initial commit

src/parser/mod.rs

@@ -0,0 +1,58 @@
+use crate::token::{Keyword, Symbol};
+use std::fmt::Debug;
+
+mod body;
+mod cursor;
+mod error;
+mod expr;
+pub use body::*;
+pub use cursor::*;
+pub use expr::*;
+pub use error::*;
+
+#[derive(Debug)]
+pub struct Module {
+    functions: Vec<Function>,
+}
+
+pub struct Function {
+    pub name: String,
+    pub body: Body,
+}
+
+impl Module {
+    pub fn parse(cursor: &mut TokenCursor) -> Result<Self, ParserError> {
+        let mut functions = Vec::new();
+        loop {
+            let Some(next) = cursor.peek() else {
+                return Ok(Self { functions });
+            };
+            if next.is_keyword(Keyword::Fn) {
+                functions.push(Function::parse(cursor)?);
+            } else {
+                return unexpected_token(cursor.next().unwrap(), "fn");
+            }
+        }
+    }
+}
+
+impl Function {
+    pub fn parse(cursor: &mut TokenCursor) -> Result<Self, ParserError> {
+        cursor.expect_kw(Keyword::Fn)?;
+        let name = cursor.expect_ident()?;
+        cursor.expect_sym(Symbol::OpenParen)?;
+        cursor.expect_sym(Symbol::CloseParen)?;
+        let body = Body::parse(cursor)?;
+        Ok(Self { name, body })
+    }
+}
+
+impl Debug for Function {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("fn ")?;
+        f.write_str(&self.name)?;
+        f.write_str("() ")?;
+        self.body.fmt(f)?;
+        Ok(())
+    }
+}