684f32fabe
The pattern
```
for h : i in [:xs.size] do
let x := xs[i]'h.2
```
is occassionally useful to iterate over an array with the index in
hand. This PR extends the `get_elem_tactic_trivial` so that one can
simply write
```
for h : i in [:xs.size] do
let x := xs[i]
```
fixes #3032.
44 lines
835 B
Text
44 lines
835 B
Text
def f1 (a : Array Nat) (i : Nat) :=
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a[i]
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def f2 (a : Array Nat) (i : Fin a.size) :=
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a[i] -- Ok
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def f3 (a : Array Nat) (h : n ≤ a.size) (i : Fin n) :=
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a[i] -- Ok
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opaque a : Array Nat
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opaque n : Nat
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axiom n_lt_a_size : n < a.size
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def f4 (i : Nat) (h : i < n) :=
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have : i < a.size := Nat.lt_trans h n_lt_a_size
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a[i]
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def f5 (i : Nat) (h : i < n) :=
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a[i]'(Nat.lt_trans h n_lt_a_size)
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def f6 (i : Nat) :=
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a[i]!
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def f7 (i : Nat) :=
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a[i]?
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#print f2
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#print f3
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#print f5
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#print f6
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#print f7
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def withRange (xs : Array Nat) : Option Nat := Id.run do
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for h : i in [:xs.size] do
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if i == xs[i] then
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return i
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return none
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def withTwoRanges (xs : Array Nat) : Option Nat := Id.run do
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for h1 : i in [:xs.size] do
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for h2 : j in [i + 1:xs.size] do
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if xs[i] == xs[j] then
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return i
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return none
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