lib/standard: revamp doc of `Map::join`
[nit.git] / lib / standard / stream.nit
index 884368d..dd1875b 100644 (file)
@@ -11,8 +11,9 @@
 # Input and output streams of characters
 module stream
 
-intrude import ropes
+intrude import text::ropes
 import error
+intrude import bytes
 
 in "C" `{
        #include <unistd.h>
@@ -46,21 +47,25 @@ abstract class Reader
        fun read_char: nullable Char is abstract
 
        # Reads a byte. Returns `null` on EOF or timeout
-       fun read_byte: nullable Int is abstract
+       fun read_byte: nullable Byte is abstract
+
+       # Reads a String of at most `i` length
+       fun read(i: Int): String do return read_bytes(i).to_s
 
        # Read at most i bytes
-       fun read(i: Int): String
+       fun read_bytes(i: Int): Bytes
        do
-               if last_error != null then return ""
-               var s = new FlatBuffer.with_capacity(i)
+               if last_error != null then return new Bytes.empty
+               var s = new NativeString(i)
+               var buf = new Bytes(s, 0, 0)
                while i > 0 and not eof do
-                       var c = read_char
+                       var c = read_byte
                        if c != null then
-                               s.add(c)
+                               buf.add c
                                i -= 1
                        end
                end
-               return s.to_s
+               return buf
        end
 
        # Read a string until the end of the line.
@@ -154,22 +159,27 @@ abstract class Reader
 
        # Read all the stream until the eof.
        #
-       # The content of the file is returned verbatim.
+       # The content of the file is returned as a String.
        #
        # ~~~
        # var txt = "Hello\n\nWorld\n"
        # var i = new StringReader(txt)
        # assert i.read_all == txt
        # ~~~
-       fun read_all: String
+       fun read_all: String do return read_all_bytes.to_s
+
+       # Read all the stream until the eof.
+       #
+       # The content of the file is returned verbatim.
+       fun read_all_bytes: Bytes
        do
-               if last_error != null then return ""
-               var s = new FlatBuffer
+               if last_error != null then return new Bytes.empty
+               var s = new Bytes.empty
                while not eof do
-                       var c = read_char
+                       var c = read_byte
                        if c != null then s.add(c)
                end
-               return s.to_s
+               return s
        end
 
        # Read a string until the end of the line and append it to `s`.
@@ -342,9 +352,16 @@ end
 # A `Stream` that can be written to
 abstract class Writer
        super Stream
+
+       # Writes bytes from `s`
+       fun write_bytes(s: Bytes) is abstract
+
        # write a string
        fun write(s: Text) is abstract
 
+       # Write a single byte
+       fun write_byte(value: Byte) is abstract
+
        # Can the stream be used to write
        fun is_writable: Bool is abstract
 end
@@ -362,7 +379,7 @@ interface Writable
 
        # Like `write_to` but return a new String (may be quite large)
        #
-       # This funtionnality is anectodical, since the point
+       # This funtionality is anectodical, since the point
        # of streamable object to to be efficienlty written to a
        # stream without having to allocate and concatenate strings
        fun write_to_string: String
@@ -388,7 +405,8 @@ abstract class BufferedReader
                        last_error = new IOError("Stream has reached eof")
                        return null
                end
-               var c = _buffer[_buffer_pos]
+               # TODO: Fix when supporting UTF-8
+               var c = _buffer[_buffer_pos].to_i.ascii
                _buffer_pos += 1
                return c
        end
@@ -400,35 +418,84 @@ abstract class BufferedReader
                        last_error = new IOError("Stream has reached eof")
                        return null
                end
-               var c = _buffer[_buffer_pos].ascii
+               var c = _buffer[_buffer_pos]
                _buffer_pos += 1
                return c
        end
 
-       redef fun read(i)
+       fun buffer_reset do
+               _buffer_length = 0
+               _buffer_pos = 0
+       end
+
+       # Peeks up to `n` bytes in the buffer
+       #
+       # The operation does not consume the buffer
+       #
+       # ~~~nitish
+       # var x = new FileReader.open("File.txt")
+       # assert x.peek(5) == x.read(5)
+       # ~~~
+       fun peek(i: Int): Bytes do
+               if eof then return new Bytes.empty
+               var remsp = _buffer_length - _buffer_pos
+               if i <= remsp then
+                       var bf = new Bytes.with_capacity(i)
+                       bf.append_ns_from(_buffer, i, _buffer_pos)
+                       return bf
+               end
+               var bf = new Bytes.with_capacity(i)
+               bf.append_ns_from(_buffer, remsp, _buffer_pos)
+               _buffer_pos = _buffer_length
+               read_intern(i - bf.length, bf)
+               remsp = _buffer_length - _buffer_pos
+               var full_len = bf.length + remsp
+               if full_len > _buffer_capacity then
+                       var c = _buffer_capacity
+                       while c < full_len do c = c * 2 + 2
+                       _buffer_capacity = c
+               end
+               var nns = new NativeString(_buffer_capacity)
+               bf.items.copy_to(nns, bf.length, 0, 0)
+               _buffer.copy_to(nns, remsp, _buffer_pos, bf.length)
+               _buffer = nns
+               _buffer_pos = 0
+               _buffer_length = full_len
+               return bf
+       end
+
+       redef fun read_bytes(i)
        do
-               if last_error != null then return ""
-               if eof then return ""
+               if last_error != null then return new Bytes.empty
+               var buf = new Bytes.with_capacity(i)
+               read_intern(i, buf)
+               return buf
+       end
+
+       # Fills `buf` with at most `i` bytes read from `self`
+       private fun read_intern(i: Int, buf: Bytes): Int do
+               if eof then return 0
                var p = _buffer_pos
-               var bufsp = _buffer.length - p
+               var bufsp = _buffer_length - p
                if bufsp >= i then
                        _buffer_pos += i
-                       return _buffer.substring(p, i).to_s
+                       buf.append_ns_from(_buffer, i, p)
+                       return i
                end
-               _buffer_pos = _buffer.length
-               var readln = _buffer.length - p
-               var s = _buffer.substring(p, readln).to_s
-               fill_buffer
-               return s + read(i - readln)
+               _buffer_pos = _buffer_length
+               var readln = _buffer_length - p
+               buf.append_ns_from(_buffer, readln, p)
+               var rd = read_intern(i - readln, buf)
+               return rd + readln
        end
 
-       redef fun read_all
+       redef fun read_all_bytes
        do
-               if last_error != null then return ""
-               var s = new FlatBuffer
+               if last_error != null then return new Bytes.empty
+               var s = new Bytes.with_capacity(10)
                while not eof do
                        var j = _buffer_pos
-                       var k = _buffer.length
+                       var k = _buffer_length
                        while j < k do
                                s.add(_buffer[j])
                                j += 1
@@ -436,7 +503,7 @@ abstract class BufferedReader
                        _buffer_pos = j
                        fill_buffer
                end
-               return s.to_s
+               return s
        end
 
        redef fun append_line_to(s)
@@ -444,11 +511,13 @@ abstract class BufferedReader
                loop
                        # First phase: look for a '\n'
                        var i = _buffer_pos
-                       while i < _buffer.length and _buffer[i] != '\n' do i += 1
+                       while i < _buffer_length and _buffer[i] != 0xAu8 do
+                               i += 1
+                       end
 
                        var eol
-                       if i < _buffer.length then
-                               assert _buffer[i] == '\n'
+                       if i < _buffer_length then
+                               assert _buffer[i] == 0xAu8
                                i += 1
                                eol = true
                        else
@@ -463,7 +532,7 @@ abstract class BufferedReader
                                # Copy from the buffer to the string
                                var j = _buffer_pos
                                while j < i do
-                                       s.add(_buffer[j])
+                                       s.bytes.add(_buffer[j])
                                        j += 1
                                end
                                _buffer_pos = i
@@ -485,29 +554,37 @@ abstract class BufferedReader
 
        redef fun eof
        do
-               if _buffer_pos < _buffer.length then return false
+               if _buffer_pos < _buffer_length then return false
                if end_reached then return true
                fill_buffer
-               return _buffer_pos >= _buffer.length and end_reached
+               return _buffer_pos >= _buffer_length and end_reached
        end
 
        # The buffer
-       private var buffer: nullable FlatBuffer = null
+       private var buffer: NativeString = new NativeString(0)
 
        # The current position in the buffer
-       private var buffer_pos: Int = 0
+       private var buffer_pos = 0
+
+       # Length of the current buffer (i.e. nuber of bytes in the buffer)
+       private var buffer_length = 0
+
+       # Capacity of the buffer
+       private var buffer_capacity = 0
 
        # Fill the buffer
        protected fun fill_buffer is abstract
 
-       # Is the last fill_buffer reach the end
+       # Has the last fill_buffer reached the end
        protected fun end_reached: Bool is abstract
 
        # Allocate a `_buffer` for a given `capacity`.
        protected fun prepare_buffer(capacity: Int)
        do
-               _buffer = new FlatBuffer.with_capacity(capacity)
+               _buffer = new NativeString(capacity)
                _buffer_pos = 0 # need to read
+               _buffer_length = 0
+               _buffer_capacity = capacity
        end
 end
 
@@ -524,8 +601,13 @@ class StringWriter
        super Writer
 
        private var content = new Array[String]
-       redef fun to_s do return content.to_s
+       redef fun to_s do return content.plain_to_s
        redef fun is_writable do return not closed
+
+       redef fun write_bytes(b) do
+               content.add(b.to_s)
+       end
+
        redef fun write(str)
        do
                assert not closed
@@ -547,13 +629,13 @@ class StringReader
        # The string to read from.
        var source: String
 
-       # The current position in the string.
+       # The current position in the string (bytewise).
        private var cursor: Int = 0
 
        redef fun read_char do
                if cursor < source.length then
+                       # Fix when supporting UTF-8
                        var c = source[cursor]
-
                        cursor += 1
                        return c
                else
@@ -563,10 +645,9 @@ class StringReader
 
        redef fun read_byte do
                if cursor < source.length then
-                       var c = source[cursor]
-
+                       var c = source.bytes[cursor]
                        cursor += 1
-                       return c.ascii
+                       return c
                else
                        return null
                end
@@ -576,11 +657,11 @@ class StringReader
                source = ""
        end
 
-       redef fun read_all do
-               var c = cursor
-               cursor = source.length
-               if c == 0 then return source
-               return source.substring_from(c)
+       redef fun read_all_bytes do
+               var nslen = source.length - cursor
+               var nns = new NativeString(nslen)
+               source.copy_to_native(nns, nslen, cursor, 0)
+               return new Bytes(nns, nslen, nslen)
        end
 
        redef fun eof do return cursor >= source.length