diff options
Diffstat (limited to 'src/luax/preprocessor.rs')
| -rw-r--r-- | src/luax/preprocessor.rs | 793 |
1 files changed, 793 insertions, 0 deletions
diff --git a/src/luax/preprocessor.rs b/src/luax/preprocessor.rs new file mode 100644 index 0000000..4934fe4 --- /dev/null +++ b/src/luax/preprocessor.rs @@ -0,0 +1,793 @@ +use std::io::Write; + +use crate::error::LuaXError; + +use crate::luax::lexer::Lexer; +use crate::luax::tokens::Token; + +use color_eyre::Result; + +/// Macro for trying to get a match from a list of functions +/// If a function returns a value, the token is returned +/// If a function returns an error, the error is returned +/// If a function returns the `InvalidStart` error, the next function is tried +macro_rules! alternatives { + () => { + Err(LuaXError::InvalidStart) + }; + ($e:expr) => { + $e + }; + ($head:expr $(,$tail:expr)* $(,)?) => { + match $head { + Ok(t) => Ok(t), + Err(e) => { + match e.downcast_ref::<LuaXError>() { + Some(LuaXError::InvalidStart) => alternatives!($($tail),*), + _ => Err(e), + } + } + } + }; +} + +macro_rules! repeat_until_not { + ($e:expr) => { + loop { + match $e { + Ok(()) => {} + Err(e) => match e.downcast_ref::<LuaXError>() { + Some(LuaXError::InvalidStart) => break, + _ => return Err(e), + }, + } + } + }; +} + +macro_rules! optionally { + ($e:expr) => { + match $e { + Ok(t) => Some(t), + Err(e) => match e.downcast_ref::<LuaXError>() { + Some(LuaXError::InvalidStart) => None, + _ => return Err(e), + }, + } + }; +} + +macro_rules! require { + ($e:expr, $err:expr $(,)?) => { + match $e { + Ok(t) => t, + Err(e) => match e.downcast_ref::<LuaXError>() { + Some(LuaXError::InvalidStart) => return Err($err.into()), + _ => return Err(e), + }, + } + }; +} + +pub struct Preprocessor<'s, W: Write> { + lexer: Lexer<'s>, + current: Token<'s>, + out_stream: W, +} + +impl<'s, W: Write> Preprocessor<'s, W> { + pub fn new(template: &'s str, mut out_stream: W) -> Result<Self> { + let mut lexer = Lexer::new(template); + let current = lexer.next_token()?.unwrap(); + Ok(Preprocessor { + lexer, + current, + out_stream, + }) + } + + fn next_token(&mut self) -> Result<()> { + if self.current != Token::Eof { + write!(self.out_stream, " {}", self.current)?; + } + println!("Current: {}", self.current); + match self.lexer.next_token()? { + Some(token) => { + self.current = token; + } + None => return Err(LuaXError::InvalidStart.into()), + } + Ok(()) + } + + fn match_token(&mut self, token: Token<'s>) -> Result<bool> { + if self.current == token { + self.next_token()?; + Ok(true) + } else { + Ok(false) + } + } + + fn consume_token(&mut self, token: Token<'s>, if_not: LuaXError) -> Result<()> { + if self.current == token { + self.next_token()?; + Ok(()) + } else { + Err(if_not.into()) + } + } + + fn next_token_silent(&mut self) -> Result<()> { + match self.lexer.next_token()? { + Some(token) => { + self.current = token; + println!("Current: {}", token); + } + None => return Err(LuaXError::InvalidStart.into()), + } + Ok(()) + } + + fn match_token_silent(&mut self, token: Token<'s>) -> Result<bool> { + if self.current == token { + self.next_token_silent()?; + Ok(true) + } else { + Ok(false) + } + } + + fn consume_token_silent(&mut self, token: Token<'s>, if_not: LuaXError) -> Result<()> { + if self.current == token { + self.next_token_silent()?; + Ok(()) + } else { + Err(if_not.into()) + } + } + + pub fn preprocess(mut self) -> Result<()> { + self.chunk() + } + + fn chunk(&mut self) -> Result<()> { + self.block() + } + + fn block(&mut self) -> Result<()> { + repeat_until_not!(self.statement()); + + optionally!(self.return_statement()); + + Ok(()) + } + + fn statement(&mut self) -> Result<()> { + if self.match_token(Token::Semicolon)? { + return Ok(()); + } + alternatives!( + self.label(), + self.break_statement(), + self.goto_statement(), + self.do_statement(), + self.while_statement(), + self.repeat_statement(), + self.if_statement(), + self.for_statement(), + self.function_statement(), + self.local_starting_statement(), + self.call_or_assignment(), + ) + } + + fn break_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Break)? { + return Err(LuaXError::InvalidStart.into()); + } + + Ok(()) + } + + fn goto_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Goto)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + Ok(()) + } + + fn do_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Do)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!(self.block(), LuaXError::ExpectedExpression); + + self.consume_token(Token::End, LuaXError::NeededToken(Token::End.to_string())) + } + + fn while_statement(&mut self) -> Result<()> { + if !self.match_token(Token::While)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!(self.expression(), LuaXError::ExpectedExpression); + + self.consume_token(Token::Do, LuaXError::NeededToken(Token::Do.to_string()))?; + + require!(self.block(), LuaXError::ExpectedExpression); + + self.consume_token(Token::End, LuaXError::NeededToken(Token::End.to_string())) + } + + fn repeat_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Repeat)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!(self.block(), LuaXError::ExpectedExpression); + + self.consume_token( + Token::Until, + LuaXError::NeededToken(Token::Until.to_string()), + )?; + + require!(self.expression(), LuaXError::ExpectedExpression); + + Ok(()) + } + + fn if_statement(&mut self) -> Result<()> { + if !self.match_token(Token::If)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!(self.expression(), LuaXError::ExpectedExpression); + + self.consume_token(Token::Then, LuaXError::NeededToken(Token::Then.to_string()))?; + + require!(self.block(), LuaXError::ExpectedExpression); + + loop { + if !self.match_token(Token::ElseIf)? { + break; + } + + require!(self.expression(), LuaXError::ExpectedExpression); + + self.consume_token(Token::Then, LuaXError::NeededToken(Token::Then.to_string()))?; + + require!(self.block(), LuaXError::ExpectedExpression); + } + + if self.match_token(Token::Else)? { + require!(self.block(), LuaXError::ExpectedExpression); + } + + self.consume_token(Token::End, LuaXError::NeededToken(Token::End.to_string())) + } + + fn for_statement(&mut self) -> Result<()> { + if !self.match_token(Token::For)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + if self.match_token(Token::Eq)? { + require!(self.expression(), LuaXError::ExpectedExpression); + + self.consume_token( + Token::Comma, + LuaXError::NeededToken(Token::Comma.to_string()), + )?; + + require!(self.expression(), LuaXError::ExpectedExpression); + + if self.match_token(Token::Comma)? { + require!(self.expression(), LuaXError::ExpectedExpression); + } + + require!(self.expression(), LuaXError::ExpectedExpression); + + if self.match_token(Token::Comma)? { + require!(self.expression(), LuaXError::ExpectedExpression); + } + } else { + loop { + if !self.match_token(Token::Comma)? { + break; + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + } + + self.consume_token(Token::In, LuaXError::NeededToken(Token::In.to_string()))?; + + require!(self.explist(), LuaXError::ExpectedExpression); + } + + self.consume_token(Token::Do, LuaXError::NeededToken(Token::Do.to_string()))?; + + require!(self.block(), LuaXError::ExpectedExpression); + + self.consume_token(Token::End, LuaXError::NeededToken(Token::End.to_string())) + } + + fn function_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Function)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!( + self.funcname(), + LuaXError::NeededToken("identifier".to_string()) + ); + + require!(self.funcbody(), LuaXError::ExpectedExpression); + + Ok(()) + } + + fn local_starting_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Local)? { + return Err(LuaXError::InvalidStart.into()); + } + + if self.match_token(Token::Function)? { + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + require!(self.funcbody(), LuaXError::ExpectedExpression); + + return Ok(()); + } + + require!( + self.attribute_name_list(), + LuaXError::NeededToken("identifier".to_string()) + ); + + if self.match_token(Token::Eq)? { + require!(self.explist(), LuaXError::ExpectedExpression); + } + + Ok(()) + } + + fn return_statement(&mut self) -> Result<()> { + if !self.match_token(Token::Return)? { + return Err(LuaXError::InvalidStart.into()); + } + + optionally!(self.expression()); + + loop { + if !self.match_token(Token::Comma)? { + break; + } + + require!(self.expression(), LuaXError::ExpectedExpression); + } + + self.match_token(Token::Semicolon)?; + + Ok(()) + } + + fn attribute(&mut self) -> Result<()> { + if !self.match_token(Token::Lt)? { + return Ok(()); + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + self.consume_token(Token::Gt, LuaXError::NeededToken(Token::Gt.to_string())) + } + + fn attribute_name_list(&mut self) -> Result<()> { + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + self.attribute()?; + + loop { + if !self.match_token(Token::Comma)? { + break; + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + self.attribute()?; + } + + Ok(()) + } + + fn label(&mut self) -> Result<()> { + if !self.match_token(Token::ColonColon)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + self.consume_token( + Token::ColonColon, + LuaXError::NeededToken(Token::ColonColon.to_string()), + ) + } + + fn funcname(&mut self) -> Result<()> { + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + + loop { + if !self.match_token(Token::Dot)? { + break; + } + + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + } + + if self.match_token(Token::Colon)? { + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + } + + Ok(()) + } + + fn explist(&mut self) -> Result<()> { + require!(self.expression(), LuaXError::ExpectedVar,); + + loop { + if !self.match_token(Token::Comma)? { + break; + } + + require!(self.expression(), LuaXError::ExpectedVar,); + } + + Ok(()) + } + + fn expression(&mut self) -> Result<()> { + alternatives!( + self.html_template(), + self.literal(), + self.function_def(), + self.access_or_call(), + self.table_constructor(), + self.unary_expression(), + )?; + + optionally!(self.binary_expression_followup()); + + Ok(()) + } + + fn literal(&mut self) -> Result<()> { + alternatives!( + self.number(), + self.string(), + self.boolean(), + self.nil_literal(), + ) + } + + fn call_or_assignment(&mut self) -> Result<()> { + if optionally!(self.access_or_call()).is_none() { + return Err(LuaXError::InvalidStart.into()); + } + + if self.match_token(Token::Eq)? { + require!(self.explist(), LuaXError::ExpectedExpression,); + } else if self.match_token(Token::Comma)? { + require!(self.access_or_call(), LuaXError::ExpectedExpression,); + while self.match_token(Token::Comma)? { + require!(self.access_or_call(), LuaXError::ExpectedExpression,); + } + if self.match_token(Token::Eq)? { + require!(self.explist(), LuaXError::ExpectedExpression,); + } + } + + Ok(()) + } + + fn access_or_call(&mut self) -> Result<()> { + if self.match_token(Token::OpenParen)? { + require!(self.expression(), LuaXError::ExpectedVar,); + self.consume_token( + Token::CloseParen, + LuaXError::NeededToken(Token::CloseParen.to_string()), + )?; + } else if optionally!(self.identifier()).is_some() { + } else { + return Err(LuaXError::InvalidStart.into()); + } + + // } else if let Some(()) = optionally!(self.html_template()) { + // return Ok(()); + + loop { + if self.match_token(Token::OpenBracket)? { + require!(self.expression(), LuaXError::ExpectedVar,); + self.consume_token( + Token::CloseBracket, + LuaXError::NeededToken(Token::CloseBracket.to_string()), + )?; + } else if self.match_token(Token::Dot)? { + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + } else if optionally!(self.args()).is_some() { + } else if self.match_token(Token::Colon)? { + require!( + self.identifier(), + LuaXError::NeededToken("identifier".to_string()) + ); + require!(self.args(), LuaXError::ExpectedExpression,); + } else { + break; + } + } + + Ok(()) + } + + fn args(&mut self) -> Result<()> { + if self.match_token(Token::OpenParen)? { + if !self.match_token(Token::CloseParen)? { + require!(self.explist(), LuaXError::ExpectedExpression,); + self.consume_token( + Token::CloseParen, + LuaXError::NeededToken(Token::CloseParen.to_string()), + ) + } else { + Ok(()) + } + } else if optionally!(self.table_constructor()).is_some() + || optionally!(self.string()).is_some() + { + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn function_def(&mut self) -> Result<()> { + if !self.match_token(Token::Function)? { + return Err(LuaXError::InvalidStart.into()); + } + + require!(self.funcbody(), LuaXError::ExpectedExpression); + + Ok(()) + } + + fn funcbody(&mut self) -> Result<()> { + self.consume_token( + Token::OpenParen, + LuaXError::NeededToken(Token::OpenParen.to_string()), + )?; + + optionally!(self.parlist()); + + self.consume_token( + Token::CloseParen, + LuaXError::NeededToken(Token::CloseParen.to_string()), + )?; + + require!(self.block(), LuaXError::ExpectedExpression); + + self.consume_token(Token::End, LuaXError::NeededToken(Token::End.to_string())) + } + + fn parlist(&mut self) -> Result<()> { + if self.match_token(Token::DotDotDot)? { + return Ok(()); + } + + if optionally!(self.identifier()).is_some() { + while self.match_token(Token::Comma)? { + if self.match_token(Token::DotDotDot)? { + return Ok(()); + } + + if optionally!(self.identifier()).is_some() { + continue; + } else { + return Err(LuaXError::ExpectedExpression.into()); + } + } + + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn table_constructor(&mut self) -> Result<()> { + if !self.match_token(Token::OpenBrace)? { + return Err(LuaXError::InvalidStart.into()); + } + + optionally!(self.fieldlist()); + + self.consume_token( + Token::CloseBrace, + LuaXError::NeededToken(Token::CloseBrace.to_string()), + ) + } + + fn fieldlist(&mut self) -> Result<()> { + require!(self.field(), LuaXError::ExpectedExpression); + + loop { + if !self.match_token(Token::Comma)? && !self.match_token(Token::Semicolon)? { + break; + } + + if self.match_token(Token::CloseBrace)? { + break; + } + + require!(self.field(), LuaXError::ExpectedExpression); + } + + Ok(()) + } + + fn field(&mut self) -> Result<()> { + if optionally!(self.identifier()).is_some() { + self.consume_token(Token::Eq, LuaXError::NeededToken(Token::Eq.to_string()))?; + require!(self.expression(), LuaXError::ExpectedExpression); + } else if self.match_token(Token::OpenBracket)? { + require!(self.expression(), LuaXError::ExpectedExpression); + self.consume_token( + Token::CloseBracket, + LuaXError::NeededToken(Token::CloseBracket.to_string()), + )?; + self.consume_token(Token::Eq, LuaXError::NeededToken(Token::Eq.to_string()))?; + require!(self.expression(), LuaXError::ExpectedExpression); + } else { + require!(self.expression(), LuaXError::ExpectedExpression); + } + + Ok(()) + } + + fn binary_expression_followup(&mut self) -> Result<()> { + loop { + if !self.match_token(Token::Plus)? + && !self.match_token(Token::Minus)? + && !self.match_token(Token::Star)? + && !self.match_token(Token::Slash)? + && !self.match_token(Token::SlashSlash)? + && !self.match_token(Token::Hat)? + && !self.match_token(Token::Percent)? + && !self.match_token(Token::Amp)? + && !self.match_token(Token::Tilde)? + && !self.match_token(Token::Pipe)? + && !self.match_token(Token::LtLt)? + && !self.match_token(Token::GtGt)? + && !self.match_token(Token::DotDot)? + && !self.match_token(Token::Lt)? + && !self.match_token(Token::Le)? + && !self.match_token(Token::Gt)? + && !self.match_token(Token::Ge)? + && !self.match_token(Token::EqEq)? + && !self.match_token(Token::TildeEq)? + && !self.match_token(Token::And)? + && !self.match_token(Token::Or)? + { + break; + } + + require!(self.expression(), LuaXError::ExpectedExpression); + } + + Ok(()) + } + + fn unary_expression(&mut self) -> Result<()> { + if !self.match_token(Token::Not)? + && !self.match_token(Token::Hash)? + && !self.match_token(Token::Minus)? + && !self.match_token(Token::Tilde)? + { + return Err(LuaXError::InvalidStart.into()); + } + + require!(self.expression(), LuaXError::ExpectedExpression); + + Ok(()) + } + + fn boolean(&mut self) -> Result<()> { + if self.match_token(Token::True)? || self.match_token(Token::False)? { + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn nil_literal(&mut self) -> Result<()> { + if self.match_token(Token::Nil)? { + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn number(&mut self) -> Result<()> { + if let Token::Number(_) = self.current { + self.next_token()?; + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn string(&mut self) -> Result<()> { + if let Token::String(..) = self.current { + self.next_token()?; + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn identifier(&mut self) -> Result<String> { + if let Token::Identifier(s) = self.current { + self.next_token()?; + Ok(s.to_string()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } + + fn html_template(&mut self) -> Result<()> { + if self.match_token_silent(Token::Dollar)? { + write!(self.out_stream, " {{ 'dollar' }}")?; + Ok(()) + } else { + Err(LuaXError::InvalidStart.into()) + } + } +} |