From df79cc64a8f7bcb485a366f967c5db51ec340484 Mon Sep 17 00:00:00 2001
From: Alexander Plavin <alexander@plav.in>
Date: Thu, 9 Nov 2023 15:54:49 -0500
Subject: [PATCH] also findall

---
 src/findall.jl | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/src/findall.jl b/src/findall.jl
index 6683e75..d89f4fe 100644
--- a/src/findall.jl
+++ b/src/findall.jl
@@ -34,8 +34,50 @@ julia> findall(in(Interval{:open,:closed}(1,6)), y) # (1,6], does not include 1
 5:14
 ```
 """
-Base.findall(interval_d::Base.Fix2{typeof(in), <:Interval}, x::AbstractRange) =
-    searchsorted_interval(x, interval_d.x; rev=step(x) < zero(step(x)))
+if VERSION < v"1.11-"
+    function Base.findall(interval_d::Base.Fix2{typeof(in),Interval{L,R,T}}, x::AbstractRange)  where {L,R,T}
+        isempty(x) && return 1:0
+    
+        interval = interval_d.x
+        il, ir = firstindex(x), lastindex(x)
+        δx = step(x)
+        a,b = if δx < zero(δx)
+            rev = findall(in(interval), reverse(x))
+            isempty(rev) && return rev
+    
+            a = (il+ir)-last(rev)
+            b = (il+ir)-first(rev)
+    
+            a,b
+        else
+            lx, rx = first(x), last(x)
+            l = max(leftendpoint(interval), lx - oneunit(δx))
+            r = min(rightendpoint(interval), rx + oneunit(δx))
+    
+            (l > rx || r < lx) && return 1:0
+    
+            a = il + max(0, round(Int, cld(l-lx, δx)))
+            a += (a ≤ ir && (x[a] == l && L == :open || x[a] < l))
+    
+            b = min(ir, round(Int, cld(r-lx, δx)) + il)
+            b -= (b ≥ il && (x[b] == r && R == :open || x[b] > r))
+    
+            a,b
+        end
+        # Reversing a range could change sign of values close to zero (cf
+        # sign of the smallest element in x and reverse(x), where x =
+        # range(BigFloat(-0.5),stop=BigFloat(1.0),length=10)), or more
+        # generally push elements in or out of the interval (as can cld),
+        # so we need to check once again.
+        a += +(a < ir && x[a] ∉ interval) - (il < a && x[a-1] ∈ interval)
+        b += -(il < b && x[b] ∉ interval) + (b < ir && x[b+1] ∈ interval)
+    
+        a:b
+    end
+else
+    Base.findall(interval_d::Base.Fix2{typeof(in), <:Interval}, x::AbstractRange) =
+        searchsorted_interval(x, interval_d.x; rev=step(x) < zero(step(x)))
+end
 
 # We overload Base._findin to avoid an ambiguity that arises with
 # Base.findall(interval_d::Base.Fix2{typeof(in),Interval{L,R,T}}, x::AbstractArray)