class Crystal::Repl::LocalVars

• Crystal::Repl::LocalVars
• Reference
• Object

Overview

Records the position in the stack for local variables.

This is almost a Hash where the keys are names and the values are indexes, but it's a bit more complex because blocks create separate scopes where name clashes can happen.

So if we have a code like this:

a = 0
b = 1
foo do |a|
  b = a
end
c = 2

We actually want to store:

• a in the first position (0-8 bytes)
• b in the second position (8-16 bytes)
• the a in the block is a different var, so we put it in (16-24)
• now that the block is over, that new a (or any variable that only exists inside the block) are no longer reachable so:
• c can also be put in (16-24)

Defined in:

Constructors

• .new(context : Context)
• .new(local_vars : LocalVars)

Instance Method Summary

• #block_level : Int32
• #current_bytesize : Int32
• #declare(name : String, type : Type) : Int32 | Nil
• #dup

  Returns a shallow copy of this object.

• #max_bytesize : Int32
• #name_to_index(name : String, block_level : Int32) : Int32
• #name_to_index?(name : String, block_level : Int32) : Int32 | Nil
• #names
• #names_at_block_level_zero
• #pop_block : Nil
• #push_block : Nil
• #to_s(io : IO) : Nil

  Appends a short String representation of this object which includes its class name and its object address.

• #type(name : String, block_level : Int32) : Type
• #type?(name : String, block_level : Int32) : Type | Nil

Constructor Detail

Instance Method Detail

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).to_s # => #<Person:0x10a199f20>