From fd91c6a9ef5f308e9483c5cbdef483e9c742c449 Mon Sep 17 00:00:00 2001
From: Azzaare <jf@baffier.fr>
Date: Wed, 17 Mar 2021 22:38:52 +0900
Subject: [PATCH] Extended fold to both mutable and immutable vector folds. Add
 CI

---
 src/PatternFolds.jl     |  4 ++--
 src/common.jl           | 26 ++++++++++++++++++++++++++
 src/immutable_vector.jl | 22 +---------------------
 src/vector.jl           |  2 ++
 test/vector.jl          | 12 ++++++++++++
 5 files changed, 43 insertions(+), 23 deletions(-)

diff --git a/src/PatternFolds.jl b/src/PatternFolds.jl
index 97d3dc0..eb0f613 100644
--- a/src/PatternFolds.jl
+++ b/src/PatternFolds.jl
@@ -7,9 +7,9 @@ using Lazy
 export PatternFold
 export IVectorFold, VectorFold
 export Interval, IntervalsFold
-export pattern, gap, folds, fold, check_pattern
+export pattern, gap, folds, check_pattern
 export length
-export unfold
+export fold, unfold
 export value
 
 # includes
diff --git a/src/common.jl b/src/common.jl
index 68e2d99..e78d3fc 100644
--- a/src/common.jl
+++ b/src/common.jl
@@ -60,3 +60,29 @@ end
 Reset the *unfolded* pattern to the first fold.
 """
 reset_pattern!(mvf) = set_fold!(mvf, 1)
+
+"""
+    fold(v::V, depth = 0)
+returns a suitable `VectorFold`, which when unfolded gives the Vector V.
+"""
+function fold(v::V, depth = 0; kind = :mutable) where {T <: Real, V <: AbstractVector{T}}
+    l = length(v)
+    for i in 1:(l ÷ 2)
+        gap = v[i + 1] - v[1]
+        fold, r = divrem(l, i)
+        if  r == 0 && check_pattern(v, i, gap, fold)
+            # return VectorFold(fold(v[1:i], depth + 1), gap, fold)
+            return make_vector_fold(v[1:i], gap, fold, kind)
+        end
+    end
+    if depth == 0
+        @warn "No non-degenerate patterns have been found" v
+        return make_vector_fold(v, zero(T), 1, kind)
+    else
+        return v
+    end
+end
+
+function make_vector_fold(pattern, gap, fold, kind = :mutable)
+    return make_vector_fold(pattern, gap, fold, Val(kind))
+end
diff --git a/src/immutable_vector.jl b/src/immutable_vector.jl
index f9c3a14..c96ce49 100644
--- a/src/immutable_vector.jl
+++ b/src/immutable_vector.jl
@@ -84,24 +84,4 @@ function check_pattern(v, i, gap, fold)
     return true
 end
 
-"""
-    fold(v::V, depth = 0)
-returns a suitable `VectorFold`, which when unfolded gives the Vector V.
-"""
-function fold(v::V, depth = 0) where {T <: Real, V <: AbstractVector{T}}
-    l = length(v)
-    for i in 1:(l ÷ 2)
-        gap = v[i + 1] - v[1]
-        fold, r = divrem(l, i)
-        if  r == 0 && check_pattern(v, i, gap, fold)
-            # return VectorFold(fold(v[1:i], depth + 1), gap, fold)
-            return VectorFold(v[1:i], gap, fold)
-        end
-    end
-    if depth == 0
-        @warn "No non-degenerate patterns have been found" v
-        return VectorFold(v, zero(T), 1)
-    else
-        return v
-    end
-end
\ No newline at end of file
+make_vector_fold(pattern, gap, fold, ::Val{:immutable}) = IVectorFold(pattern, gap, fold)
diff --git a/src/vector.jl b/src/vector.jl
index 10d593f..9dd563d 100644
--- a/src/vector.jl
+++ b/src/vector.jl
@@ -93,3 +93,5 @@ function unfold(mvf::VectorFold; from=1, to=folds(mvf))
     end
     return v
 end
+
+make_vector_fold(pattern, gap, fold, ::Val{:mutable}) = VectorFold(pattern, gap, fold)
diff --git a/test/vector.jl b/test/vector.jl
index 994f4b5..6a3991a 100644
--- a/test/vector.jl
+++ b/test/vector.jl
@@ -31,4 +31,16 @@
     end
     @test isempty(IVectorFold(Vector(),1,1))
     @test isempty(VectorFold(Vector(),1,1))
+
+    v1 = VectorFold([42,3,45,6],13,4)
+    w1 = unfold(v1)
+    v11 = fold(w1)
+
+    @test unfold(v11) == w1
+
+    v2 = VectorFold([34,34,43,43],10,3)
+    w2 = unfold(v2)
+    v22 = fold(w2)
+
+    @test unfold(v22) == w2
 end