Add escape quote utility method.

Author: jpe42

.github/workflows/gradle-nightly.yml

@@ -5,8 +5,6 @@ on:
     branches:
       - master
   pull_request:
-  schedule:
-    - cron: '0 0 * * 1,4'
 
 jobs:
   check:

.github/workflows/gradle.yml

@@ -38,4 +38,36 @@ public static long compileReplacePattern(final byte byteToFind) {
         | (pattern << 48)
         | (pattern << 56);
   }
+
+  public static String escapeQuotes(final String str) {
+    final char[] chars = str.toCharArray();
+    final char[] escaped = new char[chars.length << 1];
+    char c;
+    for (int escapes = 0, from = 0, dest = 0, to = 0; ; to++) {
+      if (to == chars.length) {
+        if (from == 0) {
+          return str;
+        } else {
+          final int len = to - from;
+          System.arraycopy(chars, from, escaped, dest, len);
+          dest += len;
+          return new String(escaped, 0, dest);
+        }
+      } else {
+        c = chars[to];
+        if (c == '\\') {
+          escapes++;
+        } else if (c == '"' && (escapes & 1) == 0) {
+          final int len = to - from;
+          System.arraycopy(chars, from, escaped, dest, len);
+          dest += len;
+          escaped[dest++] = '\\';
+          from = to;
+          escapes = 0;
+        } else {
+          escapes = 0;
+        }
+      }
+    }
+  }
 }

systems.comodal.json_iterator/src/main/java/systems/comodal/jsoniter/JIUtil.java

@@ -31,6 +31,19 @@ void test_ascii_string(final JsonIteratorFactory factory) {
     assertArrayEquals(world, ji.decodeBase64String());
   }
 
+  @Test
+  void testEscapeQuotes() {
+    var nestedJson = """
+        {"hello": "world"}""";
+    assertEquals("""
+        {\\"hello\\": \\"world\\"}""", JIUtil.escapeQuotes(nestedJson));
+
+    nestedJson = """
+        {"hello": "\\"world\\""}""";
+    assertEquals("""
+        {\\"hello\\": \\"\\"world\\"\\"}""", JIUtil.escapeQuotes(nestedJson));
+  }
+
   @ParameterizedTest
   @MethodSource("systems.comodal.jsoniter.TestFactories#factories")
   void testRandomBase64Data(final JsonIteratorFactory factory) {