Merge pull request #17 from ryukinix/valid-operators

Add valid operators to webapp and add aliases

Author: ryukinix

src/operators.lisp

@@ -7,7 +7,7 @@
 (eval-when (:compile-toplevel)
  (defconstant F nil))
 
-(defparameter *valid-operators* '(~ ^ <=> => v [+]))
+(defparameter *valid-operators* '(~ ^ <=> => -> <-> v [+]))
 
 ;; operators
 (defun ~ (p)
@@ -23,13 +23,21 @@
  (or p q))
 
 (defun => (p q)
- "Implication binary operator"
+ "Conditional binary operator"
  (v (~ p) q))
 
 (defun <=> (p q)
  "Biconditional binary operator"
  (^ (=> p q) (=> q p)))
 
+(defun -> (p q)
+ "Notation alias for conditional"
+ (=> p q))
+
+(defun <-> (p q)
+ "Notation alias for biconditional"
+ (<=> p q))
+
 (defun [+] (p q)
  "XOR operator or exclusive disjunction operator"
  (^ (~ (^ p q))

src/package.lisp

@@ -47,5 +47,6 @@
  #:truth
  #:truth-infix
  #:*output-stream*
+ #:*valid-operators*
  #:main)
  (:nicknames "INFERENCE"))

web/webapp.lisp

@@ -78,7 +78,15 @@
  :placeholder (trim-paren (prop table)))
  (:input :type "submit"
  :value "Eval"))
- (:pre (truth table))))
+ (:pre (truth table))
+ (:pre (format nil "Operators: ~a" inference:*valid-operators*))
+ (:p "Some notes: "
+ (:ul
+ (loop for note in '("My lexer doesn't works very well for parenthesis."
+ "Please, don't be evil. Use less than 10 variables."
+ "Yes, [+] it's a XOR. Mathematically: p ⊕ q."
+ "(=> ->) and (<=> <->) are aliases.")
+ do (:li (render note)))))))
 
 (defmethod render ((string string))
  (with-html