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



21
22
23
 
# File 'lib/n65/directives/enter_scope.rb', line 21

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

Class Method Details

.parse(line) ⇒ Object 



8
9
10
11
12
13
14
15
16
17
18
 
# File 'lib/n65/directives/enter_scope.rb', line 8

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

  # 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.



30
31
32
33
 
# File 'lib/n65/directives/enter_scope.rb', line 30

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

#to_s ⇒ Object 



35
36
37
 
# File 'lib/n65/directives/enter_scope.rb', line 35

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