Module: Haml::Util
- Extended by:
- Util
- Included in:
- Buffer, Precompiler, Util, Version, Sass::Engine, Sass::Script::Color
- Defined in:
- lib/haml/util.rb
Overview
A module containing various useful functions.
Defined Under Namespace
Classes: StaticConditionalContext
Constant Summary collapse
- RUBY_VERSION =
An array of ints representing the Ruby version number.
::RUBY_VERSION.split(".").map {|s| s.to_i}
Instance Method Summary collapse
-
#def_static_method(klass, name, args, *vars, erb) ⇒ Object
This is used for methods in Buffer that need to be very fast, and take a lot of boolean parameters that are known at compile-time.
-
#enum_with_index(enum) ⇒ Enumerator
A version of ‘Enumerable#enum_with_index` that works in Ruby 1.8 and 1.9.
-
#has?(attr, klass, method) ⇒ Boolean
Checks to see if a class has a given method.
-
#map_hash(hash) {|key, value| ... } ⇒ Hash
Maps the key-value pairs of a hash according to a block.
-
#map_keys(hash) {|key| ... } ⇒ Hash
Maps the keys in a hash according to a block.
-
#map_vals(hash) {|value| ... } ⇒ Hash
Maps the values in a hash according to a block.
-
#merge_adjacent_strings(enum) ⇒ Array
Concatenates all strings that are adjacent in an array, while leaving other elements as they are.
-
#powerset(arr) ⇒ Set<Set>
Computes the powerset of the given array.
-
#ruby1_8? ⇒ Boolean
Whether or not this is running under Ruby 1.8 or lower.
-
#scope(file) ⇒ String
Returns the path of a file relative to the Haml root directory.
-
#static_method_name(name, *vars) ⇒ String
Computes the name for a method defined via #def_static_method.
-
#to_hash(arr) ⇒ Hash
Converts an array of ‘[key, value]` pairs to a hash.
Instance Method Details
#def_static_method(klass, name, args, *vars, erb) ⇒ Object
This is used for methods in Buffer that need to be very fast, and take a lot of boolean parameters that are known at compile-time. Instead of passing the parameters in normally, a separate method is defined for every possible combination of those parameters; these are then called using #static_method_name.
To define a static method, an ERB template for the method is provided. All conditionals based on the static parameters are done as embedded Ruby within this template. For example:
def_static_method(Foo, :my_static_method, [:foo, :bar], :baz, :bang, <<RUBY)
<% if baz && bang %>
return foo + bar
<% elsif baz || bang %>
return foo - bar
<% else %>
return 17
<% end %>
RUBY
#static_method_name can be used to call static methods.
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# File 'lib/haml/util.rb', line 207 def def_static_method(klass, name, args, *vars) erb = vars.pop powerset(vars).each do |set| context = StaticConditionalContext.new(set).instance_eval {binding} klass.class_eval(<<METHOD) def #{static_method_name(name, *vars.map {|v| set.include?(v)})}(#{args.join(', ')}) #{ERB.new(erb).result(context)} end METHOD end end |
#enum_with_index(enum) ⇒ Enumerator
A version of ‘Enumerable#enum_with_index` that works in Ruby 1.8 and 1.9.
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# File 'lib/haml/util.rb', line 154 def enum_with_index(enum) ruby1_8? ? enum.enum_with_index : enum.each_with_index end |
#has?(attr, klass, method) ⇒ Boolean
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# File 'lib/haml/util.rb', line 146 def has?(attr, klass, method) klass.send("#{attr}s").include?(ruby1_8? ? method.to_s : method.to_sym) end |
#map_hash(hash) {|key, value| ... } ⇒ Hash
Maps the key-value pairs of a hash according to a block. For example:
map_hash({:foo => "bar", :baz => "bang"}) {|k, v| [k.to_s, v.to_sym]}
#=> {"foo" => :bar, "baz" => :bang}
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# File 'lib/haml/util.rb', line 81 def map_hash(hash, &block) to_hash(hash.map(&block)) end |
#map_keys(hash) {|key| ... } ⇒ Hash
Maps the keys in a hash according to a block. For example:
map_keys({:foo => "bar", :baz => "bang"}) {|k| k.to_s}
#=> {"foo" => "bar", "baz" => "bang"}
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# File 'lib/haml/util.rb', line 46 def map_keys(hash) to_hash(hash.map {|k, v| [yield(k), v]}) end |
#map_vals(hash) {|value| ... } ⇒ Hash
Maps the values in a hash according to a block. For example:
map_values({:foo => "bar", :baz => "bang"}) {|v| v.to_sym}
#=> {:foo => :bar, :baz => :bang}
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# File 'lib/haml/util.rb', line 63 def map_vals(hash) to_hash(hash.map {|k, v| [k, yield(v)]}) end |
#merge_adjacent_strings(enum) ⇒ Array
Concatenates all strings that are adjacent in an array, while leaving other elements as they are. For example:
merge_adjacent_strings([1, "foo", "bar", 2, "baz"])
#=> [1, "foobar", 2, "baz"]
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# File 'lib/haml/util.rb', line 114 def merge_adjacent_strings(enum) e = enum.inject([]) do |a, e| if e.is_a?(String) && a.last.is_a?(String) a.last << e else a << e end a end end |
#powerset(arr) ⇒ Set<Set>
Computes the powerset of the given array. This is the set of all subsets of the array. For example:
powerset([1, 2, 3]) #=>
Set[Set[], Set[1], Set[2], Set[3], Set[1, 2], Set[2, 3], Set[1, 3], Set[1, 2, 3]]
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# File 'lib/haml/util.rb', line 94 def powerset(arr) arr.inject([Set.new].to_set) do |powerset, el| new_powerset = Set.new powerset.each do |subset| new_powerset << subset new_powerset << subset + [el] end new_powerset end end |
#ruby1_8? ⇒ Boolean
Whether or not this is running under Ruby 1.8 or lower.
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# File 'lib/haml/util.rb', line 128 def ruby1_8? Haml::Util::RUBY_VERSION[0] == 1 && Haml::Util::RUBY_VERSION[1] < 9 end |
#scope(file) ⇒ String
Returns the path of a file relative to the Haml root directory.
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# File 'lib/haml/util.rb', line 17 def scope(file) File. File.join(File.dirname(__FILE__), '..', '..', file) end |
#static_method_name(name, *vars) ⇒ String
Computes the name for a method defined via #def_static_method.
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# File 'lib/haml/util.rb', line 224 def static_method_name(name, *vars) "#{name}_#{vars.map {|v| !!v}.join('_')}" end |
#to_hash(arr) ⇒ Hash
Converts an array of ‘[key, value]` pairs to a hash. For example:
to_hash([[:foo, "bar"], [:baz, "bang"]])
#=> {:foo => "bar", :baz => "bang"}
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# File 'lib/haml/util.rb', line 29 def to_hash(arr) arr.compact.inject({}) {|h, (k, v)| h[k] = v; h} end |