abakus, by Michael Pyne <michael.pyne@kdemail.net>
Version: 0.91

This is my attempt at creating a light-calculator based on Roberto Alsina's
initial usability suggestions, and based on the ideas of a few other KDE
hackers.

This software is distributed under the terms of the GNU GPL v2.

Synopsis:
 $ tar xvjf abakus-0.91.tar.bz2
 $ cd abakus-0.91
 $ ./configure && make && make install
 $ abakus

Type away, and press Enter to see the result.

Changes since 0.90:
* Add ability to remove all functions and variables to the context menus of
  their respective list boxes.
* Convert out-of-range numbers to NaN.
* Accept "," as a decimal separator for the benefit of European users.
* Use correct decimal separator (per KLocale settings) in output.
* For long results, show the beginning instead of the end of the result,
  since the beginning is the most significant part of the result.

Changes since 0.85:
* You now have the option of using the GNU Multiple Precision library for
  high-precision mathematics.  It requires the MPFR library to also be
  installed (normally comes with GNU MP 4.x).  It is used automatically if
  detected.
* Jes Hall has contributed DocBook documentation to make Abakus integrate into
  KDE even more tightly.  Thanks, Jes!
* User defined functions can now be defined over.
* Error handling with deriv() function improved.
* Ariya Hidayat's name was misspelled everywhere in Abakus.  Sorry, Ariya. :(
* Speaking of Ariya, Abakus now uses the impressive user interface code from
  his SpeedCrunch calculator (http://speedcrunch.berlios.de/).  This includes
  the Calc-as-you-Type tooltip, the function and variable dropdown, and
  syntax highlighting.  It's not configurable at this point, expect that in
  the next release.
* You can use the F6 key to select the expression editor if you're a big fan
  of the keyboard.
* Raising negative numbers to integral powers should work with the internal
  high-precision library now.
* You can no longer deselect the current precision menu item.
* Fix crash bug when a user-defined function refers to another user-defined
  function, and then you remove or edit the function it referred to.
* Add exact numerical derivatives for all functions supported.
* Added the asinh, acosh, and atanh functions.
* Fixed bug with loading of prior compact mode status.
* Fixed bug where result text had wrong precision when you changed the
  precision and tried drag-and-drop.
* Drag-and-drop improvements.
* Fixed bug where Custom Precision menu entry was checked even if you canceled
  the dialog.
* Made hyperbolic functions consistently ignore trigonometric mode.  (Both
  Degrees and Radians make no sense for hyperbolic trig).
* Whew! :)

v0.85 adds a lot:
* Improvements to the configure script.  Since I didn't end up using libCLN it
  was mostly for naught, but the changes will be useful for the future.
* abakus now uses the high-precision math routines from Ariya Hidayat's
  SpeedCrunch program.  Thanks, Ariya!
* High precision arithmetic can have between 0 and 75 digits of precision.
* Support for approximate derivatives.  For most functions the derivatives will
  be numerically accurate.  For those functions where I didn't feel like typing
  in the exact form of the derivative an approximation is used instead.
* Implicit multiplication has been added to the parser.  That means you can
  type stuff like "3 sin pi" without having to manually add the * in between
  3 and sin.  This also works with numbers and variables, and numbers and
  parenthesized expressions.
* GUI changes.  The main result view now uses KListView, so it gains tooltip
  support for long answers for free, along with a bevy of other improvements.
* You can right-click on an answer and copy it to the clipboard.
* Corrected information in the about box.
* Restarting abakus with compact mode enabled should is much improved.

v0.80.2 fixed an issue with the configure script for people who don't have
exactly the same version of Python I do, and forcibly prevents flex/bison
errors.

v0.80.1 fixed an issue with the configure script for people who don't already
have scons installed.

Major changes since 0.76:
* There is no more C code to interface between the parser and program.
* RPN mode is improved.  Now the stack is retained between calls, and there
  are a few commands only in RPN mode:
    1. pop   - Return the top of the stack.
    2. clear - Clear the stack.
* bksys is used instead of the custom Makefiles.
* Lots of code cleanups, including license headers.
* The nifty drag-and-drop image looks more rectangular, and is used with the
  two listviews on the right as well.
* Improved error checking, with messages that should hopefully be more
  descriptive.

Major changes since 0.75:
* Reorder internal macro so that functions are declared *before* they're
  referenced, which helps build the program on systems with math.h files that
  don't export the long double version of their math functions.
* Hitting a number or letter key right after evaluating an expression in RPN
  mode automatically prepends the 'ans' variable, which was a feature of the
  Normal mode.

Major changes since 0.70:
* Build system switched (somehow) to using qmake.  The parser and lexer are
  still included, so bison and flex are still not required.  Hopefully this
  will improve the ease of building.  Of course, this means no more colored
  make output.
* Changed most of the keyboard shortcuts to use Shift + Alt + foo instead of
  Alt + foo since that was interfering with the menu bar.
* RPN mode!!  If you enable RPN mode, then your expressions will be evaluated
  using the Reverse Polish Notation popular with users of HP calculators.  Note
  that although you can use values and functions while in RPN mode, you cannot
  set or remove them from the expression editor like you can in normal mode.
* abakus will display a small token starting with a dollar sign ($) in italics
  next to results.  You can use these tokens to quickly reference a result in
  your expression.  The most recent result is always $0, with the number
  increasing from most recent to least recent result.  For example, typing
  2 <Enter> 3 <Enter> $0 ^ $1 <Enter> would give a result of 9.
* You can right click on functions and values in the list views to remove them
  from the GUI.
* Changed the result items to use word wrapping when needed to fit all the
  text.
* Very small DCOP interface.
* More code cleanup.
* Added a .desktop file.
* Test client removed again.
* Double-clicking on an error message (or OK message) no longer inserts them
  into the edit box.

Major changes since 0.61:
* User defined Functions.
* Save state of program between runs.
* Miscellaneous fun stuff.

Currently implemented features:
* Parser built using flex and bison.  The generated files are included so it
  should compile fine for you.
* Fully C++.  The parser and lexer code require C++ to compile.
* Supports several built-in functions:
   - sin, cos, tan, sinh, cosh, tanh, asin, acos, atan in either radian or
         degree mode.
     abs, exp (e raised to the given power), ln, log (base 10),
     sqrt, ceil, floor
* Supported operators: +, -, *, /, ^ (or **).
* Includes a window showing the values and user-defined functions you have.
* Predefined constants: pi, and e (Euler' constant).
* You can assign to variables by using an expression of the form:
  identifier = expression.  You can then reuse these variables later.
* You can create user-defined functions of one variable using the syntax
  set foo(var) = <expr>, where <expr> calculates the value in terms of var.
* You can delete user-defined variables by doing: remove var
* You can delete user-defined functions by doing: remove foo().  Notice that
  the variable is NOT included in that expression.
* Functions and variables are saved on exit, and then loaded when abakus is
  started again.
* The ans variable contains the result of the last computation.
* Pressing +, -, *, or / immediately after your last computation automatically
  inserts ans for you, saving you typing.
* A compact mode for the program.
* Operator precedence should be correct, including the right association of
  the power operator.  So, 2 ^ 3 ^ 2 == 512, just as it does when you write
  it out.  You can use parentheses to force precedence.
* Parentheses are not required around functions.  So, sin 3 is a valid
  expression.  Note that sin 3 + cos 4 translates internally as (sin 3) + 
  (cos 4), not as sin (3 + cos (4)).
* I took some pains to try to make things like 3 + -2 work right.
* inf and nan are accepted as numeric input for completeness.
* abakus will automatically add ) characters to the end of the expression as
  needed to balance your expression.  This means that expressions like
  sin (cos (2 + 3 will evaluate with no error.
* A rudimentary RPN mode is included.  Most everything works, except for
  derivatives and creating functions or new variables.

Bugs:
* More functions would be nice.
* The lexer assumes that the decimal marker is a period. (.)  I'm not exactly
  sure how to cleanly solve this problem with flex. :-(
* Documentation could be better.