Commit 30fdbb8

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+MAP

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+24

-3

lines changed

+24

-3

lines changed

Lines changed: 9 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -119,10 +119,16 @@`
`119`	`119`	`)`
`120`	`120`	`REVERSE = Y(`
`121`	`121`	`lambda f: lambda xs: EMPTY(xs)`
`122`		`- (lambda _: xs)`
	`122`	`+ (lambda _: LIST)`
`123`	`123`	`(lambda _: APPEND(f(TAIL(xs)))(HEAD(xs)))`
`124`	`124`	`(TRUE)`
`125`	`125`	`)`
	`126`	`+MAP = Y(`
	`127`	`+ lambda f: lambda a: lambda xs: EMPTY(xs)`
	`128`	`+ (lambda _: LIST)`
	`129`	`+ (lambda _: PREPEND(f(a)(TAIL(xs)))(a(HEAD(xs))))`
	`130`	`+ (TRUE)`
	`131`	`+)`
`126`	`132`
`127`	`133`
`128`	`134`	`# helpers`
`@@ -134,11 +140,12 @@ def decode_number(f) -> int:`
`134`	`140`
`135`	`141`	`def decode_list(encoded) -> list:`
`136`	`142`	`decoded = []`
`137`		`- while1:`
	`143`	`+ for_inrange(100):`
`138`	`144`	`if EMPTY(encoded) is TRUE:`
`139`	`145`	`return decoded`
`140`	`146`	`decoded.append(HEAD(encoded))`
`141`	`147`	`encoded = TAIL(encoded)`
	`148`	`+ raise RuntimeError('probably infinite list')`
`142`	`149`
`143`	`150`
`144`	`151`	`# improve repr`

Lines changed: 15 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@`
`9`	`9`	`from lambdas import CONS, CAR, CDR`
`10`	`10`	`from lambdas import SIGN, UNSIGN, NEG, ISPOS, ISNEG, SADD, SSUB, SMUL`
`11`	`11`	`from lambdas import FAC, FIB`
`12`		`-from lambdas import LIST, APPEND, PREPEND, REVERSE`
	`12`	`+from lambdas import LIST, APPEND, PREPEND, REVERSE, MAP`
`13`	`13`	`from lambdas import decode_number, decode_list`
`14`	`14`
`15`	`15`
`@@ -306,5 +306,19 @@ def test_reverse(given):`
`306`	`306`	`assert decode_list(REVERSE(lst)) == given`
`307`	`307`
`308`	`308`
	`309`	`+@pytest.mark.parametrize('given, expected', [`
	`310`	`+ ([], []),`
	`311`	`+ ([ONE], [3]),`
	`312`	`+ ([ONE, TWO, THREE], [3, 4, 5]),`
	`313`	`+])`
	`314`	`+def test_map(given, expected):`
	`315`	`+ lst = LIST`
	`316`	`+ for el in reversed(given):`
	`317`	`+ lst = PREPEND(lst)(el)`
	`318`	`+ result = MAP(ADD(TWO))(lst)`
	`319`	`+ decoded = [decode_number(n) for n in decode_list(result)]`
	`320`	`+ assert decoded == expected`
	`321`	`+`
	`322`	`+`
`309`	`323`	`if __name__ == '__main__':`
`310`	`324`	`pytest.main()`

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