Fix some syntax warnings and some allocation specs

lib/stupidedi/reader/pointer.rb

@@ -338,6 +338,9 @@ def inspect
       # This operation typically allocates memory and copies part of @storage,
       # so this is avoided as much as possible.
       #
+      # Unless the optional parameter `always_allocate` is `true`, then the
+      # return value may be `#frozen?` in some cases.
+      #
       # @return [S]
       def reify(always_allocate = false)
         if @storage.frozen? \

lib/stupidedi/reader/substring.rb

@@ -177,6 +177,7 @@ def count(other)
       # substring pointer.
       #
       # @return [self]
+      Z = "abc"
       def <<(other)
         case other
         when self.class
@@ -185,7 +186,7 @@ def <<(other)
             @length += other.length
           elsif not @storage.frozen?
             # Surely no one will notice if we destructively update @storage
-            @storage[@offset + @length, @storage.length - @offset - @length] = other
+            @storage[@offset + @length, @storage.length - @offset - @length] = other.reify
             @length  += other.length
           else
             # Other pointers are sharing our storage. We need to make our own

lib/stupidedi/reader/tokenizer.rb

@@ -528,7 +528,7 @@ def _update_state(segment_tok, config)
           gscode  = version.try(:slice, 0, 6)
 
           # GS01: Functional Identifier Code
-          fgcode = segment_tok.element_toks.at(0).try(:value)
+          # fgcode = segment_tok.element_toks.at(0).try(:value)
 
           if config.functional_group.defined_at?(gscode)
             envelope_def  = config.functional_group.at(gscode)

lib/stupidedi/ruby/string.rb

@@ -90,6 +90,7 @@ def match?(pattern, pos=nil)
           if pos.nil?
             !!(self =~ pattern)
           else
+            # NOTE: Regexp#match allocates a MatchData, String#match does not
             !!match(pattern, pos)
           end
         end

spec/lib/stupidedi/reader/native_ext_spec.rb

@@ -171,7 +171,7 @@
           expect(extend_language).to be_graphic(encoding: e)
         end
 
-        if n = e[/iso-8859-(\d+)/, 1].try{|n| Integer(n) }
+        if n = e[/iso-8859-(\d+)/, 1].try{|m| Integer(m) }
           it "identifies all graphic characters" do
             bytes  = iso_8859_table.reject{|_, no| no.include?(n) }.keys
             string = bytes.sort.map(&:chr).join.force_encoding(e)

spec/lib/stupidedi/reader/pointer_spec.rb

@@ -1,11 +1,16 @@
-# frozen_string_literal: true
+# frozen_string_literal: false
+
 describe Stupidedi::Reader::Pointer do
   using Stupidedi::Refinements
 
-  def pointer(value)
-    Stupidedi::Reader::Pointer.build(value)
+  def pointer(string, frozen: nil)
+    frozen = [true, false].sample if frozen.nil?
+    string.freeze       if frozen and not string.frozen?
+    string = string.dup if not frozen and string.frozen?
+    Stupidedi::Reader::Pointer.build(string)
   end
 
+
   def pointer_(*args)
     Stupidedi::Reader::Pointer.new(args)
   end