make map on tuples accept different lengths (#49336)

fix #49299, fix #42216
JuliaLang · May 4, 2023 · bb31772 · bb31772
1 parent daea3c3
commit bb31772
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Showing 2 changed files with 17 additions and 6 deletions.
diff --git a/base/tuple.jl b/base/tuple.jl
@@ -313,14 +313,16 @@ function map(f, t::Any32)
 end
 # 2 argument function
 map(f, t::Tuple{},        s::Tuple{})        = ()
+map(f, t::Tuple,          s::Tuple{})        = ()
+map(f, t::Tuple{},        s::Tuple)          = ()
 map(f, t::Tuple{Any,},    s::Tuple{Any,})    = (@inline; (f(t[1],s[1]),))
 map(f, t::Tuple{Any,Any}, s::Tuple{Any,Any}) = (@inline; (f(t[1],s[1]), f(t[2],s[2])))
 function map(f, t::Tuple, s::Tuple)
     @inline
     (f(t[1],s[1]), map(f, tail(t), tail(s))...)
 end
 function map(f, t::Any32, s::Any32)
-    n = length(t)
+    n = min(length(t), length(s))
     A = Vector{Any}(undef, n)
     for i = 1:n
         A[i] = f(t[i], s[i])
@@ -331,12 +333,16 @@ end
 heads(ts::Tuple...) = map(t -> t[1], ts)
 tails(ts::Tuple...) = map(tail, ts)
 map(f, ::Tuple{}...) = ()
+anyempty(x::Tuple{}, xs...) = true
+anyempty(x::Tuple, xs...) = anyempty(xs...)
+anyempty() = false
 function map(f, t1::Tuple, t2::Tuple, ts::Tuple...)
     @inline
+    anyempty(t1, t2, ts...) && return ()
     (f(heads(t1, t2, ts...)...), map(f, tails(t1, t2, ts...)...)...)
 end
 function map(f, t1::Any32, t2::Any32, ts::Any32...)
-    n = length(t1)
+    n = min(length(t1), length(t2), minimum(length, ts))
     A = Vector{Any}(undef, n)
     for i = 1:n
         A[i] = f(t1[i], t2[i], map(t -> t[i], ts)...)

diff --git a/test/tuple.jl b/test/tuple.jl
@@ -265,8 +265,10 @@ end
         @test map(foo, (1,2,3,4), (1,2,3,4)) === (2,4,6,8)
         @test map(foo, longtuple, longtuple) === ntuple(i->2i,20)
         @test map(foo, vlongtuple, vlongtuple) === ntuple(i->2i,33)
-        @test_throws BoundsError map(foo, (), (1,))
-        @test_throws BoundsError map(foo, (1,), ())
+        @test map(foo, longtuple, vlongtuple) === ntuple(i->2i,20)
+        @test map(foo, vlongtuple, longtuple) === ntuple(i->2i,20)
+        @test map(foo, (), (1,)) === ()
+        @test map(foo, (1,), ()) === ()
     end
 
     @testset "n arguments" begin
@@ -276,8 +278,11 @@ end
         @test map(foo, (1,2,3,4), (1,2,3,4), (1,2,3,4)) === (3,6,9,12)
         @test map(foo, longtuple, longtuple, longtuple) === ntuple(i->3i,20)
         @test map(foo, vlongtuple, vlongtuple, vlongtuple) === ntuple(i->3i,33)
-        @test_throws BoundsError map(foo, (), (1,), (1,))
-        @test_throws BoundsError map(foo, (1,), (1,), ())
+        @test map(foo, vlongtuple, longtuple, longtuple) === ntuple(i->3i,20)
+        @test map(foo, longtuple, vlongtuple, longtuple) === ntuple(i->3i,20)
+        @test map(foo, longtuple, vlongtuple, vlongtuple) === ntuple(i->3i,20)
+        @test map(foo, (), (1,), (1,)) === ()
+        @test map(foo, (1,), (1,), ()) === ()
     end
 end