muScript: support comments

muscript/src/main/java/io/gitlab/jfronny/muscript/compiler/Lexer.java

@@ -32,7 +32,7 @@ public class Lexer {
         }
 
         // Scan expression
-        skipWhitespace();
+        skipWhitespaceAndComments();
         if (isAtEnd()) {
             createToken(Token.EOF);
             return;
@@ -132,13 +132,32 @@ public class Lexer {
         }
     }
 
-    private void skipWhitespace() {
+    private void skipWhitespaceAndComments() {
         while (true) {
             if (isAtEnd()) return;
-            char c = peek();
 
-            switch (c) {
+            switch (peek()) {
                 case ' ', '\r', '\t', '\n' -> advance();
+                case '/' -> {
+                    switch (peekNext()) {
+                        case '/' -> {
+                            while (!isAtEnd() && peek() != '\r' && peek() != '\n') advance();
+                        }
+                        case '*' -> {
+                            advance();
+                            advance();
+                            while (!isAtEnd() && (peek() != '*' || peekNext() != '/')) advance();
+                            if (!isAtEnd()) {
+                                advance();
+                                advance();
+                            }
+                        }
+                        default -> {
+                            start = current;
+                            return;
+                        }
+                    }
+                }
                 default -> {
                     start = current;
                     return;

muscript/src/test/java/io/gitlab/jfronny/muscript/test/CommentTest.java

@@ -0,0 +1,33 @@
+package io.gitlab.jfronny.muscript.test;
+
+import io.gitlab.jfronny.muscript.compiler.Parser;
+import org.junit.jupiter.api.Test;
+
+import static io.gitlab.jfronny.muscript.test.util.MuTestUtil.makeArgs;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class CommentTest {
+    @Test
+    void singleLine() {
+        assertEquals(2, Parser.parseScript("""
+                n = 5
+                n = 2
+                // n = 3
+                n
+                """).run(makeArgs()).asNumber().getValue());
+    }
+
+    @Test
+    void multiLine() {
+        assertEquals(2, Parser.parseScript("""
+                n = 2
+                /* n = 3 */
+                /*
+                  n = 3
+                  n = 4
+                  n = 5
+                */
+                n
+                """).run(makeArgs()).asNumber().getValue());
+    }
+}