From 79a265d3bf7d2728ed4f70f02e48b9d246d03f0c Mon Sep 17 00:00:00 2001
From: Rene Donner <code@donner.at>
Date: Sun, 10 May 2015 21:49:04 +0200
Subject: [PATCH] add tryparse

---
 src/Compat.jl    | 13 +++++++++++++
 test/runtests.jl |  6 ++++++
 2 files changed, 19 insertions(+)

diff --git a/src/Compat.jl b/src/Compat.jl
index 43e681149630b..f2cac919b2943 100644
--- a/src/Compat.jl
+++ b/src/Compat.jl
@@ -290,6 +290,19 @@ if VERSION < v"0.4.0-dev+656"
     include("nullable.jl")
 end
 
+if VERSION < v"0.4.0-dev+3864"
+    function tryparse(T::Type{Float32}, s)
+        r = Array(T,1)
+        float32_isvalid(s, r) ? Nullable(r[1]) : Nullable{Float32}()
+    end
+
+    function tryparse(T::Type{Float64}, s)
+        r = Array(T,1)
+        float64_isvalid(s, r) ? Nullable(r[1]) : Nullable{Float64}()
+    end
+    export tryparse
+end
+
 if VERSION < v"0.4.0-dev+3844"
     @eval module Libc
         const FILE = Base.CFILE
diff --git a/test/runtests.jl b/test/runtests.jl
index ac7bf73e62869..21497bab0ee42 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -192,6 +192,12 @@ end
 @test parse(Float64, "222") == 222.0
 @test parse(Float32, "1.1") == convert(Float32, 1.1)
 @test parse(BigFloat, "1.125") == convert(BigFloat, 1.125)
+@test isa(tryparse(Float32, "1.1"), Nullable)
+@test get(tryparse(Float32, "1.1")) == 1.1f0
+@test isa(tryparse(Float32, "a"), Nullable{Float32})
+@test isa(tryparse(Float64, "1.1"), Nullable)
+@test get(tryparse(Float64, "1.1")) == 1.1
+@test isa(tryparse(Float64, "a"), Nullable{Float64})
 
 # Make sure exports from Libc and Libdl are defined
 for x in [:strftime,:systemsleep,:getpid,:FILE,:malloc,:MS_SYNC,:munmap,:flush_cstdio,:realloc,:strptime,:Libc,:errno,:msync,:TmStruct,:calloc,:MS_INVALIDATE,:MS_ASYNC,:time,:strerror,:gethostname,:free,:mmap]