Had to fix block.call to yield so that the compiler could be happy

anno[:validate] was always nil; validation procs were never wired
into Flag(T).new. Correct key is :validation to match the field
name set by the argument macro in command/argument.cr.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ATnpoEGXj4RyuMoBLGWcjs

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*.cr]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true

.gitignore

@@ -1,14 +1,13 @@
-# Crystal build artifacts
+*
-/.build/
+!CLAUDE.md
-/bin/
+!lib/
-
+!lib/cligen
-# Compiled test binary (crystal build test.cr)
+!src/
-test
+!src/**
-
+!shard.yml
-# Shards cache
+!README.md
-/.shards/
+!design.adoc
-/lib/
+!docs/
-
+!docs/**
-# Editor
+!Makefile
-tags
+!LICENSE
-.DS_Store

design.adoc

@@ -44,10 +44,8 @@ module MyModule
       "myutil mycommand do_thing --myvar 5"
     ]
 
-    subcommand do_thing : Int32,
+    subcommand do_thing, description: "Do the THING", examples: MyModule::MyCommand::DO_THING_EXAMPLES do
-      description: "Do the THING",
+
-      examples: MyModule::MyCommand::DO_THING_EXAMPLES \
-    do
       output = 0
 
       @myvar.times do |i|
@@ -55,11 +53,11 @@ module MyModule
         output += i
       end
 
-      output
+      puts "Total : %i" % output
     end
   end
 
-  CliGen::App.process(ARGV)
+  CliGen::App.process
 end
 ----
 

lib/cligen

@@ -0,0 +1 @@
+..

src/cligen.cr

@@ -1,3 +1,5 @@
+require "./cligen/exceptions"
+require "./cligen/coercable"
 require "./cligen/parsable"
 require "./cligen/annotations"
 require "./cligen/format"
@@ -10,6 +12,11 @@ require "./cligen/app"
 module CliGen
   VERSION = "0.1.0"
 
+  macro override_help_template(filepath)
+    {% raise "ERROR : CliGen.override_help_template : File(#{filepath}) doesn't exist" unless file_exists?(filepath) %}
+    CliGen::HELP_OVERRIDE_TEMPLATE = {{`readlink -f #{filepath}`.strip.stringify}}
+  end
+
   APPNAME = File.basename(PROGRAM_NAME)
 
   record AdditionalDefaultFlag,

src/cligen/annotations.cr

@@ -14,6 +14,9 @@ module CliGen
   annotation Selection
   end
  
+  annotation PreRunCommand
+  end
+
   annotation SubCommand
   end
 end

src/cligen/app.cr

@@ -14,17 +14,29 @@ module CliGen
       @@instance = self
     end
 
-    def check! : Nil
+    def check!
-      CliGen::GLOBAL_FLAGS.each(&.check!)
+      super
-      # @flags is the amalgamation of all child flags — checked by the commands themselves
+    end
-      check_for_duplicates!([CliGen::GLOBAL_FLAGS, @flags].flatten)
+
-      @commands.each(&.check!)
+    def self.handle_command_raises(&) : Nil
+      begin
+        yield
+      rescue e : CliGen::RuntimeError
+        abort e.message
+      rescue e : CliGen::ConfigurationError 
+        abort e.message
+      rescue e : CliGen::HelpRequestedError
+        puts e.message
+        exit 0
+      end
     end
 
     # Convenience entry point; defaults to ARGV
     def self.process(args : Array(String) = ARGV.to_a) : Nil
       generate if @@instance.nil?
+      handle_command_raises do
         @@instance.not_nil!.process(args)
       end
     end
+  end
 end

src/cligen/app/generate.cr

@@ -27,10 +27,13 @@ module CliGen
               env_var: {% if anno[:env_var] %} {{anno[:env_var]}} {% else %} {{"#{cmd.name.split("::").last.upcase.id}_#{var.name.upcase}"}} {% end %},
               description: {{ anno[:description] }},
               default: {% unless var.default_value.nil? %} {{var.default_value}} {% else %} nil {% end %},
-              validate: {% if anno[:validate] %} {{anno[:validate]}} {% else %} nil {% end %},
+              validate: {% if anno[:validation] %} {{anno[:validation]}} {% else %} nil {% end %},
-              on_match: {% if anno[:on_match] %} {{anno[:on_match]}} {% else %} nil {% end %}
+              on_match: {% if anno[:on_match] %} {{anno[:on_match]}} {% else %} nil {% end %},
+              options: {% if anno[:options] %} {{anno[:options]}} {% else %} nil {% end %},
+              delimiter: {% if anno[:delimiter] %} {{anno[:delimiter]}} {% else %} "," {% end %},
+              format: {% if anno[:format] %} {{anno[:format]}} {% else %} nil {% end %}
             )
-        {% debug %}
+          {% debug if env("DEBUG") %}
           {% end %}
 
           # Keep a copy of every flag on the root for global matching
@@ -44,7 +47,7 @@ module CliGen
             post_run_commands: cmd_post_run_cmds,
             description: {{cmd_info[:description]}}
           )
-        {% debug %}
+        {% debug if env("DEBUG") %}
         {% end %}
         {% end %}
 

src/cligen/arg.cr

@@ -24,12 +24,60 @@ module CliGen
     def initialize(@value, @index)
     end
 
+    def self.flag?(val : String) : Bool
+      if val =~ CliGen::Regex::FLAG_REGEX
+        true
+      else
+        false
+      end
+    end
+
+    def flag?(val : String = @value) : Bool
+      Arg.flag?(val)
+    end
+
+    def self.int?(val : String) : Bool
+      if val =~ CliGen::Regex::INT
+        true
+      else
+        false
+      end
+    end
+
+    def int?(val : String = @value) : Bool
+      Arg.int?(val)
+    end
+
+    def self.uint?(val : String) : Bool
+      if val =~ CliGen::Regex::UINT
+        true
+      else
+        false
+      end
+    end
+
+    def uint?(val : String = @value) : Bool
+      Arg.uint?(val)
+    end
+
+    def self.float?(val : String) : Bool
+      if val =~ CliGen::Regex::FLOAT
+        true
+      else
+        false
+      end
+    end
+
+    def float?(val : String = @value) : Bool
+      Arg.float?(val)
+    end
+
     # This serves as a trigger that tells the object that it has been processed
     # 
     # This will raise an exception if it is re-called after already having been
     # processed.
     def processed
-      raise "ERROR : CliGen::Arg(index: #{@index}, value: #{@value})#processed : This arg was re-processed" if @processed
+      raise CliGen::ArgReprocessedError.new("CliGen::Arg(index: #{@index}, value: #{@value})#processed : This arg was re-processed") if @processed
       @processed = true
     end
   end

src/cligen/coercable.cr

@@ -1,3 +1,3 @@
 module CliGen::Coercable
-  abstract def coerce(arg : String) : self
+  abstract def coerce(arg : String) 
 end

src/cligen/command.cr

@@ -4,32 +4,22 @@ require "time"
 require "./annotations"
 require "./command/argument"
 require "./command/selection"
-require "./command/trigger"
+require "./command/help_template"
 require "./command/subcommand"
+require "./command/def_init"
+require "./command/define_command_initializer"
 
 module CliGen
   class Command
     macro inherited
       {% verbatim do %}
       macro finished
-        def initialize(*, handler : CliGen::BaseCommandNode)
+        {% anno = @type.annotation(CliGen::CommandInfo) %}
-          {% verbatim do %}
+        {% raise "" unless anno %}
-            {% for var in @type.instance_vars %}
+        {% if anno[:def_init] %}
-              {% anno = (var.annotation(CliGen::Argument) || var.annotation(CliGen::Selection)) %}
+          def_init
-              {% if anno %}
-                {% raise "ERROR : #{@type.name}#initialize : Argument '#{var.name}' cannot be a nilable type (#{var.type}) — flags always resolve to a concrete value" if var.type.union? %}
-                if flg = handler.flags.find{|f| f.var == {{var.name.stringify}} && f.long == {{anno[:long]}}}
-                  @{{var.id}} = flg.as(CliGen::Flag({{var.type}})).value!
-                else
-                  raise "ERROR : {{@type.name}}\#{{@def.name}} : No flag found for \"{{var.name}}\"?"
-                end
-              {% else %}
-                {% raise "ERROR : #{@type.name}#{@def.name} : Instance Variable(#{var.name}) is not handled by CliGen and does not have a default value" unless var.default_value %}
-                @{{var.id}} = {{var.default_value}}
         {% end %}
-            {% end %}
+        define_command_initializer
-          {% end %}
-        end
       end
       {% end %}
     end

src/cligen/command/argument.cr

@@ -1,41 +1,80 @@
 module CliGen
   class Command
-    macro argument(variable, long, description, short = nil, validation = nil, on_match = nil)
+    macro argument(variable, description, long = nil, short = nil, validation = nil, on_match = nil, def_setter = false, def_getter = false, options = nil, delimiter = ",", format = nil, allow_no_verification = false)
+      {% raise "ERROR : CliGen::Command.argument : def_setter must be a Bool" unless def_setter.is_a? BoolLiteral %}
       {% raise "ERROR : CliGen::Command.argument : First argument (#{variable}) must be a TypeDeclaration (ex: '<var> : <type> [= val]')" unless variable.is_a? TypeDeclaration %}
       {% name = variable.var %}
       {% type = variable.type %}
+      {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided delimiter must be a string" unless delimiter.is_a? StringLiteral %}
       {% if short %}
         {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided short must be a string" unless short.is_a? StringLiteral %}
       {% end %}
-      {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided long must be a string" unless long.is_a? StringLiteral || long == nil %}
+      {% if long %}
-      {% raise "ERROR : CliGen::Command.argument(#{name}) : You must provide a short or long" unless long || short %}
+        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided long must be a string" unless long.is_a? StringLiteral %}
+        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided long must match --[a-zA-Z0-9-_]+" unless long =~ /^--[a-zA-Z0-9-_]+/ %}
+      {% else %}
+        {% long = "--#{name.downcase}" %}
+      {% end %}
       {% raise "ERROR : CliGen::Command.argument(#{name}) : You must provide a description" unless description %}
-      {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided description must be a String" unless description.is_a? StringLiteral %}
+      {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided description must be a String" unless description.is_a? StringLiteral || description.is_a? StringInterpolation %}
       {% unless on_match.nil? %}
-        {% puts on_match %}
+        {% puts "DEBUG : #{@type.name}.argument(#{name}) : OnMatch:\n\tid: #{on_match}\n\treturn_type: #{on_match.return_type}\n\tinput_vars: #{on_match.args}" if env("DEBUG")%}
         {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided on_match must be a Proc" unless on_match.is_a? ProcLiteral %}
-        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided on_match return type must be a Bool" unless on_match.return_type == Nil %}
+        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided on_match return type must be Nil" unless on_match.return_type.resolve == Nil %}
       {% end %}
       {% unless validation.nil? %}
+        {% puts "DEBUG : #{@type.name}.argument(#{name}) : Validation:\n\tid: #{validation}\n\treturn_type: #{validation.return_type}\n\tinput_vars: #{validation.args}" if env("DEBUG")%}
         {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided validation must be a Proc" unless validation.is_a? ProcLiteral %}
-        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided validation return type must be a Bool" unless validation.return_type == Bool %}
+        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided validation return type must be a Bool" unless validation.return_type.resolve == Bool %}
         {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided validation provided validation must have an input variable" if validation.args.empty? %}
         {% arg = validation.args.first %}
         {% unless arg.restriction == type %}
-          {% example = "->(#{arg.name} : #{type}) : #{type} { #{validation.body} }" %}
+          {% example = "->(#{arg.name} : #{type}) : Bool { #{validation.body} }" %}
           {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided validation input value must be #{type}. EX: #{example}" %}
         {% end %}
       {% end %}
+      {% if options %}
+        {% options = options.resolve if options.is_a? Path %}
+        {% if options.is_a? Call %}
+        {% elsif options.is_a? ArrayLiteral %}
+        {% else %}
+        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided options must be an ArrayLiteral or a runtime method call to retrieve data" %}
+        {% end %}
+      {% end %}
+      {% if format %}
+        {% format = format.resolve if format.is_a? Path %}
+        {% raise "ERROR : CliGen::Command.argument(#{name}) : Provided format must be a RegexLiteral" unless format.is_a? RegexLiteral %}
+      {% end %}
+      {% if type.resolve <= Array && ! allow_no_verification %}
+        {% elem = type.type_vars.first %}
+        {% unless elem == Int32 %}
+          {% if format.nil? && options.nil? %}
+            {% raise "ERROR : CliGen::Command.argument(#{name}) : When providing custom data types for Array(T) or using Array(String) you must provide a format or options for argument filtering so that parsing can be done deterministically" %}
+          {% end %}
+        {% end %}
+      {% end %}
 
-      @[CliGen::Argument(short: {{short}}, long: {{long}}, description: {{description}}, validation: {{validation}}, on_match: {{on_match}})]
+      {% if type.resolve < Array && ! options.nil? %}
+      @[CliGen::Argument(short: {{short}}, long: {{long}}, description: {{description}}, validation: {{validation}}, on_match: {{on_match}}, options: [{{options}}], delimiter: {{delimiter}}, format: {{format}})]
+      {% else %}
+      @[CliGen::Argument(short: {{short}}, long: {{long}}, description: {{description}}, validation: {{validation}}, on_match: {{on_match}}, options: {{options}}, delimiter: {{delimiter}}, format: {{format}})]
+      {% end %}
       @{{variable}}
 
+      {% if def_getter %}
+      def {{variable.var}}
+        @{{name}}
+      end
+      {% end %}
+
+      {% if def_setter %}
       def {{variable.var}}= (value : {{type}})
         {% unless validation.nil? %}
-          raise "ERROR : #{@type.name}##{@def.name} : Provided value #{value} is not passing validation" unless {{validation}}.call(value)
+          raise CliGen::ValidationError.new("#{@type.name}##{@def.name} : Provided value #{value} failed validation") unless {{validation}}.call(value)
         {% end %}
         @{{name}} = value
       end
+      {% end %}
     end
   end
 end

src/cligen/command/def_init.cr

@@ -0,0 +1,22 @@
+module CliGen
+  class Command
+    macro def_init
+      def initialize
+        {% verbatim do %}
+          {% for var in @type.instance_vars %}
+            {% raise "ERROR : Can't define a default initializer if #{var.name} doesn't have a default" if var.default_value.nil? && !var.type.nilable? %}
+            @{{var.name}} = {{var.default_value}}
+          {% end %}
+        {% end %}
+      end
+
+      def after_initialize
+        @@instance = self
+      end
+
+      def self.get 
+        @@instance ||= new
+      end
+    end
+  end
+end

src/cligen/command/define_command_initializer.cr

@@ -0,0 +1,29 @@
+module CliGen
+  class Command
+    macro define_command_initializer
+      def initialize(*, handler : CliGen::BaseCommandNode)
+        {% verbatim do %}
+          {% for var in @type.instance_vars %}
+            {% anno = (var.annotation(CliGen::Argument) || var.annotation(CliGen::Selection)) %}
+            {% if anno %}
+              {% raise "ERROR : #{@type.name}#initialize : Argument '#{var.name}' cannot be a nilable type (#{var.type}) — flags always resolve to a concrete value" if var.type.union? %}
+              if flg = handler.flags.find{|f| f.var == {{var.name.stringify}} && f.long == {{anno[:long]}}}
+                flg.validate!
+                @{{var.id}} = flg.as(CliGen::Flag({{var.type}})).value!
+              else
+                raise CliGen::FlagNotFoundError.new("{{@type.name}}\#{{@def.name}} : No flag found for \"{{var.name}}\"")
+              end
+            {% else %}
+              {% raise "ERROR : #{@type.name}#{@def.name} : Instance Variable(#{var.name}) is not handled by CliGen and does not have a default value" unless var.default_value %}
+              @{{var.id}} = {{var.default_value}}
+            {% end %}
+          {% end %}
+
+          {% if @type.has_method? :after_initialize %}
+            after_initialize
+          {% end %}
+        {% end %}
+      end
+    end
+  end
+end

src/cligen/command/help_template.cr

@@ -0,0 +1,10 @@
+module CliGen
+  class Command
+    macro help_template(filepath)
+      {% raise "ERROR : CliGen::Command.help_template : #{filepath} does not exist" unless file_exists? filepath %}
+      HELP_TEMPLATE = {{`readlink -f #{filepath}`.strip.stringify}}
+      {% puts "DEBUG : #{@type.name} : Set HELP_TEMPLATE to #{filepath}" if env("DEBUG") %}
+      {% debug if env("DEBUG") %}
+    end
+  end
+end

src/cligen/command/selection.cr

@@ -1,14 +1,21 @@
 module CliGen
   class Command
-    macro selection(variable, short, long, description, options)
+    macro selection(variable, description, options, short = nil, long = nil, validation = nil, on_match = nil)
       {% raise "ERROR : CliGen::Command.selection : First selection must be a TypeDeclaration (ex: '<var> : <type> [= val]')" unless variable.is_a? TypeDeclaration %}
-      {% raise "ERROR : CliGen::Command.selection : Provided short must be a string" unless short.is_a? StringLiteral || string == nil %}
+      {% if short %}
-      {% raise "ERROR : CliGen::Command.selection : Provided long must be a string" unless long.is_a? StringLiteral || long == nil %}
+        {% raise "ERROR : CliGen::Command.selection : Provided short must be a string" unless short.is_a? StringLiteral %}
+      {% end %}
+      {% long = "--#{variable.var}" if long.nil? %}
+      {% raise "ERROR : CliGen::Command.selection : Provided long must be a flag format" unless long =~ /^--[a-zA-Z0-9-_]+/ %}
+      {% raise "ERROR : CliGen::Command.selection : Provided long must be a string" unless long.is_a? StringLiteral %}
       {% raise "ERROR : CliGen::Command.selection : You must provide a short or long" unless long || short %}
       {% raise "ERROR : CliGen::Command.selection : You must provide a description" unless description %}
       {% raise "ERROR : CliGen::Command.selection : Provided description must be a String" unless description.is_a? StringLiteral %}
-      {% raise "ERROR : CliGen::Command.selection : You must provide options" unless options %}
+      {% options = options.resolve if options.is_a? Path %}
-      {% raise "ERROR : CliGen::Command.selection : Provided options must be " unless options %}
+      {% raise "ERROR : CliGen::Command.selection : Provided options must be an ArrayLiteral" unless options.is_a? ArrayLiteral %}
+
+      @[CliGen::Argument(short: {{short}}, long: {{long}}, description: {{description}}, validation: {{validation}}, on_match: {{on_match}}, options: {{options}}, delimiter: "-")]
+      @{{variable}}
     end
   end
 end

src/cligen/command/trigger.cr

@@ -1,21 +0,0 @@
-module CliGen
-  class Command
-    macro trigger(short, long, argument = nil, &on_match)
-      {% raise "ERROR : CliGen::Command.trigger : Provided short must be a string" unless short.is_a? StringLiteral %}
-      {% raise "ERROR : CliGen::Command.trigger : Provided long must be a string" unless long.is_a? StringLiteral %}
-      {% raise "ERROR : CliGen::Command.trigger : Must provide a block for on_match trigger" unless on_match %}
-      {% name = long.gsub(/--/, "") %}
-
-      @[CliGen::Trigger(short: {{short}}, long: {{long}}, argument: {{argument}})]
-      {% if argument %}
-      def self.__cligen_trigger__{{name}}__({{name}} : {{argument}}) : Nil
-        {{on_match.body}}
-      end
-      {% else %}
-      def self.__cligen_trigger__{{name}}__ : Nil
-        {{on_match.body}}
-      end
-      {% end %}
-    end
-  end
-end

src/cligen/command_node.cr

@@ -33,10 +33,6 @@ module CliGen
       @flags = (flags + CliGen::GLOBAL_FLAGS + @commands.flat_map(&.flags)).uniq
     end
 
-    def help : String
-      ECR.render("src/cligen/template/cmd_help.ecr")
-    end
-
     def check_for_duplicates!(flags : Array(BaseFlag)) : Nil
       shorts = flags.compact_map(&.short)
       short_duplicates = [] of String
@@ -67,18 +63,31 @@ module CliGen
           message += "\nShort:\n%s" % short_duplicates.map { |f| "- #{f}" }.join("\n")
         end
 
-        raise error_buffer % [@name, message]
+        raise CliGen::DuplicateFlagError.new(error_buffer % [@name, message])
       end
     end
 
-    def get(flag_long : String) : BaseFlag?
+    def get(*, long : String) : BaseFlag?
-      @flags.find{|f| f.long_key == flag_long}
+      @flags.find{|f| f.long_key == long}
+    end
+
+    def get(*, short : String) : BaseFlag?
+      @flags.find{|f| f.short == short}
+    end
+
+    def handle_flag_raises(&) : Nil
+      begin 
+        yield
+      rescue e : CliGen::RuntimeError
+        abort e.message
+      end
     end
 
     def find_match(arg : String)
       if subcommand?(arg)
         return CliGen::MatchType::SubCommand
       end
+
       case arg
       when "-h", "--help"
         CliGen::MatchType::Help
@@ -90,8 +99,6 @@ module CliGen
         end
       when CliGen::Regex::FLAG_WITH_ARG
         CliGen::MatchType::FlagWithArg
-      when CliGen::Regex::SHORT_WITH_INLINE_ARG
-        CliGen::MatchType::ShortWithInlineArg
       when CliGen::Regex::FLAG_MULTIPLE_SHORT
         CliGen::MatchType::FlagMultipleShort
       else
@@ -111,6 +118,10 @@ module CliGen
       subcommands.any?{|f| f.name == arg}
     end
 
+    def flag?(arg : String) : Bool
+      @flags.any?(&.matches?(arg))
+    end
+
     # Converts String array to Arg array and hands off to the typed process method
     def process(args : Array(String)) : Nil
       new_args = args.each_with_index.map { |arg, i| CliGen::Arg.new(value: arg, index: i) }.to_a
@@ -143,12 +154,35 @@ module CliGen
       {% end %}
     end
 
+    def verbose? : Bool
+      @verbose_flag ||= get(long: "--verbose").not_nil!.as(Flag(Bool))
+      @verbose_flag.not_nil!.value!
+    end
+
+    def help : String
+      {% begin %}
+      {% if T.has_constant? "HELP_TEMPLATE" %}
+        {% puts "#{T} was found to have HELP_TEMPLATE defined using this instead" if env("DEBUG") %}
+        ECR.render({{T.constant("HELP_TEMPLATE")}})
+      {% elsif CliGen.has_constant? "HELP_OVERRIDE_TEMPLATE" %} # If we have a global override use it
+        {% puts "Global override found. Using" if env("DEBUG") %}
+        ECR.render({{CliGen::HELP_OVERRIDE_TEMPLATE}})
+      {% else %}
+        {% puts "No type overrided help output. Using default" if env("DEBUG") %}
+        ECR.render("lib/cligen/src/cligen/template/cmd_help.ecr")
+      {% end %} # otherwise
+        {% debug if env("DEBUG") %}
+      {% end %}
+    end
+
     def check! : Nil
       @flags.each(&.check!)
       check_for_duplicates!(@flags)
       @commands.each(&.check!)
-      raise "ERROR : CommandNode({{T}})#check! : {{T}} has no subcommands and no #main defined" \
+      {% unless T == Nil %}
+      raise CliGen::MissingDispatchError.new("CommandNode({{T}})#check! : {{T}} has no subcommands and no #main defined") \
         if subcommands.empty? && !{{T.has_method?(:main)}}
+      {% end %}
     end
 
     def process(args : Array(CliGen::Arg)) : Nil
@@ -170,55 +204,80 @@ module CliGen
             {% for cls in CliGen::Command.subclasses %}
           when CliGen::CommandNode({{cls.name}})
             match.as(CommandNode({{cls}})).process(args.reject(&.processed?))
+            exit 0
             {% end %}
           else
-            raise "ERROR : Couldn't find thing"
+            raise CliGen::UnknownCommandNodeError.new("CommandNode({{T}})#process : matched a BaseCommandNode that isn't a known CommandNode(T)")
           end
           {% end %}
           passed_execution = true
 
         when BaseFlag
+          # Ensuring we catch any exceptions to have them abort with the
+          # error message if caught
+          handle_flag_raises do
             if match.requires_arg?
-            match.process(args.reject(&.processed?))
+              match.process(args.reject(&.processed?).take_while{|v| find_match(v.value) == CliGen::MatchType::NoMatch}) 
             else
               match.process
             end
+          end
 
         when MatchType::SubCommand
-          raise "ERROR : CommandNode({{T}})#process : Subcommand(#{matched_subcommand}) was already matched" if matched_subcommand
+          raise CliGen::InternalError.new("CommandNode({{T}})#process : subcommand '#{matched_subcommand}' was already matched — duplicate subcommand token") if matched_subcommand
           matched_subcommand = arg.value
 
         when MatchType::Help
-          abort help
+          raise CliGen::HelpRequestedError.new(help)
 
         when MatchType::FlagWithArg
           if regex_match = CliGen::Regex::FLAG_WITH_ARG.match(arg.value)
             case flag_match = find_match(regex_match["flag"])
             when BaseFlag
+              handle_flag_raises do
                 flag_match.process([CliGen::Arg.new(value: regex_match["arg"], index: arg.index)])
-            else
-              raise "ERROR : CommandNode(#{@name}).process : No flag matched '#{regex_match["flag"]}'"
               end
             else
-            raise "Oh good, you broke regex. How the hell did it match in find_match but not above? What the hell is going on"
+              raise CliGen::UnknownCommandNodeError.new("CommandNode(#{@name}).process : No flag matched '#{regex_match["flag"]}'")
+            end
+          else
+            raise CliGen::RegexInvariantError.new("CommandNode(#{@name}).process : FLAG_WITH_ARG matched in find_match but failed on re-match — this is a framework bug")
           end
-
-        when MatchType::ShortWithInlineArg
-          abort "#{CliGen::APPNAME}: invalid flag '#{arg.value}' — inline values are not supported. Did you mean '#{arg.value[0..1]} #{arg.value[2..]}' ?"
 
         when MatchType::FlagMultipleShort
-          arg.value.gsub(/^-/, "").chars.map { |c| "-#{c}" }.each do |flag|
+          val = arg.value.gsub(/^-/,"")
+
+          # If the next character in the series is a flag assume the remaining are flags as well.
+          if flag?("-#{val[1]}")
+            chars = val.chars
+            chars.map { |c| "-#{c}" }.each_with_index do |flag, index|
               case match = find_match(flag)
               when BaseFlag
-              abort "#{CliGen::APPNAME}: cannot bundle flag that requires an argument: #{flag}" if match.requires_arg?
+                # If this is the last flag in the series let it process others
+                handle_flag_raises do
+                  ## If this is the last flag provided in the clump do the thing
+                  if index == chars.size - 1
+                    if match.requires_arg?
+                      match.process(args.reject(&.processed?).take_while{|v| find_match(v.value) == CliGen::MatchType::NoMatch}) 
+                    else
                       match.process
-            when MatchType::NoMatch
-              raise "ERROR : CommandNode(#{@name}).process : No flag match for '#{flag}'"
                     end
+                  else
+                    raise CliGen::FlagBundleError.new("#{CliGen::APPNAME}: cannot bundle '#{flag}' — it requires an argument") if match.requires_arg?
+                    match.process
+                  end
+                end
+              when MatchType::NoMatch
+                raise CliGen::UnknownFlagError.new("#{CliGen::APPNAME}: unknown flag '#{flag}'")
+              end
+            end
+          else
+            # In this case we assume the characters following the flag is the argument
+            raise CliGen::FlagArgumentError.new("#{CliGen::APPNAME}: inline flag arguments are not supported — did you mean '-#{val[0]} #{val[1..]}'?")
           end
 
         when MatchType::NoMatch
-          raise "ERROR : CommandNode(#{@name}).process : No command, subcommand or flag match for '#{arg.value}'"
+          raise CliGen::HelpRequestedError.new("#{CliGen::APPNAME}: unknown token '#{arg.value}'\n\n#{help}")
         end
       end
 
@@ -227,6 +286,9 @@ module CliGen
       {% unless T == Nil %}
       unless passed_execution
         cls = T.new(handler: self.as(CliGen::BaseCommandNode))
+        {% for cmd in T.methods.select(&.annotation(CliGen::PreRunCommand)) %}
+        cls.{{cmd.name}}
+        {% end %}
         {% subcmds = T.methods.select(&.annotation(CliGen::SubCommand)) %}
         {% begin %}
         case matched_subcommand
@@ -238,11 +300,16 @@ module CliGen
           {% if T.has_method?(:main) %}
             cls.main
           {% else %}
-            raise "ERROR : CommandNode({{T}})#{{@def.name}} : No subcommand matched and no #main defined"
+            puts "ERROR : CommandNode({{T}})\#{{@def.name}} : No subcommand matched and no #main defined"
+            puts help
           {% end %}
+            exit 0
         end
         {% end %}
       end
+      {% else %}
+        puts help
+        exit 0
       {% end %}
     end
   end

src/cligen/exceptions.cr

@@ -0,0 +1,77 @@
+module CliGen
+  # Base for all CliGen exceptions
+  class Error < Exception; end
+
+  # -------------------------------------------------------------------------
+  # Internal errors — framework invariant violations, should never reach users
+  # -------------------------------------------------------------------------
+
+  class InternalError < Error; end
+
+  # Arg#processed was called a second time on the same Arg
+  class ArgReprocessedError < InternalError; end
+
+  # A token matched FLAG_WITH_ARG in find_match but the regex failed on re-match
+  class RegexInvariantError < InternalError; end
+
+  # A BaseCommandNode was matched but couldn't be cast to any known CommandNode(T)
+  class UnknownCommandNodeError < InternalError; end
+
+  # -------------------------------------------------------------------------
+  # Configuration errors — shard consumer wired something up incorrectly
+  # -------------------------------------------------------------------------
+
+  class ConfigurationError < Error; end
+
+  # -h or --help was used as a flag short/long (reserved for internal help)
+  class ReservedFlagError < ConfigurationError; end
+
+  # Duplicate short or long flags detected during check!
+  class DuplicateFlagError < ConfigurationError; end
+
+  # A CommandNode(T) has no subcommands and no #main defined
+  class MissingDispatchError < ConfigurationError; end
+
+  # No flag was found in the handler for a Command ivar during initialize
+  class FlagNotFoundError < ConfigurationError; end
+
+  # A flag that requires an argument was processed with an empty argv
+  class FlagMissingArgumentError < ConfigurationError; end
+
+  # A Parsable type's parse_args did not mark any args as processed
+  class ParseableInvariantError < ConfigurationError; end
+
+  # -------------------------------------------------------------------------
+  # Runtime errors — bad user input at the CLI level
+  # -------------------------------------------------------------------------
+
+  class RuntimeError < Error; end
+
+  # A required flag was not provided and has no env var or default to fall back on
+  class MissingRequiredFlagError < RuntimeError; end
+
+  # A setter's validation proc rejected the provided value
+  class ValidationError < RuntimeError; end
+
+  # A flag token was provided where a value argument was expected
+  class FlagArgumentError < RuntimeError; end
+
+  # A provided value doesn't satisfy type or format requirements (wrong type, bad format, invalid bool/date string)
+  class InvalidFlagValueError < RuntimeError; end
+
+  # A provided value is not in the flag's allowed options list
+  class InvalidOptionError < RuntimeError; end
+
+  # An unrecognised flag token was encountered during parsing
+  class UnknownFlagError < RuntimeError; end
+
+  # A flag that requires an argument was included in a short-flag bundle
+  class FlagBundleError < RuntimeError; end
+
+  # -------------------------------------------------------------------------
+  # Help signal — not an error; exit 0 after printing
+  # -------------------------------------------------------------------------
+
+  # Raised when -h/--help is matched; carries the rendered help string
+  class HelpRequestedError < Error; end
+end

src/cligen/flag.cr

@@ -1,6 +1,14 @@
 require "./arg"
 
 module CliGen
+  # To be able to store metadata for use in the help output
+  record FlagMeta,
+    type : String,
+    array : Bool,
+    format : String?,
+    default : String,
+    options : Array(String)?
+
   abstract class BaseFlag
     getter var         : String
     getter short       : String?
@@ -8,17 +16,21 @@ module CliGen
     getter long_key    : String
     getter env_var     : String
     getter description : String
+    getter delimiter   : String
+    getter meta        : FlagMeta
 
     def initialize(
       @var         : String,
       @short       : String?,
       @long        : String,
       @env_var     : String,
-      @description : String
+      @description : String,
+      @delimiter   : String,
+      @meta        : FlagMeta
       )
       # if the user provides just a "--long" I want the @long_key to match it
-      if @long.includes?(" ")
+      if @long =~ /\s|=/
-        @long_key = @long.split(" ").first
+        @long_key = @long.split(/\s|=/).first
       else
         @long_key = @long
       end
@@ -40,6 +52,7 @@ module CliGen
     @options  : Array(T)?
     @validate : (T -> Bool)? 
     @on_match : Proc(Nil)?
+    @format   : ::Regex?
 
     def initialize(
       var         : String,
@@ -47,12 +60,37 @@ module CliGen
       long        : String,
       env_var     : String,
       description : String,
+      delimiter   : String = ",",
       @default    : T? = nil,
       @options    : Array(T)? = nil,
       @validate   : (T -> Bool)? = nil,
-      @on_match   : Proc(Nil)? = nil
+      @on_match   : Proc(Nil)? = nil,
+      @format     : ::Regex? = nil
       )
-      super(var, short, long, env_var, description)
+      {% unless T.class.has_method? :to_s %}
+        {% raise "ERROR : Flag(#{T}) : Error your flag type must have a to_s method" %}
+      {% end %}
+      {% if T < Array %}
+        {% elem = T.type_vars.first %}
+        {% raise "ERROR : Flag(#{T}) : Error your flag subtype #{elem} must have a to_s method" unless elem.class.has_method? :to_s %}
+      {% end %}
+      unless @default.nil?
+        {% if T < Array %}
+          default = "[" + @default.not_nil!.map(&.to_s).join(", ") + "]"
+        {% else %}
+          default = @default.not_nil!.to_s
+        {% end %}
+      else
+        default = ""
+      end
+      meta = FlagMeta.new(
+        type: {{T.stringify}},
+        array: {{ T < Array ? true : false }},
+        options: {% if T < Array %} @options.try(&.first.map(&.to_s)) {% else %} @options.try(&.map(&.to_s)) {% end %},
+        default: default,
+        format: @format.try(&.source)
+      )
+      super(var, short, long, env_var, description, delimiter, meta)
     end
 
     def requires_arg? : Bool
@@ -61,49 +99,114 @@ module CliGen
 
     def process(argv : Array(Arg) = [] of Arg) : Nil
       if requires_arg?
-        raise "ERROR : Flag({{T}}) : Array requires an argument but provided array is empty" if argv.empty?
+        raise CliGen::FlagMissingArgumentError.new("Flag(#{T}, long: #{@long_key}) : requires an argument but provided array is empty") if argv.empty?
+        raise CliGen::FlagArgumentError.new("Flag(#{T}, long: #{@long_key}) : a flag token was provided where a value was expected (got: #{argv.first.value})") if argv.first.flag?
       end
 
+
       {% if T == Bool %}
         @value = true
-      {% elsif T <= Array %}
+      {% elsif T < Array %}
         {% raise "ERROR : Flag(#{T}) : You cannot define multiple types of array entries" if T.type_vars.size > 1 %}
         {% elem = T.type_vars.first %}
         argv.each do |arg|
-          break if arg.value.starts_with('-')
+          break if arg.flag?
-          {% if elem == Int32 %}
+          unless @format.nil?
-            (@value ||= [] of Int32) << arg.value.to_i
+            unless arg.value.includes?(@delimiter)
-          {% elsif elem == String %}
+              unless arg.value =~ @format
-            (@value ||= [] of String) << arg.value
+                puts "DEBUG : Flag({{T}}, long: #{@long_key}) : #{arg.value} was not found to be matching the defined filter #{@format}. So breaking from parse loop" if ENV["DEBUG"]?
-          {% elsif elem < CliGen::Coercable %}
+                break
-          if arg.value.includes?(",") 
+              end
-            (@value ||= [] of {{elem}}) += arg.value.split(",").map{|i| {{elem}}.coerce(i)}
+            end
+          end
+          {% if elem < Int %}
+            {% int_case = elem.stringify =~ /^UInt/ ? "uint?".id : "int?".id %}
+            if arg.value.includes?(@delimiter)
+              @value = (@value || T.new) + arg.value.split(@delimiter).map do |val|
+                val = val.strip
+                unless arg.{{int_case}}(val)
+                  raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{val}' is not a valid {{elem}}")
+                end
+                {{elem}}.new(val)
+              end
             else
-            (@value ||= [] of {{elem}}) << {{elem}}.coerce(arg.value)
+              unless arg.{{int_case}}
+                raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{arg.value}' is not a valid {{T}}") 
+              end
+              (@value ||= T.new) << {{elem}}.new(arg.value)
+            end
+          {% elsif elem < Float %}
+            if arg.value.includes?(@delimiter)
+              @value = (@value || T.new) + arg.value.split(@delimiter).map do |val|
+                val = val.strip
+                unless CliGen::Arg.float?(val)
+                  raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{val}' is not a valid {{T}}")
+                end
+                {{elem}}.new(val)
+              end
+            else
+              unless arg.float?
+                raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{arg.value}' is not a float") 
+              end
+              (@value ||= T.new) << {{elem}}.new(arg.value)
+            end
+          {% elsif elem == String %}
+            if arg.value.includes?(@delimiter)
+              @value = (@value || [] of String) + arg.value.split(@delimiter).map { |v|
+                unless @format.nil?
+                  raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{v}' does not match required format /#{@format.not_nil!.source}/") unless v =~ @format
+                end
+                v
+              }
+            else
+              if ! @format.nil? && arg.value !~ @format
+                raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{arg.value}' does not match required format /#{@format.not_nil!.source}/") 
+              end
+            (@value ||= [] of String) << arg.value
+            end
+          {% elsif elem.class < CliGen::Coercable %}
+          if arg.value.includes?(@delimiter)
+            @value = (@value || [] of {{elem}}) + arg.value.split(@delimiter).map { |i| {{elem}}.coerce(i) }
+          else
+            @value = (@value || [] of {{elem}}) + [({{elem}}.coerce(arg.value))]
           end
           {% else %}
-            {% raise "ERROR : Flag(#{T}) : #{elem} is not a coercable type. If you wish to coerce it from a bare string include CliGen::Coercable & implement the class method" %}
+            {% raise "ERROR : Flag(#{T}) : #{elem} is not a coercable type. If you wish to coerce it from a bare string extend with CliGen::Coercable & implement the class method" %}
           {% end %}
           arg.processed
         end
-      {% elsif T == Int32 %}
+      {% elsif T < Int %}
-        @value = argv.first.value.to_i
+        {% int_case = T.stringify =~ /^UInt/ ? "uint?".id : "int?".id %}
+        unless argv.first.{{int_case}}
+          raise CliGen::InvalidFlagValueError.new("Flag(#{T}, long: #{@long_key}) : '#{argv.first.value}' is not a valid {{T}}") 
+        end
+        @value = T.new(argv.first.value)
+        argv.first.processed
+      {% elsif T < Float %}
+        unless argv.first.float?
+          raise CliGen::InvalidFlagValueError.new("Flag(#{T}, long: #{@long_key}) : '#{argv.first.value}' is not a valid {{T}}") 
+        end
+        @value = T.new(argv.first.value)
         argv.first.processed
       {% elsif T == Time %}
         @value = parse_time(argv.first.value)
         argv.first.processed
       {% elsif T == String %} # String
+        if ! @format.nil? && argv.first.value !~ @format
+          raise CliGen::InvalidFlagValueError.new("Flag(#{T}, long: #{@long_key}) : '#{argv.first.value}' does not match required format /#{@format.not_nil!.source}/") 
+        end
+
         @value = argv.first.value
         argv.first.processed
-      {% elsif T < CliGen::Parsable %}
+      {% elsif T.class < CliGen::Parsable %}
         processed = argv.select(&.processed?)
         @value = T.parse_args(argv)
         post_processed = argv.select(&.processed?)
         if processed == post_processed
-          raise "ERROR : Flag({{T}}, long: #{@long_key})#process : Your {{T}}#process_args did not mark processed args as processed. Please check your code"
+          raise CliGen::ParseableInvariantError.new("Flag({{T}}, long: #{@long_key})#process : {{T}}#parse_args did not mark any args as processed")
         end
       {% else %}
-        {% raise "ERROR : Flag({{T}}, long: #{@long_key})#process : Generic Type #{T} is not supported. To add support you must include CliGen::Parsable & implement the class method" %}
+        {% raise "ERROR : Flag({{T}}#process : Generic Type #{T} is not supported. To add support you must extend with CliGen::Parsable & implement the class method" %}
       {% end %}
 
       validate!
@@ -122,7 +225,7 @@ module CliGen
 
       v ||= @default
 
-      raise "#{CliGen::APPNAME}: required flag #{@long_key} was not provided" if v.nil?
+      raise CliGen::MissingRequiredFlagError.new("#{CliGen::APPNAME}: required flag #{@long_key} was not provided") if v.nil?
       v.not_nil!
     end
 
@@ -147,50 +250,105 @@ module CliGen
       v = value!
 
       if opts = @options
-        abort "#{CliGen::APPNAME}: '#{v}' is not a valid value for #{@long_key} (valid: #{opts.join(", ")})" unless opts.includes?(v)
+        {% if T < Array %}
+          v.each do |v2|
+            raise CliGen::InvalidOptionError.new("#{CliGen::APPNAME}: '#{v2}' is not a valid value for #{@long_key} (valid: #{opts.join(", ")})") unless opts.first.includes?(v2)
+          end
+        {% else %}
+          raise CliGen::InvalidOptionError.new("#{CliGen::APPNAME}: '#{v}' is not a valid value for #{@long_key} (valid: #{opts.join(", ")})") unless opts.includes?(v)
+        {% end %}
       end
 
       if check = @validate
-        abort "#{CliGen::APPNAME}: validation failed for #{@long_key}" unless check.call(v)
+        raise CliGen::ValidationError.new("#{CliGen::APPNAME}: validation failed for #{@long_key} (got: #{v})") unless check.call(v)
       end
     end
 
     def check! : Nil
-      raise "ERROR : Flag({{T}}, long: #{@long})#check! : -h is reserved for internal help usage" if @short == "-h" 
+      raise CliGen::ReservedFlagError.new("Flag({{T}}, long: #{@long})#check! : -h is reserved for internal help") if @short == "-h"
-      raise "ERROR : Flag({{T}}, long: #{@long})#check! : --help is reserved for internal help usage" if @long_key == "--help"
+      raise CliGen::ReservedFlagError.new("Flag({{T}}, long: #{@long})#check! : --help is reserved for internal help") if @long_key == "--help"
     end
 
     private def coerce(raw : String) : T
       {% if T == Bool %}
         case raw
-        when "t","true","1"
+        when /^(t|true|y|yes|1)$/i
           true
-        when "f","false","0"
+        when /^(f|false|n|no|0)$/i
           false
         else
-          raise "ERROR"
+          raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{raw}' is not a valid boolean (expected: t/f/true/false/y/n/yes/no/1/0)")
         end
-      {% elsif T == Int32 %}
+      {% elsif T < Int %}
-        raw.to_i
+        {% int_case = T.stringify =~ /^UInt/ ? "uint?".id : "int?".id %}
+        unless CliGen::Arg.{{int_case}}(raw)
+          raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{raw}' is not a valid {{T}}") 
+        end
+        T.new(raw)
+      {% elsif T < Float %}
+        unless CliGen::Arg.float?(raw)
+          raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{raw}' is not a valid {{T}}") 
+        end
+        T.new(raw)
       {% elsif T == Time %}
         parse_time(raw)
-      {% elsif T <= Array %}
+      {% elsif T < Array %}
+        if raw.includes?(@delimiter)
           {% elem = T.type_vars.first %}
-        {% if elem == Int32 %}
+          raw.split(@delimiter).map do |val|
-          raw.split(',').map(&.to_i)
+            unless @format.nil?
+              raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{val}' does not match required format /#{@format.not_nil!.source}/") unless val =~ @format
+            end
+
+            {% if elem < Int %}
+              val = val.strip
+              {% int_case = elem.stringify =~ /^UInt/ ? "uint?".id : "int?".id %}
+              unless CliGen::Arg.{{int_case}}(val)
+                raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{val}' is not a valid {{elem}}") 
+              end
+              {{elem}}.new(val)
+            {% elsif elem < Float %}
+              unless CliGen::Arg.float?(val)
+                raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{val}' is not a valid {{elem}}") 
+              end
+              {{elem}}.new(val)
             {% elsif elem == String %}
-          raw.split(',')
+              val
-        {% elsif elem < CliGen::Coercable %}
+            {% elsif elem.class < CliGen::Coercable %}
-          raw.split(',').map{|i| {{elem}}.coerce(i)}
+              {{elem}}.coerce(val)
             {% else %}
-          {% raise "ERROR : Flag(#{T}) : #{elem} is not a coercable type. If you wish to coerce it from a bare string include CliGen::Coercable & implement the class method" %}
+              {% raise "ERROR : Flag(#{T}) : #{elem} is not a coercable type. If you wish to coerce it from a bare string extend CliGen::Coercable & implement the class method" %}
             {% end %}
+          end
+        else
+          if ! @format.nil? && raw !~ @format
+            raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{raw}' does not match required format /#{@format.not_nil!.source}/") 
+          end
+          {% if elem < Int %}
+            {% int_case = elem.stringify =~ /^UInt/ ? "uint?".id : "int?".id %}
+            unless CliGen::Arg.{{int_case}}(raw)
+              raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{raw}' is not a valid {{elem}}") 
+            end
+            [ {{elem}}.new(raw) ]
+          {% elsif elem < Float %}
+            unless CliGen::Arg.float?(raw)
+              raise CliGen::InvalidFlagValueError.new("Flag({{T}}, long: #{@long_key}) : '#{raw}' is not a valid {{elem}}") 
+            end
+            [ {{elem}}.new(raw) ]
+          {% elsif elem == String %}
+            [ raw ]
+          {% elsif elem.class < CliGen::Coercable %}
+            [ {{elem}}.coerce(raw) ]
+          {% else %}
+            {% raise "ERROR : Flag(#{T}) : #{T} is not a coercable type. If you wish to coerce it from a bare string extend CliGen::Coercable & implement the class method" %}
+          {% end %}
+        end
       {% elsif T == String %} # String
         raw
-      {% elsif T < CliGen::Coercable %}
+      {% elsif T.class < CliGen::Coercable %}
         T.coerce(raw)
       {% else %}
-        {% raise "ERROR : Flag(#{T}) : #{T} is not a coercable type. If you wish to coerce it from a bare string include CliGen::Coercable & implement the class method" %}
+        {% raise "ERROR : Flag(#{T}) : #{T} is not a coercable type. If you wish to coerce it from a bare string extend CliGen::Coercable & implement the class method" %}
       {% end %}
     end
 
@@ -199,7 +357,7 @@ module CliGen
         CliGen::Regex::INPUT_DATETIME_REGEX,
         CliGen::Regex::INPUT_DATE_REGEX
       ]
-      abort "#{CliGen::APPNAME}: invalid date/time format '#{raw}' (expected YYYY-MM-DD or YYYY-MM-DD HH:MM:SS)" unless formats.any? { |f| raw.match(f) }
+      raise CliGen::InvalidFlagValueError.new("#{CliGen::APPNAME}: invalid date/time format '#{raw}' (expected YYYY-MM-DD or YYYY-MM-DD HH:MM:SS)") unless formats.any? { |f| raw.match(f) }
       if raw.match(formats[0])
         Time.parse_local(raw, CliGen::Format::INPUT_DATETIME_FORMAT)
       else

src/cligen/global_flag.cr

@@ -3,6 +3,15 @@ require "./flag"
 module CliGen
   GLOBAL_FLAGS = [] of BaseFlag
 
+  GLOBAL_FLAGS << Flag(Bool).new(
+    var: "",
+    short: "-v",
+    long: "--verbose",
+    env_var: "VERBOSE",
+    default: false,
+    description: "Enable verbose output from program & help output"
+  )
+
   macro add_global_flag(type, long, description, env_var = nil, short = nil, validation = nil, &on_match)
     {% raise "ERROR : CliGen.add_global_flag : type must be a TypeNode" unless type.is_a? TypeNode %}
     {% raise "ERROR : CliGen.add_global_flag : long must begin a StringLiteral" unless long.is_a? StringLiteral %}

src/cligen/parsable.cr

@@ -1,3 +1,3 @@
-module CliGen::Parseable
+module CliGen::Parsable
-  abstract def parse_args(args : Array(CliGen::Arg)) : self
+  abstract def parse_args(args : Array(CliGen::Arg)) 
 end

src/cligen/regex.cr

@@ -1,9 +1,12 @@
 module CliGen::Regex
-  FLAG_REGEX=/^(-[a-zA-Z]|--[a-zA-Z-_]+)$/
+  FLAG_REGEX=/^(-[a-zA-Z]|--[a-zA-Z-_0-9]+)$/
   FLAG_WITH_ARG=/^(?<flag>(-[a-zA-Z]|--[a-zA-Z-_]+))="?(?<arg>\S+?)"?$/
-  FLAG_MULTIPLE_SHORT=/^-[a-zA-Z]+$/
+  FLAG_MULTIPLE_SHORT=/^-[a-zA-Z0-9]+/
-  SHORT_WITH_INLINE_ARG=/^-[a-zA-Z][a-zA-Z0-9]+$/
 
   INPUT_DATETIME_REGEX = /^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}$/
   INPUT_DATE_REGEX = /^[0-9]{4}-[0-9]{2}-[0-9]{2}$/
+
+  FLOAT = /^[-+]?[[:digit:]]+(\.[[:digit:]]+)?$/
+  UINT = /^[[:digit:]]+$/
+  INT = /^[-+]?[[:digit:]]+$/
 end

src/cligen/template/cmd_help.ecr

@@ -3,21 +3,36 @@ Command: <%= @name %>
 Description: <%= @description %>
 <%- end -%>
 
+<%- unless @flags.empty? -%>
+<%- len = @flags.map{|f| f.short.nil? ? f.long.size : "#{f.short},#{f.long}".size}.max + 5 -%>
+
 Flags:
 ---------------------------------------------------------------
 <%- @flags.each do |flag| -%>
-  <%- unless flag.short.nil? -%>
+  <%- if flag.short.nil? -%>
-    <%= "%-15s %s" % ["#{flag.short.not_nil!.strip},#{flag.long.strip}", flag.description.strip] %>
+    <%- flags = [flag.long.strip] -%>
   <%- else -%>
-    <%= "%-15s %s" % [flag.long.strip, flag.description.strip] %>
+    <%- flags = [flag.short,flag.long.strip] -%>
+  <%- end -%>
+    <%= "%-#{len}s %s" % [flags.join(","), flag.description.strip] %><%= flag.meta.options.nil? ? "" : " (valid: #{flag.meta.options.not_nil!.join(", ")})" %><%= flag.meta.default.empty? ? "" : " (default: #{flag.meta.default.not_nil!})" %>
+  <%- if verbose? -%>
+    <%= "%-#{len}s %s" % ["", "Type: #{flag.meta.type}"] %>
+    <%= "%-#{len}s %s" % ["", "ENV VAR: #{flag.env_var}"] %>
+    <%- unless flag.meta.format.nil? -%>
+    <%= "%-#{len}s %s" % ["", "Valid Format: #{flag.meta.format}"] %>
+    <%- end -%>
+    <%- if flag.meta.array -%>
+    <%= "%-#{len}s %s" % ["", "Delimiter: #{flag.delimiter}"] %>
+    <%- end -%>
   <%- end -%>
 
+<%- end -%>
 <%- end -%>
 <%- unless @commands.empty? -%>
 Other Commands
 ---------------------------------------------------------------
   <%- @commands.each do |command| -%>
-    <%= "%-10s %s" % [ command.name, command.description ] %>
+    <%= "%-#{len}s %s" % [ command.name, command.description ] %>
   <%- end -%>
 
 <%- end -%>
@@ -25,7 +40,7 @@ Other Commands
 SubCommands of <%= @name %>:
 ---------------------------------------------------------------
   <%- subcommands.each do |cmd| -%>
-    <%= "%-10s %s" % [cmd.name, cmd.description] %>
+    <%= "%-#{len}s %s" % [cmd.name, cmd.description] %>
   <%- end -%>
 
   <%- cmds = subcommands.select{|c| ! c.examples.nil? } -%>