Prelude (Idris Java RTS 0.9.14 API)

java.lang.Object
- org.idris.rts.Prelude

```
public class Prelude
extends Object
```
Backend primitives needed for Prelude

Author:

Jan Bessai

Constructor Summary

Constructors
Constructor and Description

Prelude()

Constructors
Constructor and Description
`Prelude()`

Method Summary

Methods
Modifier and Type	Method and Description
`static Object`	`do_popen(String command, String mode)` Fork a process and return a file handle for reading or writing from/to its standard output/input.
`static void`	`exit(int exitCode)` Exit the the current program.
`static void`	`fflush(Object file)` Flush a file to disk.
`static int`	`fgetc(Object file)` Read one char from a file and return it or -1 on end of file or errors.
`static void`	`fileClose(Object file)` Close a file handle
`static int`	`fileEOF(Object file)` Test if a file has reached its end during `idris_readStr` operations.
`static int`	`fileError(Object file)` Tests for a file error.
`static SeekableByteChannel`	`fileOpen(String name, String privs)` Open a file.
`static int`	`fpoll(Object file)` Wait for one second or until input becomes available for the given file.
`static void`	`fputStr(Object file, String string)` Write a string to a file handle.
`static void`	`free(Object buf)` Release a memory buffer.
`static int`	`getchar()` Receive a char from `System.in`
`static String`	`getenv(String x)` Query the system environment for a value.
`static String`	`getEnvPair(int n)` Get the n-th "key=value" property from the environment.
`static int`	`idris_checkMessages(Object dest)` Check if a message has arrived.
`static int`	`idris_eqPtr(Object reference1, Object reference2)` Compare two references for equality.
`static void`	`idris_forceGC(Object thread)` Force garbage collection to be triggered.
`static String`	`idris_getArg(int num)` Get the num-th commandline argument.
`static void`	`idris_initArgs(String[] args)` Initialize the command line arguments.
`static void`	`idris_memmove(Object dstBuf, Object srcBuf, int dstOffset, int srcOffset, int size)` Copy data in buffers.
`static void`	`idris_memset(Object buf, int offset, Object c, int size)` Initialize a memory location.
`static int`	`idris_numArgs()` Get the number of command line arguments.
`static byte`	`idris_peek(Object buf, int offset)` Read a byte from a buffer.
`static void`	`idris_poke(Object buf, int offset, Object data)` Write a byte to a buffer.
`static String`	`idris_readStr(Object file)` Read a line from a file.
`static Object`	`idris_recvMessage(Object dest)` Receive a message.
`static void`	`idris_sendMessage(Object from, Object dest, Object message)` Pass a message to another thread.
`static int`	`idris_time()` Get the time in seconds since 1970-01-01 00:00:00 UTC.
`static int`	`isNull(Object o)` Check if an object is `null`
`static int`	`isNullString(String s)` Check if a string is `null`
`static Object`	`malloc(int size)` Allocate raw memory.
`static int`	`pclose(Object file)` Wait for a forked process and close its file handle.
`static void`	`putchar(int c)` Output a character to `System.out`
`static void`	`putStr(String str)` Output a string to `System.out`
`static int`	`setenv(String key, String value, int overwrite)` Set a system environment value.
`static int`	`unsetenv(String key)` Unset a system environment value.
`static void`	`usleep(int microsecs)` Sleep for some time.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Prelude
```
public Prelude()
```
- Method Detail
  - idris_initArgs
```
public static void idris_initArgs(String[] args)
```
    Initialize the command line arguments.
    
    Parameters:
    args - arguments to initialize
  - idris_numArgs
```
public static int idris_numArgs()
```
    Get the number of command line arguments.
    
    Returns:
    number of arguments
  - idris_getArg
```
public static String idris_getArg(int num)
```
    Get the num-th commandline argument.
    
    Parameters:
    num - argument position
    
    Returns:
    argument previously initialized by idris_initArgs
  - getenv
```
public static String getenv(String x)
```
    Query the system environment for a value. Maps to java properties.
    
    Parameters:
    x - query key
    
    Returns:
    value stored in the system environment for the given key
  - setenv
```
public static int setenv(String key,
         String value,
         int overwrite)
```
    Set a system environment value. Maps to java properties.
    
    Parameters:
    key - property name to set
    value - property value to set
    overwrite - a value other than zero indicates, that existing values should be overwritten
    
    Returns:
    1 if the operation was successful 0 otherwise.
  - getEnvPair
```
public static String getEnvPair(int n)
```
    Get the n-th "key=value" property from the environment.
    
    Parameters:
    n -
    
    Returns:
    the property in "key=value" form or null if it does not exist
  - unsetenv
```
public static int unsetenv(String key)
```
    Unset a system environment value. Maps to java properties.
    
    Parameters:
    key - the value to clear
    
    Returns:
    1 if the value could be removed, 0 otherwise
  - exit
```
public static void exit(int exitCode)
```
    Exit the the current program.
    
    Parameters:
    exitCode - program result
  - usleep
```
public static void usleep(int microsecs)
```
    Sleep for some time.
    
    Parameters:
    microsecs - number of microseconds to sleep
  - idris_time
```
public static int idris_time()
```
    Get the time in seconds since 1970-01-01 00:00:00 UTC.
    
    Returns:
    the current time
  - idris_sendMessage
```
public static void idris_sendMessage(Object from,
                     Object dest,
                     Object message)
                              throws InterruptedException
```
    Pass a message to another thread. Block until message queue access is possible.
    
    Parameters:
    from - source thread
    dest - target thread
    message - object containing the message
    
    Throws:
    
    InterruptedException - if waiting for the message queue failed
  - idris_checkMessages
```
public static int idris_checkMessages(Object dest)
                               throws InterruptedException
```
    Check if a message has arrived. Block until message queue access is possible.
    
    Parameters:
    dest - thread to check messages for
    
    Returns:
    number of messages which arrived
    
    Throws:
    
    InterruptedException - if waiting for the message queue failed
  - idris_recvMessage
```
public static Object idris_recvMessage(Object dest)
                                throws InterruptedException
```
    Receive a message. Block until a message has arrived.
    
    Parameters:
    dest - thread to receive messages for
    
    Returns:
    the received message
    
    Throws:
    
    InterruptedException - if waiting for the message failed
  - putStr
```
public static void putStr(String str)
```
    Output a string to System.out
    
    Parameters:
    str - message to write to stdout
  - putchar
```
public static void putchar(int c)
```
    Output a character to System.out
    
    Parameters:
    c - char to write to stdout
  - getchar
```
public static int getchar()
```
    Receive a char from System.in
    
    Returns:
    the character read from stdin or -1 if non was available
  - fileOpen
```
public static SeekableByteChannel fileOpen(String name,
                           String privs)
```
    Open a file.
    
    Parameters:
    name - filename
    privs - privileges as described in man fopen(3)
    
    Returns:
    handle to the newly opened file or null if an error occurred
  - do_popen
```
public static Object do_popen(String command,
              String mode)
```
    Fork a process and return a file handle for reading or writing from/to its standard output/input.
    
    Parameters:
    command - command to run
    mode - "r" for reading, "w" for writing
    
    Returns:
    the file handle to read/write or null if an error occurred
  - pclose
```
public static int pclose(Object file)
```
    Wait for a forked process and close its file handle.
    
    Parameters:
    file - the file handle to wait for
    
    Returns:
    the exit code of the terminated process or -1 to indicate an error
  - fileClose
```
public static void fileClose(Object file)
```
    Close a file handle
    
    Parameters:
    file - handle to close
  - fpoll
```
public static int fpoll(Object file)
```
    Wait for one second or until input becomes available for the given file.
    
    Parameters:
    file - the file to wait for
    
    Returns:
    -1 on error, 0 if no input became available, 1 if input is available
  - fputStr
```
public static void fputStr(Object file,
           String string)
```
    Write a string to a file handle.
    
    Parameters:
    file - handle to write to. Has to be a PrintStream or a SeekableByteChannel.
    string - output
  - fgetc
```
public static int fgetc(Object file)
```
    Read one char from a file and return it or -1 on end of file or errors.
    
    Parameters:
    file - the file to read from
    
    Returns:
    -1 on errors or the character read
  - idris_readStr
```
public static String idris_readStr(Object file)
```
    Read a line from a file. Chooses the line.seperator System property as delimiter.
    
    Parameters:
    file - handle to read from
    
    Returns:
    next line from the handle
  - fileEOF
```
public static int fileEOF(Object file)
```
    Test if a file has reached its end during idris_readStr operations.
    
    Parameters:
    file - handle to test
    
    Returns:
    1 if the file has ended, 0 otherwise
  - fileError
```
public static int fileError(Object file)
```
    Tests for a file error.
    
    Parameters:
    file - the handle to check
    
    Returns:
    0 if no error is found, 1 if there is an error
  - fflush
```
public static void fflush(Object file)
```
    Flush a file to disk.
    
    Parameters:
    file - handle to write to
  - isNull
```
public static int isNull(Object o)
```
    Check if an object is null
    
    Parameters:
    o - object to check
    
    Returns:
    1 if the object is null 0 otherwise
  - isNullString
```
public static int isNullString(String s)
```
    Check if a string is null
    
    Parameters:
    s - string to check
    
    Returns:
    1 if the string is null 0 otherwise
  - malloc
```
public static Object malloc(int size)
```
    Allocate raw memory.
    
    Parameters:
    size - number of bytes to allocate
    
    Returns:
    a ByteBuffer capable of storing the requested amount of bytes
  - idris_memset
```
public static void idris_memset(Object buf,
                int offset,
                Object c,
                int size)
```
    Initialize a memory location.
    
    Parameters:
    buf - ByteBuffer to initialize
    offset - bytes to skip at the beginning of the buffer
    c - byte value to use for initialization
    size - number of bytes to initialize
  - free
```
public static void free(Object buf)
```
    Release a memory buffer.
    
    Parameters:
    buf - buffer to release
  - idris_peek
```
public static byte idris_peek(Object buf,
              int offset)
```
    Read a byte from a buffer.
    
    Parameters:
    buf - ByteBuffer to read from
    offset - address to read
    
    Returns:
    the byte read
  - idris_poke
```
public static void idris_poke(Object buf,
              int offset,
              Object data)
```
    Write a byte to a buffer.
    
    Parameters:
    buf - ByteBuffer to write to
    offset - address to write at
    data - byte to write out
  - idris_memmove
```
public static void idris_memmove(Object dstBuf,
                 Object srcBuf,
                 int dstOffset,
                 int srcOffset,
                 int size)
```
    Copy data in buffers.
    
    Parameters:
    dstBuf - ByteBuffer to copy data to
    srcBuf - ByteBuffer to copy data from
    dstOffset - bytes to skip from the destination start
    srcOffset - bytes to skip from the source start
    size - number of bytes to move
  - idris_forceGC
```
public static void idris_forceGC(Object thread)
```
    Force garbage collection to be triggered.
    
    Parameters:
    thread - the thread to be forced (currently ignored, since System.gc() is thread agnostic.
  - idris_eqPtr
```
public static int idris_eqPtr(Object reference1,
              Object reference2)
```
    Compare two references for equality.
    
    Parameters:
    reference1 - the first reference to compare
    reference2 - the second reference to compare
    
    Returns:
    1 if the two references are equal, 0 otherwise.

Class Prelude

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Prelude

Method Detail

idris_initArgs

idris_numArgs

idris_getArg

getenv

setenv

getEnvPair

unsetenv

exit

usleep

idris_time

idris_sendMessage

idris_checkMessages

idris_recvMessage

putStr

putchar

getchar

fileOpen

do_popen

pclose

fileClose

fpoll

fputStr

fgetc

idris_readStr

fileEOF

fileError

fflush

isNull

isNullString

malloc

idris_memset

free

idris_peek

idris_poke

idris_memmove

idris_forceGC

idris_eqPtr