commit 14ec6c27b73b716cd5db5a751d8cd114396635c2
Author: leo <wanderer@dotya.ml>
Date:   Sun May 14 16:47:01 2023 +0200

    initial commit

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..27963fa
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,22 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+
+# go files (excluding templates)
+[*.{go,mod,sum}]
+indent_style = tab
+indent_size = 4
+tab_width = 4
+
+[*.nix]
+indent_style = space
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{yaml,yml}]
+indent_style = space
+indent_size = 2
diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..6125787
--- /dev/null
+++ b/.envrc
@@ -0,0 +1,7 @@
+use flake
+
+# ref: https://github.com/direnv/direnv/wiki/Vim
+# comment out if not planning to use this
+#add_extra_vimrc
+
+# vim: ff=unix ft=sh
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..b838fe7
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+*.md		diff=markdown
+*.go		diff=golang
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e7181ee
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,8 @@
+.direnv
+
+# binaries/symlinks to binaries
+result
+result-*
+
+# coverage or other binary files
+*.out
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..80247fa
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,103 @@
+# Copyright 2023 wanderer <a_mirre at utb dot cz>
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+---
+run:
+  go: 1.20.3
+  tests: true
+
+issues:
+  max-issues-per-linter: 0
+  max-same-issues: 0
+
+linters:
+  enable:
+    - bidichk
+    # - dupl
+    # The linter 'deadcode' is deprecated (since v1.49.0) due to: The owner
+    # seems to have abandoned the linter.  Replaced by unused.
+    # - deadcode
+    - decorder
+    - dogsled
+    - exportloopref
+    - forbidigo
+    - gas
+    - gocognit
+    - goconst
+    - gocritic
+    - godot
+    - govet
+    - gofmt
+    - gofumpt
+    - goimports
+    - goprintffuncname
+    - gosec
+    - ineffassign
+    # The linter 'ifshort' is deprecated (since v1.48.0) due to: The repository
+    # of the linter has been deprecated by the owner.
+    # - ifshort
+    - misspell
+    # - prealloc
+    - revive
+    - tparallel
+    - unconvert
+    - unparam
+    - unused
+    # The linter 'varcheck' is deprecated (since v1.49.0) due to: The owner
+    # seems to have abandoned the linter.  Replaced by unused.
+    # - varcheck
+    - wastedassign
+    - whitespace
+    - wsl
+
+linter-settings:
+  dupl:
+    threshold: 100
+  gocritic:
+    enabled-tags:
+      - diagnostic
+      - experimental
+      - opinionated
+      - performance
+      - style
+    disabled-checks:
+      - dupImport  # https://github.com/go-critic/go-critic/issues/845
+      - ifElseChain
+      - octalLiteral
+      - whyNoLint
+      - wrapperFunc
+  gocyclo:
+    min-complexity: 15
+  gofumpt:
+    extra-rules: true
+    lang-version: "1.18"
+  govet:
+    check-shadowing: true
+  revive:
+    severity: warning
+    confidence: 0.8
+    errorCode: 1
+    warningCode: 1
+    rules:
+      - name: blank-imports
+      - name: context-as-argument
+      - name: context-keys-type
+      - name: dot-imports
+      - name: error-return
+      - name: error-strings
+      - name: error-naming
+      - name: exported
+      - name: if-return
+      - name: increment-decrement
+      - name: var-naming
+      - name: var-declaration
+      - name: package-comments
+      - name: range
+      - name: receiver-naming
+      - name: time-naming
+      - name: unexported-return
+      - name: indent-error-flow
+      - name: errorf
+      - name: duplicated-imports
+      - name: modifies-value-receiver
+...
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..b2a966d
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,56 @@
+---
+fail_fast: false
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.4.0
+    hooks:
+      - id: check-merge-conflict
+  - repo: meta
+    hooks:
+      - id: check-hooks-apply
+  - repo: local
+    hooks:
+      - id: pre-commit-validate-config
+        name: pre-commit validate config
+        entry: pre-commit validate-config
+        pass_filenames: false
+        files: '^.pre-commit-config.yaml$'
+        language: system
+  - repo: https://github.com/TekWizely/pre-commit-golang
+    rev: v1.0.0-rc.1
+    hooks:
+      - id: go-mod-tidy
+      - id: go-test-mod
+      - id: golangci-lint-mod
+      - id: go-build-mod
+  - repo: local
+    hooks:
+      - id: statix
+        name: statix
+        entry: statix check .
+        always_run: false
+        pass_filenames: false
+        files: '\.*.nix$'
+        language: system
+      - id: nix-fmt
+        name: nix fmt
+        entry: nix fmt -- --check .
+        always_run: false
+        pass_filenames: false
+        files: '\.*.nix$'
+        language: system
+      - id: flake-check
+        name: nix flake check
+        entry: nix flake check --keep-going
+        always_run: false
+        pass_filenames: false
+        files: "flake.(nix|lock)$"
+        language: system
+      - id: nix-build-go-proj
+        name: nix build go proj
+        entry: nix build .#proj
+        pass_filenames: false
+        # trigger this hook on changes to any of nix (also flake.lock) files
+        # and go's mod or sum files
+        files: '\.*.(nix|lock|mod|sum)$'
+        language: system
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b970b98
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# [ak0da](https://git.dotya.ml/wanderer/ak0da)
+
+this repo contains code of compulsory tasks for `AK0DA` course.
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..c580745
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,16 @@
+(
+  import
+  (
+    let
+      lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+    in
+      fetchTarball {
+        url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+        sha256 = lock.nodes.flake-compat.locked.narHash;
+      }
+  )
+  {
+    src = ./.;
+  }
+)
+.defaultNix
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..b5ee88f
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,60 @@
+{
+  "nodes": {
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1673956053,
+        "narHash": "sha256-4gtG9iQuiKITOjNQQeQIpoIB6b16fm+504Ch3sNKLd8=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "35bb57c0c8d8b62bbfd284272c928ceb64ddbde9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "nix-filter": {
+      "locked": {
+        "lastModified": 1681154353,
+        "narHash": "sha256-MCJ5FHOlbfQRFwN0brqPbCunLEVw05D/3sRVoNVt2tI=",
+        "owner": "numtide",
+        "repo": "nix-filter",
+        "rev": "f529f42792ade8e32c4be274af6b6d60857fbee7",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "nix-filter",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1683968890,
+        "narHash": "sha256-FuNtjMvT07cJydY5NRyRhIni/dEwkSkijmFEdsmqdkA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "ea11a3977f4cba013d8680667616be827c967ac0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "nix-filter": "nix-filter",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..c716d03
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,176 @@
+{
+  description = "Data Analysis";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-compat = {
+      url = "github:edolstra/flake-compat";
+      flake = false;
+    };
+    nix-filter = {
+      url = "github:numtide/nix-filter";
+    };
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    nix-filter,
+    ...
+  }: let
+    projname = "ak0da";
+
+    # to work with older version of flakes
+    lastModifiedDate =
+      self.lastModifiedDate or self.lastModified or "19700101";
+
+    # Generate a user-friendly version number.
+    version = "v0.0.0";
+
+    supportedSystems = ["x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin"];
+    forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+    pkgs = forAllSystems (system: nixpkgs.legacyPackages.${system});
+    # Nixpkgs instantiated for supported system types.
+    nixpkgsFor = forAllSystems (system:
+      import nixpkgs {
+        inherit system;
+        overlays = [
+          # no overlay imports atm
+          # (import ./overlay.nix)
+        ];
+      });
+  in {
+    formatter = forAllSystems (
+      system:
+        nixpkgsFor.${system}.alejandra
+    );
+    packages = forAllSystems (system: let
+      baseurl = "https://git.dotya.ml/wanderer/ak0da/";
+      pkgs = nixpkgsFor.${system};
+      inherit (pkgs) lib overlays;
+    in rec {
+      proj = with pkgs;
+        buildGo120Module rec {
+          pname = "proj";
+          buildInputs = [
+            go_1_20
+          ];
+          nativeBuildInputs = [pkgconfig];
+
+          overrideModAttrs = _: {
+            # GOPROXY = "direct";
+            GOFLAGS = "-buildmode=pie -trimpath -mod=readonly -modcacherw";
+          };
+
+          inherit version;
+          doCheck = false;
+          # use go.mod for managing go deps, instead of vendor-only dir
+          proxyVendor = true;
+          tags = []; # go "-tags" to build with
+          ldflags = [
+            "-s"
+            "-w"
+          ];
+
+          # dont't forget to update vendorSha256 whenever go.mod or go.sum change
+          vendorSha256 = null;
+
+          # In 'nix develop', we don't need a copy of the source tree
+          # in the Nix store.
+          src = nix-filter.lib.filter {
+            # when in doubt, check out
+            # https://github.com/numtide/nix-filter#design-notes
+            # tl;dr: it'd be best to include folders, however there are
+            # currently issues with that approach.
+            root = lib.cleanSource ./.;
+            exclude = [
+              ./flake.nix
+              ./flake.lock
+              ./default.nix
+              ./shell.nix
+              ./overlay.nix
+
+              ./README.md
+
+              ./.envrc
+              ./.gitattributes
+              ./.gitignore
+              ./.golangci.yml
+              ./.editorconfig
+              ./.pre-commit-config.yaml
+
+              # program output
+              ./out
+              ./res
+
+              # nix result symlink
+              ./result
+
+              # the entire .git folder
+              ./.git
+            ];
+          };
+
+          meta = {
+            description = "implementation of the compulsory task for ak0da";
+            homepage = baseurl;
+            license = lib.licenses.gpl3;
+            maintainers = ["wanderer"];
+            platforms = lib.platforms.linux ++ lib.platforms.darwin;
+          };
+        };
+
+      default = proj;
+    });
+
+    apps = forAllSystems (system: rec {
+      proj = {
+        type = "app";
+        program = "${self.packages.${system}.${projname}}/bin/proj";
+      };
+      default = proj;
+    });
+
+    devShells = forAllSystems (system: let
+      upcache = pkgs.writeShellScriptBin "upcache" ''
+        ## refs:
+        ##   https://fzakaria.com/2020/08/11/caching-your-nix-shell.html
+        ##   https://nixos.wiki/wiki/Caching_nix_shell_build_inputs
+        nix-store --query --references $(nix-instantiate shell.nix) | \
+          xargs nix-store --realise | \
+          xargs nix-store --query --requisites | \
+          cachix push ${projname}
+        nix build --json \
+          | jq -r '.[].outputs | to_entries[].value' \
+          | cachix push ${projname}
+      '';
+      add-license = pkgs.writeShellScriptBin "add-license" ''
+        go run github.com/google/addlicense@v1.0.0 -v \
+          -c "wanderer <a_mirre at utb dot cz>" \
+          -l "GPL-3.0-or-later" -s .
+      '';
+    in {
+      default = pkgs.${system}.mkShellNoCC {
+        name = "${projname}-" + version;
+
+        GOFLAGS = "-buildmode=pie -trimpath -mod=readonly -modcacherw";
+        GOLDFLAGS = "-s -w";
+        CGO_CFLAGS = "-g0 -Ofast -mtune=native -flto";
+        CGO_LDFLAGS = "-Wl,-O1,-sort-common,-as-needed,-z,relro,-z,now,-flto -pthread";
+
+        shellHook = ''
+          echo " -- in ${projname} dev shell..."
+        '';
+
+        packages = with pkgs.${system}; [
+          pre-commit
+          statix
+
+          # deps
+          go_1_20
+          go-tools
+          gofumpt
+        ];
+      };
+    });
+  };
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..7038405
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module git.dotya.ml/wanderer/ak0da
+
+go 1.20
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..da29a2c
--- /dev/null
+++ b/main.go
@@ -0,0 +1,4 @@
+package main
+
+func main() {
+}
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..017cf3f
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,16 @@
+(
+  import
+  (
+    let
+      lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+    in
+      fetchTarball {
+        url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+        sha256 = lock.nodes.flake-compat.locked.narHash;
+      }
+  )
+  {
+    src = ./.;
+  }
+)
+.shellNix