From f929d43354c536865d9158a9170f5a1c7bf404a7 Mon Sep 17 00:00:00 2001
From: Takafumi Arakaki <aka.tkf@gmail.com>
Date: Sun, 24 Apr 2022 02:20:48 -0400
Subject: [PATCH 1/2] Add `Try.unwrap_or_else`

---
 src/Try.jl                      |  1 +
 src/branch.jl                   | 43 ++++++++++++++++++++++++---------
 src/docs/unwrap_or_else.md      | 15 ++++++++++++
 test/TryTests/src/test_tools.jl |  5 ++++
 4 files changed, 53 insertions(+), 11 deletions(-)
 create mode 100644 src/docs/unwrap_or_else.md

diff --git a/src/Try.jl b/src/Try.jl
index bf48984..3b89ba6 100644
--- a/src/Try.jl
+++ b/src/Try.jl
@@ -39,6 +39,7 @@ function var"@?" end
 
 function and_then end
 function or_else end
+function unwrap_or_else end
 
 module Internal
 
diff --git a/src/branch.jl b/src/branch.jl
index 989624f..0c59d6d 100644
--- a/src/branch.jl
+++ b/src/branch.jl
@@ -66,12 +66,6 @@ macro and_return(ex)
     end
 end
 
-function Try.and_then(f::F) where {F}
-    function and_then_closure(result)
-        Try.and_then(f, result)
-    end
-end
-
 function Try.and_then(f, result)
     br = branch(result)
     if br isa Continue
@@ -81,17 +75,44 @@ function Try.and_then(f, result)
     end
 end
 
-function Try.or_else(f::F) where {F}
-    function or_else_closure(result)
-        Try.or_else(f, result)
+function Try.or_else(f, result)
+    br = branch(result)
+    if br isa Break
+        f(valueof(br))
+    else
+        br.result
     end
 end
 
-function Try.or_else(f, result)
+function Try.unwrap_or_else(f, result)
     br = branch(result)
     if br isa Break
         f(valueof(br))
     else
-        br.result
+        valueof(br.result)
+    end
+end
+
+###
+### Currying
+###
+
+# TODO: Automate currying?
+
+function Try.and_then(f::F) where {F}
+    function and_then_closure(result)
+        Try.and_then(f, result)
+    end
+end
+
+function Try.or_else(f::F) where {F}
+    function or_else_closure(result)
+        Try.or_else(f, result)
+    end
+end
+
+function Try.unwrap_or_else(f::F) where {F}
+    function unwrap_or_else(result)
+        Try.unwrap_or_else(f, result)
     end
 end
diff --git a/src/docs/unwrap_or_else.md b/src/docs/unwrap_or_else.md
new file mode 100644
index 0000000..7273f00
--- /dev/null
+++ b/src/docs/unwrap_or_else.md
@@ -0,0 +1,15 @@
+    Try.unwrap_or_else(_, Ok(value)) -> value
+    Try.unwrap_or_else(f, Err(x))  -> f(x)
+
+Unwrap an [`Ok`](@ref) value or compute a result from the value wrapped in [`Err`](@ref).
+
+# Examples
+```julia
+julia> using Try
+
+julia> Try.unwrap_or_else(length, Try.Ok(1))
+1
+
+julia> Try.unwrap_or_else(length, Try.Err("four"))
+4
+```
diff --git a/test/TryTests/src/test_tools.jl b/test/TryTests/src/test_tools.jl
index 0469c7b..532b498 100644
--- a/test/TryTests/src/test_tools.jl
+++ b/test/TryTests/src/test_tools.jl
@@ -67,6 +67,11 @@ function test_or_return()
     @test Try.unwrap(try_map_prealloc2(x -> x + 1, 1:3)) == 2:4
 end
 
+function test_unwrap_or_else()
+    @test Try.unwrap_or_else(length, Try.Ok(1)) == 1
+    @test Try.unwrap_or_else(length, Try.Err("four")) == 4
+end
+
 function test_curry()
     value =
         tryconvert(String, 1) |>

From 6e5f8c43624f321caae6946339a833fac9d100c2 Mon Sep 17 00:00:00 2001
From: Takafumi Arakaki <aka.tkf@gmail.com>
Date: Sun, 24 Apr 2022 02:34:35 -0400
Subject: [PATCH 2/2] Fix `Try.unwrap_or_else`

---
 src/branch.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/branch.jl b/src/branch.jl
index 0c59d6d..44db4f7 100644
--- a/src/branch.jl
+++ b/src/branch.jl
@@ -89,7 +89,7 @@ function Try.unwrap_or_else(f, result)
     if br isa Break
         f(valueof(br))
     else
-        valueof(br.result)
+        valueof(br)
     end
 end