Module: BOAST::TypeTransition

Included in:
BOAST
Defined in:
lib/BOAST/Transitions.rb

Constant Summary collapse

@@transitions = 
Hash::new { |hash, key| hash[key] = Hash::new{ |has, ke| has[ke] = Hash::new } }

Instance Method Summary collapse

Instance Method Details

#get_transition(type1, type2, operator) ⇒ Object 



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# File 'lib/BOAST/Transitions.rb', line 4

def get_transition(type1, type2, operator)
  #STDERR.puts @@transitions.inspect
  match_type1 = @@transitions.keys.select { |e1| true if type1 <= e1 }
  raise "Unknown type!" if match_type1.length == 0
  match_type1.sort!
  #STDERR.puts match_type1.inspect
  match_type1.each { |t1|
    match_type2 = @@transitions[t1].keys.select{ |e2| true if type2 <= e2 }
    match_type2.sort!
    #STDERR.puts match_type2.inspect
    match_type2.each { |t2|
      #STDERR.puts @@transitions[t1][t2].inspect
      return [@@transitions[t1][t2][operator], operator] if @@transitions[t1][t2][operator]
      return [@@transitions[t1][t2][:default], operator] if @@transitions[t1][t2][:default]
    }
  }
  raise "Unresolvable transition!"
end

#set_transition(type1, type2, operator, return_type) ⇒ Object 



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# File 'lib/BOAST/Transitions.rb', line 23

def set_transition(type1, type2, operator, return_type)
  @@transitions[type1][type2][operator] = return_type
end

#transition(var1, var2, operator) ⇒ Object 



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# File 'lib/BOAST/Transitions.rb', line 27

def transition(var1, var2, operator)
  signed = false
  size = nil
  return_type, operator = get_transition(var1.type.class, var2.type.class, operator)
  #STDERR.puts "#{return_type} : #{var1.type.class} #{operator} #{var2.type.class}"
  if var1.type.class <= return_type and var2.type.class <= return_type then
    signed = signed or var1.type.signed if var1.type.respond_to?(:signed)
    signed = signed or var2.type.signed if var2.type.respond_to?(:signed)
    if var1.type.respond_to?(:size) and var2.type.respond_to?(:size) then
      size = [var1.type.size, var2.type.size].max
    end
    [BOAST::Variable::new("dummy", return_type, :size => size, :signed => signed), operator]
  elsif var1.type.class <= return_type then
    return [var1, operator]
  elsif var2.type.class <= return_type then
    return [var2, operator]
  end
end