Add "constructor from fields" generator

README.md

@@ -103,6 +103,7 @@ Changes patched live into the sources:
         }
 
 * add missing field declarations for properties (unless those have getters implemented as methods)
+* add an initializing constructor for fields marked with `!c`
 
 Collected in `xdry.m`:
 

lib/xdry/generators/ctor_from_field.rb

@@ -0,0 +1,91 @@
+
+module XDry
+module Generators
+
+  class ConstructorFromField < Generator
+    id "ctor-from-field"
+
+    def process_class oclass
+      attributes = oclass.attributes.select { |a| a.wants_constructor? }
+      return if attributes.empty?
+
+      patch_implementation! oclass, attributes
+      patch_interface! oclass, attributes
+    end
+
+    def patch_implementation! oclass, attributes
+      impl_selector_def = impl_selector_def_for(attributes)
+
+      init_code = Emitter.capture do |o|
+        o.method "(id)#{impl_selector_def}" do
+          o.if "self = [super init]" do
+          end
+          o << "return self;"
+        end
+      end
+
+      MethodPatcher.new(patcher, oclass, impl_selector_def.selector, ImplementationStartIP.new(oclass), init_code) do |omethod|
+        impl = omethod.impl
+        ip = InsideConstructorIfSuperIP.new(impl)
+
+        lines = Emitter.capture do |o|
+          attributes.zip(impl_selector_def.components).each do |oattr, selector_component|
+            name, type = oattr.name, oattr.type
+            capitalized_name = name.capitalized_identifier
+
+            retain_policy = Boxing.retain_policy_of type
+
+            unless impl.children.any? { |n| NLine === n && n.line =~ /^(?:self\s*.\s*#{oattr.name}|#{oattr.field_name})\s*=/ }
+
+              var_name = impl.start_node.selector_def.var_name_after_keyword(selector_component.keyword)
+
+              field_ref = oattr.field_name
+              field_ref = "self->#{field_ref}" if field_ref == var_name
+
+              retained = retain_policy.retain(var_name)
+              o << "#{field_ref} = #{retained};"
+            end
+          end
+        end
+
+        ip.insert @patcher, lines unless lines.empty?
+      end
+    end
+
+    def patch_interface! oclass, attributes
+      intf_selector_def = intf_selector_def_for(attributes)
+
+      omethod = oclass.find_method(intf_selector_def.selector)
+      unless omethod && omethod.has_header?
+
+        ip = BeforeInterfaceEndIP.new(oclass)
+        lines = Emitter.capture do |o|
+          o << "- (id)#{intf_selector_def};"
+        end
+        ip.insert patcher, [""] + lines + [""]
+
+      end
+    end
+
+    def impl_selector_def_for attributes
+      CompoundSelectorDef.new(attributes.each_with_index.collect { |a, i| selector_component_for(a, i, true) })
+    end
+
+    def intf_selector_def_for attributes
+      CompoundSelectorDef.new(attributes.each_with_index.collect { |a, i| selector_component_for(a, i, false) })
+    end
+
+    def selector_component_for attribute, index, is_impl
+      keyword = attribute.name
+      keyword = "initWith#{keyword.capitalized_identifier}" if index == 0
+
+      arg_name = attribute.name
+      arg_name = arg_name.prefixed_as_arg_name if is_impl && arg_name == attribute.field_name
+
+      SelectorComponent.new("#{keyword}:", arg_name, attribute.type)
+    end
+
+  end
+
+end
+end

lib/xdry/generators/dictionary_coding.rb

@@ -20,10 +20,7 @@ def process_class oclass
         name, type = oattr.name, oattr.type
         field_name = oattr.field_name
         raw_name = "#{name}Raw"
-        capitalized_name = case name
-          when 'id', 'uid' then name.upcase
-          else name[0..0].upcase + name[1..-1]
-          end
+        capitalized_name = name.capitalized_identifier
         key_const = "#{capitalized_name}Key"
 
         type_boxer = Boxing.converter_for type
@@ -112,10 +109,7 @@ def each_persistent_attr oclass
       oclass.attributes.select { |a| a.persistent? }.each do |oattr|
         name, type = oattr.name, oattr.type
         field_name = oattr.field_name
-        capitalized_name = case name
-          when 'id', 'uid' then name.upcase
-          else name[0..0].upcase + name[1..-1]
-          end
+        capitalized_name = name.capitalized_identifier
         key_const = "#{capitalized_name}Key"
 
         type_boxer = Boxing.converter_for type

lib/xdry/parsing/model.rb

@@ -203,6 +203,10 @@ def wants_property?
       has_field_def? && field_def.wants_property?
     end
 
+    def wants_constructor?
+      has_field_def? && field_def.wants_constructor?
+    end
+
     def getter_selector
       # FIXME: need to account for a possible selector override declared in @property
       @name
@@ -240,6 +244,10 @@ def add_method_impl! method_impl
       @impl = method_impl.bind(self)
     end
 
+    def has_header?
+      not @header.nil?
+    end
+
     def has_impl?
       not @impl.nil?
     end

lib/xdry/parsing/nodes.rb

@@ -54,6 +54,10 @@ def wants_property?
       tagged_with? 'wants-property'
     end
 
+    def wants_constructor?
+      tagged_with? 'wants-constructor'
+    end
+
     def to_s
       "#{@type} #{@name}#{tags_comment}"
     end

lib/xdry/parsing/parsers.rb

@@ -54,13 +54,15 @@ def initialize scope
 
     def parse_line! line, eol_comments, indent
       @this_line_tags = Set.new
-      if line =~ /!p\b/
-        marker = $&
-        is_full_line = line.gsub(marker, '').strip.empty?
-        klass = is_full_line ? NFullLineMarker : NPartLineMarker
-        yield klass.new(marker)
-        (is_full_line ? @tags : @this_line_tags) << 'wants-property'
-        return if is_full_line
+      [[/!p\b/, 'wants-property'], [/!c\b/, 'wants-constructor']].each do |regexp, tag|
+        if line =~ regexp
+          marker = $&
+          is_full_line = line.gsub(marker, '').strip.empty?
+          klass = is_full_line ? NFullLineMarker : NPartLineMarker
+          yield klass.new(marker)
+          (is_full_line ? @tags : @this_line_tags) << tag
+          return if is_full_line
+        end
       end
       case line
       when /\}/

lib/xdry/patching/patcher.rb

@@ -37,7 +37,7 @@ def do_delete_lines file_ref, line_index, line_count
         lines[line_index .. line_index+line_count-1].each { |line| puts "    #{line}" }
       end
 
-      file_ref.fixup_positions! line_index+1+line_count, -line_count
+      file_ref.fixup_positions! line_index+line_count, -line_count
       lines[line_index .. line_index+line_count-1] = []
     end
 

lib/xdry/support/string_additions.rb

@@ -6,6 +6,19 @@ module StringAdditions
     def blank?
       self =~ /^\s*$/
     end
+
+    def capitalized_identifier
+      case self
+        when 'id', 'uid' then upcase
+        else self[0..0].upcase + self[1..-1]
+      end
+    end
+
+    def prefixed_as_arg_name
+      prefix = case self when /^[aeiou]/ then 'an' else 'a' end
+
+      prefix + self.capitalized_identifier
+    end
 
   end