fix(lexer): accept identifiers that start with digits

handlebars/src/main/antlr4/com/github/jknack/handlebars/internal/HbsLexer.g4

@@ -334,6 +334,8 @@ ID
   :
   ID_START ID_SUFFIX*
   | ID_ESCAPE ID_SUFFIX*
+  // digit-leading identifiers such as 24Hr, which handlebars.js accepts
+  | [0-9]+ ID_START ID_SUFFIX*
  ;
 
 fragment

handlebars/src/test/java/com/github/jknack/handlebars/issues/Issue1078.java

@@ -0,0 +1,37 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.issues;
+
+import java.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+import com.github.jknack.handlebars.v4Test;
+
+public class Issue1078 extends v4Test {
+
+  @Test
+  public void shouldResolveIdentifiersThatStartWithDigits() throws IOException {
+    shouldCompileTo(
+        "<p>{{24HrServicePh}}</p>",
+        $("hash", $("24HrServicePh", "1-800-000-0000")),
+        "<p>1-800-000-0000</p>");
+  }
+
+  @Test
+  public void shouldResolveDigitLeadingIdentifiersInBlocks() throws IOException {
+    shouldCompileTo(
+        "{{#if 24Hr}}yes{{/if}}", $("hash", $("24Hr", true)), "yes");
+  }
+
+  @Test
+  public void shouldStillParseNumericLiteralsAsParameters() throws IOException {
+    shouldCompileTo(
+        "{{foo 24}} {{foo 24.5}}",
+        $("helpers", $("foo", "ok")),
+        "ok ok");
+  }
+}