make recode! type stable

src/recode.jl

@@ -57,13 +57,11 @@ function recode!(dest::AbstractArray{T}, src::AbstractArray, default::Any, pairs
         throw(DimensionMismatch("dest and src must be of the same length (got $(length(dest)) and $(length(src)))"))
     end
 
-    opt_pairs = map(optimize_pair, pairs)
-
     @inbounds for i in eachindex(dest, src)
         x = src[i]
 
-        for j in 1:length(opt_pairs)
-            p = opt_pairs[j]
+        for j in 1:length(pairs)
+            p = optimize_pair(pairs[j])
             # we use isequal and recode_in because we cannot really distinguish scalars from collections
             if x ≅ p.first || recode_in(x, p.first)
                 dest[i] = p.second
@@ -101,9 +99,7 @@ function recode!(dest::CategoricalArray{T}, src::AbstractArray, default::Any, pa
         throw(DimensionMismatch("dest and src must be of the same length (got $(length(dest)) and $(length(src)))"))
     end
 
-    opt_pairs = map(optimize_pair, pairs)
-
-    vals = T[p.second for p in opt_pairs]
+    vals = T[p.second for p in pairs]
     default !== nothing && push!(vals, default)
 
     levels!(dest.pool, filter!(!ismissing, unique(vals)))
@@ -117,8 +113,8 @@ function recode!(dest::CategoricalArray{T}, src::AbstractArray, default::Any, pa
     @inbounds for i in eachindex(drefs, src)
         x = src[i]
 
-        for j in 1:length(opt_pairs)
-            p = opt_pairs[j]
+        for j in 1:length(pairs)
+            p = optimize_pair(pairs[j])
             # we use isequal and recode_in because we cannot really distinguish scalars from collections
             if x ≅ p.first || recode_in(x, p.first)
                 drefs[i] = dupvals ? pairmap[j] : j