Initial StringIO implementation

meh · meh · commit 7df60160195e · 2013-07-30T00:25:12.000+02:00
diff --git a/corelib/opal.rb b/corelib/opal.rb
@@ -18,6 +18,7 @@
 require 'opal/time'
 require 'opal/struct'
 require 'opal/native'
+require 'opal/io'
 
 # regexp matches
 $& = $~ = $` = $' = nil
@@ -27,6 +28,7 @@
 
 # split lines
 $/            = "\n"
+$,            = " "
 
 # native global
 $$ = $global = Native(`Opal.global`)
diff --git a/corelib/opal/error.rb b/corelib/opal/error.rb
@@ -43,6 +43,7 @@ class IndexError < StandardError; end
     class StopIteration < IndexError; end
     class KeyError < IndexError; end
   class RangeError < StandardError; end
+  class IOError < StandardError; end
 
 class ScriptError < Exception; end
   class SyntaxError < ScriptError; end
diff --git a/corelib/opal/io.rb b/corelib/opal/io.rb
@@ -0,0 +1,39 @@
+class IO
+  SEEK_SET = 0
+  SEEK_CUR = 1
+  SEEK_END = 2
+
+  module Writable
+    def <<(string)
+      write(string)
+
+      self
+    end
+
+    def print(*args)
+      write args.map { |arg| String(arg) }.join($,)
+    end
+
+    def puts(*args)
+      write args.map { |arg| String(arg) }.join($/)
+    end
+  end
+
+  module Readable
+    def readbyte
+      getbyte
+    end
+
+    def readchar
+      getc
+    end
+
+    def readline(sep = $/)
+      raise NotImplementedError
+    end
+
+    def readpartial(integer, outbuf = nil)
+      raise NotImplementedError
+    end
+  end
+end
diff --git a/stdlib/stringio.rb b/stdlib/stringio.rb
@@ -0,0 +1,173 @@
+class StringIO < IO
+  include IO::Readable
+  include IO::Writable
+
+  def self.open(string = "", mode = nil, &block)
+    io  = new(string, mode)
+    res = block.call(io)
+    io.close
+
+    res
+  end
+
+  attr_accessor :string
+
+  def initialize(string = "", mode = 'rw')
+    @string   = string
+    @position = string.length
+
+    if mode.include?('r') and not mode.include?('w')
+      @closed = :write
+    elsif mode.include?('w') and not mode.include?('r')
+      @closed = :read
+    end
+  end
+
+  def eof?
+    check_readable
+
+    @position == @string.length
+  end
+
+  alias eof eof?
+
+  def seek(pos, whence = IO::SEEK_SET)
+    case whence
+    when IO::SEEK_SET
+      @position = pos
+
+    when IO::SEEK_CUR
+      if @position + pos > @string.length
+        @position = @string.length
+      else
+        @position += pos
+      end
+
+    when IO::SEEK_END
+      if pos > @string.length
+        @position = 0
+      else
+        @position -= pos
+      end
+    end
+
+    0
+  end
+
+  def tell
+    @position
+  end
+
+  alias pos tell
+
+  alias pos= seek
+
+  def rewind
+    seek 0
+  end
+
+  def each_byte(&block)
+    return enum_for :each_byte unless block
+
+    check_readable
+
+    i = @position
+    until eof?
+      block.call(@string[i].ord)
+      i += 1
+    end
+
+    self
+  end
+
+  def each_char(&block)
+    return enum_for :each_char unless block
+
+    check_readable
+
+    i = @position
+    until eof?
+      block.call(@string[i])
+      i += 1
+    end
+
+    self
+  end
+
+  def write(string)
+    check_writable
+
+    string = String(string)
+
+    if @string.length == @position
+      @string += string
+    else
+      before = @string[0 .. @position - 1]
+      after  = @string[@position + string.length .. -1]
+
+      @string = before + string + after
+    end
+  end
+
+  def read(length = nil, outbuf = nil)
+    check_readable
+
+    return if eof?
+
+    string = if length
+      @string[@position, length]
+    else
+      @string[@position .. -1]
+    end
+
+    if outbuf
+      outbuf.write(string)
+    else
+      string
+    end
+  end
+
+  def close
+    @closed = :both
+  end
+
+  def close_read
+    if @closed == :write
+      @closed = :both
+    else
+      @closed = :read
+    end
+  end
+
+  def close_write
+    if @closed == :read
+      @closed = :both
+    else
+      @closed = :write
+    end
+  end
+
+  def closed?
+    @closed == :both
+  end
+
+  def closed_read?
+    @closed == :read || @closed == :both
+  end
+
+  def closed_write?
+    @closed == :write || @closed == :both
+  end
+
+  def check_writable
+    if closed_write?
+      raise IOError, "not opened for writing"
+    end
+  end
+
+  def check_readable
+    if closed_read?
+      raise IOError, "not opened for reading"
+    end
+  end
+end
