reader(
						reader, state, options,
					)?));
				}
			}

			let stmt = Statement::from_reader(reader, state, options)?;
			Ok(StatementOrDeclaration::Statement(stmt))
		}
	}

	fn to_string_from_buffer<T: source_map::ToString>(
		&self,
		buf: &mut T,
		options: &crate::ToStringOptions,
		local: crate::LocalToStringInformation,
	) {
		match self {
			StatementOrDeclaration::Statement(item) => {
				item.to_string_from_buffer(buf, options, local);
			}
			StatementOrDeclaration::Declaration(item) => {
				item.to_string_from_buffer(buf, options, local);
			}
			StatementOrDeclaration::Marker(_, _) => {
				assert!(options.expect_markers, "Unexpected marker in AST");
			}
			StatementOrDeclaration::Imported { moved, from, originally: _ } => {
				moved.to_string_from_buffer(buf, options, local.change_source(*from));
			}
		}
	}
}

/// A "block" of braced statements and declarations
#[apply(derive_ASTNode)]
#[derive(Debug, Clone, get_field_by_type::GetFieldByType)]
#[get_field_by_type_target(Span)]
pub struct Block(pub Vec<StatementOrDeclaration>, pub Span);

impl Eq for Block {}

impl PartialEq for Block {
	fn eq(&self, other: &Self) -> bool {
		self.0 == other.0
	}
}

pub struct BlockLike<'a> {
	pub items: &'a Vec<StatementOrDeclaration>,
}

pub struct BlockLikeMut<'a> {
	pub items: &'a mut Vec<StatementOrDeclaration>,
}

impl<'a> From<&'a Block> for BlockLike<'a> {
	fn from(block: &'a Block) -> Self {
		BlockLike { items: &block.0 }
	}
}

impl<'a> From<&'a mut Block> for BlockLikeMut<'a> {
	fn from(block: &'a mut Block) -> Self {
		BlockLikeMut { items: &mut block.0 }
	}
}

impl ASTNode for Block {
	fn from_reader(
		reader: &mut impl TokenReader<TSXToken, crate::TokenStart>,
		state: &mut crate::ParsingState,
		options: &ParseOptions,
	) -> ParseResult<Self> {
		let start = reader.expect_next(TSXToken::OpenBrace)?;
		let items = parse_statements_and_declarations(reader, state, options)?;
		let end_span = reader.expect_next_get_end(TSXToken::CloseBrace)?;
		Ok(Self(items, start.union(end_span)))
	}

	fn to_string_from_buffer<T: source_map::ToString>(
		&self,
		buf: &mut T,
		options: &crate::ToStringOptions,
		local: crate::LocalToStringInformation,
	) {
		if options.pretty && self.0.is_empty() {
			buf.push_str("{}");
		} else {
			buf.push('{');
			if local.depth > 0 && options.pretty {
				buf.push_new_line();
			}
			statements_and_declarations_to_string(&self.0, buf, options, local);
			if options.pretty && !self.0.is_empty() {
				buf.push_new_line();
			}
			if local.depth > 1 {
				options.add_indent(local.depth - 1, buf);
			}
			buf.push('}');
		}
	}

	fn get_position(&self) -> Span {
		self.1
	}
}

impl Block {
	pub fn items(&self) -> core::slice::Iter<'_, StatementOrDeclaration> {
		self.0.iter()
	}

	pub fn items_mut(&mut self) -> core::slice::IterMut<'_, StatementOrDeclaration> {
		self.0.iter_mut()
	}
}

impl Visitable for Block {
	fn visit<TData>(
		&self,
		visitors: &mut (impl crate::VisitorReceiver<TData> + ?Sized),
		data: &mut TData,
		options: &VisitOptions,
		chain: &mut temporary_annex::Annex<crate::visiting::Chain>,
	) {
		if options.visit_nested_blocks || chain.is_empty() {
			{
				visitors.visit_block(&crate::block::BlockLike { items: &self.0 }, data, chain);
			}
			let items = self.items();
			if options.reverse_statements {
				items.rev().for_each(|item| item.visit(visitors, data, options, chain));
			} else {
				items.for_each(|item| item.visit(visitors, data, options, chain));
			}
		}
	}

	fn visit_mut<TData>(
		&mut self,
		visitors: &mut (impl crate::VisitorMutReceiver<TData> + ?Sized),
		data: &mut TData,
		options: &VisitOptions,
		chain: &mut temporary_annex::Annex<crate::visiting::Chain>,
	) {
		if options.visit_nested_blocks || chain.is_empty() {
			{
				visitors.visit_block_mut(
					&mut crate::block::BlockLikeMut { items: &mut self.0 },
					data,
					chain,
				);
			}
			let items = self.items_mut();
			if options.reverse_statements {
				items.for_each(|statement| statement.visit_mut(visitors, data, options, chain));
			} else {
				items
					.rev()
					.for_each(|statement| statement.visit_mut(visitors, data, options, chain));
			}
		}
	}
}

/// For ifs and other statements
#[derive(Debug, Clone, PartialEq, EnumFrom)]
#[apply(derive_ASTNode!)]
pub enum BlockOrSingleStatement {
	Braced(Block),
	SingleStatement(Box<Statement>),
}

impl Visitable for BlockOrSingleStatement {
	fn visit<TData>(
		&self,
		visitors: &mut (impl crate::visiting::VisitorReceiver<TData> + ?Sized),
		data: &mut TData,
		options: &VisitOptions,
		chain: &mut temporary_annex::Annex<crate::visiting::Chain>,
	) {
		match self {
			BlockOrSingleStatement::Braced(b) => {
				b.visit(visitors, data, options, chain);
			}
			BlockOrSingleStatement::SingleStatement(s) => {
				s.visit(visitors, data, options, chain);
				visitors.visit_statement(
					crate::visiting::BlockItem::SingleStatement(s),
					data,
					chain,
				);
			}
		}
	}

	fn visit_mut<TData>(
		&mut self,
		visitors: &mut (impl crate::visiting::VisitorMutReceiver<TData> + ?Sized),
		data: &mut TData,
		options: &VisitOptions,
		chain: &mut temporary_annex::Annex<crate::visiting::Chain>,
	) {
		match self {
			BlockOrSingleStatement::Braced(ref mut b) => {
				b.visit_mut(visitors, data, options, chain);
			}
			BlockOrSingleStatement::SingleStatement(ref mut s) => {
				s.visit_mut(visitors, data, options, chain);
				visitors.visit_statement_mut(
					crate::visiting::BlockItemMut::SingleStatement(s),
					data,
					chain,
				);
			}
		}
	}
}

impl From<Statement> for BlockOrSingleStatement {
	fn from(stmt: Statement) -> Self {
		Self::SingleStatement(Box::new(stmt))
	}
}

impl ASTNode for BlockOrSingleStatement {
	fn get_position(&self) -> Span {
		match self {
			BlockOrSingleStatement::Braced(blk) => blk.get_position(),
			BlockOrSingleStatement::SingleStatement(stmt) => stmt.get_position(),
		}
	}

	fn from_reader(
		reader: &mut impl TokenReader<TSXToken, crate::TokenStart>,
		state: &mut crate::ParsingState,
		options: &ParseOptions,
	) -> ParseResult<Self> {
		let stmt = Statement::from_reader(reader, state, options)?;
		Ok(match stmt {
			Statement::Block(blk) => Self::Braced(blk),
			stmt => {
				if stmt.requires_semi_colon() {
					let _ = expect_semi_colon(
						reader,
						&state.line_starts,
						stmt.get_position().end,
						options,
					)?;
				}
				Box::new(stmt).into()
			}
		})
	}

	fn to_string_from_buffer<T: source_map::ToString>(
		&self,
		buf: &mut T,
		options: &crate::ToStringOptions,
		local: crate::LocalToStringInformation,
	) {
		if buf.should_halt() {
			return;
		}
		match self {
			BlockOrSingleStatement::Braced(block) => {
				block.to_string_from_buffer(buf, options, local);
			}
			BlockOrSingleStatement::SingleStatement(statement) => {
				if let Statement::Empty(..) = &**statement {
					buf.push(';');
				} else if options.pretty && !options.single_statement_on_new_line {
					buf.push_new_line();
					options.push_gap_optionally(buf);
					statement.to_string_from_buffer(buf, options, local.next_level());
				} else {
					statement.to_string_from_buffer(buf, options, local);
					if statement.requires_semi_colon() {
						buf.push(';');
					}
				}
			}
		}
	}
}

/// Parse statements, regardless of bracing or not
pub(crate) fn parse_statements_and_declarations(
	reader: &mut impl TokenReader<TSXToken, crate::TokenStart>,
	state: &mut crate::ParsingState,
	options: &ParseOptions,
) -> ParseResult<Vec<StatementOrDeclaration>> {
	let mut items = Vec::new();
	while let Some(Token(token_type, _)) = reader.peek() {
		if let TSXToken::EOS | TSXToken::CloseBrace = token_type {
			break;
		}

		let item = StatementOrDeclaration::from_reader(reader, state, options)?;
		let requires_semi_colon = item.requires_semi_colon();
		let end = item.get_position().end;

		let blank_lines_after_statement = if requires_semi_colon {
			expect_semi_colon(reader, &state.line_starts, end, options)?
		} else if options.retain_blank_lines {
			let Token(kind, next) = reader.peek().ok_or_else(crate::parse_lexing_error)?;
			if let TSXToken::EOS = kind {
				1
			} else {
				let lines =
					state.line_starts.byte_indexes_crosses_lines(end as usize, next.0 as usize);
				lines.saturating_sub(1)
			}
		} else {
			0
		};

		if let (true, StatementOrDeclaration::Statement(Statement::Empty(..))) =
			(items.is_empty(), &item)
		{
			continue;
		}
		items.push(item);
		for _ in 0..blank_lines_after_statement {
			// TODO span
			let span = Span { start: end, end, source: () };
			items.push(StatementOrDeclaration::Statement(Statement::Empty(span)));
		}
	}
	Ok(items)
}

pub fn statements_and_declarations_to_string<T: source_map::ToString>(
	items: &[StatementOrDeclaration],
	buf: &mut T,
	options: &crate::ToStringOptions,
	local: crate::LocalToStringInformation,
) {
	let mut last_was_empty = false;
	for (at_end, item) in items.iter().endiate() {
		if !options.pretty {
			if let StatementOrDeclaration::Statement(Statement::Expression(
				crate::expressions::MultipleExpression::Single(crate::Expression::Null(..)),
			)) = item
			{
				continue;
			}
		}

		if options.pretty {
			// Don't print more than two lines in a row
			if let StatementOrDeclaration::Statement(
				Statement::AestheticSemiColon(_) | Statement::Empty(_),
			) = item
			{
				if last_was_empty {
					continue;
				}
				last_was_empty = true;
			} else {
				last_was_empty = false;
			}
		}

		if let (false, StatementOrDeclaration::Declaration(dec)) =
			(options.include_type_annotations, item)
		{
			match dec {
				Declaration::Function(item) if item.on.name.is_declare => {
					continue;
				}
				Declaration::Class(item) if item.on.name.is_declare => {
					continue;
				}
				_ => {}
			}
		}

		options.add_indent(local.depth, buf);
		item.to_string_from_buffer(buf, options, local);
		if (!at_end || options.trailing_semicolon) && item.requires_semi_colon() {
			buf.push(';');
		}
		// TODO only append new line if something added
		if !at_end && options.pretty {
			buf.push_new_line();
		}
	}
}