From ea5639724fa4d861ef9d7f170d6ec88f9025044f Mon Sep 17 00:00:00 2001
From: Sheehan Olver <solver@mac.com>
Date: Tue, 3 Oct 2023 16:11:10 +0100
Subject: [PATCH] Make BandedMatrix immutable (#403)

* Make BandedMatrix immutable

* Don't export isbanded

* Add brandn

* Update BandedMatrices.jl

* Update index.md
---
 Project.toml               |  2 +-
 docs/src/index.md          | 10 +++++++++-
 src/BandedMatrices.jl      |  2 +-
 src/banded/BandedMatrix.jl | 11 +++++++++--
 test/test_subarray.jl      |  2 +-
 test/test_symbanded.jl     |  2 +-
 test/test_tribanded.jl     |  2 +-
 7 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/Project.toml b/Project.toml
index 7787cc6b..b21737d6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "BandedMatrices"
 uuid = "aae01518-5342-5314-be14-df237901396f"
-version = "0.17.38"
+version = "1.0.0"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
diff --git a/docs/src/index.md b/docs/src/index.md
index 2c778e3d..5ba7b5aa 100644
--- a/docs/src/index.md
+++ b/docs/src/index.md
@@ -11,6 +11,10 @@ BandedMatrix
 brand
 ```
 
+```@docs
+brandn
+```
+
 ```@meta
 DocTestSetup = quote
     using BandedMatrices
@@ -98,6 +102,10 @@ band
 BandRange
 ```
 
+```@docs
+BandedMatrices.isbanded
+```
+
 To loop over the nonzero elements of a BandedMatrix, you can use `colrange(A, c)` and `rowrange(A, r)`.
 
 
@@ -116,7 +124,7 @@ interface consists of the following:
 | Required methods | Brief description |
 | :--------------- | :--------------- |
 | `bandwidths(A)` | Returns a tuple containing the sub-diagonal and super-diagonal bandwidth |
-| `isbanded(A)`    | Override to return `true` |
+| `BandedMatrices.isbanded(A)`    | Override to return `true` |
 
 | Optional methods | Brief description |
 | :--------------- | :--------------- |
diff --git a/src/BandedMatrices.jl b/src/BandedMatrices.jl
index 7e6268ee..914b97de 100644
--- a/src/BandedMatrices.jl
+++ b/src/BandedMatrices.jl
@@ -48,6 +48,7 @@ const TransposeFact = isdefined(LinearAlgebra, :TransposeFactorization) ?
 export BandedMatrix,
        bandrange,
        brand,
+       brandn,
        bandwidth,
        BandError,
        band,
@@ -56,7 +57,6 @@ export BandedMatrix,
        bandwidths,
        colrange,
        rowrange,
-       isbanded,
        Zeros,
        Fill,
        Ones,
diff --git a/src/banded/BandedMatrix.jl b/src/banded/BandedMatrix.jl
index 3b1fcb9a..aed5eca3 100644
--- a/src/banded/BandedMatrix.jl
+++ b/src/banded/BandedMatrix.jl
@@ -13,7 +13,7 @@
 
 function _BandedMatrix end
 
-mutable struct BandedMatrix{T, CONTAINER, RAXIS} <: AbstractBandedMatrix{T}
+struct BandedMatrix{T, CONTAINER, RAXIS} <: AbstractBandedMatrix{T}
     data::CONTAINER  # l+u+1 x n (# of columns)
     raxis::RAXIS # axis for rows (col axis comes from data)
     l::Int # lower bandwidth ≥0
@@ -163,7 +163,7 @@ promote_rule(::Type{BandedMatrix{T1, C1}}, ::Type{BandedMatrix{T2, C2}}) where {
     BandedMatrix{promote_type(T1,T2), promote_type(C1, C2)}
 
 
-for (op,bop) in ((:(rand),:brand),)
+for (op,bop) in ((:rand,:brand), (:randn,:brandn))
     @eval begin
         $bop(::Type{T},n::Integer,m::Integer,a::Integer,b::Integer) where {T} =
             _BandedMatrix($op(T,max(0,b+a+1),m),n,a,b)
@@ -193,6 +193,13 @@ Creates an `n×m` banded matrix  with random numbers in the bandwidth of type `T
 """
 brand
 
+"""
+    brandn(T,n,m,l,u)
+
+Creates an `n×m` banded matrix  with random normals in the bandwidth of type `T` with bandwidths `(l,u)`
+"""
+brand
+
 ## Conversions from AbstractArrays, we include FillArrays in case `zeros` is ever faster
 BandedMatrix{T}(A::AbstractMatrix, bnds::NTuple{2,Integer}) where T =
     BandedMatrix{T, Matrix{T}}(A, bnds)
diff --git a/test/test_subarray.jl b/test/test_subarray.jl
index 99fc8dab..854b28c9 100644
--- a/test/test_subarray.jl
+++ b/test/test_subarray.jl
@@ -1,6 +1,6 @@
 using BandedMatrices, FillArrays, ArrayLayouts, Test
 import LinearAlgebra: axpy!
-import BandedMatrices: BandedColumns, bandeddata, MemoryLayout, BandedSubBandedMatrix, _BandedMatrix, sub_materialize
+import BandedMatrices: BandedColumns, bandeddata, MemoryLayout, BandedSubBandedMatrix, _BandedMatrix, sub_materialize, isbanded
 
 
 @testset "BandedMatrix SubArray" begin
diff --git a/test/test_symbanded.jl b/test/test_symbanded.jl
index 6c13b2bd..8174f884 100644
--- a/test/test_symbanded.jl
+++ b/test/test_symbanded.jl
@@ -1,6 +1,6 @@
 using ArrayLayouts
 using BandedMatrices
-import BandedMatrices: MemoryLayout, SymmetricLayout, HermitianLayout, BandedColumns
+import BandedMatrices: MemoryLayout, SymmetricLayout, HermitianLayout, BandedColumns, isbanded
 using FillArrays
 using GenericLinearAlgebra
 using LinearAlgebra
diff --git a/test/test_tribanded.jl b/test/test_tribanded.jl
index 357e04c4..13802ad6 100644
--- a/test/test_tribanded.jl
+++ b/test/test_tribanded.jl
@@ -1,5 +1,5 @@
 using BandedMatrices, LinearAlgebra, ArrayLayouts, Test
-import BandedMatrices: BandedColumns, BandedRows
+import BandedMatrices: BandedColumns, BandedRows, isbanded
 
 
 @testset "Triangular" begin