Class: Johnson::Runtime

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

Overview

An interface to a JavaScript engine.

Direct Known Subclasses

SpiderMonkey::Runtime

Constant Summary collapse

PRELUDE_PATH = 
File.expand_path File.dirname(__FILE__) +
"/js/prelude.js"
CORE_PATH =

:nodoc:

File.expand_path File.dirname(__FILE__) +
"/js/core.js"
PRELUDE =

:nodoc:

IO.read PRELUDE_PATH
CORE =

:nodoc:

IO.read CORE_PATH

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Runtime

Install the Johnson prelude into this runtime environment.



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# File 'lib/johnson/runtime.rb', line 47

def initialize # :notnew:
  evaluate PRELUDE, PRELUDE_PATH, 1
  global.Johnson.runtime = self
  global['Ruby'] = Object
  evaluate CORE, CORE_PATH, 1
end

Class Method Details

.new(*args) ⇒ Object

Create a new Runtime instance, using the default JavaScript engine.

Optionally takes a parameter specifying which engine to use, but this is deprecated; instead, just create an instance of that engine’s runtime directly.

:call-seq:

new(runtime_class=nil)



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# File 'lib/johnson/runtime.rb', line 32

def self.new(*args)
  return super if self < Johnson::Runtime

  delegate = args.first
  if delegate.is_a? Class
    delegate.new
  elsif delegate
    delegate
  else
    Johnson::SpiderMonkey::Runtime.new
  end
end

Instance Method Details

#[](key) ⇒ Object

Access the key property of the JavaScript global object.



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# File 'lib/johnson/runtime.rb', line 56

def [](key)
  global[key]
end

#[]=(key, value) ⇒ Object

Set the key property of the JavaScript global object to value.



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# File 'lib/johnson/runtime.rb', line 63

def []=(key, value)
  global[key] = value
end

#compile(script, filename = nil, linenum = nil) ⇒ Object

Compile the JavaScript source in script. If supplied, the script is marked as starting on line linenum of filename.

Raises:

  • (NotImplementedError) 


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# File 'lib/johnson/runtime.rb', line 111

def compile(script, filename=nil, linenum=nil)
  raise NotImplementedError
end

#delegate ⇒ Object

Deprecated: Previously, returned the underlying JavaScript engine instance. Now returns self.



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# File 'lib/johnson/runtime.rb', line 17

def delegate
  self
end

#evaluate(script, filename = nil, linenum = nil) ⇒ Object

Execute the JavaScript source in script. If supplied, the script is marked as starting on line linenum of filename.

Equivalent to calling RubyLandScript#execute on the result of Runtime#compile.



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# File 'lib/johnson/runtime.rb', line 74

def evaluate(script, filename = nil, linenum = nil)
  return nil if script.nil?
  compiled_script = compile(script, filename, linenum)
  evaluate_compiled_script(compiled_script)
end

#evaluate_compiled_script(script) ⇒ Object

Evaluates the given JS script, that should have been returned by a previous call to #compile().

Raises:

  • (NotImplementedError) 


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# File 'lib/johnson/runtime.rb', line 118

def evaluate_compiled_script(script)
  raise NotImplementedError
end

#global ⇒ Object

The JavaScript unique Global Object.

Raises:

  • (NotImplementedError) 


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# File 'lib/johnson/runtime.rb', line 83

def global
  raise NotImplementedError
end

#load(*files) ⇒ Object

Load and execute the named JavaScript files.

Checks for (and skips) a shebang line at the top of any of them.



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# File 'lib/johnson/runtime.rb', line 91

def load(*files)
  files.map { |f|
    evaluate(File.read(f).gsub(/\A#!.*$/, ''), f, 1)
  }.last
end

#require(*files) ⇒ Object

Search the Ruby load path for each of the named files, and evaluate them *if they have not yet been loaded*.

Calls Johnson.require() in JavaScript on each filename in turn.



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# File 'lib/johnson/runtime.rb', line 102

def require(*files)
  files.each do |file|
    evaluate("Johnson.require('#{file}');")
  end
end