OpenEuphoria: Euphoria v4.1

# OpenEuphoria Manual

## Euphoria v4.1

routine or constant name search

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## 9.42 Version 2.1 Alpha January 15, 1999

- We've made a number of changes to the packaging, pricing, and registration incentives for the Euphoria product:
  - The Dual-Platform (DOS32+WIN32) package, formerly $53 has been reduced to $39 U.S., effective immediately.
  - The Single-Platform (DOS32-only) package, formerly $32, has been discontinued.
  - The printed manual has been discontinued. Instead, there is now an official HTML version of the manual, included with the Public Domain .zip file.
  - All useful 3rd-party include files, such as Win32Lib.ew and many others, will be "stamped" by RDS with a code number that makes them free, just like the files in euphoria\include. They will not add to your statement count, provided you do not significantly modify them. This will also allow 3rd-party developers to get better diagnostic information from their users.
  - Binding, shrouding and profiling will now be part of the Complete Edition only. These are features that beginners do not require, but serious users might find valuable.
- Short-form assignment operators `+=`, `-=`, `*=`, `/=`, and `&=` have been added. For example, instead of saying:

    count = count + 1

You can now say:

    count += 1

Instead of saying:

    matrix[row][column] = matrix[row][column] * 5.0

You can say:

    matrix[row][column] *= 5.0
      </euuode>
      Instead of saying:
      <eucode>
      test_scores[start..finish] = test_scores[start..finish] / 100

You can say:

    test_scores[start..finish] /= 100

- Euphoria now uses "short-circuit" evaluation of `and` and `or` expressions in if/elsif/while conditions. e.g. in an `and` condition:

    if A and B then ...

the interpreter will skip the evaluation of expression B whenever expression A is 0 (false), since it knows that the overall result must be false. In an `or` condition:

    while A or B do ...

the interpreter will skip the evaluation of expression B whenever expression A is non-zero (true), since it knows that the overall result must be true.
Euphoria code written prior to version 2.1 may no longer work correctly if expression B contains a function with side-effects such as setting a global variable, doing I/O etc. In practice this kind of code is very rare, but just in case, a warning will now be issued if a function with side-effects might be short-circuited.
By skipping the evaluation of B, short-circuit evaluation is typically faster, and will allow you to write statements such as:

    if atom(x) or length(x)=1 then ...

that would generate an error on older versions of Euphoria whenever x was an atom, since length() is not defined for atoms.

- Several new routines were added.
  - Built-in to ex.exe/exw.exe:
    - profile() - turns profiling on/off so you can focus your profile and profile_time runs on particular events within your program."
    - system_exec() - gives you the exit code from calling a .exe or .com file, or another Euphoria program.
    - equal() - compares any 2 Euphoria objects for equality. equivalent to: compare(a,b) = 0 but more readable.
  - Added to various include files:
    - walk_dir() - recursively goes through a directory and subdirectories, calling a routine that you supply.
    - reverse() - returns a sequence in reverse order.
    - sprint() - returns the string representation of any Euphoria object.
    - arcsin() - inverse trig function.
    - arccos() - inverse trig function.
    - get_bytes() - returns the next n bytes from a file.
    - prompt_number() - prompts the user to enter a number.
    - prompt_string() - prompts the user to enter a string.
    - instance() - WIN32: returns the instance handle of the program.
    - PI - the constant PI - 3.14159... was added to misc.e.
- The main Euphoria documentation can now be viewed locally with a Web browser. The plain-text files refman.doc and library.doc are still available in the doc subdirectory, but we now have refman.htm and library.htm in the new html subdirectory. We have developed a tool (written in Euphoria) that lets us easily maintain both an up-to-date HTML version, and an up-to-date plain-text version of refman and library.
- The documentation has also been clarified and expanded in many places.
- WIN32: you can create an unlimited number of Euphoria call-back routines, as long as each routine is a function with 0 to 8 parameters. In version 2.0 you could only have one call-back routine and it had to have exactly 4 parameters.
- The `xor` keyword has been added to complement: and/or/not and xor_bits() e.g.

    if a xor b then...

`xor` works on sequences too. It's similar to `or`.

- The dir(path) library routine now officially supports the use of wildcards * and ? in the path that you supply. This feature was always available, but wasn't documented until now. e.g.

    info = dir("mydata\\*.d?t")

- optimization: Subroutine call+return overhead was reduced by an average of 30%. The speed-up occurs for all normal function/procedure/type calls, user-defined type-checks, call_proc()/call_func() calls using a routine id, and Windows call-backs. Only recursive calls cost the same as before. Programs with a reasonably-high frequency of calls can easily be 10% faster overall because of this.
- optimization: Branch `straightening` has been implemented. The compiler will optimize branches in the internal code such that a branch from A->B where location B contains a branch to location C, will be optimized to a direct branch from A->C. Even something like A->B->C->D can be straightened to A->D. This often occurs in while-loops that contain if-statements.
- optimization: In many cases, variable initialization checks are now replaced by "no-ops" after the first check is performed. Euphoria was already optimizing out many checks at compile-time.
- optimization: get() and value() are now much faster in most cases thanks to Jiri Babor and some further optimizations by RDS. The new v2.1 ex.exe with the new v2.1 get.e is:
  quote:

  1.45x faster reading a sequence of f.p. numbers from a file and<br> 2.25x faster when reading a sequence of integers from a file.

- optimization: power(x,2) is converted internally to x*x which is faster in all cases, especially when x is a large integer or a f.p. number.
- optimization: Thanks to Jiri Babor, int_to_bits() is at least 15% faster in most cases.
- optimization: Plotting a long sequence of pixels in 16-color graphics modes is about 3% faster.
- optimization: draw_line() has been sped up by a few percent.
- Language War has had a major face-lift. It now runs in pixel-graphics mode 18 (640 x 480 x 16 colors) instead of text mode. It also has `fine-grain` parallelism, i.e. virtually anything can happen in parallel with anything else. Multiple torpedos, phasors etc can be drawn on the screen simultaneously, while ships are moving, commands are being entered, things are exploding etc. Even the timing needed for the PC speaker sound effects is handled by the task scheduler. There are no time-delay "busy" loops executed during the game. The galaxy scan now shows you a scaled picture of the whole galaxy, rather than just a bunch of numbers.
- The default print format for atoms was changed from "%g" to "%.10g". This format is used by print(), ?, the trace facility, and ex.err dumps. This allows large integers -9,999,999,999 to +9,999,999,999 to be printed as integers, rather than as scientific notation. It also provides about 10 digits of accuracy to be displayed on fractional numbers, rather than just 6. Art Adamson and others made it clear that more digits should be displayed.
- The state of all with/without settings is saved upon entering an included file, and restored at the end of the included file. An included file can change the settings, but they will be restored at the end of the included file. e.g. warnings might be turned off just within the included file (and any files it includes). As a result some programs now display warnings where none were seen before.
- Warnings are now displayed <_ba>after</_ba> your program finishes execution, so they won't be erased by clear_screen(), graphics_mode() etc. Some programs now show warnings where none were seen before.
- The security of scrambled code and bound code has been improved thanks to ideas contributed by Rusty Davis. When a bound program starts executing, a quick integrity check will be made to detect any corruption or tampering. It's still ok to add data to the end of a bound .exe file, as long as your last line is `abort(x)`.
- The ed editor now lets you view and edit beyond column 80.
- ed has a new command: Esc m (modifications). It will show the differences between the original file on disk and the current edit buffer. This can be very useful when you've forgotten what changes you've made, and you are wondering if it's safe to save them.
- The trace window now provides an upper case Q command which lets the program run to completion, ignoring any trace(1) commands. Lower case q lets it run to the next trace(1).
- safe.e (debug version of machine.e) has been enhanced. It will now automatically catch additional cases where data is illegally written just before, or just after, the boundaries of an allocated block of memory. This can be particularly useful in WIN32 where Windows might overwrite one of your under-sized blocks. Without a tool such as safe.e, this type of bug could take hours or even days to track down.
- The euphoria\tutorial directory was created to hold several small tutorial programs.
- The limit on the number of open files was raised to 25 from 15. Three of these files are 0,1,2: standard-input, standard-output and standard-error, so you can now have up to 22 of your own files open simultaneously. (As far as we know, no one ever exceeded the old limit, but it seemed wise to raise it.)
- When the user simply types `ex` or `exw` and is prompted for the name of the Euphoria .ex or .exw file to run, command_line() will now be updated to include the filename as the second command-line argument, just as if the user had originally typed: `ex filename`. Thanks to Mathew Hounsell for suggesting this.
- mset.ex now saves pictures in .bmp format. Previously it was using a non-standard, compressed format.
- lines.ex (lines.bat) now reports non-blank/non-comment lines as well. This is <_ba>not</_ba> the same as the "statement count" used by Euphoria for the diagnostic limit, but it's usually within +/- 10%, assuming you write one statement per line.
- Numeric literals greater than 1e308 (roughly) are now set to +/- `inf`. They used to cause a compile-time error.

| Up |  |  | TOC | Index
<< 8 API Reference | < 9.41 Version 2.1 Beta March 5, 1999 | Up: 9 Release Notes | 9.43 Version 2.0 March 25, 1998 > | 10 Index >>