-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | a minimal, extensible and precise calculator
--   
--   Hascal is a minimal calculator with infix-operations supporting
--   addition, subtraction, division, multiplication, exponentiation and
--   logarithming. Brackets are not supported yet. Futhermore, it's easy to
--   add custom operators.
@package hascal
@version 1.1


-- | <tt>Hascal</tt> is both a simple but extendable calculator library for
--   Haskell and a command-line program using it.
--   
--   Also, its source code is a nice example for a minimalistic Haskell
--   project.
module Hascal

-- | <a>operators</a> is the default list of operators.
--   
--   An operator consists of one character and a function with of type
--   <tt>CReal -&gt; CReal -&gt; CReal</tt>.
--   
--   <a>operators</a> includes:
--   
--   <ul>
--   <li>addition, represented by <tt>'+'</tt></li>
--   <li>subtraction, represented by <tt>'-'</tt></li>
--   <li>multiplication, represented by <tt>'c'</tt></li>
--   <li>division, represented by <tt>'/'</tt></li>
--   <li>exponentiation, represented by <tt>'^'</tt></li>
--   <li>logarithming (with flipped arguments, see below), represented by
--   <tt>'?'</tt></li>
--   </ul>
--   
--   such that these laws are held:
--   
--   <pre>
--   (a - b == c) == (a == b + c)
--   (a / b == c) == (a == b * c)
--   (a ? b == c) == (a == b ^ c)
--   </pre>
operators :: [(Char, CReal -> CReal -> CReal)]

-- | <a>eval</a> gets a list of operators and a string containing a
--   mathematical expression/term which only uses those operators listed in
--   the first argument, and returns the result of that term.
eval :: [(Char, CReal -> CReal -> CReal)] -> String -> CReal

-- | <a>hascal</a> is the default evaluator:
--   
--   <pre>
--   hascal = eval operators
--   </pre>
hascal :: String -> CReal