backyard-parser 0.1.10

use backyard_lexer::token::TokenType;
use backyard_nodes::{
  ElseNode,
  IfNode,
  Location,
  Node,
  utils::{ IntoBoxedNode, IntoBoxedOptionNode },
};

use crate::{
  error::ParserError,
  parser::{ LocationHelper, LoopArgument, OptionNodeOrInternal, Parser },
  utils::{ match_pattern, Lookup, LookupResult, LookupResultWrapper },
};

use super::{ block::BlockParser, comment::CommentParser };

#[derive(Debug, Clone)]
pub struct IfParser;

impl IfParser {
  pub fn test<'arena, 'a>(
    parser: &mut Parser<'arena, 'a>,
    _: &mut LoopArgument
  ) -> Option<std::vec::Vec<LookupResult<'arena>>> {
    match_pattern(
      parser,
      &[Lookup::Equal(&[TokenType::If]), Lookup::Equal(&[TokenType::LeftParenthesis])]
    )
  }

  pub fn parse<'arena, 'a, 'b>(
    parser: &mut Parser<'arena, 'a>,
    matched: std::vec::Vec<LookupResult<'arena>>,
    start_loc: Location,
    args: &mut LoopArgument<'arena, 'b>
  ) -> Result<Node<'arena>, ParserError> {
    if let [_, _] = matched.as_slice() {
      let condition = parser
        .get_statement(
          &mut LoopArgument::with_tokens(parser.arena, "if", &[], &[TokenType::RightParenthesis])
        )?
        .ok_internal()?;
      parser.position += 1;
      let (is_short, valid) = BlockParser::new_or_short_or_single(
        parser,
        &[TokenType::ElseIf, TokenType::Else, TokenType::EndIf],
        args
      )?;
      if is_short {
        parser.position -= 1;
      }
      let invalid = parser.get_statement(
        &mut LoopArgument::safe(
          parser.arena,
          "if_invalid",
          &[],
          &[TokenType::RightCurlyBracket, TokenType::EndIf],
          &[
            (ElseParser::test, ElseParser::parse),
            (CommentParser::test, CommentParser::parse),
          ]
        )
      )?;
      if is_short {
        if let Ok(token) = parser.get_token(parser.position) {
          if [TokenType::EndIf].contains(&token.token_type) {
            parser.position += 1;
          }
        }
      }
      return Ok(
        IfNode::loc(
          condition.into_boxed(parser.arena),
          valid.into_boxed(parser.arena),
          invalid.into_boxed(parser.arena),
          is_short,
          parser.gen_loc(start_loc)
        )
      );
    }
    Err(ParserError::Internal)
  }
}

#[derive(Debug, Clone)]
pub struct ElseParser;

impl ElseParser {
  pub fn test<'arena, 'a>(
    parser: &mut Parser<'arena, 'a>,
    _: &mut LoopArgument
  ) -> Option<std::vec::Vec<LookupResult<'arena>>> {
    match_pattern(parser, &[Lookup::Equal(&[TokenType::Else, TokenType::ElseIf])])
  }

  pub fn parse<'arena, 'a, 'b>(
    parser: &mut Parser<'arena, 'a>,
    matched: std::vec::Vec<LookupResult<'arena>>,
    start_loc: Location,
    args: &mut LoopArgument<'arena, 'b>
  ) -> Result<Node<'arena>, ParserError> {
    if let [keyword] = matched.as_slice() {
      if let LookupResultWrapper::Equal(keyword) = &keyword.wrapper {
        if parser.get_token(*keyword)?.token_type == TokenType::ElseIf {
          let token_pos = parser.position;
          let token = parser.get_token(token_pos)?;
          let loc = token.get_location().unwrap();
          parser.position += 1;
          let expr = IfParser::parse(
            parser,
            vec![
              LookupResult { size: 1, wrapper: LookupResultWrapper::Equal(*keyword) },
              LookupResult { size: 1, wrapper: LookupResultWrapper::Equal(token_pos) }
            ],
            loc,
            args
          )?;
          return Ok(ElseNode::loc(expr.into_boxed(parser.arena), false, parser.gen_loc(start_loc)));
        }
      }
      if let Ok(next_token) = parser.get_token(parser.position) {
        if next_token.token_type == TokenType::If {
          let next_token_pos = parser.position;
          parser.position += 1;
          let token = parser.get_token(parser.position)?;
          let loc = token.get_location().unwrap();
          parser.position += 1;
          let expr = IfParser::parse(
            parser,
            vec![
              LookupResult { size: 1, wrapper: LookupResultWrapper::Equal(next_token_pos) },
              LookupResult { size: 1, wrapper: LookupResultWrapper::Equal(next_token_pos + 1) }
            ],
            loc,
            args
          )?;
          return Ok(ElseNode::loc(expr.into_boxed(parser.arena), false, parser.gen_loc(start_loc)));
        }
      }
      let (is_short, valid) = BlockParser::new_or_short_or_single(
        parser,
        &[TokenType::ElseIf, TokenType::Else, TokenType::EndIf],
        args
      )?;
      return Ok(ElseNode::loc(valid.into_boxed(parser.arena), is_short, parser.gen_loc(start_loc)));
    }
    Err(ParserError::Internal)
  }
}