rubyx/lib/virtual/compiler/basic_expressions.rb
2015-06-02 09:05:27 +03:00

101 lines
3.6 KiB
Ruby

module Virtual
# collection of the simple ones, int and strings and such
module Compiler
# Constant expressions can by definition be evaluated at compile time.
# But that does not solve their storage, ie they need to be accessible at runtime from _somewhere_
# So we view ConstantExpressions like functions that return the value of the constant.
# In other words, their storage is the return slot as it would be for a method
# The current approach moves the constant into a variable before using it
# But in the future (in the one that holds great things) we optimize those unneccesay moves away
# attr_reader :value
def self.compile_integer expression , method
int = expression.value
to = Return.new(Integer , int)
method.info.add_code Set.new( to , int)
to
end
def self.compile_true expression , method
to = Return.new(Reference , true )
method.info.add_code Set.new( to , true )
to
end
def self.compile_false expression , method
to = Return.new(Reference , false)
method.info.add_code Set.new( to , false )
to
end
def self.compile_nil expression , method
to = Return.new(Reference , nil)
method.info.add_code Set.new( to , nil )
to
end
# attr_reader :name
# compiling name needs to check if it's a variable and if so resolve it
# otherwise it's a method without args and a send is issued.
# whichever way this goes the result is stored in the return slot (as all compiles)
def self.compile_name expression , method
return Self.new( Reference.new(method.for_class)) if expression.name == :self
name = expression.name.to_sym
if method.has_var(name)
# either an argument, so it's stored in message
if( index = method.has_arg(name))
method.info.add_code MessageGet.new(expression.name , index)
else # or a local so it is in the frame
method.info.add_code FrameGet.new(expression.name , index)
end
else
call = Ast::CallSiteExpression.new(expression.name , [] ) #receiver self is implicit
Compiler.compile(call, method)
end
end
def self.compile_module expression , method
clazz = Space.space.get_class_by_name name
raise "uups #{clazz}.#{name}" unless clazz
to = Return.new(Reference , clazz )
method.info.add_code Set.new( to , clazz )
to
end
# attr_reader :string
def self.compile_string expression , method
value = expression.string.to_sym
to = Return.new(Reference , value)
method.info.constants << value
method.info.add_code Set.new( to , value )
to
end
#attr_reader :left, :right
def self.compile_assignment expression , method
unless expression.left.instance_of? Ast::NameExpression
raise "must assign to NameExpression , not #{expression.left}"
end
r = Compiler.compile(expression.right , method )
raise "oh noo, nil from where #{expression.right.inspect}" unless r
index = method.has_arg(expression.left.name.to_sym)
if index
method.info.add_code Set.new(Return.new , MessageSlot.new(index , r,type , r ))
else
index = method.ensure_local(expression.left.name.to_sym)
method.info.add_code Set.new(Return.new , FrameSlot.new(index , r.type , r ))
end
r
end
def self.compile_variable expression, method
method.info.add_code InstanceGet.new(expression.name)
Return.new( Mystery )
end
end
end