- code improvement: add function 'getVariableValueAsBoolean' in JavaScript style

src/prettify/parser/Prettify.java

diff --git a/src/prettify/parser/Prettify.java b/src/prettify/parser/Prettify.java
index 622b2d8..e14ff14 100644
--- a/src/prettify/parser/Prettify.java
+++ b/src/prettify/parser/Prettify.java
@@ -611,13 +611,13 @@
   protected CreateSimpleLexer sourceDecorator(Map<String, Object> options) throws Exception {
     List<List<Object>> shortcutStylePatterns = new ArrayList<List<Object>>();
     List<List<Object>> fallthroughStylePatterns = new ArrayList<List<Object>>();
-    if (options.get("tripleQuotedStrings") != null) {
+    if (Util.getVariableValueAsBoolean(options.get("tripleQuotedStrings"))) {
       // '''multi-line-string''', 'single-line-string', and double-quoted
       shortcutStylePatterns.add(Arrays.asList(new Object[]{PR_STRING,
                 Pattern.compile("^(?:\\'\\'\\'(?:[^\\'\\\\]|\\\\[\\s\\S]|\\'{1,2}(?=[^\\']))*(?:\\'\\'\\'|$)|\\\"\\\"\\\"(?:[^\\\"\\\\]|\\\\[\\s\\S]|\\\"{1,2}(?=[^\\\"]))*(?:\\\"\\\"\\\"|$)|\\'(?:[^\\\\\\']|\\\\[\\s\\S])*(?:\\'|$)|\\\"(?:[^\\\\\\\"]|\\\\[\\s\\S])*(?:\\\"|$))"),
                 null,
                 "'\""}));
-    } else if (options.get("multiLineStrings") != null) {
+    } else if (Util.getVariableValueAsBoolean(options.get("multiLineStrings"))) {
       // 'multi-line-string', "multi-line-string"
       shortcutStylePatterns.add(Arrays.asList(new Object[]{PR_STRING,
                 Pattern.compile("^(?:\\'(?:[^\\\\\\']|\\\\[\\s\\S])*(?:\\'|$)|\\\"(?:[^\\\\\\\"]|\\\\[\\s\\S])*(?:\\\"|$)|\\`(?:[^\\\\\\`]|\\\\[\\s\\S])*(?:\\`|$))"),
@@ -630,15 +630,15 @@
                 null,
                 "\"'"}));
     }
-    if (options.get("verbatimStrings") != null) {
+    if (Util.getVariableValueAsBoolean(options.get("verbatimStrings"))) {
       // verbatim-string-literal production from the C# grammar.  See issue 93.
       fallthroughStylePatterns.add(Arrays.asList(new Object[]{PR_STRING,
                 Pattern.compile("^@\\\"(?:[^\\\"]|\\\"\\\")*(?:\\\"|$)"),
                 null}));
     }
     Object hc = options.get("hashComments");
-    if (hc != null) {
-      if (options.get("cStyleComments") != null) {
+    if (Util.getVariableValueAsBoolean(hc)) {
+      if (Util.getVariableValueAsBoolean(options.get("cStyleComments"))) {
         if ((hc instanceof Integer) && (Integer) hc > 1) {  // multiline hash comments
           shortcutStylePatterns.add(Arrays.asList(new Object[]{PR_COMMENT,
                     Pattern.compile("^#(?:##(?:[^#]|#(?!##))*(?:###|$)|.*)"),
@@ -662,7 +662,7 @@
                   "#"}));
       }
     }
-    if (options.get("cStyleComments") != null) {
+    if (Util.getVariableValueAsBoolean(options.get("cStyleComments"))) {
       fallthroughStylePatterns.add(Arrays.asList(new Object[]{PR_COMMENT,
                 Pattern.compile("^\\/\\/[^\r\n]*"),
                 null}));
@@ -672,7 +672,7 @@
                 null}));
     }
     Object regexLiterals = options.get("regexLiterals");
-    if (regexLiterals != null) {
+    if (Util.getVariableValueAsBoolean(regexLiterals)) {
       /**
        * @const
        */
@@ -706,12 +706,13 @@
     }
 
     Pattern types = (Pattern) options.get("types");
-    if (types != null) {
+    if (Util.getVariableValueAsBoolean(types)) {
       fallthroughStylePatterns.add(Arrays.asList(new Object[]{PR_TYPE, types}));
     }
 
-    if (options.get("keywords") != null) {
-      String keywords = ((String) options.get("keywords")).replaceAll("^ | $", "");
+    String keywords = (String) options.get("keywords");
+    if (keywords != null) {
+      keywords = keywords.replaceAll("^ | $", "");
       if (keywords.length() != 0) {
         fallthroughStylePatterns.add(Arrays.asList(new Object[]{PR_KEYWORD,
                   Pattern.compile("^(?:" + keywords.replaceAll("[\\s,]+", "|") + ")\\b"),
@@ -790,7 +791,7 @@
     // when hc is truthy to include # in the run of punctuation characters
     // only when not followint [|&;<>].
     String punctuation = "^.[^\\s\\w.$@'\"`/\\\\]*";
-    if (options.get("regexLiterals") != null) {
+    if (Util.getVariableValueAsBoolean(options.get("regexLiterals"))) {
         punctuation += "(?!\\s*/)";
     }
     fallthroughStylePatterns.add(Arrays.asList(new Object[]{PR_PUNCTUATION,

src/prettify/parser/Util.java

diff --git a/src/prettify/parser/Util.java b/src/prettify/parser/Util.java
index 4613ef8..7147bd7 100644
--- a/src/prettify/parser/Util.java
+++ b/src/prettify/parser/Util.java
@@ -32,6 +32,32 @@
   }
   
   /**
+   * Treat a variable as an boolean in JavaScript style. Note this function can
+   * only handle string, integer and boolean currently. All other data type, if
+   * null, return false, not null return true.
+   *
+   * @param var the variable to get value from
+   * @return the boolean value
+   */
+  public static Boolean getVariableValueAsBoolean(Object var) {
+    Boolean returnResult = null;
+
+    if (var == null) {
+      returnResult = false;
+    } else if (var instanceof String) {
+      returnResult = !((String) var).isEmpty();
+    } else if (var instanceof Integer) {
+      returnResult = ((Integer) var) != 0;
+    } else if (var instanceof Boolean) {
+      returnResult = (Boolean) var;
+    } else {
+      returnResult = true;
+    }
+
+    return returnResult;
+  }
+
+  /**
    * Treat a variable as an integer in JavaScript style. Note this function can
    * only handle integer and boolean currently.
    *