Checkpoint

tests/lexer/LexerScanPrologTest.kt

@@ -1,8 +1,14 @@
 package lexer
 
 import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
 import kotlin.test.assertEquals
 
+/**
+ * Tests for the Prolog lexer.
+ *
+ * These tests are based on the Prolog syntax.
+ */
 class LexerScanPrologTest {
     @Test
     fun scan_simple_atom() {
@@ -25,4 +31,31 @@ class LexerScanPrologTest {
         assertEquals(TokenType.DOT, tokens[1].type, "Expected DOT token, got ${tokens[1].type}")
         assertEquals(TokenType.EOF, tokens[2].type, "Expected EOF token, got ${tokens[2].type}")
     }
-}
+
+    @Test
+    fun scan_variable_with_number() {
+        val tokens = Lexer("X1.").scan()
+
+        assertEquals(3, tokens.size)
+
+        assertEquals(TokenType.ALPHANUMERIC, tokens[0].type, "Expected ALPHANUMERIC token, got ${tokens[0].type}")
+        assertEquals(TokenType.DOT, tokens[1].type, "Expected DOT token, got ${tokens[1].type}")
+        assertEquals(TokenType.EOF, tokens[2].type, "Expected EOF token, got ${tokens[2].type}")
+    }
+
+    @Test
+    fun scan_variable_with_underscore() {
+        val tokens = Lexer("X_1.").scan()
+
+        assertEquals(3, tokens.size)
+
+        assertEquals(TokenType.ALPHANUMERIC, tokens[0].type, "Expected ALPHANUMERIC token, got ${tokens[0].type}")
+        assertEquals(TokenType.DOT, tokens[1].type, "Expected DOT token, got ${tokens[1].type}")
+        assertEquals(TokenType.EOF, tokens[2].type, "Expected EOF token, got ${tokens[2].type}")
+    }
+
+    @Test
+    fun scan_variable_that_starts_with_a_number() {
+        assertThrows<Error> { Lexer("1X.").scan() }
+    }
+}

tests/lexer/LexerScanTest.kt

@@ -1,8 +1,5 @@
-package be.ugent.logprog.lexer
+package lexer
 
-import lexer.Error
-import lexer.Lexer
-import lexer.TokenType
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import org.junit.jupiter.api.Assertions.*