chore: Naming conventions

tests/lexer/ScanPrologTests.kt

@@ -0,0 +1,61 @@
+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 ScanPrologTests {
+    @Test
+    fun scan_simple_atom() {
+        val tokens = Lexer("atom.").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() {
+        val tokens = Lexer("X.").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_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() }
+    }
+}