expression parser supports a backslash in a variables name; see #581

src/main/java/de/neemann/digital/analyse/parser/Tokenizer.java

@@ -17,9 +17,9 @@ public class Tokenizer {
     enum Token {UNKNOWN, IDENT, AND, OR, NOT, XOR, OPEN, CLOSE, ONE, ZERO, EOF, COMMA, EQUAL, NOTEQUAL, POSTNOT}
 
     private final Reader in;
+    private final StringBuilder builder;
     private Token token;
     private boolean isToken;
-    private StringBuilder builder;
     private boolean isUnreadChar = false;
     private int unreadChar;
 
@@ -174,7 +174,7 @@ public class Tokenizer {
     private boolean isIdentChar(int c) {
         return (c >= 'a' && c <= 'z')
                 || (c >= 'A' && c <= 'Z')
-                || (c == '_');
+                || (c == '_') || (c == '\\');
     }
 
     private boolean isNumberChar(int c) {

src/test/java/de/neemann/digital/analyse/parser/ParserTest.java

@@ -27,6 +27,7 @@ public class ParserTest extends TestCase {
     public void testIdent() throws Exception {
         assertEquals(new Variable("C"), createSingle("C"));
         assertEquals(new Variable("A_1"), createSingle("A_1"));
+        assertEquals(new Variable("A\\_1"), createSingle("A\\_1"));
     }
 
     public void testConst() throws Exception {