Class: Delorean::Engine

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(module_name, sset = nil) ⇒ Engine

Returns a new instance of Engine.



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# File 'lib/delorean/engine.rb', line 11

def initialize(module_name, sset=nil)
  # name of current module
  @module_name = module_name
  @sset = sset
  reset
end

Instance Attribute Details

#comp_set ⇒ Object (readonly)

Returns the value of attribute comp_set.



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# File 'lib/delorean/engine.rb', line 8

def comp_set
  @comp_set
end

#imports ⇒ Object (readonly)

Returns the value of attribute imports.



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# File 'lib/delorean/engine.rb', line 8

def imports
  @imports
end

#last_node ⇒ Object (readonly)

Returns the value of attribute last_node.



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# File 'lib/delorean/engine.rb', line 8

def last_node
  @last_node
end

#line_no ⇒ Object (readonly)

Returns the value of attribute line_no.



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# File 'lib/delorean/engine.rb', line 8

def line_no
  @line_no
end

#m ⇒ Object (readonly)

Returns the value of attribute m.



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# File 'lib/delorean/engine.rb', line 8

def m
  @m
end

#module_name ⇒ Object (readonly)

Returns the value of attribute module_name.



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# File 'lib/delorean/engine.rb', line 8

def module_name
  @module_name
end

#pm ⇒ Object (readonly)

Returns the value of attribute pm.



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# File 'lib/delorean/engine.rb', line 8

def pm
  @pm
end

#sset ⇒ Object (readonly)

Returns the value of attribute sset.



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# File 'lib/delorean/engine.rb', line 8

def sset
  @sset
end

Class Method Details

.grok_runtime_exception(exc) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 388

def self.grok_runtime_exception(exc)
  # parse out the delorean-related backtrace records
  bt = exc.backtrace.map{ |x|
    x.match(/^#{MOD}(.+?):(\d+)(|:in `(.+)')$/);
    $1 && [$1, $2.to_i, $4.sub(/#{POST}$/, '')]
  }.reject(&:!)

  {"error" => exc.message, "backtrace" => bt}
end

Instance Method Details

#curr_line ⇒ Object 



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# File 'lib/delorean/engine.rb', line 39

def curr_line
  @multi_no || @line_no
end

#enumerate_attrs ⇒ Object

enumerate qualified list of all attrs



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# File 'lib/delorean/engine.rb', line 315

def enumerate_attrs
  @node_attrs.keys.each_with_object({}) { |node, h|
    h[node] = enumerate_attrs_by_node(node)
  }
end

#enumerate_attrs_by_node(node) ⇒ Object

enumerate qualified list of attrs by node



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# File 'lib/delorean/engine.rb', line 322

def enumerate_attrs_by_node(node)
  raise "bad node" unless node

  begin
    klass = node.is_a?(String) ? @m.module_eval(node) : node
  rescue NameError
    # FIXME: a little hacky.  Should raise an exception.
    return []
  end

  raise "bad node class #{klass}" unless klass.is_a?(Class)

  klass.methods.map(&:to_s).select { |x|
    x.end_with?(POST)
  }.map { |x|
    x.sub(/#{POST}$/, '')
  }
end

#enumerate_nodes ⇒ Object

enumerate all nodes



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# File 'lib/delorean/engine.rb', line 310

def enumerate_nodes
  SortedSet[* @node_attrs.keys]
end

#enumerate_params ⇒ Object

enumerate all params



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# File 'lib/delorean/engine.rb', line 342

def enumerate_params
  @param_set
end

#enumerate_params_by_node(node) ⇒ Object

enumerate params by a single node



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# File 'lib/delorean/engine.rb', line 347

def enumerate_params_by_node(node)
  attrs = enumerate_attrs_by_node(node)
  Set.new( attrs.select {|a| @param_set.include?(a)} )
end

#err(exc, msg) ⇒ Object

Raises:

  • (exc) 


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# File 'lib/delorean/engine.rb', line 194

def err(exc, msg)
  raise exc.new(msg, @module_name, curr_line)
end

#eval_to_hash(node, attrs, params = {}) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 383

def eval_to_hash(node, attrs, params={})
  res = evaluate(node, attrs, params)
  Hash[* attrs.zip(res).flatten(1)]
end

#evaluate(node, attrs, params = {}) ⇒ Object

Runtime



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# File 'lib/delorean/engine.rb', line 356

def evaluate(node, attrs, params={})
  raise "bad params" unless params.is_a?(Hash)

  if node.is_a?(Class)
    klass = node
  else
    raise "bad node '#{node}'" unless node =~ /^[A-Z][a-zA-Z0-9_]*$/

    begin
      klass = @m.module_eval(node)
    rescue NameError
      err(UndefinedNodeError, "node #{node} is undefined")
    end
  end

  params[:_engine] = self

  type_arr = attrs.is_a?(Array)
  attrs = [attrs] unless type_arr

  res = attrs.map { |attr|
    raise "bad attribute '#{attr}'" unless attr =~ /^[a-z][A-Za-z0-9_]*$/
    klass.send("#{attr}#{POST}".to_sym, params)
  }
  type_arr ? res : res[0]
end

#gen_import(name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 58

def gen_import(name)
  @imports.merge!(@imports[name].imports)

  @m.const_set("#{MOD}#{name}", @imports[name].m)
end

#generate(t) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 230

def generate(t)
  t.check(self)

  begin
    # generate ruby code
    gen = t.rewrite(self)
  rescue RuntimeError => exc
    err(ParseError, "codegen error: " + exc.message)
  end

  # puts gen

  begin
    # evaluate generated code in @m
    @m.module_eval(gen, "#{MOD}#{module_name}", curr_line)
  rescue => exc
    # bad ruby code generated, shoudn't happen
    err(ParseError, "codegen error: " + exc.message)
  end
end

#get_import_engine(name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 64

def get_import_engine(name)
  err(ParseError, "#{name} not imported") unless @imports[name]
  @imports[name]
end

#hcount ⇒ Object

used in counting literal hashes



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# File 'lib/delorean/engine.rb', line 35

def hcount
  @hcount += 1
end

#is_node_defined(name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 69

def is_node_defined(name)
  @pm.constants.member? name.to_sym
end

#parse(source) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 251

def parse(source)
  raise "can't call parse again without reset" if @pm

  # @m module is used at runtime for code evaluation.  @pm module
  # is only used during parsing to check for errors.
  @m, @pm = BaseModule.clone, Module.new

  multi_line, @multi_no = nil, nil

  source.each_line do |line|
    @line_no += 1

    # skip comments
    next if line.match(/^\s*\#/)

    # remove trailing blanks
    line.rstrip!

    next if line.length == 0

    if multi_line
      # if line starts with >4 spaces, assume it's a multline
      # continuation.
      if line =~ /\A {5}/
        multi_line += line
        next
      else
        t = parser.parse(multi_line)
        err(ParseError, "syntax error") unless t

        generate(t)
        multi_line, @multi_no = nil, nil
      end
    end

    t = parser.parse(line)

    if !t
      err(ParseError, "syntax error") unless line =~ /^\s+/

      multi_line = line
      @multi_no = @line_no
    else
      generate(t)
    end
  end

  if multi_line
    t = parser.parse(multi_line)
    err(ParseError, "syntax error") unless t
    generate(t)
  end
end

#parse_call_attr(node_name, attr_name) ⇒ Object

Parse-time check to see if attr is available. If not, error is raised.



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# File 'lib/delorean/engine.rb', line 111

def parse_call_attr(node_name, attr_name)
  return [] if comp_set.member?(attr_name)

  # get the class associated with node
  klass = @pm.module_eval(node_name)

  # puts attr_name, "#{attr_name}#{POST}".to_sym, klass.methods.inspect

  begin
    klass.send("#{attr_name}#{POST}".to_sym, [])
  rescue NoMethodError
    err(UndefinedError, "'#{attr_name}' not defined in #{node_name}")
  end
end

#parse_call_last_node_attr(attr_name) ⇒ Object

Parse-time check to see if attr is available on current node.



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# File 'lib/delorean/engine.rb', line 127

def parse_call_last_node_attr(attr_name)
  err(ParseError, "Not inside a node") unless @last_node
  parse_call_attr(@last_node, attr_name)
end

#parse_check_call_fn(fn, argcount, class_name = nil) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 198

def parse_check_call_fn(fn, argcount, class_name=nil)
  klass = case class_name
          when nil
            @m::BaseClass
          when String
            parse_class(class_name)
          else
            class_name
          end

  err(UndefinedFunctionError, "Function #{fn} not found") unless
    klass.methods.member? fn.to_sym

  # signature methods must be named FUNCTION_NAME_SIG
  sig = "#{fn}#{SIG}".upcase.to_sym

  err(UndefinedFunctionError, "Signature #{sig} not found") unless
    klass.constants.member? sig

  min, max = klass.const_get(sig)

  err(BadCallError, "Too many args to #{fn} (#{argcount} > #{max})") if
    argcount > max

  err(BadCallError, "Too few args to #{fn} (#{argcount} < #{min})") if
    argcount < min
end

#parse_check_defined_mod_node(pname, mname) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 89

def parse_check_defined_mod_node(pname, mname)
  engine = mname ? get_import_engine(mname) : self
  engine.parse_check_defined_node(pname, true)
end

#parse_check_defined_node(name, flag) ⇒ Object

Check to see if node with given name is defined. flag tells the method about our expectation. flag=true means that we make sure that name is defined. flag=false is the opposite.



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# File 'lib/delorean/engine.rb', line 76

def parse_check_defined_node(name, flag)
  isdef = is_node_defined(name)

  if isdef != flag
    isdef ? err(RedefinedError, "#{name} already defined") :
      err(UndefinedError, "#{name} not defined yet")
  end
end

#parse_class(class_name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 179

def parse_class(class_name)
  begin
    # need the runtime module here (@m) since we need to
    # introspect methods/attrs.
    klass = @m.module_eval(class_name)
  rescue NoMethodError, NameError
    err(UndefinedError, "Can't find class: #{class_name}")
  end

  err(UndefinedError, "Access to non-class: #{class_name}") unless
    klass.instance_of?(Class)

  klass
end

#parse_define_attr(name, spec) ⇒ Object

parse-time attr definition



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# File 'lib/delorean/engine.rb', line 146

def parse_define_attr(name, spec)
  err(ParseError, "Can't define '#{name}' outside a node") unless
    @last_node

  err(RedefinedError, "Can't redefine '#{name}' in node #{@last_node}") if
    @node_attrs[@last_node].member? name

  @node_attrs[@last_node] << name

  checks = spec.map { |a|
    n = a.index('.') ? a : "#{@last_node}.#{a}"
    "_x.member?('#{n}') ? raise('#{n}') : #{a}#{POST}(_x + ['#{n}'])"
  }.join(';')

  code =
    "class #{@last_node}; def self.#{name}#{POST}(_x); #{checks}; end; end"

  # pp code

  @pm.module_eval(code)

  begin
    parse_call_attr(@last_node, name)
  rescue RuntimeError
    err(RecursionError, "'#{name}' is recursive")
  end
end

#parse_define_node(name, pname, mname = nil) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 94

def parse_define_node(name, pname, mname=nil)
  parse_check_defined_node(name, false)
  parse_check_defined_mod_node(pname, mname) if pname

  sname = pname ? super_name(pname, mname) : 'Object'

  @pm.module_eval("class #{name} < #{sname}; end")

  # latest defined node
  @last_node = name

  # mapping of node name to list of attrs it defines
  @node_attrs[name] = []
end

#parse_define_param(name, spec) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 174

def parse_define_param(name, spec)
  parse_define_attr(name, spec)
  @param_set.add(name)
end

#parse_define_var(var_name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 132

def parse_define_var(var_name)
  err(RedefinedError,
      "List comprehension can't redefine variable '#{var_name}'") if
    comp_set.member? var_name

  comp_set.add var_name
end

#parse_import(name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 43

def parse_import(name)
  err(ParseError, "No script set") unless sset

  err(ParseError, "Module #{name} importing itself") if
    name == module_name

  begin
    @imports[name] = sset.get_engine(name)
  rescue => exc
    err(ImportError, exc.to_s)
  end

  @pm.const_set("#{MOD}#{name}", @imports[name].pm)
end

#parse_undef_var(var_name) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 140

def parse_undef_var(var_name)
  err(ParseError, "internal error") unless comp_set.member? var_name
  comp_set.delete var_name
end

#parser ⇒ Object 



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# File 'lib/delorean/engine.rb', line 226

def parser
  @@parser ||= DeloreanParser.new
end

#reset ⇒ Object 



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# File 'lib/delorean/engine.rb', line 18

def reset
  @m, @pm = nil, nil
  @last_node, @node_attrs = nil, {}
  @line_no, @multi_no = 0, nil

  # set of comprehension vars
  @comp_set = Set.new

  # set of all params
  @param_set = Set.new

  @imports = {}

  @hcount = 0
end

#super_name(pname, mname) ⇒ Object 



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# File 'lib/delorean/engine.rb', line 85

def super_name(pname, mname)
  mname ? "#{MOD}#{mname}::#{pname}" : pname
end