From 891f0b3d601c881716df8b1b3aadb0e27fc4d488 Mon Sep 17 00:00:00 2001
From: "freidlan@informatik.hu-berlin.de" <freidlan@informatik.hu-berlin.de>
Date: Wed, 15 Jun 2022 22:14:31 +0200
Subject: [PATCH] =?UTF-8?q?L=C3=B6sung?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
---
src/lexer.rs | 2 +-
src/lib.rs | 4 +-
src/parser.rs | 272 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 275 insertions(+), 3 deletions(-)
create mode 100644 src/parser.rs
diff --git a/src/lexer.rs b/src/lexer.rs
index a955a4d..d71c6d9 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -131,7 +131,7 @@ pub enum C1Token {
#[regex(r"[ \t\f]+", logos::skip)]
Whitespace,
- #[regex(r"[\n]")]
+ #[regex(r"(\r\n|\r|\n)")]
Linebreak,
// Logos requires one token variant to handle errors,
diff --git a/src/lib.rs b/src/lib.rs
index 82c0db8..1435b81 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
mod lexer;
+mod parser;
// Type definition for the Result that is being used by the parser. You may change it to anything
// you want
@@ -8,5 +9,4 @@ pub use lexer::C1Lexer;
pub use lexer::C1Token;
// You will need a re-export of your C1Parser definition. Here is an example:
-// mod parser;
-// pub use parser::C1Parser;
+pub use parser::C1Parser;
diff --git a/src/parser.rs b/src/parser.rs
new file mode 100644
index 0000000..30fac85
--- /dev/null
+++ b/src/parser.rs
@@ -0,0 +1,272 @@
+use crate::{C1Lexer, C1Token, ParseResult};
+
+pub struct C1Parser<'a> {
+ lx: C1Lexer<'a>,
+}
+
+impl C1Parser<'_> {
+ pub fn parse(text: &'_ str) -> ParseResult {
+ let mut parser: C1Parser = C1Parser { lx: C1Lexer::new(text) };
+ return Ok(parser.program());
+
+ }
+
+
+
+
+ fn program(&mut self) {
+ while self.lx.current_token().is_some() {
+ let _ = self.functiondefinition();
+ }
+ }
+
+
+ fn functiondefinition(&mut self) -> ParseResult {
+ self.statement_type()?;
+ self.check_and_eat_token(Some(C1Token::Identifier))?;
+ self.check_and_eat_token(Some(C1Token::LeftParenthesis))?;
+ self.check_and_eat_token(Some(C1Token::RightParenthesis))?;
+ self.check_and_eat_token(Some(C1Token::LeftBrace))?;
+ self.statementlist()?;
+ self.check_and_eat_token(Some(C1Token::RightBrace))
+ }
+
+ fn statement_type(&mut self) -> ParseResult {
+ return match self.lx.current_token() {
+ Some(C1Token::KwBoolean) | Some(C1Token::KwFloat) | Some(C1Token::KwInt) | Some(C1Token::KwVoid) => {
+ self.eat();
+ Result::Ok(())
+ },
+ _ => Result::Err(self.error_format()),
+ };
+ }
+
+ fn statementlist(&mut self) -> ParseResult {
+ print!("statementlist->");
+ if self.lx.current_token() == Some(C1Token::RightBrace) {
+ return Result::Ok(());
+ }
+ self.block()?;
+ self.statementlist()
+ }
+
+ fn block(&mut self) -> ParseResult {
+ print!("block->");
+ if self.current_matches(C1Token::LeftBrace) {
+ self.eat();
+ self.statementlist()?;
+ return self.check_and_eat_token(Some(C1Token::RightBrace));
+ }
+ self.statement()
+ }
+
+ fn statement(&mut self) -> ParseResult {
+ print!("statement->");
+ return match self.lx.current_token() {
+ Some(C1Token::KwIf) => self.ifstatement(),
+ Some(C1Token::KwReturn) => {
+ self.returnstatement()?;
+ self.check_and_eat_token(Some(C1Token::Semicolon))
+ },
+ Some(C1Token::KwPrintf) => {
+ self.printfstatement()?;
+ self.check_and_eat_token(Some(C1Token::Semicolon))
+ },
+ Some(C1Token::Identifier) => {
+ if self.next_matches(C1Token::LeftParenthesis) {
+ self.functioncall()?;
+ return self.check_and_eat_token(Some(C1Token::Semicolon));
+ } else if self.next_matches(C1Token::Assign) {
+ self.statassignment()?;
+ return self.check_and_eat_token(Some(C1Token::Semicolon));
+ }
+ Result::Err(self.error_format())
+ },
+ _ => Result::Err(self.error_format()),
+ };
+ }
+
+ fn ifstatement(&mut self) -> ParseResult {
+ self.check_and_eat_token(Some(C1Token::KwIf))?;
+ self.check_and_eat_token(Some(C1Token::LeftParenthesis))?;
+ self.assignment()?;
+ self.check_and_eat_token(Some(C1Token::RightParenthesis))?;
+ self.block()
+ }
+
+ fn returnstatement(&mut self) -> ParseResult {
+ self.check_and_eat_token(Some(C1Token::KwReturn))?;
+ self.returnstatement_alt()
+ }
+
+ fn returnstatement_alt(&mut self) -> ParseResult {
+ if self.current_matches(C1Token::Semicolon) {
+ return Result::Ok(());
+ };
+ self.assignment()
+ }
+
+ fn printfstatement(&mut self) -> ParseResult {
+ self.check_and_eat_token(Some(C1Token::KwPrintf))?;
+ self.check_and_eat_token(Some(C1Token::LeftParenthesis))?;
+ self.assignment()?;
+ self.check_and_eat_token(Some(C1Token::RightParenthesis))
+ }
+
+ fn statassignment(&mut self) -> ParseResult {
+ self.check_and_eat_token(Some(C1Token::Identifier))?;
+ self.check_and_eat_token(Some(C1Token::Assign))?;
+ self.assignment()
+ }
+
+ fn functioncall(&mut self) -> ParseResult {
+ self.check_and_eat_token(Some(C1Token::Identifier))?;
+ self.check_and_eat_token(Some(C1Token::LeftParenthesis))?;
+ self.check_and_eat_token(Some(C1Token::RightParenthesis))
+ }
+
+ fn assignment(&mut self) -> ParseResult {
+ if self.current_matches(C1Token::Identifier) {
+ if self.next_matches(C1Token::Assign) {
+ return self.assignment();
+ }
+ }
+ self.expr()
+ }
+
+ fn expr(&mut self) -> ParseResult {
+ print!("simplexpr->");
+ self.simpexpr()?;
+ self.expr_2()
+ }
+
+ fn expr_2(&mut self) -> ParseResult {
+ if self.current_matches(C1Token::Semicolon) || self.current_matches(C1Token::RightParenthesis) {
+ return Result::Ok(());
+ }
+ self.compare()?;
+ self.simpexpr()
+ }
+
+ fn compare(&mut self) -> ParseResult {
+ return match self.lx.current_token() {
+ Some(C1Token::Equal) | Some(C1Token::NotEqual) | Some(C1Token::Less) | Some(C1Token::LessEqual) | Some(C1Token::GreaterEqual) | Some(C1Token::Greater) => {
+ self.eat();
+ Result::Ok(())
+ },
+ _ => Result::Err(self.error_format()),
+ }
+ }
+
+ fn simpexpr(&mut self) -> ParseResult {
+ self.minus()?;
+ self.term()?;
+ self.simpexpr_2()
+ }
+
+ fn simpexpr_2(&mut self) -> ParseResult {
+ match self.lx.current_token() {
+ Some(C1Token::Plus) | Some(C1Token::Minus) | Some(C1Token::Or) => {
+ self.lowop()?;
+ self.term()?;
+ self.simpexpr_2()
+ },
+ _ => Result::Ok(()),
+ }
+ }
+
+ fn minus(&mut self) -> ParseResult {
+ if self.current_matches(C1Token::Minus) {
+ self.eat();
+ };
+ return Result::Ok(());
+ }
+
+ fn lowop(&mut self) -> ParseResult {
+ return match self.lx.current_token() {
+ Some(C1Token::Plus) | Some(C1Token::Minus) | Some(C1Token::Or) => {
+ self.eat();
+ Result::Ok(())
+ },
+ _ => Result::Err(self.error_format()),
+ };
+ }
+
+ fn term(&mut self) -> ParseResult {
+ self.factor()?;
+ self.term_2()
+ }
+
+ fn term_2(&mut self) -> ParseResult {
+ return match self.lx.current_token() {
+ Some(C1Token::Asterisk) | Some(C1Token::Slash) | Some(C1Token::And) => {
+ self.highop()?;
+ self.factor()?;
+ self.term_2()
+ },
+ _ => Result::Ok(()),
+ }
+ }
+
+ fn highop(&mut self) -> ParseResult {
+ return match self.lx.current_token() {
+ Some(C1Token::Asterisk) | Some(C1Token::Slash) | Some(C1Token::And) => {
+ self.eat();
+ Result::Ok(())
+ },
+ _ => Result::Err(self.error_format()),
+ };
+ }
+
+ fn factor(&mut self) -> ParseResult {
+ print!("factor->");
+ return match self.lx.current_token() {
+ Some(C1Token::ConstFloat) | Some(C1Token::ConstInt) | Some(C1Token::ConstBoolean) => {
+ self.eat();
+ Result::Ok(())
+ },
+ Some(C1Token::Identifier) => {
+ if self.next_matches(C1Token::LeftParenthesis) {
+ return self.functioncall();
+ }
+ self.eat();
+ Result::Ok(())
+ },
+ Some(C1Token::LeftParenthesis) => {
+ self.eat();
+ self.assignment()?;
+ self.check_and_eat_token(Some(C1Token::RightParenthesis))
+ },
+ _ => Result::Err(self.error_format()),
+ }
+ }
+
+ //konsumiert aktuelles Token
+ fn eat(&mut self) {
+ self.lx.eat();
+ }
+
+ //Fehler wird zurückgegeben
+ fn error_format(&self) -> String {
+ return format!("Error on line: {}", self.lx.current_line_number().unwrap());
+ }
+
+ //überprüft, ob das ihr übergebene Token gleich dem aktuellen
+ fn check_and_eat_token(&mut self, token: Option<C1Token>) -> ParseResult {
+ if self.lx.current_token() == token {
+ self.eat();
+ return Result::Ok(());
+ }
+ return Result::Err(self.error_format());
+ }
+
+ //wie check_and_eat_token, gibt Vergleich zurück
+ fn current_matches(&mut self, token: C1Token) -> bool {
+ self.lx.current_token() == Some(token)
+ }
+
+ //wie check_and_eat_token für nächstes Token, gibt Vergleich zurück
+ fn next_matches(&mut self, token: C1Token) -> bool {
+ self.lx.peek_token() == Some(token)
+ }
+}
\ No newline at end of file
--
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