atari-fixed.clj

(def sqr-8bit-contract
  (contract atari-constraints
    "Defines the constraints for Atari 2600 squaring"
    [n] [(< n 16) integer? pos? => (< % 256)]))

(def sqr-8bit
  (with-constraints
    constrained-sqr 
    sqr-8bit-contract))


(sqr-8bit 15)
;=> 225

(sqr-8bit -5)
; java.lang.AssertionError: 
;   Assert failed: (pos? n)

(sqr-8bit 15.9687194)
; java.lang.AssertionError: 
;   Assert failed: (integer? n)

(sqr-8bit 16)
; java.lang.AssertionError: 
;   Assert failed: (< n 16)

atari.clj

(def sqr-8bit-contract
  (contract atari-constraints
    "Defines the constraints for Atari 2600 squaring"
    [_] [number? => (< % 256)]))

(def sqr-8bit
  (with-constraints
    constrained-sqr 
    sqr-8bit-contract))

(sqr-8bit 5)
;=> 25

(sqr-8bit 0)
; java.lang.AssertionError: 
;   Assert failed: (not= 0 num)

cnstrfn.clj

(defconstrainedfn sqr
  "Squares a number"
  [n] [(number? n) (not= 0 n) ;; requires/domain
       => 
       (pos? %) (number? %)]  ;; ensures/range
  (* n n))

dblr-cnstrfn.clj

(defconstrainedfn doubler
  "Defines a function that doubles its input."
  ([n] [(number? n) => (= (* 2 n) %)]
     (* 2 n))

  ([x y] [(every? number? [x y])
          =>
          (number? %)
          (= (* 2 (+ x y)) %)]
     (* 2 (+ x y))))

defcontract.clj

(defcontract sqr-contract
  "Defines the constraints for squaring"
  [n] [number? (not= 0 n) => pos? number?])

provide-contracts.clj

(provide-contracts 
  [sqr "Constraints for squaring" 
    [x] [number? (not= 0 x) => number? pos?]])

(sqr 0)
; java.lang.AssertionError: 
;   Assert failed: (not= 0 n)

provide-existing.clj

(defcontract sqr-contract
  "Defines the constraints on squaring."
  [n] [number? (not= 0 n) => pos? number?])

(sqr 0)
;=> 0

(provide-contracts
  [sqr "Apply the contract for squaring" 
       sqr-contract])

(sqr 0)
; java.lang.AssertionError: 
;   Assert failed: (not= 0 n)

sqr-cnstr-contract.clj

(def sqr-contract
  (contract sqr-constraints
    "Defines the constraints for squaring"
    [n] [number? (not= 0 n) => pos? number?]))

sqr-simple.clj

(defconstrainedfn sqr
  "Squares a number"
  [n] [number? (not= 0 n) => pos? number?]
  (* n n))

trammel-new-syn.clj

(use '[fogus.me.trammel 
         :only [provide-contracts]])

(defn sqr [n] (* n n))

(sqr 10)
;=> 100
(sqr 0)
;=> 0

(provide-contracts 
  [sqr "Constraints for squaring" 
    [x] [number? (not= 0 x) => number? pos?]])

(sqr 10)
;=> 100
(sqr 0)
; java.lang.AssertionError: 
;   Assert failed: (not= 0 x)