X-Git-Url: http://nitlanguage.org diff --git a/lib/standard/stream.nit b/lib/standard/stream.nit index 46ad73c..7df1bd1 100644 --- a/lib/standard/stream.nit +++ b/lib/standard/stream.nit @@ -25,11 +25,11 @@ class IOError super Error end -# Abstract stream class -abstract class IOS +# Any kind of stream to read/write/both to or from a source +abstract class Stream # Error produced by the file stream # - # var ifs = new IFStream.open("donotmakethisfile.binx") + # var ifs = new FileReader.open("donotmakethisfile.binx") # ifs.read_all # ifs.close # assert ifs.last_error != null @@ -39,9 +39,9 @@ abstract class IOS fun close is abstract end -# Abstract input streams -abstract class IStream - super IOS +# A `Stream` that can be read from +abstract class Reader + super Stream # Read a character. Return its ASCII value, -1 on EOF or timeout fun read_char: Int is abstract @@ -66,7 +66,7 @@ abstract class IStream # # ~~~ # var txt = "Hello\n\nWorld\n" - # var i = new StringIStream(txt) + # var i = new StringReader(txt) # assert i.read_line == "Hello" # assert i.read_line == "" # assert i.read_line == "World" @@ -79,7 +79,7 @@ abstract class IStream # # ~~~ # var txt2 = "Hello\r\n\n\rWorld" - # var i2 = new StringIStream(txt2) + # var i2 = new StringReader(txt2) # assert i2.read_line == "Hello" # assert i2.read_line == "" # assert i2.read_line == "\rWorld" @@ -102,7 +102,7 @@ abstract class IStream # # ~~~ # var txt = "Hello\n\nWorld\n" - # var i = new StringIStream(txt) + # var i = new StringReader(txt) # assert i.read_lines == ["Hello", "", "World"] # ~~~ # @@ -126,7 +126,7 @@ abstract class IStream # # ~~~ # var txt = "Hello\n\nWorld\n" - # var i = new StringIStream(txt) + # var i = new StringReader(txt) # assert i.each_line.to_a == ["Hello", "", "World"] # ~~~ # @@ -134,7 +134,7 @@ abstract class IStream # Therefore, the stream should no be closed until the end of the stream. # # ~~~ - # i = new StringIStream(txt) + # i = new StringReader(txt) # var el = i.each_line # # assert el.item == "Hello" @@ -155,7 +155,7 @@ abstract class IStream # # ~~~ # var txt = "Hello\n\nWorld\n" - # var i = new StringIStream(txt) + # var i = new StringReader(txt) # assert i.read_all == txt # ~~~ fun read_all: String @@ -177,7 +177,7 @@ abstract class IStream # # ~~~ # var txt = "Hello\n\nWorld\n" - # var i = new StringIStream(txt) + # var i = new StringReader(txt) # var b = new FlatBuffer # i.append_line_to(b) # assert b == "Hello\n" @@ -192,7 +192,7 @@ abstract class IStream # a non-eol terminated last line was returned. # # ~~~ - # var i2 = new StringIStream("hello") + # var i2 = new StringReader("hello") # assert not i2.eof # var b2 = new FlatBuffer # i2.append_line_to(b2) @@ -220,15 +220,75 @@ abstract class IStream # Is there something to read. # This function returns 'false' if there is something to read. fun eof: Bool is abstract + + # Read the next sequence of non whitespace characters. + # + # Leading whitespace characters are skipped. + # The first whitespace character that follows the result is consumed. + # + # An empty string is returned if the end of the file or an error is encounter. + # + # ~~~ + # var w = new StringReader(" Hello, \n\t World!") + # assert w.read_word == "Hello," + # assert w.read_char == '\n'.ascii + # assert w.read_word == "World!" + # assert w.read_word == "" + # ~~~ + # + # `Char::is_whitespace` determines what is a whitespace. + fun read_word: String + do + var buf = new FlatBuffer + var c = read_nonwhitespace + if c > 0 then + buf.add(c.ascii) + while not eof do + c = read_char + if c < 0 then break + var a = c.ascii + if a.is_whitespace then break + buf.add(a) + end + end + var res = buf.to_s + return res + end + + # Skip whitespace characters (if any) then return the following non-whitespace character. + # + # Returns the code point of the character. + # Return -1 on end of file or error. + # + # In fact, this method works like `read_char` except it skips whitespace. + # + # ~~~ + # var w = new StringReader(" \nab\tc") + # assert w.read_nonwhitespace == 'a'.ascii + # assert w.read_nonwhitespace == 'b'.ascii + # assert w.read_nonwhitespace == 'c'.ascii + # assert w.read_nonwhitespace == -1 + # ~~~ + # + # `Char::is_whitespace` determines what is a whitespace. + fun read_nonwhitespace: Int + do + var c = -1 + while not eof do + c = read_char + if c < 0 or not c.ascii.is_whitespace then break + end + return c + end end -# Iterator returned by `IStream::each_line`. +# Iterator returned by `Reader::each_line`. # See the aforementioned method for details. class LineIterator super Iterator[String] # The original stream - var stream: IStream + var stream: Reader redef fun is_ok do @@ -269,18 +329,18 @@ class LineIterator end end -# IStream capable of declaring if readable without blocking -abstract class PollableIStream - super IStream +# `Reader` capable of declaring if readable without blocking +abstract class PollableReader + super Reader # Is there something to read? (without blocking) fun poll_in: Bool is abstract end -# Abstract output stream -abstract class OStream - super IOS +# A `Stream` that can be written to +abstract class Writer + super Stream # write a string fun write(s: Text) is abstract @@ -288,16 +348,16 @@ abstract class OStream fun is_writable: Bool is abstract end -# Things that can be efficienlty writen to a OStream +# Things that can be efficienlty written to a `Writer` # -# The point of this interface it to allow is instance to be efficenty -# writen into a OStream without having to allocate a big String object +# The point of this interface is to allow the instance to be efficiently +# written into a `Writer`. # -# ready-to-save documents usually provide this interface. -interface Streamable +# Ready-to-save documents usually provide this interface. +interface Writable # Write itself to a `stream` # The specific logic it let to the concrete subclasses - fun write_to(stream: OStream) is abstract + fun write_to(stream: Writer) is abstract # Like `write_to` but return a new String (may be quite large) # @@ -306,20 +366,20 @@ interface Streamable # stream without having to allocate and concatenate strings fun write_to_string: String do - var stream = new StringOStream + var stream = new StringWriter write_to(stream) return stream.to_s end end redef class Text - super Streamable + super Writable redef fun write_to(stream) do stream.write(self) end -# Input streams with a buffer -abstract class BufferedIStream - super IStream +# Input streams with a buffered input for efficiency purposes +abstract class BufferedReader + super Reader redef fun read_char do if last_error != null then return -1 @@ -344,6 +404,7 @@ abstract class BufferedIStream if _buffer_pos + i >= _buffer.length then var from = _buffer_pos _buffer_pos = _buffer.length + if from == 0 then return _buffer.to_s return _buffer.substring_from(from).to_s end _buffer_pos += i @@ -439,17 +500,17 @@ abstract class BufferedIStream end end -# An Input/Output Stream -abstract class IOStream - super IStream - super OStream +# A `Stream` that can be written to and read from +abstract class Duplex + super Reader + super Writer end -# Stream to a String. +# `Stream` that can be used to write to a `String` # -# Mainly used for compatibility with OStream type and tests. -class StringOStream - super OStream +# Mainly used for compatibility with Writer type and tests. +class StringWriter + super Writer private var content = new Array[String] redef fun to_s do return content.to_s @@ -466,11 +527,11 @@ class StringOStream redef fun close do closed = true end -# Stream from a String. +# `Stream` used to read from a `String` # -# Mainly used for compatibility with IStream type and tests. -class StringIStream - super IStream +# Mainly used for compatibility with Reader type and tests. +class StringReader + super Reader # The string to read from. var source: String @@ -493,5 +554,12 @@ class StringIStream source = "" end + redef fun read_all do + var c = cursor + cursor = source.length + if c == 0 then return source + return source.substring_from(c) + end + redef fun eof do return cursor >= source.length end