fj.data

Class IO<A>

java.lang.Object

fj.data.IO<A>

Type Parameters:

A - the type of the result produced by the wrapped iteratee

public abstract class IO<A>
extends java.lang.Object

IO monad for processing files, with main methods #enumFileLines(File, Option, IterV), #enumFileChars(File, Option, IterV) and #enumFileCharChunks(File, Option, IterV) (the latter one is the fastest as char chunks read from the file are directly passed to the iteratee without indirection in between).

Field Summary

Fields

Modifier and Type	Field and Description
static F<java.io.Reader,IO<Unit>>	closeReader

Constructor Summary

Constructors

Constructor and Description
IO()

Method Summary

Methods

Modifier and Type	Method and Description
<B> IO<B>	bind(F<A,IO<B>> f)
static <A,B,C> IO<C>	bracket(IO<A> init, F<A,IO<B>> fin, F<A,IO<C>> body)
static IO<java.io.BufferedReader>	bufferedReader(java.io.File f, Option<java.nio.charset.Charset> encoding)
static <A> F<java.io.Reader,F<Iteratee.IterV<char[],A>,IO<Iteratee.IterV<char[],A>>>>	charChunkReader() A function that feeds an iteratee with character chunks read from a Reader (char[] of size DEFAULT_BUFFER_SIZE).
static <A> F<java.io.Reader,F<Iteratee.IterV<java.lang.Character,A>,IO<Iteratee.IterV<java.lang.Character,A>>>>	charChunkReader2() A function that feeds an iteratee with characters read from a Reader (chars are read in chunks of size DEFAULT_BUFFER_SIZE).
static IO<Unit>	closeReader(java.io.Reader r)
static <A> IO<Iteratee.IterV<char[],A>>	enumFileCharChunks(java.io.File f, Option<java.nio.charset.Charset> encoding, Iteratee.IterV<char[],A> i) An IO monad that reads char chunks from the given file and passes them to the given iteratee.
static <A> IO<Iteratee.IterV<java.lang.Character,A>>	enumFileChars(java.io.File f, Option<java.nio.charset.Charset> encoding, Iteratee.IterV<java.lang.Character,A> i) An IO monad that reads char chunks from the given file and passes single chars to the given iteratee.
static <A> IO<Iteratee.IterV<java.lang.String,A>>	enumFileLines(java.io.File f, Option<java.nio.charset.Charset> encoding, Iteratee.IterV<java.lang.String,A> i) An IO monad that reads lines from the given file (using a BufferedReader) and passes lines to the provided iteratee.
static IO<java.io.Reader>	fileReader(java.io.File f, Option<java.nio.charset.Charset> encoding)
static <A> F<java.io.BufferedReader,F<Iteratee.IterV<java.lang.String,A>,IO<Iteratee.IterV<java.lang.String,A>>>>	lineReader() A function that feeds an iteratee with lines read from a BufferedReader.
<B> IO<B>	map(F<A,B> f)
abstract A	run()
static <A> IO<A>	unit(A a)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

closeReader

public static final F<java.io.Reader,IO<Unit>> closeReader

Constructor Detail

IO

public IO()

Method Detail

closeReader

public static IO<Unit> closeReader(java.io.Reader r)

enumFileLines

public static <A> IO<Iteratee.IterV<java.lang.String,A>> enumFileLines(java.io.File f,
                                                       Option<java.nio.charset.Charset> encoding,
                                                       Iteratee.IterV<java.lang.String,A> i)

An IO monad that reads lines from the given file (using a BufferedReader) and passes lines to the provided iteratee. May not be suitable for files with very long lines, consider to use #enumFileCharChunks(File, IterV) or #enumFileChars(File, IterV) as an alternative.

Parameters:

f - the file to read, must not be null

encoding - the encoding to use, Option.none() means platform default

i - the iteratee that is fed with lines read from the file

enumFileCharChunks

public static <A> IO<Iteratee.IterV<char[],A>> enumFileCharChunks(java.io.File f,
                                                  Option<java.nio.charset.Charset> encoding,
                                                  Iteratee.IterV<char[],A> i)

An IO monad that reads char chunks from the given file and passes them to the given iteratee.

Parameters:

f - the file to read, must not be null

encoding - the encoding to use, Option.none() means platform default

i - the iteratee that is fed with char chunks read from the file

enumFileChars

public static <A> IO<Iteratee.IterV<java.lang.Character,A>> enumFileChars(java.io.File f,
                                                          Option<java.nio.charset.Charset> encoding,
                                                          Iteratee.IterV<java.lang.Character,A> i)

An IO monad that reads char chunks from the given file and passes single chars to the given iteratee.

Parameters:

f - the file to read, must not be null

encoding - the encoding to use, Option.none() means platform default

i - the iteratee that is fed with chars read from the file

bufferedReader

public static IO<java.io.BufferedReader> bufferedReader(java.io.File f,
                                        Option<java.nio.charset.Charset> encoding)

fileReader

public static IO<java.io.Reader> fileReader(java.io.File f,
                            Option<java.nio.charset.Charset> encoding)

bracket

public static final <A,B,C> IO<C> bracket(IO<A> init,
                    F<A,IO<B>> fin,
                    F<A,IO<C>> body)

unit

public static final <A> IO<A> unit(A a)

lineReader

public static <A> F<java.io.BufferedReader,F<Iteratee.IterV<java.lang.String,A>,IO<Iteratee.IterV<java.lang.String,A>>>> lineReader()

A function that feeds an iteratee with lines read from a BufferedReader.

charChunkReader

public static <A> F<java.io.Reader,F<Iteratee.IterV<char[],A>,IO<Iteratee.IterV<char[],A>>>> charChunkReader()

A function that feeds an iteratee with character chunks read from a Reader (char[] of size DEFAULT_BUFFER_SIZE).

charChunkReader2

public static <A> F<java.io.Reader,F<Iteratee.IterV<java.lang.Character,A>,IO<Iteratee.IterV<java.lang.Character,A>>>> charChunkReader2()

A function that feeds an iteratee with characters read from a Reader (chars are read in chunks of size DEFAULT_BUFFER_SIZE).

run

public abstract A run()
               throws java.io.IOException

Throws:

java.io.IOException

map

public final <B> IO<B> map(F<A,B> f)

bind

public final <B> IO<B> bind(F<A,IO<B>> f)