Assume :nothrow in iterating over tuples (#54330)

On master, ```julia julia> Base.infer_effects(iterate, (Tuple{Int,Int,Int}, Int)) (+c,+e,!n,+t,+s,+m,+u) ``` Since the indexing is only carried out for valid indices, it should be safe to mark this as `nothrow`. After this PR, ```julia julia> Base.infer_effects(iterate, (Tuple{Int,Int,Int}, Int)) (+c,+e,+n,+t,+s,+m,+u) ``` --------- Co-authored-by: Shuhei Kadowaki <[email protected]>
JuliaLang · May 2, 2024 · f712512 · f712512
1 parent b385b4f
commit f712512
Show file tree

Hide file tree

Showing 2 changed files with 3 additions and 0 deletions.
diff --git a/base/tuple.jl b/base/tuple.jl
@@ -68,6 +68,7 @@ end
 
 function iterate(@nospecialize(t::Tuple), i::Int=1)
     @inline
+    @_nothrow_meta
     return (1 <= i <= length(t)) ? (t[i], i + 1) : nothing
 end
 

diff --git a/test/tuple.jl b/test/tuple.jl
@@ -209,6 +209,8 @@ end
 
     @test eachindex((2,5,"foo")) === Base.OneTo(3)
     @test eachindex((2,5,"foo"), (1,2,5,7)) === Base.OneTo(4)
+
+    @test Core.Compiler.is_nothrow(Base.infer_effects(iterate, (Tuple{Int,Int,Int}, Int)))
 end
-Original file line number
+Diff line change
@@ Expand Up / @@ -68,6 +68,7 @@ end @@
     function iterate(@nospecialize(t::Tuple), i::Int=1)
         @inline
+        @_nothrow_meta
         return (1 <= i <= length(t)) ? (t[i], i + 1) : nothing
     end
@@ Expand Down @@