Proc should return a Hash

README.md

@@ -697,21 +697,21 @@ You can define custom shortcuts using lambdas.
 In this example we add `~` to create a shortcut with a special processing (adding a prefix) for the class attribute.
 
 ~~~ ruby
-Slim::Engine.set_options shortcut: {'~' => {attr: ->(v) {["class", "\"styled-#{v}\""]}}}
+Slim::Engine.set_options shortcut: {'~' => {attr: ->(v) {{class: "styled-#{v}"}}}}
 ~~~
 
 We can use it in Slim code like this
 
 ~~~ slim
 h1~title Hello
-~text~question How are you?
+~text~question.paragraph How are you?
 ~~~
 
 which renders to
 
 ~~~ html
 <h1 class="styled-title">Hello</h1>
-<div class="styled-text styled-question">How are you?</div>
+<div class="styled-text styled-question paragraph">How are you?</div>
 ~~~
 
 #### ID shortcut `#` and class shortcut `.`

lib/slim/parser.rb

@@ -342,11 +342,10 @@ def parse_tag(tag)
         syntax_error!('Illegal shortcut') unless shortcut = @attr_shortcut[$1]
 
         if shortcut.is_a?(Proc)
-          value = shortcut.call($2)
-          attributes << [:html, :attr, value[0], [:dynamic, value[1]]]
+          values = shortcut.call($2)
+          values.each {|a, v| attributes << [:html, :attr, a, [:static, v]] }
         else
-          value = [:static, $2]
-          shortcut.each {|a| attributes << [:html, :attr, a, value] }
+          shortcut.each {|a| attributes << [:html, :attr, a, [:static, $2]] }
         end
 
         if additional_attr_pairs = @additional_attrs[$1]

test/core/test_html_structure.rb

@@ -120,24 +120,32 @@ def test_render_with_custom_lambda_shortcut
 ~foo Hello
 }
     assert_html '<div class="styled-foo">Hello</div>',
-                source, shortcut: {'~' => {attr: ->(v) {["class", "\"styled-#{v}\""]}}}
+                source, shortcut: {'~' => {attr: ->(v) {{class: "styled-#{v}"}}}}
   end
 
   def test_render_with_custom_lambda_shortcut_and_multiple_values
     source = %q{
 ~foo~bar Hello
 }
     assert_html '<div class="styled-foo styled-bar">Hello</div>',
-                source, shortcut: {'~' => {attr: ->(v) {["class", "\"styled-#{v}\""]}}}
+                source, shortcut: {'~' => {attr: ->(v) {{class: "styled-#{v}"}}}}
   end
 
-#   def test_render_with_custom_lambda_shortcut_and_existing_class
-#     source = %q{
-# ~foo.baz Hello
-# }
-#     assert_html '<div class="styled-foo baz">Hello</div>',
-#                 source, shortcut: {'~' => {attr: ->(v) {["class", "\"styled-#{v}\""]}}}
-#   end
+  def test_render_with_custom_lambda_shortcut_and_existing_class
+    source = %q{
+~foo.baz Hello
+}
+    assert_html '<div class="styled-foo baz">Hello</div>',
+                source, shortcut: {'~' => {attr: ->(v) {{class: "styled-#{v}"}}}, '.' => {attr: 'class'}}
+  end
+
+  def test_render_with_existing_class_and_custom_lambda_shortcut
+    source = %q{
+.baz~foo Hello
+}
+    assert_html '<div class="baz styled-foo">Hello</div>',
+                source, shortcut: {'~' => {attr: ->(v) {{class: "styled-#{v}"}}}, '.' => {attr: 'class'}}
+  end
 
   def test_render_with_text_block
     source = %q{