Make --regexp-instrumentation-output-format an enum option

Author: eregon

src/main/ruby/truffleruby/core/truffle/regexp_operations.rb

@@ -175,7 +175,7 @@ def self.match_stats(joni_matches:)
     def self.print_stats
       output_format = Truffle::Boot.get_option('regexp-instrumentation-output-format')
 
-      if output_format == 'text'
+      if output_format == :TEXT
         puts '--------------------'
         puts 'Regular expression statistics'
         puts '--------------------'
@@ -204,7 +204,7 @@ def self.print_stats
 
           puts '--------------------'
         end
-      elsif output_format == 'json'
+      elsif output_format == :JSON
         ret = {}
 
         if Truffle::Boot.get_option('regexp-instrument-creation')

src/options.yml

@@ -237,7 +237,7 @@ INTERNAL: # Options for debugging the TruffleRuby implementation
     REGEXP_INSTRUMENT_CREATION: [regexp-instrument-creation, boolean, false, Enable instrumentation to gather stats on regexp creation]
     REGEXP_INSTRUMENT_MATCH: [regexp-instrument-match, boolean, false, Enable instrumentation to gather stats on regexp matching]
     REGEXP_INSTRUMENT_MATCH_DETAILED: [regexp-instrument-match-detailed, boolean, false, Enable instrumentation to gather detailed stats on strings matched against a regexp]
-    REGEXP_INSTRUMENT_OUTPUT_FORMAT: [regexp-instrumentation-output-format, string, 'text', 'Output format for regexp instrumentation (\\\"text\\\" or \\\"json\\\")']
+    REGEXP_INSTRUMENT_OUTPUT_FORMAT: [regexp-instrumentation-output-format, enum/output_format, text, 'Output format for regexp instrumentation']
 
     # Options for metrics, the output cannot be used directly without processing
     METRICS_TIME_PARSING_FILE: [metrics-time-parsing-file, boolean, false, 'Measure time for parsing, translating and executing files, per file']

src/shared/java/org/truffleruby/shared/options/OutputFormat.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2016, 2019 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 2.0, or
+ * GNU General Public License version 2, or
+ * GNU Lesser General Public License version 2.1.
+ */
+package org.truffleruby.shared.options;
+
+import java.util.Locale;
+
+public enum Verbosity {
+    NIL,
+    FALSE,
+    TRUE;
+
+    @Override
+    public String toString() {
+        return name().toLowerCase(Locale.ENGLISH);
+    }
+}