Class: Gloo::Persist::FileLoader

Inherits:
Object
  • Object
show all
Defined in:
lib/gloo/persist/file_loader.rb

Constant Summary collapse

BEGIN_BLOCK = 
'BEGIN'.freeze
END_BLOCK = 
'END'.freeze
SPACE_CNT = 
2
LIB_DIRECTIVE =

A 'load lib name' (or 'load ext name') statement at the top of a file, before the first object declaration. It makes a core library's object types available to the declarations that follow. Same syntax as the load verb, but the loader runs it before building the object tree instead of a script running it afterward.

/\A(?:load|ld)\s+(?:lib|ext)\s+\S+\s*\z/i.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(engine, pn) ⇒ FileLoader

Set up a file storage for an object.



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# File 'lib/gloo/persist/file_loader.rb', line 28

def initialize( engine, pn )
  @engine = engine
  @mech = @engine.platform.get_file_mech( @engine )
  @pn = pn
  @tabs = 0
  @obj = nil
  @in_multiline = false
  @exiting_multiline = false
  @in_block = false
  @block_value = ''
  @body_started = false
  @debug = false
end

Instance Attribute Details

#obj ⇒ Object (readonly)

Returns the value of attribute obj.



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# File 'lib/gloo/persist/file_loader.rb', line 23

def obj
  @obj
end

Instance Method Details

#determine_indent(line) ⇒ Object

Determine the relative indent level for the line.



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# File 'lib/gloo/persist/file_loader.rb', line 127

def determine_indent( line )
  tabs = tab_count( line )
  @indent = 0 # same level as prior line
  if tabs > @tabs # indent
    # TODO:  What if indent is more than one more level?
    @tabs = tabs
    @indent = 1
  elsif tabs < @tabs # outdent
    diff = @tabs - tabs
    @tabs -= diff
    @indent -= diff
  end
  puts "tabs: #{@tabs}, indent: #{@indent}, line: #{line}" if @debug
end

#handle_one_line(line) ⇒ Object

Process one one of the file we're loading.



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# File 'lib/gloo/persist/file_loader.rb', line 94

def handle_one_line( line )
  if line.strip.end_with? BEGIN_BLOCK
    @in_block = true
    @save_line = line
  elsif @in_block
    if line.strip == END_BLOCK
      @in_block = false
      determine_indent @save_line
      process_line @save_line
    else
      @block_value << line
    end
  else
    determine_indent line
    process_line line
  end
end

#join_continuations(data) ⇒ Object

Join continuation lines.



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# File 'lib/gloo/persist/file_loader.rb', line 87

def join_continuations( data )
  return data.gsub( "\\\n", '' )
end

#load ⇒ Object

Load the objects from the file.



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# File 'lib/gloo/persist/file_loader.rb', line 45

def load
  unless @mech.exist?( @pn )
    @engine.err "File '#{@pn}' does not exist."
    return
  end

  @engine.log.debug "Loading file '#{@pn}'"
  @tabs = 0
  @parent_stack = []
  @parent = @engine.heap.root
  @parent_stack.push @parent
  f = @mech.read( @pn )

  f = join_continuations( f )

  f.each_line do |line|
    next if skip_line? line

    if !@body_started && line =~ LIB_DIRECTIVE
      run_lib_directive line
      next
    end
    @body_started = true

    handle_one_line line
  end
end

#process_line(line) ⇒ Object

Process one line and add objects.



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# File 'lib/gloo/persist/file_loader.rb', line 145

def process_line( line )
  # reset multiline unless we're actually indented
  if @in_multiline && @multi_indent > @indent
    puts "Done multiline mi: #{@multi_indent}, i: #{@indent}" if @debug
    @in_multiline = false
    @exiting_multiline = true
  end

  if @in_multiline
    @last.add_line line
  else
    setup_process_obj_line
    process_obj_line line
  end
end

#process_obj_line(line) ⇒ Object

Process one line and add objects.



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# File 'lib/gloo/persist/file_loader.rb', line 184

def process_obj_line( line )
  name, type, value = split_line( line )
  unless @block_value == ''
    value = @block_value
    @block_value = ''
  end
  params = { name: name, type: type, value: value, parent: @parent }
  @last = @engine.factory.create( params )

  if value&.empty? && @last&.multiline_value?
    @multi_indent = 0
    @in_multiline = true
    puts "*** Start multiline. multi_indent: #{@multi_indent}" if @debug
  end

  @obj = @last if @obj.nil?
end

#run_lib_directive(line) ⇒ Object

Run a top-of-file 'load lib name' directive. It goes through the same load verb a script would use, so libraries are loaded and their object types registered before the declarations that depend on them are parsed.



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# File 'lib/gloo/persist/file_loader.rb', line 79

def run_lib_directive( line )
  @engine.log.debug "Loading file directive: #{line.strip}"
  @engine.parser.run line.strip
end

#setup_process_obj_line ⇒ Object

Setup and get ready to process an object line.



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# File 'lib/gloo/persist/file_loader.rb', line 164

def setup_process_obj_line
  if @exiting_multiline
    @exiting_multiline = false
    @indent += 1
  end

  if @indent.positive?
    @parent = @last
    @parent_stack.push @parent
  elsif @indent.negative?
    @indent.abs.times do
      @parent_stack.pop
      @parent = @parent_stack.last
    end
  end
end

#skip_line?(line) ⇒ Boolean

Is this line a comment or a blank line? If so we'll skip it.

Returns:

  • (Boolean) 


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# File 'lib/gloo/persist/file_loader.rb', line 116

def skip_line?( line )
  line = line.strip
  return true if line.empty?
  return true if line[ 0 ] == '#'

  return false
end

#split_line(line) ⇒ Object

Split the line into 3 parts.



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# File 'lib/gloo/persist/file_loader.rb', line 222

def split_line( line )
  o = LineSplitter.new( line, @tabs )
  return o.split
end

#tab_count(line) ⇒ Object

Get the number of leading tabs.



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# File 'lib/gloo/persist/file_loader.rb', line 205

def tab_count( line )
  i = 0

  if line[ i ] == ' '
    i += 1 while line[ i ] == ' '
    tab_equiv = ( i / SPACE_CNT ).to_i
    puts "Found #{i} spaces => #{tab_equiv}" if @debug
    return tab_equiv
  end

  i += 1 while line[ i ] == "\t"
  return i
end