16bd7ea455
This PR deprecates `List.iota`, which we make no essential use of. `iota n` can be replaced with `(range' 1 n).reverse`. The verification lemmas for `range'` already have better coverage than those for `iota`. Any downstream projects using it (I am not aware of any) are encouraged to adopt it.
117 lines
1.3 KiB
Text
117 lines
1.3 KiB
Text
import Lean.Data.PersistentArray
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def check (x : IO Nat) (expected : IO Nat) : IO Unit := do
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unless (← x) == (← expected) do
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throw $ IO.userError "unexpected result"
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def f1 (xs : Lean.PArray Nat) (top : Nat) : IO Nat := do
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let mut sum := 0
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for x in xs do
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if x % 2 == 0 then
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IO.println s!"x: {x}"
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sum := sum + x
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if sum > top then
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return sum
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IO.println s!"sum: {sum}"
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return sum
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/--
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info: x: 2
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x: 4
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x: 10
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---
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info: 16
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-/
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#guard_msgs in
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#eval f1 [1, 2, 3, 4, 5, 10, 20].toPArray' 10
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/--
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info: x: 2
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x: 4
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x: 10
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-/
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#guard_msgs in
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#eval check (f1 [1, 2, 3, 4, 5, 10, 20].toPArray' 10) (pure 16)
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def f2 (xs : Lean.PArray Nat) (top : Nat) : IO Nat := do
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let mut sum := 0
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for x in xs do
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if x % 2 == 0 then
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IO.println s!"x: {x}"
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sum := sum + x
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if sum > top then
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break
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IO.println s!"sum: {sum}"
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return sum
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/--
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info: x: 0
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x: 2
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x: 4
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x: 6
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x: 8
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x: 10
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x: 12
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x: 14
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x: 16
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x: 18
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x: 20
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x: 22
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x: 24
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x: 26
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x: 28
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x: 30
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x: 32
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x: 34
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x: 36
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x: 38
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x: 40
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x: 42
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x: 44
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x: 46
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x: 48
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x: 50
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x: 52
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x: 54
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x: 56
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x: 58
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x: 60
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x: 62
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x: 64
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x: 0
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x: 2
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x: 4
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x: 6
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x: 8
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x: 10
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x: 12
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x: 14
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x: 16
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x: 18
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x: 20
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x: 22
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x: 24
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x: 26
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x: 28
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x: 30
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x: 32
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x: 34
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x: 36
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x: 38
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x: 40
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x: 42
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x: 44
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x: 46
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x: 48
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x: 50
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x: 52
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x: 54
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x: 56
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x: 58
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x: 60
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x: 62
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x: 64
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sum: 1056
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-/
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#guard_msgs in
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#eval check (f1 (List.range 100).toPArray' 1000) (f2 (List.range 100).toPArray' 1000)
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