Parse binary / *

CHANGELOG.md

@@ -19,6 +19,7 @@
 - Parse block of code
 - Parse multiple statements inside a block
 - Parse unary operator (`!` & `-`)
+- Parse binary operators `/`, `*`
 
 
 ## v0.0.7

src/syntax/expression/factor.rs

@@ -3,6 +3,42 @@ use crate::{
     syntax::{ast::Expression, ParseResult},
 };
 
+/// Parses a factor expression.
+///
+/// ```ebnf
+/// factor = unary, (("/" | "*"), unary)*;
+/// ```
 pub fn try_parse(tokens: &Vec<Token>, pos: usize) -> ParseResult<Expression, ()> {
-    return super::unary::try_parse(tokens, pos);
+    let (unary, next_pos) = match super::unary::try_parse(tokens, pos) {
+        ParseResult::Ok(expr, next_pos) => (expr, next_pos),
+        _ => return ParseResult::Unmatched,
+    };
+
+    parse_many(tokens, next_pos, unary)
+}
+
+fn parse_many(
+    tokens: &Vec<Token>,
+    pos: usize,
+    prev_expr: Expression,
+) -> ParseResult<Expression, ()> {
+    // (("/" | "*"), unary)*
+
+    match tokens.get(pos) {
+        Some(token) if token.value == "/" || token.value == "*" => {
+            match super::unary::try_parse(tokens, pos + 1) {
+                ParseResult::Ok(expr, next_pos) => {
+                    let expr = Expression::BinaryOperator(
+                        Box::new(prev_expr),
+                        Box::new(expr),
+                        Box::new(token.value.clone()),
+                    );
+
+                    parse_many(tokens, next_pos, expr)
+                }
+                _ => ParseResult::Unmatched,
+            }
+        }
+        _ => ParseResult::Ok(prev_expr, pos),
+    }
 }

src/syntax/expression/unary.rs

@@ -7,7 +7,7 @@ use crate::{
 ///
 /// ```ebnf
 /// unary = ("!" | "-"), expression
-/// | primary;
+///       | primary;
 /// ```
 pub fn try_parse(tokens: &Vec<Token>, pos: usize) -> ParseResult<Expression, ()> {
     match tokens.get(pos) {
@@ -20,6 +20,7 @@ pub fn try_parse(tokens: &Vec<Token>, pos: usize) -> ParseResult<Expression, ()>
                 _ => ParseResult::Unmatched,
             }
         }
-        _ => return primary::try_parse(tokens, pos),
+        _ => primary::try_parse(tokens, pos),
     }
 }
+