From c79947cfe207a62afbee0415cc0db33bf3b3fc4c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mos=C3=A8=20Giordano?= <giordano@users.noreply.github.com>
Date: Tue, 28 Dec 2021 13:03:47 +0100
Subject: [PATCH] Extend `Base.tryparse` (#112)

---
 NEWS.md        |  5 ++++-
 src/parsing.jl | 10 ++++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index d8caebd5..26901282 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,12 +1,15 @@
 # History of Measurements.jl
 
-## v2.7.0 (2021-??-??)
+## v2.7.0 (2021-12-28)
 
 ### New features
 
 * Support hashing of `Measurement` objects
   ([#103](https://github.com/JuliaPhysics/Measurements.jl/issues/103),
   [#104](https://github.com/JuliaPhysics/Measurements.jl/pull/104)).
+* New method `Base.tryparse(::Type{Measurement}, ::AbstractString)`
+  ([#110](https://github.com/JuliaPhysics/Measurements.jl/issues/110),
+  [#112](https://github.com/JuliaPhysics/Measurements.jl/pull/112)).
 
 ### Deprecations
 
diff --git a/src/parsing.jl b/src/parsing.jl
index 3b3805b8..0488409b 100644
--- a/src/parsing.jl
+++ b/src/parsing.jl
@@ -83,7 +83,7 @@ julia> measurement("-1234e-1")
 """
 measurement(str::AbstractString) = parse(Measurement{Float64}, str)
 
-function Base.parse(::Type{Measurement{T}}, str::S) where {T<:AbstractFloat, S<:AbstractString}
+function Base.tryparse(::Type{Measurement{T}}, str::S) where {T<:AbstractFloat, S<:AbstractString}
     m = match(rxp_error_with_parentheses, str)
     if m !== nothing # "123(45)e6"
         val_str::S, val_dec, err_str::S, err_dec_str, expn = m.captures
@@ -105,7 +105,7 @@ function Base.parse(::Type{Measurement{T}}, str::S) where {T<:AbstractFloat, S<:
                 val_str, err_str, val_dec, expn =
                     m.captures[1], "0", nothing, nothing
             else
-                throw(ArgumentError("cannot parse $(repr(str)) as Measurement{$T}"))
+                return nothing
             end
         end
     end
@@ -127,3 +127,9 @@ function Base.parse(::Type{Measurement{T}}, str::S) where {T<:AbstractFloat, S<:
     end
     return measurement(val, err)
 end
+
+function Base.parse(::Type{Measurement{T}}, str::S) where {T<:AbstractFloat, S<:AbstractString}
+    out = tryparse(Measurement{T}, str)
+    out === nothing && throw(ArgumentError("cannot parse $(repr(str)) as Measurement{$T}"))
+    return out
+end