First commit

Author: camelid

.github/workflows/ci.yml

@@ -0,0 +1,22 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build
+      run: cargo build --verbose
+    - name: Run tests
+      run: cargo test --verbose

.gitignore

@@ -0,0 +1 @@
+/target

Cargo.lock

@@ -0,0 +1,13 @@
+[package]
+name = "type-layout"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+# TODO: enable overflow checks in release builds?
+
+[dependencies]
+
+[dev-dependencies]
+insta = "1.0"

Cargo.toml

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Noah Lev
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

LICENSE

@@ -0,0 +1,3 @@
+# type-layout
+
+**Note:** I am not currently accepting pull requests.

README.md

@@ -0,0 +1,24 @@
+-- The type equivalent to Maybe Bool
+-- <None of {} | Some of <False of {} | True of {}>>
+
+-- The None value (aka, Nothing)
+<None = {}> as <None of {} | Some of <False of {} | True of {}>>
+
+-- The Some False value (aka, Just False)
+<Some = <False = {}> as <False of {} | True of {}>> as <None of {} | Some of <False of {} | True of {}>>
+
+-- The Some True value
+<Some = <True = {}> as <False of {} | True of {}>> as <None of {} | Some of <False of {} | True of {}>>
+
+
+-- A basic pattern match. Equivalent to `opt.unwrap_or(false)` in Rust.
+alias Bool = <False of {} | True of {}> in
+-- Maybe Bool
+alias MBool = <None of {} | Some of Bool> in
+let Some_of_True : MBool = <Some = <True = {}> as Bool> as MBool  in
+let Some_of_False : MBool = <Some = <False = {}> as Bool> as MBool  in
+let None : MBool = <None = {}> as MBool  in
+match None : MBool {
+    <None = _ : {}> as MBool => <False = {}> as Bool,
+    <Some = b : Bool> as MBool => b : Bool,
+}

example.fun

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly-2021-11-08"

rust-toolchain.toml

@@ -0,0 +1 @@
+use_small_heuristics = "Max"

rustfmt.toml

@@ -0,0 +1,28 @@
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Debruijn {
+    index: u64,
+}
+
+impl Debruijn {
+    pub const ZERO: Self = Self::new(0);
+
+    pub const fn new(index: u64) -> Self {
+        Self { index }
+    }
+
+    pub const fn index(self) -> u64 {
+        self.index
+    }
+
+    pub fn shift_by(mut self, by: u64) -> Self {
+        self.index = self.index.checked_add(by).unwrap();
+        self
+    }
+}
+
+impl std::fmt::Display for Debruijn {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let Self { index } = self;
+        write!(f, "#{}", index)
+    }
+}