Lexing/parsing generic args.

dmc-lib/src/ast/function.rs

@@ -109,7 +109,7 @@ impl Function {
                 Parameter::new(
                     "self",
                     SourceRange::new(0, 0),
-                    TypeUse::new("Self", SourceRange::new(0, 0)),
+                    TypeUse::new("Self", SourceRange::new(0, 0), vec![]),
                 ),
             );
         }

dmc-lib/src/ast/type_use.rs

@@ -9,15 +9,21 @@ use std::rc::Rc;
 pub struct TypeUse {
     declared_name: String,
     declared_name_source_range: SourceRange,
+    generic_arguments: Vec<TypeUse>,
     scope_id: Option<usize>,
     type_info: Option<TypeInfo>,
 }
 
 impl TypeUse {
-    pub fn new(declared_name: &str, declared_name_source_range: SourceRange) -> Self {
+    pub fn new(
+        declared_name: &str,
+        declared_name_source_range: SourceRange,
+        generic_arguments: Vec<TypeUse>,
+    ) -> Self {
         Self {
             declared_name: declared_name.into(),
             declared_name_source_range,
+            generic_arguments,
             scope_id: None,
             type_info: None,
         }

dmc-lib/src/lexer.rs

@@ -54,10 +54,6 @@ impl<'a> Lexer<'a> {
             Token::new(self.position, self.position + 1, TokenKind::Modulo)
         } else if chunk.starts_with("+") {
             Token::new(self.position, self.position + 1, TokenKind::Plus)
-        } else if chunk.starts_with("<<") {
-            Token::new(self.position, self.position + 2, TokenKind::LeftShift)
-        } else if chunk.starts_with(">>") {
-            Token::new(self.position, self.position + 2, TokenKind::RightShift)
         } else if chunk.starts_with("&") {
             Token::new(self.position, self.position + 1, TokenKind::Ampersand)
         } else if chunk.starts_with("^") {
@@ -76,6 +72,10 @@ impl<'a> Lexer<'a> {
             Token::new(self.position, self.position + 1, TokenKind::LeftSquare)
         } else if chunk.starts_with("]") {
             Token::new(self.position, self.position + 1, TokenKind::RightSquare)
+        } else if chunk.starts_with("<") {
+            Token::new(self.position, self.position + 1, TokenKind::Lt)
+        } else if chunk.starts_with(">") {
+            Token::new(self.position, self.position + 1, TokenKind::Gt)
         } else {
             // more than one char token
             if chunk.starts_with(|c: char| c.is_ascii_digit()) {

dmc-lib/src/parser.rs

@@ -56,6 +56,12 @@ macro_rules! matches_statement_first {
     };
 }
 
+macro_rules! matches_type_use_first {
+    ( $token_kind: expr ) => {
+        matches!($token_kind, TokenKind::LeftSquare | TokenKind::Identifier)
+    };
+}
+
 struct Parser<'a> {
     input: &'a str,
     lexer: Lexer<'a>,
@@ -163,6 +169,26 @@ impl<'a> Parser<'a> {
         }
     }
 
+    fn expect_position_advance(
+        &mut self,
+        token_kind: TokenKind,
+        start_position: usize,
+    ) -> Result<Token, Vec<Diagnostic>> {
+        let matched = self.expect_advance(token_kind)?;
+        if matched.start() == start_position {
+            Ok(matched)
+        } else {
+            Err(vec![
+                Diagnostic::new(
+                    &format!("Expected {:?} but found {:?}", token_kind, matched.kind()),
+                    matched.start(),
+                    matched.end(),
+                )
+                .with_reporter(file!(), line!()),
+            ])
+        }
+    }
+
     fn peek_current(&self, token_kind: TokenKind) -> bool {
         match &self.current {
             None => panic!("Unexpected end of input."),
@@ -488,9 +514,19 @@ impl<'a> Parser<'a> {
                 }
                 TokenKind::Identifier => {
                     let identifier_token = self.expect_advance(TokenKind::Identifier)?;
+                    let generic_arguments =
+                        if self.current.is_some() && self.peek_current(TokenKind::Lt) {
+                            self.advance(); // <
+                            let generic_arguments = self.generic_arguments_list()?;
+                            self.expect_advance(TokenKind::Gt)?; // >
+                            generic_arguments
+                        } else {
+                            vec![]
+                        };
                     Ok(TypeUse::new(
                         self.token_text(&identifier_token),
                         SourceRange::new(identifier_token.start(), identifier_token.end()),
+                        generic_arguments,
                     ))
                 }
                 _ => Err(vec![Diagnostic::new(
@@ -510,6 +546,19 @@ impl<'a> Parser<'a> {
         )])
     }
 
+    fn generic_arguments_list(&mut self) -> Result<Vec<TypeUse>, Vec<Diagnostic>> {
+        let mut generic_arguments: Vec<TypeUse> = vec![];
+        while self.current.is_some() && matches_type_use_first!(self.get_current().kind()) {
+            generic_arguments.push(self.type_use()?);
+            if self.current.is_some() && self.peek_current(TokenKind::Comma) {
+                self.advance(); // comma
+            } else {
+                break;
+            }
+        }
+        Ok(generic_arguments)
+    }
+
     fn public_class_member(
         &mut self,
         fields: &mut Vec<Field>,
@@ -747,8 +796,10 @@ impl<'a> Parser<'a> {
         while self.current.is_some() {
             let current = self.get_current();
             match current.kind() {
-                TokenKind::LeftShift => {
-                    self.advance(); // left shift
+                TokenKind::Lt => {
+                    let second_lt_start = current.start() + 1;
+                    self.advance(); // first <
+                    self.expect_position_advance(TokenKind::Lt, second_lt_start)?; // second <
                     let rhs = self.additive_expression()?;
                     let source_range =
                         SourceRange::new(result.source_range().start(), rhs.source_range().end());
@@ -759,8 +810,10 @@ impl<'a> Parser<'a> {
                         source_range,
                     ));
                 }
-                TokenKind::RightShift => {
-                    self.advance(); // right shift
+                TokenKind::Gt => {
+                    let second_gt_start = current.start() + 1;
+                    self.advance(); // first >
+                    self.expect_position_advance(TokenKind::Gt, second_gt_start)?; // second gt
                     let rhs = self.additive_expression()?;
                     let source_range =
                         SourceRange::new(result.source_range().start(), rhs.source_range().end());
@@ -1170,6 +1223,16 @@ mod smoke_tests {
             ",
         )
     }
+
+    #[test]
+    fn array_generic_arg() {
+        smoke_test("fn main(args: Array<String>) end");
+    }
+
+    #[test]
+    fn nested_generic_args() {
+        smoke_test("fn main(foo: Array<Bar<Foo>>) end");
+    }
 }
 
 #[cfg(test)]

dmc-lib/src/token.rs

@@ -45,8 +45,6 @@ pub enum TokenKind {
     Star,
     Slash,
     Modulo,
-    LeftShift,
-    RightShift,
     Ampersand,
     Caret,
     Bar,
@@ -58,4 +56,6 @@ pub enum TokenKind {
     Ctor,
     LeftSquare,
     RightSquare,
+    Lt,
+    Gt,
 }