Implement parser for a simple language that roughly corresponds to appendix A in Aho's 2nd edition

2 files changed, 77 insertions, 5 deletions

diff --git a/src/test/java/com/seaofnodes/simple/lexer/TestLexer.java b/src/test/java/com/seaofnodes/simple/lexer/TestLexer.java
index 335bcf5e..18a4634d 100644
--- a/src/test/java/com/seaofnodes/simple/lexer/TestLexer.java
+++ b/src/test/java/com/seaofnodes/simple/lexer/TestLexer.java
@@ -3,8 +3,6 @@
  *
  * Contributor(s):
  *
- * The Initial Developer of the Original Software is Cliff Click.
- *
  * This file is part of the Sea Of Nodes Simple Programming language
  * implementation. See https://github.com/SeaOfNodes/Simple
  *
@@ -17,6 +15,10 @@
 
 package com.seaofnodes.simple.lexer;
 
+import com.seaofnodes.simple.common.ErrorListener;
+import com.seaofnodes.simple.lexer.ecstasy.Lexer;
+import com.seaofnodes.simple.lexer.ecstasy.Source;
+import com.seaofnodes.simple.lexer.ecstasy.Token;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
@@ -26,8 +28,10 @@ public class TestLexer {
     public void testLexLineComment()
     {
         final String source = "//a comment\nx";
-        Lexer lexer = new Lexer("test", source);
-        String token = lexer.token();
-        Assertions.assertEquals("x", token);
+        Lexer lexer = new Lexer(new Source(source), new ErrorListener());
+        Token token = lexer.next();
+        Assertions.assertEquals(token.getId(), Token.Id.EOL_COMMENT);
+        token = lexer.next();
+        Assertions.assertEquals("x", token.getValueText());
     }
 }
diff --git a/src/test/java/com/seaofnodes/simple/lexer/TestParser.java b/src/test/java/com/seaofnodes/simple/lexer/TestParser.java
new file mode 100644
index 00000000..7d2f3752
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/lexer/TestParser.java
@@ -0,0 +1,68 @@
+/**
+ * DO NOT REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Contributor(s):
+ *
+ * This file is part of the Sea Of Nodes Simple Programming language
+ * implementation. See https://github.com/SeaOfNodes/Simple
+ *
+ * The contents of this file are subject to the terms of the
+ * Apache License Version 2 (the "APL"). You may not use this
+ * file except in compliance with the License. A copy of the
+ * APL may be obtained from:
+ * http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+package com.seaofnodes.simple.lexer;
+
+import com.seaofnodes.simple.common.ErrorListener;
+import com.seaofnodes.simple.lexer.ecstasy.Lexer;
+import com.seaofnodes.simple.lexer.ecstasy.Source;
+import com.seaofnodes.simple.parser.Ast;
+import com.seaofnodes.simple.parser.Parser;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class TestParser {
+
+    @Test
+    public void testParseSingleDecl()
+    {
+        final String source = "var i: Int;";
+        Lexer lexer = new Lexer(new Source(source), new ErrorListener());
+        Parser parser = new Parser(lexer);
+        var ast = parser.parse();
+        Assertions.assertTrue(ast instanceof Ast.Block
+            && ((Ast.Block) ast).stmtList.size() == 1);
+    }
+
+    @Test
+    public void testParseTwoDecls() {
+        final String source = "var i: Int;\nvar j: Int;";
+        Lexer lexer = new Lexer(new Source(source), new ErrorListener());
+        Parser parser = new Parser(lexer);
+        var ast = parser.parse();
+        Assertions.assertTrue(ast instanceof Ast.Block
+                && ((Ast.Block) ast).stmtList.size() == 2);
+    }
+
+    @Test
+    public void testIfAndWhile() {
+        final String source =
+                """
+                var i: Int;
+                var j: Int;
+                
+                i = 0;
+                j = 100;
+                while ( 1 ) {
+                    i = i + 1;
+                    j = j - 1;
+                    if ( i >= j ) break;
+                }
+                """;
+        Lexer lexer = new Lexer(new Source(source), new ErrorListener());
+        Parser parser = new Parser(lexer);
+        var ast = parser.parse();
+    }
+}