Class: N65::EnterScope

Inherits:
InstructionBase show all
Defined in:
lib/n65/directives/enter_scope.rb

Overview

This directive to include bytes

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from InstructionBase

#unresolved_symbols?

Constructor Details

#initialize(name = nil) ⇒ EnterScope

Initialize with filename



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# File 'lib/n65/directives/enter_scope.rb', line 28

def initialize(name = nil)
  @name = name
end

Class Method Details

.parse(line) ⇒ Object

Try to parse an incbin directive



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# File 'lib/n65/directives/enter_scope.rb', line 12

def self.parse(line)
  ##  Anonymous scope
  match_data = line.match(/^\.scope$/)
  unless match_data.nil?
    return EnterScope.new
  end

  ##  Named scope
  match_data = line.match(/^\.scope\s+([a-zA-Z][a-zA-Z0-9_]+)$/)
  return nil if match_data.nil?
  EnterScope.new(match_data[1])
end

Instance Method Details

#exec(assembler) ⇒ Object

Execute on the assembler, also create a symbol referring to 

the current pc which contains a hyphen, and is impossible for
the user to create.  This makes a scope simultaneously act as
a label to the current PC.  If someone tries to use a scope
name as a label, it can return the address when the scope opened.



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# File 'lib/n65/directives/enter_scope.rb', line 39

def exec(assembler)
  assembler.symbol_table.enter_scope(@name)
  unless @name.nil?
    assembler.symbol_table.define_symbol("-#{@name}", assembler.program_counter)
  end
end

#to_s ⇒ Object

Display



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# File 'lib/n65/directives/enter_scope.rb', line 49

def to_s
  ".scope #{@name}"
end