Added parsing for pointers & made LLVM a feature

6 files changed, 65 insertions, 21 deletions

diff --git a/examples/pointer.sloth b/examples/pointer.sloth
new file mode 100644
index 0000000..7d7ca10
--- /dev/null
+++ b/examples/pointer.sloth
@@ -0,0 +1,5 @@
+fn main() Int {
+	val x: Int = 0;
+	val xPtr: Int = *x;
+	val x: Int = @xPtr;
+}
\ No newline at end of file
diff --git a/sloth/Cargo.toml b/sloth/Cargo.toml
index f58f40e..044622f 100644
--- a/sloth/Cargo.toml
+++ b/sloth/Cargo.toml
@@ -6,8 +6,19 @@ version.workspace = true
 edition.workspace = true
 
 [dependencies]
-llvm-sys = "150"
-inkwell = { version = "0.2.0", features = ["llvm15-0"] }
 itertools = "0.10.5"
 rand = "0.8.5"
 thiserror = "1.0.40"
+
+[dependencies.llvm-sys]
+version = "150"
+optional = true
+
+[dependencies.inkwell]
+version = "0.2.0"
+features = ["llvm15-0"]
+optional = true
+
+[features]
+default = ["llvm"]
+llvm = ["dep:llvm-sys", "dep:inkwell"]
\ No newline at end of file
diff --git a/sloth/src/lexer.rs b/sloth/src/lexer.rs
index 0b2399f..5033c99 100644
--- a/sloth/src/lexer.rs
+++ b/sloth/src/lexer.rs
@@ -67,6 +67,8 @@ pub enum TokenType {
     GtEq,   // >=
     GtGtEq, // >>=
 
+    At, // @
+
     Comma,
 
     Question,         // ?
@@ -158,6 +160,7 @@ impl Display for TokenType {
             TokenType::GtGt => ">>",
             TokenType::GtEq => ">=",
             TokenType::GtGtEq => ">>=",
+            TokenType::At => "@",
             TokenType::Comma => ",",
             TokenType::Question => "?",
             TokenType::QuestionDot => "?.",
@@ -455,6 +458,8 @@ impl<'a> Iterator for Lexer<'a> {
             ['>', '=', ..] => self.advance_by_with(2, TokenType::GtEq),
             ['>', ..] => self.advance_with(TokenType::Gt),
 
+            ['@', ..] => self.advance_with(TokenType::At),
+
             [',', ..] => self.advance_with(TokenType::Comma),
 
             ['.', '.', ..] => self.advance_by_with(2, TokenType::DotDot),
@@ -533,7 +538,7 @@ mod tests {
     #[test]
     fn lex_operators() {
         let source = "+ ++ - * ** / % ~ += ++= -= *= **= /= %= ~= & && | || ^ = == ! !! != < << \
-                      <<= <= > >> >>= >= , ? ?. ?? . .. : :: ; -> =>";
+                      <<= <= > >> >>= >= @ , ? ?. ?? . .. : :: ; -> =>";
         let tokens = Lexer::new(source).map(|it| it.tt).collect_vec();
 
         assert_eq!(&tokens, &[
@@ -571,6 +576,7 @@ mod tests {
             TokenType::GtGt,
             TokenType::GtGtEq,
             TokenType::GtEq,
+            TokenType::At,
             TokenType::Comma,
             TokenType::Question,
             TokenType::QuestionDot,
diff --git a/sloth/src/main.rs b/sloth/src/main.rs
index 23946b2..f66a1be 100644
--- a/sloth/src/main.rs
+++ b/sloth/src/main.rs
@@ -7,17 +7,15 @@
 )]
 
 pub mod analysis;
-pub mod codegen;
 pub mod lexer;
 pub mod parser;
 pub mod symtable;
 
-use std::fs::File;
+#[cfg(feature = "llvm")]
+pub mod codegen;
+
 use std::{env, fs};
 
-use codegen::Codegen;
-use inkwell::context::Context;
-use inkwell::targets::FileType;
 use itertools::Itertools;
 use lexer::Lexer;
 use parser::AstParser;
@@ -32,7 +30,7 @@ fn main() {
     if args.len() < 2 {
         println!("Sloth programming language interpreter\n");
         println!("Usage: sloth <file...>");
-        return;
+        std::process::exit(1);
     }
 
     // Reading source files
@@ -40,7 +38,7 @@ fn main() {
     for path in args.iter().skip(1) {
         let Ok(contents) = fs::read_to_string(path) else {
             eprintln!("Error while reading '{path}'");
-            return;
+            std::process::exit(1);
         };
         source.push_str(&contents);
         let len = contents.lines().collect_vec().len();
@@ -52,6 +50,7 @@ fn main() {
 
     // Parsing
     let tokens = Lexer::new(&source).collect_vec();
+    println!("{tokens:#?}");
     let global_symtable = mk_symtable();
 
     let mut ast = match AstParser::parse(tokens, global_symtable) {
@@ -62,7 +61,7 @@ fn main() {
                 args[1 + (error.line() / 1_000) as usize],
                 error.line() % 1000 + 1,
             );
-            return;
+            std::process::exit(1);
         }
     };
 
@@ -72,16 +71,25 @@ fn main() {
             args[1 + (error.line() / 1_000) as usize],
             error.line() % 1000 + 1,
         );
-        return;
+        std::process::exit(1);
     }
 
-    // Generating code for module
-    let context = Context::create();
-    let mut codegen = Codegen::new(&context, "s");
-    let mut output_file = File::create("output.o").unwrap();
+    // Generating code for module if LLVM enabled
+    #[cfg(feature = "llvm")]
+    {
+        use std::fs::File;
 
-    codegen.codegen(&ast);
-    codegen.write_obj(&mut output_file, FileType::Object);
+        use codegen::Codegen;
+        use inkwell::context::Context;
+        use inkwell::targets::FileType;
+
+        let context = Context::create();
+        let mut codegen = Codegen::new(&context, "s");
+        let mut output_file = File::create("output.o").unwrap();
+
+        codegen.codegen(&ast);
+        codegen.write_obj(&mut output_file, FileType::Object);
+    }
 }
 
 fn mk_symtable() -> SymbolTable {
diff --git a/sloth/src/parser/ast.rs b/sloth/src/parser/ast.rs
index 7bc2c1b..a82a6df 100644
--- a/sloth/src/parser/ast.rs
+++ b/sloth/src/parser/ast.rs
@@ -424,6 +424,9 @@ impl Display for BinaryOp {
 pub enum UnaryOp {
     Not,
     Neg,
+
+    Reference,
+    Dereference,
 }
 
 impl TryFrom<TokenType> for UnaryOp {
@@ -434,6 +437,9 @@ impl TryFrom<TokenType> for UnaryOp {
             TokenType::Bang => Self::Not,
             TokenType::Minus => Self::Neg,
 
+            TokenType::Star => Self::Reference,
+            TokenType::At => Self::Dereference,
+
             _ => return Err(ParsingError::InvalidOp),
         };
 
@@ -446,6 +452,9 @@ impl Display for UnaryOp {
         let value = match self {
             UnaryOp::Not => "!",
             UnaryOp::Neg => "-",
+
+            UnaryOp::Reference => "*",
+            UnaryOp::Dereference => "@",
         };
 
         write!(f, "{value}")
diff --git a/sloth/src/parser/expr.rs b/sloth/src/parser/expr.rs
index ac7a19e..60f1610 100644
--- a/sloth/src/parser/expr.rs
+++ b/sloth/src/parser/expr.rs
@@ -10,9 +10,14 @@ impl<'a> AstParser<'a> {
     }
 
     fn unary(&mut self) -> Result<Expr, ParsingError> {
-        if !self.eof() && matches!(self.peek().tt, TokenType::Bang | TokenType::Minus) {
-            let oeprator_tt = self.advance().unwrap().tt.clone();
-            let operator = UnaryOp::try_from(oeprator_tt)?;
+        if !self.eof()
+            && matches!(
+                self.peek().tt,
+                TokenType::Bang | TokenType::Minus | TokenType::Star | TokenType::At
+            )
+        {
+            let operator_tt = self.advance().unwrap().tt.clone();
+            let operator = UnaryOp::try_from(operator_tt)?;
 
             let value = self.unary()?;