From acf69d0cb86a862437084735db22b9fa15ae65ba Mon Sep 17 00:00:00 2001
From: gfngfn <suwa-takashi141@g.ecc.u-tokyo.ac.jp>
Date: Sat, 20 Nov 2021 16:41:00 +0900
Subject: [PATCH 1/2] add 'examples/calc'

---
 examples/calc/rebar.config     |  7 +++++++
 examples/calc/rebar.lock       |  4 ++++
 examples/calc/sesterl.yaml     | 26 ++++++++++++++++++++++++++
 examples/calc/src/calc.app.src | 13 +++++++++++++
 examples/calc/src/calc.sest    | 30 ++++++++++++++++++++++++++++++
 5 files changed, 80 insertions(+)
 create mode 100644 examples/calc/rebar.config
 create mode 100644 examples/calc/rebar.lock
 create mode 100644 examples/calc/sesterl.yaml
 create mode 100644 examples/calc/src/calc.app.src
 create mode 100644 examples/calc/src/calc.sest

diff --git a/examples/calc/rebar.config b/examples/calc/rebar.config
new file mode 100644
index 00000000..8d49e30a
--- /dev/null
+++ b/examples/calc/rebar.config
@@ -0,0 +1,7 @@
+{plugins, [{rebar_sesterl, {git, "https://github.com/gfngfn/rebar_sesterl_plugin.git", {branch, "master"}}}]}.
+{src_dirs, ["./_generated", "./src"]}.
+{deps, [{sesterl_stdlib, {git, "https://github.com/gfngfn/sesterl_stdlib", {tag, "v0.4.1"}}}]}.
+{profiles, [{test, [{deps, []}]}]}.
+{eunit_tests, [{dir, "_generated_test"}]}.
+{relx, [{release, {calc, "0.1.0"}, [calc]}, {dev_mode, false}]}.
+{sesterl_opts, [{output_dir, "./_generated"},{test_output_dir, "_generated_test"}]}.
diff --git a/examples/calc/rebar.lock b/examples/calc/rebar.lock
new file mode 100644
index 00000000..d48c9573
--- /dev/null
+++ b/examples/calc/rebar.lock
@@ -0,0 +1,4 @@
+[{<<"sesterl_stdlib">>,
+  {git,"https://github.com/gfngfn/sesterl_stdlib",
+       {ref,"0c45578e2d91d3b127135ada704e9f80b3997fd7"}},
+  0}].
diff --git a/examples/calc/sesterl.yaml b/examples/calc/sesterl.yaml
new file mode 100644
index 00000000..561cd93a
--- /dev/null
+++ b/examples/calc/sesterl.yaml
@@ -0,0 +1,26 @@
+package: "calc"
+language: "v0.2.0"
+
+main_module: "Calc"
+
+source_directories:
+  - "./src"
+
+dependencies:
+  - name: "sesterl_stdlib"
+    source:
+      type: "git"
+      repository: "https://github.com/gfngfn/sesterl_stdlib"
+      spec:
+        type: "tag"
+        value: "v0.4.1"
+
+erlang:
+  output_directory: "./_generated"
+  relx:
+    release:
+      name: "calc"
+      version: "0.1.0"
+      applications:
+        - "calc"
+  dev_mode: true
diff --git a/examples/calc/src/calc.app.src b/examples/calc/src/calc.app.src
new file mode 100644
index 00000000..3b13ff0a
--- /dev/null
+++ b/examples/calc/src/calc.app.src
@@ -0,0 +1,13 @@
+{application, calc, [
+    {description, "calc"},
+    {vsn, "0.1.0"},
+    {registered, []},
+    {modules, []},
+    {applications, [
+        kernel,
+        stdlib
+    ]},
+    {env, []},
+    {licenses, ["MIT"]},
+    {links, []}
+]}.
diff --git a/examples/calc/src/calc.sest b/examples/calc/src/calc.sest
new file mode 100644
index 00000000..5a80bb03
--- /dev/null
+++ b/examples/calc/src/calc.sest
@@ -0,0 +1,30 @@
+module Calc :> sig
+  val fact : fun(int) -> int
+  val sum : fun(list<int>) -> int
+  val id<$a> : fun($a) -> $a
+  val first<$a, $b> : fun({$a, $b}) -> $a
+  val have_same_length<$a, $b> : fun(list<$a>, list<$b>) -> bool
+end = struct
+  open Stdlib
+
+  val fact(n) =
+    let rec aux(acc, n) =
+      if n <= 0 then acc else aux(n * acc, n - 1)
+    in
+    aux(1, n)
+
+  val sum(ns) =
+    List.foldl(
+      fun(acc, n) -> acc + n end,
+      0,
+      ns)
+
+  val id(x) = x
+
+  val first({x, _}) = x
+
+  val have_same_length<$a, $b>(xs : list<$a>, ys : list<$b>) : bool =
+    List.length(xs) == List.length(ys)
+
+
+end

From 920ced26e355b704735bc0b87da2afd9b4a2d9dd Mon Sep 17 00:00:00 2001
From: gfngfn <suwa-takashi141@g.ecc.u-tokyo.ac.jp>
Date: Sun, 21 Nov 2021 16:43:53 +0900
Subject: [PATCH 2/2] update 'examples/calc'

---
 examples/calc/src/BinTree.sest | 24 ++++++++++++++++++++++++
 examples/calc/src/calc.sest    | 19 +++++++++----------
 2 files changed, 33 insertions(+), 10 deletions(-)
 create mode 100644 examples/calc/src/BinTree.sest

diff --git a/examples/calc/src/BinTree.sest b/examples/calc/src/BinTree.sest
new file mode 100644
index 00000000..8f137b3b
--- /dev/null
+++ b/examples/calc/src/BinTree.sest
@@ -0,0 +1,24 @@
+module BinTree :> sig
+  type t :: (o) -> o
+  val leaf<$a> : fun($a) -> t<$a>
+  val node<$a> : fun($a, t<$a>, t<$a>) -> t<$a>
+  val tree_size<$a> : fun(t<$a>) -> int
+end = struct
+
+  type t<$a> =
+    | Empty
+    | Node($a, t<$a>, t<$a>)
+
+  val leaf(x) =
+    Node(x, Empty, Empty)
+
+  val node(x, tree1, tree2) =
+    Node(x, tree1, tree2)
+
+  val rec tree_size(tree) =
+    case tree of
+    | Empty                 -> 0
+    | Node(_, tree1, tree2) -> 1 + tree_size(tree1) + tree_size(tree2)
+    end
+
+end
diff --git a/examples/calc/src/calc.sest b/examples/calc/src/calc.sest
index 5a80bb03..990df131 100644
--- a/examples/calc/src/calc.sest
+++ b/examples/calc/src/calc.sest
@@ -2,7 +2,7 @@ module Calc :> sig
   val fact : fun(int) -> int
   val sum : fun(list<int>) -> int
   val id<$a> : fun($a) -> $a
-  val first<$a, $b> : fun({$a, $b}) -> $a
+  val swap<$a, $b> : fun({$a, $b}) -> {$b, $a}
   val have_same_length<$a, $b> : fun(list<$a>, list<$b>) -> bool
 end = struct
   open Stdlib
@@ -14,17 +14,16 @@ end = struct
     aux(1, n)
 
   val sum(ns) =
-    List.foldl(
-      fun(acc, n) -> acc + n end,
-      0,
-      ns)
+    List.foldl(fun(acc, n) -> acc + n end, 0, ns)
 
   val id(x) = x
 
-  val first({x, _}) = x
-
-  val have_same_length<$a, $b>(xs : list<$a>, ys : list<$b>) : bool =
-    List.length(xs) == List.length(ys)
-
+  val swap({x, y}) = {y, x}
 
+  val rec have_same_length<$a, $b>(xs : list<$a>, ys : list<$b>) : bool =
+    case {xs, ys} of
+    | {[], []}                 -> true
+    | {_ :: xtail, _ :: ytail} -> have_same_length(xtail, ytail)
+    | _                        -> false
+    end
 end