lsnbr

K = \ x _ . x F = \ _ x . x B = \ f g x . f (g x) if = \ b y n . b y n not = \ b . b F K le0 = \ n . n K (B not le0) (B not le0) ge0 = \ n . n K le0 le0 lt0 = B not ge0 gt0 = B not le0 pow' = \ b e . e 11 (\ _ . 22) (\ _ . pow' b e) # EvalError also for e>=0 #pow = \ b e . lt0 e () (pow' b e) # No Exception for e<0 even # Infinite loop for e<0 odd due to some strictness evaluating (pow' b e) #pow = \ b e . lt0 e (\ _ . ()) (pow' b e) # Gets rid of infinite loop for e<0 odd #pow = \ b e . lt0 e (\ _ . ()) (\ x . pow' b e x) # EvalError for e>=0 pow = \ b e . lt0 e (\ _ . ()) (\ _ . pow' b e) () zero = \ n . n K (\ _ . F) (\ _ . F) eq = \ m n . m ( n K (\ _ . F) (\ _ . F) ) ( \ a . n F (\ b . eq a b) (\ _ . F) ) ( \ a . n F (\ _ . F) (\ b . eq a b) ) # This works # qwertz = \ n . zero n (123) () # This as well # qwertz' = \ n . 123 # qwertz = \ n . zero n (qwertz' n) () # But this does not qwertz' = \ n . n 123 (\ _ . 123) (\ _ . 123) qwertz = \ n . zero n (qwertz' n) () # But this does again # qwertz' = \ n . n 123 (\ _ . 123) (\ _ . 123) # qwertz = \ n . eq 0 n (qwertz' n) ()

import { assert, LC, getSolution } from "./lc-test.js";
const { Zero,Bit0,Bit1 } = LC.compile(String.raw`
Zero =       \ zero _bit0 _bit1 . zero
Bit0 = \ n . \ _zero bit0 _bit1 . bit0 n
Bit1 = \ n . \ _zero _bit0 bit1 . bit1 n
`);
const fromInt = n => n ? n&1 ? Bit1(fromInt(-(n>>1))) : Bit0(fromInt(-(n>>1))) : Zero ;
const padded = m => m (false) ( n => n (true) ( () => padded(n) ) (padded) ) (padded) ;
const unsafeToInt = m => m (LC.Primitive(0)) ( n => - 2 * unsafeToInt(n) ) ( n => 1 - 2 * unsafeToInt(n) ) ;
const toInt = n => {
  if ( LC.configure().enforceBinaryScottInvariant && padded(n) )
    throw new TypeError(`toInt: padded number ${ unsafeToInt(n) }`);
  else
    return unsafeToInt(n);
} ;
LC.configure({ purity: "LetRec", numEncoding: { fromInt, toInt }, enforceBinaryScottInvariant: true, verbosity: "Concise" });

const solution = LC.compile(getSolution());
const { lt0, le0, ge0, gt0, pow } = solution;

const { if: iff } = solution;
const toBoolean = p => iff (p) (true) (false) ;

const { qwertz } = solution;




  
describe("fixed tests", function() {

  it("eq, uneq 0", function() {
    for ( let n=-10; n<=10; n++ )
      assert.strictEqual( toBoolean(lt0(n)),     n<0,  `lt0 ${ n }` ),
      assert.strictEqual( toBoolean(le0(n)),     n<=0, `le0 ${ n }` ),
      assert.strictEqual( toBoolean(ge0(n)),     n>=0, `ge0 ${ n }` ),
      assert.strictEqual( toBoolean(gt0(n)),     n>0,  `gt0 ${ n }` );
  });

  it("pow with e=0", function() {
    for ( let b=-5; b<=5; b++ ) {
      console.log(`b=${b}, e=0`);
      assert.numEql( pow(b)(0), 11, `pow ${b} 0` );
    }
  });
  
  it("pow with e>0 even", function() {
    for ( let e=2; e<=6; e=e+2 ) {
      console.log(`b=7, e=${e}`);
      assert.numEql( pow(7)(e), 22, `pow 7 ${e}` );
    }
  });
  
  // should go into infinite loop
//   it("pow with e>0 odd", function() {
//     assert.numEql( pow(7)(1), NaN, `pow 7 -1` );
//   });
  
  it("pow with e<0 even", function() {
    assert.throws( () => pow(7)(-2), null, null, `pow ${ 7 } ${ -2 }` );
  });
  
  it("pow with e<0 odd", function() {
    assert.throws( () => pow(7)(-1), null, null, `pow ${ 7 } ${ -1 }` );
  });
  
  it("test qwertz", function() {
    assert.numEql( qwertz(0), 123, `qwertz 0` );
  });

});

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