Add Try.unwrap_or_else

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
 

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)
+    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

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
+```

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) |>