stack = [env, env, …] then we have: roots = reduce(merge, reverse([roots, roots, …])) graph = reduce(merge, reverse([graph, graph, …])) paths = reduce(merge, reverse([paths, paths, …])) The subscripted roots correspond to the subscripted environments, env, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. Avaria�on on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representa�on

Base.@kwdef can now be used for parametric structs, and for structs with supertypes (#29316). • merge(::NamedTuple, ::NamedTuple...) can now be used with more than 2 NamedTuples (#29259). • New ncodeunits(c::Char) stack = [env, env, …] then we have: roots = reduce(merge, reverse([roots, roots, …])) graph = reduce(merge, reverse([graph, graph, …])) paths = reduce(merge, reverse([paths, paths, …])) The subscripted roots correspond to the subscripted environments, env, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument

Base.@kwdef can now be used for parametric structs, and for structs with supertypes (#29316). • merge(::NamedTuple, ::NamedTuple...) can now be used with more than 2 NamedTuples (#29259). • New ncodeunits(c::Char) stack = [env, env, …] then we have: roots = reduce(merge, reverse([roots, roots, …])) graph = reduce(merge, reverse([graph, graph, …])) paths = reduce(merge, reverse([paths, paths, …])) The subscripted roots correspond to the subscripted environments, env, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument

stack = [env, env, …] then we have: roots = reduce(merge, reverse([roots, roots, …])) graph = reduce(merge, reverse([graph, graph, …])) paths = reduce(merge, reverse([paths, paths, …])) The subscripted roots correspond to the subscripted environments, env, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. Avaria�on on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representa�on

[env₁, env₂, …] then we have: roots = reduce(merge, reverse([roots₁, roots₂, …])) graph = reduce(merge, reverse([graph₁, graph₂, …])) paths = reduce(merge, reverse([paths₁, paths₂, …])) The subscripted correspond to the subscripted environments, envᵢ, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. A variation on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representation

[env₁, env₂, …] then we have: roots = reduce(merge, reverse([roots₁, roots₂, …])) graph = reduce(merge, reverse([graph₁, graph₂, …])) paths = reduce(merge, reverse([paths₁, paths₂, …])) The subscripted correspond to the subscripted environments, envᵢ, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. A variation on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representation

[env₁, env₂, …] then we have: roots = reduce(merge, reverse([roots₁, roots₂, …])) graph = reduce(merge, reverse([graph₁, graph₂, …])) paths = reduce(merge, reverse([paths₁, paths₂, …])) The subscripted correspond to the subscripted environments, envᵢ, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. A variation on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representation

supersede merge and merge! with combine argument. They don't have the restriction for combine to be a Function and also provide one-argument method that returns a closure. The old methods of merge and merge [env₁, env₂, …] then we have: roots = reduce(merge, reverse([roots₁, roots₂, …])) graph = reduce(merge, reverse([graph₁, graph₂, …])) paths = reduce(merge, reverse([paths₁, paths₂, …])) The subscripted correspond to the subscripted environments, envᵢ, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument

[env₁, env₂, …] then we have: roots = reduce(merge, reverse([roots₁, roots₂, …])) graph = reduce(merge, reverse([graph₁, graph₂, …])) paths = reduce(merge, reverse([paths₁, paths₂, …])) The subscripted correspond to the subscripted environments, envᵢ, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. A variation on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representation

[env₁, env₂, …] then we have: roots = reduce(merge, reverse([roots₁, roots₂, …])) graph = reduce(merge, reverse([graph₁, graph₂, …])) paths = reduce(merge, reverse([paths₁, paths₂, …])) The subscripted correspond to the subscripted environments, envᵢ, contained in stack. The reverse is present because merge favors the last argument rather than first when there are collisions between keys in its argument compilers do. A variation on this approach, which avoids the appearance of type instability is to merge the Int and BigInt types into a single hybrid integer type, that internally changes representation