A ruby script that turns an enum definition into a switch statement.

switchem.rb

#!/usr/bin/env ruby
require 'optparse'

enum_string = ""
statements = "<#statements#>"
switch_expression = "<#expression#>"
tab_width = 4
use_tabs = false;

OptionParser.new do |option|
  option.on('-e', '--enum [enum]', String, 'The enum definition, whole or part.') do |in_enum| 
    enum_string = in_enum
  end

  option.on('-s', '--statements [statements]', String, 'A string to be inserted in each case.') do |in_statements|
    statements = in_statements
  end

  option.on('-x', '--expression [expression]', String, 'The expression to switch over.') do |in_expression|
    switch_expression = in_expression
  end

  option.on('-t', '--use-tabs', 'Use tabs instead of spaces.') do |in_use_tabs|
    use_tabs = true
  end

  option.on('-w', '--tab-width [tabwidth]', Integer, 'The number of spaces in a tab.') do |in_tab_width|
    tab_width = in_tab_width
  end
end.parse!(ARGV)

tab =  use_tabs ? "\t" : " " * tab_width

temp_enum = enum_string.split(/[\{\}]/) # Get rid of the brackets in case we're given a full definition
if temp_enum.count > 1 then enum_string = temp_enum[1] end # If it was a full definition the good stuff will be the second item

switch_statement = "switch (#{switch_expression}) {\n"

enum_string.split(',').each do |item|
  item = item.split('=')[0].strip # Get rid of the assignment
  if !item.empty? then switch_statement << "#{tab}case #{item}:\n#{tab * 2}#{statements}\n#{tab * 2}break;\n" end
end

switch_statement << "#{tab}default:\n#{tab * 2}break;\n}\n"

copy_command = "echo \"#{switch_statement}\" | pbcopy"
%x( #{copy_command} )
puts 'Done!'

You can pass either a full enum definition, or just the comma separated enum values you want to use.

Example 1

Full enum definition

switchem.rb -e "typedef NS_ENUM(NSInteger, SomeEnum) {
    SomeEnumValue,
    SomeEnumAnotherValue,
    SomeEnumOneLastValue
};"

Output

switch () {
    case SomeEnumValue:

        break;
    case SomeEnumAnotherValue:

        break;
    case SomeEnumOneLastValue:

        break;
    default:
        break;
}

Example 2

Partial enum definition

switchem.rb -e "SomeEnumValue,
    SomeEnumAnotherValue,"

Output

switch () {
    case SomeEnumValue:

        break;
    case SomeEnumAnotherValue:

        break;
    default:
        break;
}

There are a few ways to customize the output:

• You can use tabs instead of spaces by passing -t or --use-tabs
• Set the number of spaces in a tab with -w or --tab-width
• You can pass a variable name to switch over with -v or --switch-variable
• You can also provide a string to be inserted inside each case with -a or --action