Added explicit function inlining.

8 files changed, 123 insertions, 26 deletions

diff --git a/changelog.md b/changelog.md
new file mode 100644
index 000000000..74d4372dc
--- /dev/null
+++ b/changelog.md
@@ -0,0 +1,13 @@
+# Based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+
+## [Un-released]
+### Added
+* Inline functions.
+### Changed
+### Removed
+### Fixed
+### Deprecated
+### Security
+
+[Un-released]: https://github.com/LuxLang/lux/compare/0.6.5...HEAD
+
diff --git a/documentation/bookmark/recursion_schemes.md b/documentation/bookmark/recursion_schemes.md
index 5c41438df..31a013123 100644
--- a/documentation/bookmark/recursion_schemes.md
+++ b/documentation/bookmark/recursion_schemes.md
@@ -1,18 +1,20 @@
 # Reference
 
-1. [Probability Tree Diagrams. Recursion Schemes. Why Finding the Right Solution is Sometimes Hard?](https://rpeszek.github.io/posts/2021-07-18-prob-tree-scheme.html)
-1. [Unifying Structured Recursion Schemes](https://www.cs.ox.ac.uk/people/nicolas.wu/papers/URS.pdf)
-1. http://maartenfokkinga.github.io/utwente/mmf91m.pdf
-1. http://blog.sumtypeofway.com/an-introduction-to-recursion-schemes/
-1. http://blog.sumtypeofway.com/recursion-schemes-part-2/
-1. http://blog.sumtypeofway.com/recursion-schemes-part-iii-folds-in-context/
-1. http://blog.sumtypeofway.com/recursion-schemes-part-iv-time-is-of-the-essence/
-1. http://comonad.com/reader/2009/recursion-schemes/
-1. [Peeling the Banana: Recursion Schemes from First Principles - Zainab Ali](https://www.youtube.com/watch?v=XZ9nPZbaYfE)
-1. https://github.com/passy/awesome-recursion-schemes
-1. [YOW! Lambda Jam 2018 - Amy Wong - Introduction to recursion scheme](https://www.youtube.com/watch?v=YnqPdlJd38o)
-1. https://bartoszmilewski.com/2018/08/20/recursion-schemes-for-higher-algebras/
-1. https://blog.sumtypeofway.com/recursion-schemes-part-6-comonads-composition-and-generality/
-1. https://chrilves.github.io/hugo/posts/recursion_schemes_intro/
-1. [Recursion Schemes: A Field Guide (Redux)](http://comonad.com/reader/2009/recursion-schemes/)
+0. [An Introduction to Recursion Schemes](https://blog.sumtypeofway.com/posts/introduction-to-recursion-schemes.html)
+0. [Recursion Schemes, Part II: A Mob of Morphisms](https://blog.sumtypeofway.com/posts/recursion-schemes-part-2.html)
+0. [Recursion Schemes, Part III: Folds in Context](https://blog.sumtypeofway.com/posts/recursion-schemes-part-3.html)
+0. [Recursion Schemes, Part IV: Time is of the Essence](https://blog.sumtypeofway.com/posts/recursion-schemes-part-4.html)
+0. [Recursion Schemes, Part 4½: Better Living Through Base Functors](https://blog.sumtypeofway.com/posts/recursion-schemes-part-4-point-5.html)
+0. [Recursion Schemes, Part V: Hello, Hylomorphisms](https://blog.sumtypeofway.com/posts/recursion-schemes-part-5.html)
+0. [Recursion Schemes, Part VI: Comonads, Composition, and Generality](https://blog.sumtypeofway.com/posts/recursion-schemes-part-6.html)
+0. [Probability Tree Diagrams. Recursion Schemes. Why Finding the Right Solution is Sometimes Hard?](https://rpeszek.github.io/posts/2021-07-18-prob-tree-scheme.html)
+0. [Unifying Structured Recursion Schemes](https://www.cs.ox.ac.uk/people/nicolas.wu/papers/URS.pdf)
+0. http://maartenfokkinga.github.io/utwente/mmf91m.pdf
+0. http://comonad.com/reader/2009/recursion-schemes/
+0. [Peeling the Banana: Recursion Schemes from First Principles - Zainab Ali](https://www.youtube.com/watch?v=XZ9nPZbaYfE)
+0. https://github.com/passy/awesome-recursion-schemes
+0. [YOW! Lambda Jam 2018 - Amy Wong - Introduction to recursion scheme](https://www.youtube.com/watch?v=YnqPdlJd38o)
+0. https://bartoszmilewski.com/2018/08/20/recursion-schemes-for-higher-algebras/
+0. https://chrilves.github.io/hugo/posts/recursion_schemes_intro/
+0. [Recursion Schemes: A Field Guide (Redux)](http://comonad.com/reader/2009/recursion-schemes/)
 
diff --git a/lux-jvm/source/luxc/lang/translation/jvm/extension/host.lux b/lux-jvm/source/luxc/lang/translation/jvm/extension/host.lux
index 78033cc96..28a5c34bc 100644
--- a/lux-jvm/source/luxc/lang/translation/jvm/extension/host.lux
+++ b/lux-jvm/source/luxc/lang/translation/jvm/extension/host.lux
@@ -1015,13 +1015,14 @@
         inputs! (|> inputsTI
                     list.enumeration
                     (list#each (function (_ [register [type term]])
-                                 (case (type.primitive? type)
-                                   {.#Right type}
-                                   (_.ALOAD (++ register))
-                                   
-                                   {.#Left type}
+                                 (let [then! (case (type.primitive? type)
+                                               {.#Right type}
+                                               (_.unwrap type)
+                                               
+                                               {.#Left type}
+                                               (_.CHECKCAST type))]
                                    (|>> (_.ALOAD (++ register))
-                                        (_.CHECKCAST type)))))
+                                        then!))))
                     _.fuse)
         store_capturedI (|> env
                             list.size
diff --git a/lux-mode/lux-mode.el b/lux-mode/lux-mode.el
index c3c9e8ec2..b41c3848a 100644
--- a/lux-mode/lux-mode.el
+++ b/lux-mode/lux-mode.el
@@ -400,7 +400,7 @@ Called by `imenu--generic-function'."
 							(function-definition (altRE "function" "|>>" "<<|" "||>"))
 							(remember (altRE "remember" "to_do" "fix_me"))
 							(definition (altRE "\\.using"
-											   "def:" "type:" "program:"
+											   "def:" "type:" "program:" "inline:"
 											   "implementation:"
 											   "macro:" "syntax:"
 											   "exception:"
diff --git a/stdlib/source/library/lux/abstract/functor.lux b/stdlib/source/library/lux/abstract/functor.lux
index fb5f412a3..fb3dab4c8 100644
--- a/stdlib/source/library/lux/abstract/functor.lux
+++ b/stdlib/source/library/lux/abstract/functor.lux
@@ -9,9 +9,6 @@
             (-> (f a) (f b))))
       each)))
 
-(type: .public (Fix f)
-  (f (Fix f)))
-
 (type: .public (Or f g)
   (All (_ a) (.Or (f a) (g a))))
 
diff --git a/stdlib/source/library/lux/control/function/inline.lux b/stdlib/source/library/lux/control/function/inline.lux
new file mode 100644
index 000000000..ef0836888
--- /dev/null
+++ b/stdlib/source/library/lux/control/function/inline.lux
@@ -0,0 +1,50 @@
+(.using
+ [library
+  [lux "*"
+   ["[0]" meta]
+   [abstract
+    ["[0]" monad {"+" do}]]
+   [control
+    ["<>" parser
+     ["<[0]>" code {"+" Parser}]]]
+   [data
+    [collection
+     ["[0]" list ("[1]#[0]" monad)]]]
+   ["[0]" macro
+    ["[0]" code]
+    [syntax {"+" syntax:}
+     ["|[0]|" export]]]]])
+
+(def: declaration
+  (Parser [Text (List Code)])
+  (<code>.form (<>.and <code>.local_symbol (<>.some <code>.any))))
+
+(def: inline
+  (Parser [Code [Text (List Code)] Code Code])
+  (|export|.parser
+   ($_ <>.and
+       ..declaration
+       <code>.any
+       <code>.any
+       )))
+
+(syntax: .public (inline: [[privacy [name parameters] type term] ..inline])
+  (do [! meta.monad]
+    [@ meta.current_module_name
+     g!parameters (|> (macro.symbol "parameter")
+                      (list.repeated (list.size parameters))
+                      (monad.all !))
+     .let [inlined (` (("lux in-module"
+                        (~ (code.text @))
+                        (.: (~ type)
+                            (.function ((~ (code.local_symbol name)) (~+ parameters))
+                              (~ term))))
+                       (~+ (list#each (function (_ g!parameter)
+                                        (` ((~' ~) (~ g!parameter))))
+                                      g!parameters))))
+           g!parameters (|> g!parameters
+                            (list#each (function (_ parameter)
+                                         (list parameter (` (~! <code>.any)))))
+                            list#conjoint)]]
+    (in (list (` ((~! syntax:) (~ privacy) ((~ (code.local_symbol name)) [(~+ g!parameters)])
+                  (.# (~! meta.monad) (~' in) (.list (.`' (~ inlined))))))))))
diff --git a/stdlib/source/test/lux/control/function.lux b/stdlib/source/test/lux/control/function.lux
index d9444edd1..eed6c9635 100644
--- a/stdlib/source/test/lux/control/function.lux
+++ b/stdlib/source/test/lux/control/function.lux
@@ -17,7 +17,8 @@
    ["[1][0]" contract]
    ["[1][0]" memo]
    ["[1][0]" mixin]
-   ["[1][0]" mutual]])
+   ["[1][0]" mutual]
+   ["[1][0]" inline]])
 
 (def: .public test
   Test
@@ -62,4 +63,5 @@
             /memo.test
             /mixin.test
             /mutual.test
+            /inline.test
             ))))
diff --git a/stdlib/source/test/lux/control/function/inline.lux b/stdlib/source/test/lux/control/function/inline.lux
new file mode 100644
index 000000000..7c05e39e0
--- /dev/null
+++ b/stdlib/source/test/lux/control/function/inline.lux
@@ -0,0 +1,32 @@
+(.using
+ [library
+  [lux "*"
+   ["_" test {"+" Test}]
+   [abstract
+    [monad {"+" do}]]
+   [math
+    ["[0]" random]
+    [number
+     ["i" int]]]]]
+ [\\library
+  ["[0]" /]])
+
+(template: (!quadrance/2 m0 m1)
+  [(i.+ (i.* m0 m0) (i.* m1 m1))])
+
+(/.inline: .public (quadrance/2 m0 m1)
+  (-> Int Int Int)
+  (!quadrance/2 m0 m1))
+
+(def: .public test
+  Test
+  (<| (_.covering /._)
+      (do [! random.monad]
+        [.let [measurement (# ! each (i.% +1000) random.int)]
+         m0 measurement
+         m1 measurement])
+      ($_ _.and
+          (_.cover [/.inline:]
+                   (i.= (..!quadrance/2 m0 m1)
+                        (..quadrance/2 m0 m1)))
+          )))