Add IfNode for compiled nodes

opal · Oct 22, 2013 · 87b0524 · 87b0524
1 parent 05c1a26
commit 87b0524
Show file tree

Hide file tree

Showing 4 changed files with 106 additions and 46 deletions.
diff --git a/lib/opal/nodes.rb b/lib/opal/nodes.rb
@@ -5,6 +5,7 @@
 require 'opal/nodes/call'
 require 'opal/nodes/call_special'
 require 'opal/nodes/class'
+require 'opal/nodes/if'
 require 'opal/nodes/logic'
 require 'opal/nodes/definitions'
 require 'opal/nodes/yield'

diff --git a/lib/opal/nodes/helpers.rb b/lib/opal/nodes/helpers.rb
@@ -30,6 +30,50 @@ def line(*strs)
       def empty_line
         push "\n"
       end
+
+      def js_truthy(sexp)
+        if js_truthy_optimize(sexp)
+          return
+        end
+
+        with_temp do |tmp|
+          push "(#{tmp} = ", expr(sexp), ") !== false && #{tmp} !== nil"
+        end
+      end
+
+      def js_falsy(sexp)
+        if sexp.type == :call
+          mid = sexp[2]
+          if mid == :block_given?
+            push(*@parser.handle_block_given(sexp, true))
+            return
+          end
+        end
+
+        with_temp do |tmp|
+          push "(#{tmp} = ", expr(sexp), ") === false || #{tmp} === nil"
+        end
+      end
+
+      def js_truthy_optimize(sexp)
+        if sexp.type == :call
+          mid = sexp[2]
+
+          if mid == :block_given?
+            push expr(sexp)
+            true
+          elsif Parser::COMPARE.include? mid.to_s
+            push expr(sexp)
+            true
+          elsif mid == :"=="
+            push expr(sexp)
+            true
+          end
+        elsif [:lvar, :self].include? sexp.type
+          push expr(sexp.dup), " !== false && ", expr(sexp.dup), " !== nil"
+          true
+        end
+      end
     end
   end
 end
diff --git a/lib/opal/nodes/if.rb b/lib/opal/nodes/if.rb
@@ -0,0 +1,58 @@
+require 'opal/nodes/base'
+
+module Opal
+  class Parser
+    class IfNode < Node
+      children :test, :true_body, :false_body
+
+      def compile
+        truthy, falsy = self.truthy, self.falsy
+
+        push "if ("
+
+        # optimize unless (we don't want a else() unless we need to)
+        if falsy and !truthy
+          truthy = falsy
+          falsy = nil
+          js_falsy test
+        else
+          js_truthy test
+        end
+
+        push ") {"
+
+        # skip if-body if no truthy sexp
+        indent { line stmt(truthy) } if truthy
+
+        if falsy
+          if falsy.type == :if
+            line "} else ", stmt(falsy)
+          else
+            indent do
+              line "} else {"
+              line stmt(falsy)
+            end
+
+            line "}"
+          end
+        else
+          push "}"
+        end
+
+        wrap "(function() {", "; return nil; })()" if needs_wrapper?
+      end
+
+      def truthy
+        needs_wrapper? ? @parser.returns(true_body || s(:nil)) : true_body
+      end
+
+      def falsy
+        needs_wrapper? ? @parser.returns(false_body || s(:nil)) : false_body
+      end
+
+      def needs_wrapper?
+        expr? or recv?
+      end
+    end
+  end
+end
diff --git a/lib/opal/parser.rb b/lib/opal/parser.rb
@@ -115,6 +115,9 @@ def add_handler(klass, *types)
     add_handler WhileNode, :while
     add_handler UntilNode, :until
 
+    # if
+    add_handler IfNode, :if
+
     # rescue/ensure
     add_handler EnsureNode, :ensure
     add_handler RescueNode, :rescue
@@ -1035,52 +1038,6 @@ def process_masgn(sexp, level)
       code
     end
 
-    # s(:if, test, truthy, falsy)
-    def process_if(sexp, level)
-      test, truthy, falsy = sexp
-      returnable = (level == :expr or level == :recv)
-
-      if returnable
-        truthy = returns(truthy || s(:nil))
-        falsy = returns(falsy || s(:nil))
-      end
-
-      # optimize unless (we don't want else unless we need to)
-      if falsy and !truthy
-        truthy = falsy
-        falsy  = nil
-        check  = js_falsy test
-      else
-        check = js_truthy test
-      end
-
-      result = [f("if (", sexp), check, f(") {\n", sexp)]
-
-      indent { result.push(f(@indent, sexp), process(truthy, :stmt)) } if truthy
-
-      outdent = @indent
-
-      if falsy
-        if falsy[0] == :if
-          result.push(f("\n#{outdent}} else "), process(falsy, :stmt))
-        else
-          indent {
-            result.push(f("\n#{outdent}} else {\n#@indent", sexp), process(falsy, :stmt))
-          }
-          result << f("\n#@indent}", sexp)
-        end
-      else
-        result << f("\n#@indent}", sexp)
-      end
-
-      if returnable
-        result.unshift f("(function() { ", sexp)
-        result.push f("; return nil; }).call(self)", sexp)
-      end
-
-      result
-    end
-
     def js_truthy_optimize(sexp)
       if sexp.first == :call
         mid = sexp[2]