From 1e5cfb4a1ebf038a306e8aae131be809f960c639 Mon Sep 17 00:00:00 2001
From: Sam Harwell <sam@tunnelvisionlabs.com>
Date: Tue, 30 Oct 2012 08:46:02 -0500
Subject: [PATCH] Add unit test for behavior of lexer with
 input-position-sensitive predicates

---
 .../test/org/antlr/v4/test/TestLexerExec.java | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/tool/test/org/antlr/v4/test/TestLexerExec.java b/tool/test/org/antlr/v4/test/TestLexerExec.java
index 1f04c7e99..4e4838d6f 100644
--- a/tool/test/org/antlr/v4/test/TestLexerExec.java
+++ b/tool/test/org/antlr/v4/test/TestLexerExec.java
@@ -266,6 +266,31 @@ public class TestLexerExec extends BaseTest {
 		assertEquals(expecting, found);
 	}
 
+	@Test public void testLexerInputPositionSensitivePredicates() throws Exception {
+		// The predicates here make sense on the left edge, but are currently
+		// only working on the right edge... resolving this would remove the
+		// need for Lexer.getSpeculativeText as well.
+		String grammar =
+			"lexer grammar L;\n"+
+			"WORD1 : ID1+ {System.out.println(getText());} ;\n"+
+			"WORD2 : ID2+ {System.out.println(getText());} ;\n"+
+			"fragment ID1 : {getCharPositionInLine()<2}? [a-zA-Z];\n"+
+			"fragment ID2 : {getCharPositionInLine()>=2}? [a-zA-Z];\n"+
+			"WS : (' '|'\\n') -> skip;\n";
+		String found = execLexer("L.g4", grammar, "L", "a cde\nabcde\n");
+		String expecting =
+			"a\n" +
+			"cde\n" +
+			"ab\n" +
+			"cde\n" +
+			"[@0,0:0='a',<1>,1:0]\n" +
+			"[@1,2:4='cde',<2>,1:2]\n" +
+			"[@2,6:7='ab',<1>,2:0]\n" +
+			"[@3,8:10='cde',<2>,2:2]\n" +
+			"[@4,12:11='<EOF>',<-1>,3:0]\n";
+		assertEquals(expecting, found);
+	}
+
 	@Test public void testActionExecutedInDFA() throws Exception {
 		String grammar =
 			"lexer grammar L;\n"+