string-keys-to-int: now usable.

src/string-keys-to-int.cr

@@ -1,10 +1,37 @@
 require "cbor"
+require "option_parser"
 
-if ARGV.size >= 1 && ARGV[0] == "-h"
-	puts "usage: cbor-from-string-to-int-hash-keys < file.cbor"
-	puts "usage: cbor-from-string-to-int-hash-keys [attribute] < file"
+#
+# JSON format has a limitation on the type of hash keys: it has to be a string.
+# CBOR doesn't come with such limitation.
+# string-keys-to-int: automatically converts string keys into integers, whenever all
+# the keys in a hash can be converted.
+#
+
+class Context
+	class_property do_nothing = false
+	class_property print_data = false
+end
+
+OptionParser.parse do |parser|
+	parser.banner = "usage: string-keys-to-int < file.cbor"
+
+	parser.on "-n", "--nothing",
+		"Do nothing, just print when keys would have been converted." do
+		Context.do_nothing = true
+	end
+
+	parser.on "-p", "--print-data",
+		"Do nothing, print keys to convert, input and output data." do
+		Context.do_nothing = true
+		Context.print_data = true
+	end
+
+	parser.on "-h", "--help", "Displays this help and exits." do
+		puts parser
 		exit 0
 	end
+end
 
 def are_hash_keys_all_int?(data)
 	case d = data
@@ -23,7 +50,19 @@ end
 def change(data)
 	# 1. change keys
 	if are_hash_keys_all_int? data 
-		puts "YES, DO IT, keys: #{data.as(Hash).keys}"
+		if Context.do_nothing
+			puts "keys to convert: #{data.as(Hash).keys}"
+		end
+
+		# Do something
+		case d = data
+		when Hash
+			keys = d.keys
+			keys.each do |k|
+				d[k.as(String).to_i32] = d[k]
+				d.delete k
+			end
+		end
 	end
 
 	# 2. dig
@@ -34,6 +73,8 @@ def change(data)
 			change d[k]
 		end
 	end
+rescue e
+	STDERR.puts "something went wrong: #{e}"
 end
 
 buffer = Bytes.new 1_000_000 # 1 MB
@@ -43,12 +84,22 @@ until STDIN.read(buffer) == 0
 	while data = decoder.read_value
 		break if data == 0
 
-		# pp data
+		if Context.print_data
+			puts "input data:"
+			pp data
+		end
 
 		change data
 
-		# STDOUT.write data.to_cbor
-		# STDOUT.flush
+		if Context.print_data
+			puts "output data:"
+			pp data
+		end
+
+		unless Context.do_nothing
+			STDOUT.write data.to_cbor
+			STDOUT.flush
+		end
 	end
 	buffer = Bytes.new 1_000_000 # 1 MB
 end