commit be389d27235a8556df14dace7728acd05a4bcd18
Author: adnanioricce <adnangonzagadevio@gmail.com>
Date:   Wed Aug 14 14:02:08 2024 -0300

    [Init] - adding version control for docs and tutorial follow up

diff --git a/adhoc-env.bash b/adhoc-env.bash
new file mode 100644
index 0000000..7e39ab1
--- /dev/null
+++ b/adhoc-env.bash
@@ -0,0 +1,2 @@
+#!/usr/bin/env nix-shell
+#! nix-shell -p git neovim nodejs
diff --git a/nix-language/AttributeSets/attributeAccess.nix b/nix-language/AttributeSets/attributeAccess.nix
new file mode 100644
index 0000000..f2cab6e
--- /dev/null
+++ b/nix-language/AttributeSets/attributeAccess.nix
@@ -0,0 +1,13 @@
+let
+  attrset = { x = 1; };
+in
+  attrset.x
+
+# nested attributes
+#let
+#  attrset2 = { a = { b = { c = 1; }; }; };
+#in
+#attrset2.a.b.c
+
+# nested expression with dot notation
+#{ a.b.c = 1; }
\ No newline at end of file
diff --git a/nix-language/AttributeSets/attributeSet.nix b/nix-language/AttributeSets/attributeSet.nix
new file mode 100644
index 0000000..8c0bbe7
--- /dev/null
+++ b/nix-language/AttributeSets/attributeSet.nix
@@ -0,0 +1,14 @@
+{
+  string = "hello";
+  integer = 1;
+  float = 3.141;
+  bool = true;
+  null = null;
+  list = [ 1 "two" false ];
+  attribute-set = {
+    a = "hello";
+    b = 2;
+    c = 2.718;
+    d = false;
+  }; # comments are supported
+}
diff --git a/nix-language/AttributeSets/recursiveAttribute.nix b/nix-language/AttributeSets/recursiveAttribute.nix
new file mode 100644
index 0000000..c0afb3e
--- /dev/null
+++ b/nix-language/AttributeSets/recursiveAttribute.nix
@@ -0,0 +1,12 @@
+rec {
+  one = 1;
+  two = one + 1;
+  three = two + 1;
+}
+
+# failing counter-example
+#{
+#  one = 1;
+#  two = one + 1;
+#  three = two + 1;
+#}
diff --git a/nix-language/Derivations/default.nix b/nix-language/Derivations/default.nix
new file mode 100644
index 0000000..d1c7e29
--- /dev/null
+++ b/nix-language/Derivations/default.nix
@@ -0,0 +1,3 @@
+let
+  pkgs = import <nixpkgs> {};
+in "${pkgs.nix}"
diff --git a/nix-language/Dockerfile b/nix-language/Dockerfile
new file mode 100644
index 0000000..8b0688a
--- /dev/null
+++ b/nix-language/Dockerfile
@@ -0,0 +1,5 @@
+FROM nixos/nix
+
+RUN nix-channel --updates
+
+# RUN nix-build -A pythonFull '<nixpkgs>'
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/LookupPaths/default.nix b/nix-language/FileSystemPaths/LookupPaths/default.nix
new file mode 100644
index 0000000..adff05f
--- /dev/null
+++ b/nix-language/FileSystemPaths/LookupPaths/default.nix
@@ -0,0 +1,2 @@
+# other name is "angle bracket syntax"
+<nixpkgs>
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/LookupPaths/lib.nix b/nix-language/FileSystemPaths/LookupPaths/lib.nix
new file mode 100644
index 0000000..ded92a7
--- /dev/null
+++ b/nix-language/FileSystemPaths/LookupPaths/lib.nix
@@ -0,0 +1 @@
+<nixpkgs/lib>
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/absolute.nix b/nix-language/FileSystemPaths/absolute.nix
new file mode 100644
index 0000000..8ca9927
--- /dev/null
+++ b/nix-language/FileSystemPaths/absolute.nix
@@ -0,0 +1 @@
+/absolute/path
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/currentDir.nix b/nix-language/FileSystemPaths/currentDir.nix
new file mode 100644
index 0000000..0f6d39d
--- /dev/null
+++ b/nix-language/FileSystemPaths/currentDir.nix
@@ -0,0 +1 @@
+./.
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/parentDir.nix b/nix-language/FileSystemPaths/parentDir.nix
new file mode 100644
index 0000000..4badd8e
--- /dev/null
+++ b/nix-language/FileSystemPaths/parentDir.nix
@@ -0,0 +1 @@
+../.
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/relative.2.nix b/nix-language/FileSystemPaths/relative.2.nix
new file mode 100644
index 0000000..b5a2f72
--- /dev/null
+++ b/nix-language/FileSystemPaths/relative.2.nix
@@ -0,0 +1 @@
+relative/path
\ No newline at end of file
diff --git a/nix-language/FileSystemPaths/relative.nix b/nix-language/FileSystemPaths/relative.nix
new file mode 100644
index 0000000..5a93bb2
--- /dev/null
+++ b/nix-language/FileSystemPaths/relative.nix
@@ -0,0 +1 @@
+./relative
\ No newline at end of file
diff --git a/nix-language/FunctionLibraries/addOne.nix b/nix-language/FunctionLibraries/addOne.nix
new file mode 100644
index 0000000..25f13fc
--- /dev/null
+++ b/nix-language/FunctionLibraries/addOne.nix
@@ -0,0 +1 @@
+x: x + 1
diff --git a/nix-language/FunctionLibraries/addOneAndTwo.nix b/nix-language/FunctionLibraries/addOneAndTwo.nix
new file mode 100644
index 0000000..e0ef584
--- /dev/null
+++ b/nix-language/FunctionLibraries/addOneAndTwo.nix
@@ -0,0 +1 @@
+1 + 2
diff --git a/nix-language/FunctionLibraries/builtins.nix b/nix-language/FunctionLibraries/builtins.nix
new file mode 100644
index 0000000..54c9395
--- /dev/null
+++ b/nix-language/FunctionLibraries/builtins.nix
@@ -0,0 +1 @@
+builtins.toString
\ No newline at end of file
diff --git a/nix-language/FunctionLibraries/import.nix b/nix-language/FunctionLibraries/import.nix
new file mode 100644
index 0000000..241513d
--- /dev/null
+++ b/nix-language/FunctionLibraries/import.nix
@@ -0,0 +1 @@
+import ./addOneAndTwo.nix
\ No newline at end of file
diff --git a/nix-language/FunctionLibraries/importImmediately.nix b/nix-language/FunctionLibraries/importImmediately.nix
new file mode 100644
index 0000000..845636c
--- /dev/null
+++ b/nix-language/FunctionLibraries/importImmediately.nix
@@ -0,0 +1 @@
+import ./addOne.nix 1
\ No newline at end of file
diff --git a/nix-language/FunctionLibraries/pkgs.lib.nix b/nix-language/FunctionLibraries/pkgs.lib.nix
new file mode 100644
index 0000000..2db7571
--- /dev/null
+++ b/nix-language/FunctionLibraries/pkgs.lib.nix
@@ -0,0 +1,8 @@
+# The nixpkgs repository contains an attribute set called lib, 
+# which provides a large number of useful functions.
+# They are implemented in the Nix language
+# , as opposed to builtins, which are part of the language itself.
+let
+    pkgs = import <nixpkgs> {};
+in
+pkgs.lib.strings.toUpper "lookup paths considered harmful"
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/additionalAttributes.example.nix b/nix-language/Functions/AttributeSetArgument/additionalAttributes.example.nix
new file mode 100644
index 0000000..e0a67a7
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/additionalAttributes.example.nix
@@ -0,0 +1,5 @@
+let
+    f = { a, b, ... }: a + b;
+in
+f { a = 1; b = 2; c = 3; }
+
diff --git a/nix-language/Functions/AttributeSetArgument/additionalAttributes.nix b/nix-language/Functions/AttributeSetArgument/additionalAttributes.nix
new file mode 100644
index 0000000..2ee5925
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/additionalAttributes.nix
@@ -0,0 +1 @@
+{a, b, ...}: a + b
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/counterExample.nix b/nix-language/Functions/AttributeSetArgument/counterExample.nix
new file mode 100644
index 0000000..d5e0594
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/counterExample.nix
@@ -0,0 +1,4 @@
+let
+  f = {a, b}: a + b;
+in
+f { a = 1; b = 2; c = 3; }
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/default.nix b/nix-language/Functions/AttributeSetArgument/default.nix
new file mode 100644
index 0000000..e8ec475
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/default.nix
@@ -0,0 +1 @@
+{a, b}: a + b
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/defaultValues.emptySet.nix b/nix-language/Functions/AttributeSetArgument/defaultValues.emptySet.nix
new file mode 100644
index 0000000..58b960f
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/defaultValues.emptySet.nix
@@ -0,0 +1,4 @@
+let
+  f = {a ? 0, b ? 0}: a + b;
+in
+f { } # empty attribute set
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/defaultValues.nix b/nix-language/Functions/AttributeSetArgument/defaultValues.nix
new file mode 100644
index 0000000..c37e171
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/defaultValues.nix
@@ -0,0 +1,4 @@
+let
+  f = {a, b ? 0}: a + b;
+in
+f { a = 1; }
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/example.nix b/nix-language/Functions/AttributeSetArgument/example.nix
new file mode 100644
index 0000000..07ccd74
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/example.nix
@@ -0,0 +1,4 @@
+let
+  f = {a, b}: a + b;
+in
+f { a = 1; b = 2; }
\ No newline at end of file
diff --git a/nix-language/Functions/AttributeSetArgument/namedAttributes.alternative.nix b/nix-language/Functions/AttributeSetArgument/namedAttributes.alternative.nix
new file mode 100644
index 0000000..cd6bc41
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/namedAttributes.alternative.nix
@@ -0,0 +1,5 @@
+# args@{a,b,...}: a + b + args.c
+let
+  f = {a, b, ...}@args: a + b + args.c;
+in
+f { a = 1; b = 2; c = 3; }
diff --git a/nix-language/Functions/AttributeSetArgument/namedAttributes.nix b/nix-language/Functions/AttributeSetArgument/namedAttributes.nix
new file mode 100644
index 0000000..2b8c375
--- /dev/null
+++ b/nix-language/Functions/AttributeSetArgument/namedAttributes.nix
@@ -0,0 +1 @@
+{a,b,...}@args: a + b + args.c
diff --git a/nix-language/Functions/CallingFunctions/functionCall.attrSet.nix b/nix-language/Functions/CallingFunctions/functionCall.attrSet.nix
new file mode 100644
index 0000000..e55e324
--- /dev/null
+++ b/nix-language/Functions/CallingFunctions/functionCall.attrSet.nix
@@ -0,0 +1,5 @@
+let
+    f = x: x.a;
+    v = { a = 1; };
+in
+f v
\ No newline at end of file
diff --git a/nix-language/Functions/CallingFunctions/functionCall.nix b/nix-language/Functions/CallingFunctions/functionCall.nix
new file mode 100644
index 0000000..377ba69
--- /dev/null
+++ b/nix-language/Functions/CallingFunctions/functionCall.nix
@@ -0,0 +1,4 @@
+let
+    f = x: x.a;
+in
+    f {a = 1; }
\ No newline at end of file
diff --git a/nix-language/Functions/CallingFunctions/functionCall.parenthesis.nix b/nix-language/Functions/CallingFunctions/functionCall.parenthesis.nix
new file mode 100644
index 0000000..8b8ec1f
--- /dev/null
+++ b/nix-language/Functions/CallingFunctions/functionCall.parenthesis.nix
@@ -0,0 +1 @@
+(x: x + 1) 1
\ No newline at end of file
diff --git a/nix-language/Functions/CallingFunctions/functionOnListWithoutParenthesis.nix b/nix-language/Functions/CallingFunctions/functionOnListWithoutParenthesis.nix
new file mode 100644
index 0000000..0186fa6
--- /dev/null
+++ b/nix-language/Functions/CallingFunctions/functionOnListWithoutParenthesis.nix
@@ -0,0 +1,6 @@
+let
+    f = x: x + 1;
+    a = 1;
+in 
+# placing f and a on the list
+    [ f a ]
\ No newline at end of file
diff --git a/nix-language/Functions/CallingFunctions/parenthesisOnList.nix b/nix-language/Functions/CallingFunctions/parenthesisOnList.nix
new file mode 100644
index 0000000..26a3fe9
--- /dev/null
+++ b/nix-language/Functions/CallingFunctions/parenthesisOnList.nix
@@ -0,0 +1,7 @@
+let
+    f = x: x + 1;
+    a = 1;
+ 
+in 
+# applies f to a
+    [ (f a) ]
diff --git a/nix-language/Functions/MultipleArgs/callingTwoArgFunction.oneValue.nix b/nix-language/Functions/MultipleArgs/callingTwoArgFunction.oneValue.nix
new file mode 100644
index 0000000..a21578a
--- /dev/null
+++ b/nix-language/Functions/MultipleArgs/callingTwoArgFunction.oneValue.nix
@@ -0,0 +1,4 @@
+let
+    f = x: y: x + y;
+in
+f 1
\ No newline at end of file
diff --git a/nix-language/Functions/MultipleArgs/callingTwoArgFunction.twoValue.nix b/nix-language/Functions/MultipleArgs/callingTwoArgFunction.twoValue.nix
new file mode 100644
index 0000000..6ecbe60
--- /dev/null
+++ b/nix-language/Functions/MultipleArgs/callingTwoArgFunction.twoValue.nix
@@ -0,0 +1,4 @@
+let
+    f = x: y: x + y;
+in
+f 1 2
\ No newline at end of file
diff --git a/nix-language/Functions/MultipleArgs/default.nix b/nix-language/Functions/MultipleArgs/default.nix
new file mode 100644
index 0000000..b0ae024
--- /dev/null
+++ b/nix-language/Functions/MultipleArgs/default.nix
@@ -0,0 +1 @@
+x: y: x + y
diff --git a/nix-language/Functions/MultipleArgs/twoArgFunction.nix b/nix-language/Functions/MultipleArgs/twoArgFunction.nix
new file mode 100644
index 0000000..f7b2a11
--- /dev/null
+++ b/nix-language/Functions/MultipleArgs/twoArgFunction.nix
@@ -0,0 +1 @@
+x: y: x + y
\ No newline at end of file
diff --git a/nix-language/Functions/attributeSetArg.nix b/nix-language/Functions/attributeSetArg.nix
new file mode 100644
index 0000000..2cba7ec
--- /dev/null
+++ b/nix-language/Functions/attributeSetArg.nix
@@ -0,0 +1 @@
+{ a, b }: a + b
\ No newline at end of file
diff --git a/nix-language/Functions/attributeSetArg.withAdditional.nix b/nix-language/Functions/attributeSetArg.withAdditional.nix
new file mode 100644
index 0000000..70a1a8a
--- /dev/null
+++ b/nix-language/Functions/attributeSetArg.withAdditional.nix
@@ -0,0 +1 @@
+{ a, b, ...}: a + b
\ No newline at end of file
diff --git a/nix-language/Functions/attributeSetArg.withDefault.nix b/nix-language/Functions/attributeSetArg.withDefault.nix
new file mode 100644
index 0000000..01e74ca
--- /dev/null
+++ b/nix-language/Functions/attributeSetArg.withDefault.nix
@@ -0,0 +1 @@
+{ a, b ? 0 }: a + b
\ No newline at end of file
diff --git a/nix-language/Functions/default.nix b/nix-language/Functions/default.nix
new file mode 100644
index 0000000..14c5c4b
--- /dev/null
+++ b/nix-language/Functions/default.nix
@@ -0,0 +1 @@
+x: x + 1
\ No newline at end of file
diff --git a/nix-language/Functions/multipleArgs.nesting.nix b/nix-language/Functions/multipleArgs.nesting.nix
new file mode 100644
index 0000000..f7b2a11
--- /dev/null
+++ b/nix-language/Functions/multipleArgs.nesting.nix
@@ -0,0 +1 @@
+x: y: x + y
\ No newline at end of file
diff --git a/nix-language/Functions/nameAttributeSetArg.nix b/nix-language/Functions/nameAttributeSetArg.nix
new file mode 100644
index 0000000..b84b813
--- /dev/null
+++ b/nix-language/Functions/nameAttributeSetArg.nix
@@ -0,0 +1,3 @@
+args@{ a,b,... }: a + b + args.c
+# or
+#{ a,b,...}@args: a + b + args.c
\ No newline at end of file
diff --git a/nix-language/Functions/namedFunction.nix b/nix-language/Functions/namedFunction.nix
new file mode 100644
index 0000000..0dcab75
--- /dev/null
+++ b/nix-language/Functions/namedFunction.nix
@@ -0,0 +1,3 @@
+let
+    f = x: x + 1;
+in f
\ No newline at end of file
diff --git a/nix-language/Functions/singleArgument.nix b/nix-language/Functions/singleArgument.nix
new file mode 100644
index 0000000..01de18d
--- /dev/null
+++ b/nix-language/Functions/singleArgument.nix
@@ -0,0 +1 @@
+x; x + 1
diff --git a/nix-language/Impurities/data b/nix-language/Impurities/data
new file mode 100644
index 0000000..190a180
--- /dev/null
+++ b/nix-language/Impurities/data
@@ -0,0 +1 @@
+123
diff --git a/nix-language/Impurities/fetchers.nix b/nix-language/Impurities/fetchers.nix
new file mode 100644
index 0000000..0c6752e
--- /dev/null
+++ b/nix-language/Impurities/fetchers.nix
@@ -0,0 +1 @@
+builtins.fetchurl "https://github.com/NixOS/nix/archive/7c3ab5751568a0bc63430b33a5169c5e4784a0ff.tar.gz"
diff --git a/nix-language/Impurities/fetchers.tarball.nix b/nix-language/Impurities/fetchers.tarball.nix
new file mode 100644
index 0000000..422ef82
--- /dev/null
+++ b/nix-language/Impurities/fetchers.tarball.nix
@@ -0,0 +1 @@
+builtins.fetchTarball "https://github.com/NixOS/nix/archive/7c3ab5751568a0bc63430b33a5169c5e4784a0ff.tar.gz"
diff --git a/nix-language/Impurities/paths.nix b/nix-language/Impurities/paths.nix
new file mode 100644
index 0000000..222c617
--- /dev/null
+++ b/nix-language/Impurities/paths.nix
@@ -0,0 +1,4 @@
+#For directories the same thing happens: 
+#The entire directory (including nested files and directories) is copied to the Nix store
+#,and the evaluated string becomes the Nix store path of the directory.
+"${./data}"
diff --git a/nix-language/IndentedStrings/default.nix b/nix-language/IndentedStrings/default.nix
new file mode 100644
index 0000000..4931c53
--- /dev/null
+++ b/nix-language/IndentedStrings/default.nix
@@ -0,0 +1,5 @@
+''
+multi
+line
+string
+''
\ No newline at end of file
diff --git a/nix-language/IndentedStrings/defaultWithSpaces.nix b/nix-language/IndentedStrings/defaultWithSpaces.nix
new file mode 100644
index 0000000..c98b599
--- /dev/null
+++ b/nix-language/IndentedStrings/defaultWithSpaces.nix
@@ -0,0 +1,5 @@
+''
+  one
+   two
+    three
+''
\ No newline at end of file
diff --git a/nix-language/Inheritance/inheritance.nix b/nix-language/Inheritance/inheritance.nix
new file mode 100644
index 0000000..7c31044
--- /dev/null
+++ b/nix-language/Inheritance/inheritance.nix
@@ -0,0 +1,30 @@
+#inherit is shorthand for assigning the value of a name from an existing scope 
+#to the same name in a nested scope. 
+#It is for convenience to avoid repeating the same name multiple times.
+let
+  x = 1;
+  y = 2;
+in
+{
+  inherit x y;
+}
+
+# the fragment ```inherit x y;``` is equivalent to:
+# ``` x = x;y = y;
+
+# It is also possible to inherit names from a specific attribute set with parentheses (inherit (...) ...).
+#let
+#  a = { x = 1; y = 2; };
+#in
+#{
+#  inherit (a) x y;
+#}
+
+# The fragment
+#inherit (a) x y;
+# is equivalent to
+#x = a.x; y = a.y;
+# inherit also work inside ``let`` expressions.
+#let
+#  inherit ({ x = 1; y = 2; }) x y;
+#in [ x y ]
\ No newline at end of file
diff --git a/nix-language/README.md b/nix-language/README.md
new file mode 100644
index 0000000..de0f341
--- /dev/null
+++ b/nix-language/README.md
@@ -0,0 +1,2 @@
+# Nix Language Learn
+This folder has some files copied from the [nix tutorial](https://nix.dev/tutorials/nix-language.html). For more, search the [nix manual](https://nix.dev/manual/nix/2.18/language/index.html)
\ No newline at end of file
diff --git a/nix-language/WorkedExamples/nixosConfig.nix b/nix-language/WorkedExamples/nixosConfig.nix
new file mode 100644
index 0000000..ba8ca7a
--- /dev/null
+++ b/nix-language/WorkedExamples/nixosConfig.nix
@@ -0,0 +1,9 @@
+{ config, pkgs, ... }: {
+
+  imports = [ ./hardware-configuration.nix ];
+
+  environment.systemPackages = with pkgs; [ git ];
+
+  # ...
+
+}
\ No newline at end of file
diff --git a/nix-language/WorkedExamples/package.nix b/nix-language/WorkedExamples/package.nix
new file mode 100644
index 0000000..7c6a876
--- /dev/null
+++ b/nix-language/WorkedExamples/package.nix
@@ -0,0 +1,18 @@
+{ lib, stdenv, fetchurl }:
+
+stdenv.mkDerivation rec {
+
+  pname = "hello";
+
+  version = "2.12";
+
+  src = fetchurl {
+    url = "mirror://gnu/${pname}/${pname}-${version}.tar.gz";
+    sha256 = "1ayhp9v4m4rdhjmnl2bq3cibrbqqkgjbl3s7yk2nhlh8vj3ay16g";
+  };
+
+  meta = with lib; {
+    license = licenses.gpl3Plus;
+  };
+
+}
\ No newline at end of file
diff --git a/nix-language/WorkedExamples/shellEnv.nix b/nix-language/WorkedExamples/shellEnv.nix
new file mode 100644
index 0000000..dd06c55
--- /dev/null
+++ b/nix-language/WorkedExamples/shellEnv.nix
@@ -0,0 +1,10 @@
+{ pkgs ? import <nixpkgs> {} }:
+let
+  message = "hello world";
+in
+pkgs.mkShellNoCC {
+  packages = with pkgs; [ cowsay ];
+  shellHook = ''
+    cowsay ${message}
+  '';
+}
\ No newline at end of file
diff --git a/nix-language/abc.nix b/nix-language/abc.nix
new file mode 100644
index 0000000..06bfdf8
--- /dev/null
+++ b/nix-language/abc.nix
@@ -0,0 +1 @@
+{ a.b.c = 1; }
diff --git a/nix-language/default.nix b/nix-language/default.nix
new file mode 100644
index 0000000..e0ef584
--- /dev/null
+++ b/nix-language/default.nix
@@ -0,0 +1 @@
+1 + 2
diff --git a/nix-language/letin.nix b/nix-language/letin.nix
new file mode 100644
index 0000000..2594897
--- /dev/null
+++ b/nix-language/letin.nix
@@ -0,0 +1,4 @@
+let
+ a = 1;
+ in
+ a + a
diff --git a/nix-language/letin_ab.nix b/nix-language/letin_ab.nix
new file mode 100644
index 0000000..35fcb79
--- /dev/null
+++ b/nix-language/letin_ab.nix
@@ -0,0 +1,26 @@
+let
+  b = a + 1;
+  a = 1;
+in
+a + b
+# Alternatives:
+
+# with rec
+#rec {
+#  b = a + 1;
+#  c = a + b;
+#  a = 1;
+#}
+
+# lists
+#rec {
+#  b = a + 1;
+#  c = a + b;
+#  a = 1;
+#}
+
+# failing counter-exmaple
+#{
+#  a = let x = 1; in x;
+#  b = x;
+#}
\ No newline at end of file
diff --git a/nix-language/notesOnWhitespace.nix b/nix-language/notesOnWhitespace.nix
new file mode 100644
index 0000000..9e4bc9b
--- /dev/null
+++ b/nix-language/notesOnWhitespace.nix
@@ -0,0 +1,10 @@
+# White space is used to delimit lexical tokens, where required. It is otherwise insignificant.
+# Line breaks, indentation, and additional spaces are for readers' convenience.
+# the following are equivalent
+
+#let
+# x = 1;
+# y = 2;
+# in x + y
+
+let a=1;b=2;in a+b
diff --git a/nix-language/oneAndTwo.nix b/nix-language/oneAndTwo.nix
new file mode 100644
index 0000000..e0ef584
--- /dev/null
+++ b/nix-language/oneAndTwo.nix
@@ -0,0 +1 @@
+1 + 2
diff --git a/nix-language/stringInterpolation/confusionWithShell.nix b/nix-language/stringInterpolation/confusionWithShell.nix
new file mode 100644
index 0000000..82646e6
--- /dev/null
+++ b/nix-language/stringInterpolation/confusionWithShell.nix
@@ -0,0 +1,5 @@
+# the $out is a shell script variable
+let
+  out = "Nix";
+in
+"echo ${out} > $out"
\ No newline at end of file
diff --git a/nix-language/stringInterpolation/stringInterpolation.counter.nix b/nix-language/stringInterpolation/stringInterpolation.counter.nix
new file mode 100644
index 0000000..fb96061
--- /dev/null
+++ b/nix-language/stringInterpolation/stringInterpolation.counter.nix
@@ -0,0 +1,4 @@
+let
+  x = 1;
+in
+"${x} + ${x} = ${x + x}"
\ No newline at end of file
diff --git a/nix-language/stringInterpolation/stringInterpolation.nix b/nix-language/stringInterpolation/stringInterpolation.nix
new file mode 100644
index 0000000..94575a5
--- /dev/null
+++ b/nix-language/stringInterpolation/stringInterpolation.nix
@@ -0,0 +1,4 @@
+let
+  name = "Nix";
+in
+"hello ${name}"
\ No newline at end of file
diff --git a/nix-language/stringInterpolation/stringInterpolationHardToRead.nix b/nix-language/stringInterpolation/stringInterpolationHardToRead.nix
new file mode 100644
index 0000000..0d5e785
--- /dev/null
+++ b/nix-language/stringInterpolation/stringInterpolationHardToRead.nix
@@ -0,0 +1,4 @@
+let
+  a = "no";
+in
+"${a + " ${a + " ${a}"}"}"
\ No newline at end of file
diff --git a/nix-language/with.nix b/nix-language/with.nix
new file mode 100644
index 0000000..8b1a701
--- /dev/null
+++ b/nix-language/with.nix
@@ -0,0 +1,32 @@
+let
+  a = {
+    x = 1;
+    y = 2;
+    z = 3;
+  };
+in
+with a; [ x y z ]
+
+# The following is equivalent to the previous expression
+# let
+#   a = {
+#     x = 1;
+#     y = 2;
+#     z = 3;
+#   };
+# in
+# [ a.x a.y a.z ]
+
+
+# Failing counter exmaple
+#let
+#  a = {
+#    x = 1;
+#    y = 2;
+#    z = 3;
+#  };
+#in
+#{
+#  b = with a; [ x y z ];
+#  c = x;
+#}
\ No newline at end of file
diff --git a/nixpkgs-releases.sh b/nixpkgs-releases.sh
new file mode 100755
index 0000000..805b55e
--- /dev/null
+++ b/nixpkgs-releases.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env nix-shell
+#! nix-shell -i bash --pure
+#! nix-shell -p bash cacert curl jq python3Packages.xmljson
+#! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/2a601aafdc5605a5133a2ca506a34a3a73377247.tar.gz
+
+curl https://github.com/NixOS/nixpkgs/releases.atom | xml2json | jq .