add @benchmarkset & @case for defining benchmark suite (#147)

Author: Roger-luo

src/BenchmarkTools.jl

@@ -52,7 +52,9 @@ export BenchmarkGroup,
        improvements,
        @tagged,
        addgroup!,
-       leaves
+       leaves,
+       @benchmarkset,
+       @case
 
 ######################
 # Execution Strategy #

src/groups.jl

@@ -301,3 +301,53 @@ function Base.show(io::IO, group::BenchmarkGroup)
         count += 1
     end
 end
+
+
+const benchmark_stack = []
+
+macro benchmarkset(title, ex)
+    esc(benchmarkset_m(title, ex))
+end
+
+macro case(title, xs...)
+    esc(:($(Symbol("#suite#"))[$title] = @benchmarkable $(xs...)))
+end
+
+function benchmarkset_m(title, ex::Expr)
+    stack = GlobalRef(BenchmarkTools, :benchmark_stack)
+    init = quote
+        if isempty($stack)
+            push!($stack, $BenchmarkGroup())
+        end
+    end
+    exec = quote
+        if length($stack) == 1
+            pop!($stack)
+        end
+    end
+    return if ex.head === :block
+        quote
+            $init
+            $(benchmarkset_block(title, ex))
+            $exec
+        end
+    elseif ex.head === :for
+        quote
+            $init
+            $(Expr(ex.head, ex.args[1], benchmarkset_block(title, ex.args[2]))) 
+            $exec
+        end
+    end
+end
+
+function benchmarkset_block(title, ex::Expr)
+    stack = GlobalRef(BenchmarkTools, :benchmark_stack)
+    quote
+        let $(Symbol("#root#")) = last($stack)
+            $(Symbol("#root#"))[$title] = $(Symbol("#suite#")) = BenchmarkGroup()
+            push!($stack, $(Symbol("#suite#")))
+            $ex
+            pop!($stack)
+        end
+    end
+end

test/GroupsTests.jl

@@ -278,6 +278,16 @@ g2[[1, "a", :b]] = "hello"  # should create higher levels on the fly
 
 @test g1 == g2
 
+@testset "benchmarkset" begin
+    g1 = @benchmarkset "test set" begin
+       @case "test case 1" 1 + 1
+       @case "test case 2" 2 + 2
+    end
+
+    @test haskey(g1, "test set")
+    @test haskey(g1["test set"], "test case 1")
+    @test haskey(g1["test set"], "test case 2")
+end
 # pretty printing #
 #-----------------#