From bf1398744938a79536e374a36e675cd7d814350e Mon Sep 17 00:00:00 2001
From: Devin Bidwell <dbidwell94@biddydev.com>
Date: Thu, 21 Nov 2024 23:48:30 -0700
Subject: [PATCH] binary wip

---
 src/parser/mod.rs    | 38 ++++++++++++++++++++++++++++++++++++--
 src/tokenizer/mod.rs | 25 ++++++++++++++++++++++---
 2 files changed, 58 insertions(+), 5 deletions(-)

diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index b1c8eb6..78102cb 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -17,6 +17,8 @@ pub enum ParseError {
     DuplicateIdentifier { token: Token },
     #[error("Invalid Syntax\n\nLine: {0}, Column: {1}\nReason: {reason}", token.line, token.column)]
     InvalidSyntax { token: Token, reason: String },
+    #[error("This keyword is either not supported or not yet implemented\n\nLine: {0}, Column: {1}\nToken: {2}\n", token.line, token.column, token.token_type)]
+    UnsupportedKeyword { token: Token},
     #[error("Unexpected EOF")]
     UnexpectedEOF,
 }
@@ -132,15 +134,31 @@ impl Parser {
     }
 
     fn expression(&mut self) -> Result<Option<tree_node::Expression>, ParseError> {
+        macro_rules! matches_keyword {
+            ($keyword:expr, $($pattern:pat),+) => {
+                matches!($keyword, $($pattern)|+)
+            };
+        }
+
+
         let Some(current_token) = self.current_token.as_ref() else {
             return Ok(None);
         };
 
+
         if token_matches!(current_token, TokenType::EOF) {
             return Ok(None);
         }
 
         let expr = Some(match current_token.token_type {
+            // match unsupported keywords
+            TokenType::Keyword(e) 
+                if matches_keyword!(e, Keyword::Import, Keyword::Export, Keyword::Enum, Keyword::If, Keyword::Else) => {
+                return Err(ParseError::UnsupportedKeyword {
+                    token: current_token.clone(),
+                })
+            },
+
             // match declarations with a `let` keyword
             TokenType::Keyword(Keyword::Let) => self.declaration()?,
 
@@ -161,7 +179,7 @@ impl Parser {
             TokenType::Symbol(Symbol::LBrace) => Expression::BlockExpression(self.block()?),
 
             // match literal expressions with a semi-colon afterwards
-            TokenType::Number(_) | TokenType::String(_) if !self_matches_peek!(self, TokenType::Symbol(s) if s.is_operator() || s.is_comparison() || s.is_logical()) => {
+            TokenType::Number(_) | TokenType::String(_) => {
                 Expression::Literal(self.literal()?)
             }
 
@@ -234,7 +252,7 @@ impl Parser {
             }
         };
 
-        todo!()
+        Ok(expr)
     }
 
     fn priority(&mut self) -> Result<Box<Expression>, ParseError> {
@@ -562,4 +580,20 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn test_binary() -> Result<()> {
+        let input = r#"
+            let x = 1 + 2;
+        "#;
+
+        let tokenizer = Tokenizer::from(input.to_owned());
+        let mut parser = Parser::new(tokenizer);
+
+        let expression = parser.parse()?.unwrap();
+
+        assert_eq!("(let x = (1 + 2))", expression.to_string());
+        
+        Ok(())
+    }
 }
diff --git a/src/tokenizer/mod.rs b/src/tokenizer/mod.rs
index aee2838..6ae2651 100644
--- a/src/tokenizer/mod.rs
+++ b/src/tokenizer/mod.rs
@@ -469,7 +469,7 @@ impl TokenizerBuffer {
             }
             self.history.extend(tokens);
         } else if seek_to < 0 {
-            let seek_to = seek_to.abs() as usize;
+            let seek_to = seek_to.unsigned_abs() as usize;
             let mut tokens = Vec::with_capacity(seek_to);
             for _ in 0..seek_to {
                 if let Some(token) = self.history.pop_back() {
@@ -489,11 +489,13 @@ impl TokenizerBuffer {
 
     /// Adds to or removes from the History stack, allowing the user to move back and forth in the stream
     pub fn seek(&mut self, from: SeekFrom) -> Result<(), TokenizerError> {
-        Ok(match from {
+        match from {
             SeekFrom::Current(seek_to) => self.seek_from_current(seek_to)?,
             SeekFrom::End(_) => unimplemented!("SeekFrom::End will not be implemented"),
             SeekFrom::Start(_) => unimplemented!("SeekFrom::Start will not be implemented"),
-        })
+        }
+
+        Ok(())
     }
 }
 
@@ -511,6 +513,23 @@ mod tests {
         }
     "#;
 
+    #[test]
+    fn test_seek_from_current() -> Result<()> {
+        let tokenizer = Tokenizer::from(TEST_STRING.to_owned());
+        let mut buffer = TokenizerBuffer::new(tokenizer);
+
+        let token = buffer.next()?.unwrap();
+        assert_eq!(token.token_type, TokenType::Keyword(Keyword::Fn));
+
+        buffer.seek(SeekFrom::Current(1))?;
+
+        let token = buffer.next()?.unwrap();
+
+        assert_eq!(token.token_type, TokenType::Symbol(Symbol::LParen));
+
+        Ok(())
+    }
+
     #[test]
     fn test_tokenizer_from_path_ok() {
         let tokenizer = Tokenizer::from_path(TEST_FILE);