Class: Prism::LibRubyParser::PrismBuffer

Inherits:
Object
  • Object
show all
Defined in:
lib/prism/ffi.rb

Overview

This object represents a pm_buffer_t. We only use it as an opaque pointer, so it doesn’t need to know the fields of pm_buffer_t.

Constant Summary collapse

SIZEOF =

:nodoc:

LibRubyParser.pm_buffer_sizeof

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pointer) ⇒ PrismBuffer

Returns a new instance of PrismBuffer.



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# File 'lib/prism/ffi.rb', line 104

def initialize(pointer)
  @pointer = pointer
end

Instance Attribute Details

#pointer ⇒ Object (readonly)

Returns the value of attribute pointer.



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# File 'lib/prism/ffi.rb', line 102

def pointer
  @pointer
end

Class Method Details

.with(&block) ⇒ Object

Initialize a new buffer and yield it to the block. The buffer will be automatically freed when the block returns.



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# File 'lib/prism/ffi.rb', line 122

def self.with(&block)
  pointer = FFI::MemoryPointer.new(SIZEOF)

  begin
    raise unless LibRubyParser.pm_buffer_init(pointer)
    yield new(pointer)
  ensure
    LibRubyParser.pm_buffer_free(pointer)
    pointer.free
  end
end

Instance Method Details

#length ⇒ Object 



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# File 'lib/prism/ffi.rb', line 112

def length
  LibRubyParser.pm_buffer_length(pointer)
end

#read ⇒ Object 



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# File 'lib/prism/ffi.rb', line 116

def read
  value.read_string(length)
end

#value ⇒ Object 



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# File 'lib/prism/ffi.rb', line 108

def value
  LibRubyParser.pm_buffer_value(pointer)
end