Class: Inline::Scala

Inherits:
Object
  • Object
show all
Defined in:
lib/scala_inline.rb

Overview

A Java builder for RubyInline. Provides the basic methods needed to allow assembling a set of Java methods that compile into a class and get bound to the same names in the containing module.

Constant Summary collapse

JFile = 
java.io.File

Instance Method Summary collapse

Constructor Details

#initialize(mod) ⇒ Scala

Returns a new instance of Scala.



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# File 'lib/scala_inline.rb', line 20

def initialize(mod)
  @context = mod
  @src = ""
  @imports = []
  @sigs = []
end

Instance Method Details

#build ⇒ Object 



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# File 'lib/scala_inline.rb', line 57

def build      
  if @pkg
    directory = "#{Inline.directory}/#{@pkg.gsub('.', '/')}"
    unless File.directory? directory then
      $stderr.puts "NOTE: creating #{directory} for RubyInline" if $DEBUG
      FileUtils.mkdir_p directory
    end
    
    @name = "Scala#{@src.hash.abs}"
    @load_name = "#{@pkg}.#{@name}"
    filename = "#{directory}/#{@name}.scala"
  
    imports = "import " + @imports.join("\nimport ") if @imports.size > 0
    full_src = "
      package #{@pkg}
      #{imports}
      object #{@name} {
      #{@src}
      }
    "
  else
    @load_name = @name = "Java#{@src.hash.abs}"
    filename = "#{Inline.directory}/#{@name}.scala"
  
    imports = "import " + @imports.join("\nimport ") if @imports.size > 0
    full_src = "
      #{imports}
      object #{@name} {
      #{@src}
      }
    "
  end
  
  File.open(filename, "w") {|file| file.write(full_src)}
  cmd_args = [filename, "-classpath", "#{System.getProperty('scala.home')}/lib/scala-library.jar", "-d", "#{Inline.directory}"]
  Main.process(cmd_args.to_java(:string))
end

#import(cls) ⇒ Object

Add an “import” line with the given class, as in builder.import “java.util.ArrayList”. The imports will be composed into an appropriate block of code and added to the top of the source.



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# File 'lib/scala_inline.rb', line 40

def import(cls)
  if cls.respond_to? :java_class
    @imports << cls.java_class.name
  else
    @imports << cls.to_s
  end
end

#load ⇒ Object 



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# File 'lib/scala_inline.rb', line 95

def load
  @context.module_eval "const_set :#{@name}, ::Java::#{@load_name}"
  @sigs.each do |sig|
    @context.module_eval "def #{sig[0]}(*args); #{@name}.#{sig[0]}(*args); end"
  end
end

#load_cache ⇒ Object 



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# File 'lib/scala_inline.rb', line 27

def load_cache
  false
end

#package(pkg) ⇒ Object

Set the package to use for the Java class being generated, as in builder.package “org.foo.bar”



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# File 'lib/scala_inline.rb', line 33

def package(pkg)
  @pkg = pkg
end

#scala(src) ⇒ Object

Add a Scala method to the built Scala source. This expects the method to be public and static, so it can be called as a function.



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# File 'lib/scala_inline.rb', line 50

def scala(src)
  @src << src << "\n"
  signature = src.match(/def\W+([a-zA-Z0-9_]+)\((.*)\)/)
  raise "Could not parse method signature" unless signature
  @sigs << [signature[1], signature[2]]
end