add nix & update readme

.envrc

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# the shebang is ignored, but nice for editors
+
+if type -P lorri &>/dev/null; then
+  eval "$(lorri direnv)"
+else
+  echo 'while direnv evaluated .envrc, could not find the command "lorri" [https://github.com/nix-community/lorri]'
+  use nix
+fi

README.md

@@ -1,123 +1,3 @@
 # Rush
 
-Rust shell. Inspired by Ion.
-
 In case you're reading this: rush is in the works and not a priority. Features may be missing even if defined below.
-
-## Scopes
-
-Variables are block scoped.
-
-Block scope creation:
-- `if`
-- `while`
-- `else`
-- `for..`
-- `$(expr)`
-
-Functions have a copy of their scope.
-
-Files create file scopes, to which functions are scoped.
-
-## Syntax
-
-`;` is 'alias' for new line.
-
-Syntax and type errors crash the program.
-
-Variables are scoped to their block, and immediately freed when their block is left.
-
-### Variables
-
-String variable value can be obtained using `$`, arrays using `@`.
-
-When an array is stringified (referred to with `$`), it's contents are joined with space.
-No special treatment of `PATH`.
-
-Currently, the shell doesn't error out when variable doesn't exist, instead, it's replaced by an empty string.
-
-Assigned using `let`.
-Left side is evaluated to a string as well.
-Variable names must be valid ascii characters, or part of namespace (`namespace::var` syntax).
-
-```sh
-let a = d
-let $b = c
-echo $d # c
-```
-
-Arrays are assigned using `[ var ]`. You can join arrays and strings by simply passing them there, like `[ $var @var ]`.
-Arrays and maps cannot be nested during definition (`[ $var [@var] ]` should have the same effect).
-
-All assignments are done via the `let` keyword. If the variable exists, it is overwritten (even in upper scopes).
-Instead of `=`, other operations are supported:
-
-* `*=` - multiply
-* `+=` - addition
-* `-=` - substraction
-* `/=` - division
-* `//=` - int division
-* `%=` - modulo
-* `::=` - append
-* `@@=` - prepend
-
-#### Special variables
-
-`env::` namespace contains the environment (and doesn't error out if the variable doesn't exist, instead, empty string is returned)
-`color::` (alias `c::`) has a number of colors
-
-### Return
-
-Sets the exit code (and possibly exits function/script early). If no return is set, the return code is set to the return code of the last expression (`$?`).
-
-### Math
-
-Using `$(())` syntax. Math priority applies. Brackets are supported. Variables used without their prepender. Indexing is possible.
-
-### String and Array methods
-
-* $trim(str) - Trims the string (both sides)
-* $trimLeft(str) - Trims the string (start/left)
-* $trimright(str) - Trims the string (end/right)
-* $escape(str) - Escapes string
-* $unescape(str) - Unescapes string
-* @split(str by) - Splits `str` by `by` into array
-* @join(str by=" ") - Joins `str` together `by`
-
-Slices: `[x..y]` gets a substring (or subarray) of the variable. When `x` ommited, defaults to `0` (the start). When `y` ommited, defaults to end.
-
-### Control
-
-Bracketless. Scopes are ended by the keyword `end`.
-
-- `if` - Runs it's scope if the command returns `0`. Useful in pair with `test` builtin. `else` supported. `else if` doesn't require another `end`.
-- `for val of @arr` - Runs for each value of the array (or hashmap)
-- `for val of X..Y` - Runs for each number in the range `X` and `Y` (both inclusive).
-- `while` - Runs in loop as long as the command returns `0`
-
-### Functions
-
-Defined by `fn name [...arg] [--flags]`. `arg` can be ommited, or repeated.
-`--flags` can be used to add additional functionality.
-
-Functions are scoped per file, even if they use `on-event` or similar to be triggered.
-Use `source` to load external files with functions to be triggered.
-
-- `--desc` sets the functions description.
-- `--on-event` will run the function when an event is run
-
-#### Builtins
-
-`let` is a special case which cannot be dynamically addressed (i.e. using `$(echo let) var = value`).
-
-* `let` for assigning variables (`let var = value`)
-* `export` for exporting variables to env (`export var` to export var, or `export var = value`)
-* `test` tests for evaluation (`=` for equality, `>`, `<`, `<=`, `>=` for number comparisons)
-* `exists` for existence of a given string, or if given a flag (`-F`unctions, `-v`ariables, `-e`nv, `-f`ile, `-d`irectory, `-r`eadable file, `-w`ritable file, e`-x`ecutable file), existence of the selected object
-* `true` returns `0`
-* `false` returns `1`
-* `source` to run another file in the same file scope
-* `typeof` returns the type of arguments passed
-* `inspect` shows the object in a debug output
-
-Some GNU standard utils may be overwritten by rush builtins, but must be made compatible.

shell.nix

@@ -0,0 +1,32 @@
+{ pkgs ? import <nixpkgs> {} }:
+let
+    unstable = import (fetchTarball "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz") { };
+    # rust-rover things
+    rust-toolchain =
+        pkgs.symlinkJoin {
+            name = "rust-toolchain";
+            paths = with unstable; [rustc cargo rustPlatform.rustcSrc clippy rustfmt gcc rust-analyzer];
+        };
+in
+pkgs.mkShell rec {
+    buildInputs = with unstable;[
+        openssl
+        pkg-config
+        cmake
+        zlib
+        rust-toolchain
+
+        cargo-flamegraph
+        hyperfine
+        valgrind
+
+        lld
+    ];
+    nativeBuildInputs = with unstable; [
+        pkg-config
+    ];
+    LD_LIBRARY_PATH = "${unstable.lib.makeLibraryPath buildInputs}";
+    OPENSSL_DIR="${unstable.openssl.dev}";
+    OPENSSL_LIB_DIR="${unstable.openssl.out}/lib";
+    RUST_SRC_PATH = "${unstable.rust.packages.stable.rustPlatform.rustLibSrc}";
+}