WeberLogic

Logic interpreter https://github.com/cameronbwhite/WeberLogic

Latest on Hackage:0.1.2

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

BSD3 licensed by Cameron Brandon White

WeberLogic

Logic interpreter and parsing library

Install

cabal update
cabal install WeberLogic

Interpreter

$ ./WeberLogic
Enter Command
> truthTable: a&b+c->~a&b
'a'   'b'   'c'   | (((a&b)+c)->(~a&b))
True  True  True  | False
True  True  False | False
True  False True  | False
True  False False | True 
False True  True  | True 
False True  False | True 
False False True  | False
False False False | True 

Enter Command
> toNand: a&b->c 
(((((a|b)|(a|b))|((a|b)|(a|b)))|(((a|b)|(a|b))|((a|b)|(a|b))))|(c|c))

Enter Command
> toNor: a&b->c
(((((a/a)/(b/b))/((a/a)/(b/b)))/c)/((((a/a)/(b/b))/((a/a)/(b/b)))/c))

Library

The library contains two modules.

  1. WeberLogic.Parser
  2. WeberLogic.Actions

WeberLogic.Parser

The WeberLogic.Parser provides functions which read stings and return an abstract syntax tree (AST). The AST in implement with a data type called LogicExp and Letter.

  • Data Types
    • LogicExp - A recursively defined data type which implements as abstract syntax tree. It provides the following type constructors which function as nodes in the AST: Not, And, Or, Implies, Iff, Nand, and Nor. The Predicate type constructor functions as the AST leaves.

    > import WeberLogic.Parser
    > Predicate 'A' [(Variable 'x', Name 'a')]
    > Not (Predicate 'A' [(Variable 'x', Name 'a')])
    > And (Predicate 'A' [(Variable 'x', Name 'a')]) (Predicate 'B' [])
    • Letter - This Data Constructor provies two Type constructors Variable and Name. They are used in the construction of Predicate which requires a list of type Letter

    > import WeberLogic.Parser
    > Predicate 'A' [(Variable 'x', Name 'a')]
  • Functions
    • parseExp

    > import WeberLogic.Parser
    > a = parseExp "Axa"
    > b = parseExp "~Axa"
    > c = parseExp "Axa&B"
    • parseArg

    > import WeberLogic.Parser
    > a = parseExp "|- Axa"
    > b = parseExp "~Axa, B |- Cax"
    > c = parseExp "Axa&B, B, C |- Ax->By"

WeberLogic.Actions

The WeberLogic.Actions modules provides functions which manipulate the LogicExp AST.

> import WeberLogic.Parser
> import WeberLogic.Actions

> mapM_ putStrLn $ truthTableStr $ readExp "A&B"
'a'   'b'   | (a&~b)
True  True  | False
True  False | True 
False True  | False
False False | False

> toNand $ readExp "A&~B" 
((a|(b|b))|(a|(b|b)))

> toNor $ readExp "A&~B" 
((a/a)/((b/b)/(b/b)))
Depends on:
Used by 1 package:
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