[fine] Fix bugs, testing

oden-script/src/parser.rs

@@ -184,6 +184,7 @@ impl<'a> Parser<'a> {
     }
 
     fn expression_with_power(&mut self, minimum_power: u8) -> ExprRef {
+        self.trace("expression with power");
         self.advance();
         let mut expr = self.prefix_expression();
         loop {
@@ -203,6 +204,7 @@ impl<'a> Parser<'a> {
     }
 
     fn prefix_expression(&mut self) -> ExprRef {
+        self.trace("prefix");
         let token = self.previous.as_ref();
         match token {
             Some(token) => match token.kind() {
@@ -222,6 +224,7 @@ impl<'a> Parser<'a> {
     }
 
     fn infix_expression(&mut self, power: u8, left: ExprRef) -> ExprRef {
+        self.trace("infix");
         let kind = self.previous.as_ref().unwrap().kind();
         match kind {
             TokenKind::Plus | TokenKind::Minus | TokenKind::Star | TokenKind::Slash => {
@@ -245,7 +248,7 @@ impl<'a> Parser<'a> {
     }
 
     fn grouping(&mut self) -> ExprRef {
-        let result = self.number();
+        let result = self.expression();
         self.consume(
             Some(TokenKind::RightParen),
             "expected ')' after an expression",
@@ -264,7 +267,6 @@ impl<'a> Parser<'a> {
     }
 
     fn binary(&mut self, power: u8, left: ExprRef) -> ExprRef {
-        let right = self.expression_with_power(power + 1);
         let op = match self.previous.as_ref().unwrap().kind() {
             TokenKind::Plus => BinaryOp::Add,
             TokenKind::Minus => BinaryOp::Subtract,
@@ -274,6 +276,7 @@ impl<'a> Parser<'a> {
             TokenKind::Or => BinaryOp::Or,
             _ => panic!("unsuitable binary: {:?}: no op", self.previous),
         };
+        let right = self.expression_with_power(power + 1);
 
         self.tree.add_expr(Expr::Binary(op, left, right))
     }
@@ -343,6 +346,24 @@ impl<'a> Parser<'a> {
         self.tree
             .add_error(SyntaxError::new(line, column, final_message));
     }
+
+    fn trace(&self, _msg: &str) {
+        // let cpos = self.tokens.token_position(&self.current);
+        // let ppos = self.tokens.token_position(&self.previous);
+
+        // eprintln!(
+        //     "[{}:{}:{}] [{}:{}:{}]: {msg}",
+        //     ppos.0,
+        //     ppos.1,
+        //     self.previous
+        //         .as_ref()
+        //         .map(|t| t.as_str())
+        //         .unwrap_or("<eof>"),
+        //     cpos.0,
+        //     cpos.1,
+        //     self.current.as_ref().map(|t| t.as_str()).unwrap_or("<eof>")
+        // );
+    }
 }
 
 #[cfg(test)]
@@ -350,11 +371,27 @@ mod tests {
     use super::*;
     use pretty_assertions::assert_eq;
 
-    #[test]
-    pub fn number_expressions() {
-        // How am I going to test this?
-        let (tree, expr) = Parser::new("23.5").parse();
-        assert_eq!(Vec::<SyntaxError>::new(), tree.errors);
-        assert_eq!("23.5", tree.dump_expr(&expr));
+    fn test_successful_expression_parse(source: &str, expected: &str) {
+        let (tree, expr) = Parser::new(source).parse();
+        assert_eq!(
+            Vec::<SyntaxError>::new(),
+            tree.errors,
+            "Expected successful parse"
+        );
+        assert_eq!(expected, tree.dump_expr(&expr));
     }
+
+    macro_rules! test_expr {
+        ($name:ident, $input:expr, $expected:expr) => {
+            #[test]
+            fn $name() {
+                test_successful_expression_parse($input, $expected);
+            }
+        };
+    }
+
+    test_expr!(number_expr, "12", "12");
+    test_expr!(add_expr, "1 + 2", "(+ 1 2)");
+    test_expr!(prec_expr, "1 + 2 * 3 - 7 * 7", "(- (+ 1 (* 2 3)) (* 7 7))");
+    test_expr!(unary, "-((23)) * 5", "(* (- 23) 5)");
 }

oden-script/src/tokens.rs

@@ -391,20 +391,8 @@ impl<'a> std::iter::Iterator for Tokens<'a> {
             ')' => self.token(pos, TokenKind::RightParen),
             ',' => self.token(pos, TokenKind::Comma),
             '.' => self.token(pos, TokenKind::Dot),
-            '-' => {
-                if self.matches_next(|c| c.is_ascii_digit()) {
-                    self.number(pos)
-                } else {
-                    self.token(pos, TokenKind::Minus)
-                }
-            }
-            '+' => {
-                if self.matches_next(|c| c.is_ascii_digit()) {
-                    self.number(pos)
-                } else {
-                    self.token(pos, TokenKind::Plus)
-                }
-            }
+            '-' => self.token(pos, TokenKind::Minus),
+            '+' => self.token(pos, TokenKind::Plus),
             ';' => self.token(pos, TokenKind::Semicolon),
             '/' => self.token(pos, TokenKind::Slash),
             '*' => self.token(pos, TokenKind::Star),