From 61565ad09fe68330c4c2a816a665e4b748adfb12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Legat?= <benoit.legat@gmail.com>
Date: Mon, 29 Jun 2020 09:57:47 +0200
Subject: [PATCH] Implement length for lazy iterators

---
 src/Utilities/lazy_iterators.jl  | 1 +
 test/Utilities/lazy_iterators.jl | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/src/Utilities/lazy_iterators.jl b/src/Utilities/lazy_iterators.jl
index a7b44938a9..8e40030585 100644
--- a/src/Utilities/lazy_iterators.jl
+++ b/src/Utilities/lazy_iterators.jl
@@ -22,6 +22,7 @@ function LazyMap{T}(f::Function, data) where {T}
     return LazyMap{T, typeof(data)}(f, data)
 end
 Base.size(it::LazyMap) = size(it.data)
+Base.length(it::LazyMap) = length(it.data)
 function Base.iterate(it::LazyMap, args...)
     elem_state = iterate(it.data, args...)
     if elem_state === nothing
diff --git a/test/Utilities/lazy_iterators.jl b/test/Utilities/lazy_iterators.jl
index 9da31338b6..0b3db20412 100644
--- a/test/Utilities/lazy_iterators.jl
+++ b/test/Utilities/lazy_iterators.jl
@@ -6,6 +6,7 @@ const MOIU = MOI.Utilities
 @testset "EmptyVector{$T}" for T in [Int, Float64]
     v = MOIU.EmptyVector{T}()
     @test size(v) == (0,)
+    @test length(v) == 0
     @test isempty(v)
     @test eltype(v) == T
     @test iterate(v) === nothing
@@ -17,6 +18,7 @@ end
 @testset "LazyMap{$T}" for T in [Int, Float64]
     v = MOIU.LazyMap{T}(x -> x^2, [2, 3])
     @test size(v) == (2,)
+    @test length(v) == 2
     @test !isempty(v)
     @test eltype(v) == T
     c = collect(v)