refactor: massively reorganize and add nix infrastructure

2024/documents/by-course/phil-1/paper-1/package.nix

@@ -0,0 +1,35 @@
+{
+  pkgs,
+  typstPackagesCache,
+  typixLib,
+  cleanTypstSource,
+  ...
+}:
+let
+  src = cleanTypstSource ./.;
+  commonArgs = {
+    typstSource = "main.typ";
+
+    fontPaths = [
+      # Add paths to fonts here
+      # "${pkgs.roboto}/share/fonts/truetype"
+    ];
+
+    virtualPaths = [
+      # Add paths that must be locally accessible to typst here
+      # {
+      #   dest = "icons";
+      #   src = "${inputs.font-awesome}/svgs/regular";
+      # }
+    ];
+
+    XDG_CACHE_HOME = typstPackagesCache;
+  };
+
+in
+typixLib.buildTypstProject (
+  commonArgs
+  // {
+    inherit src;
+  }
+)

2024/documents/by-name/digression-linear-algebra/package.nix

@@ -0,0 +1,35 @@
+{
+  pkgs,
+  typstPackagesCache,
+  typixLib,
+  cleanTypstSource,
+  ...
+}:
+let
+  src = cleanTypstSource ./.;
+  commonArgs = {
+    typstSource = "main.typ";
+
+    fontPaths = [
+      # Add paths to fonts here
+      # "${pkgs.roboto}/share/fonts/truetype"
+    ];
+
+    virtualPaths = [
+      # Add paths that must be locally accessible to typst here
+      # {
+      #   dest = "icons";
+      #   src = "${inputs.font-awesome}/svgs/regular";
+      # }
+    ];
+
+    XDG_CACHE_HOME = typstPackagesCache;
+  };
+
+in
+typixLib.buildTypstProject (
+  commonArgs
+  // {
+    inherit src;
+  }
+)

2024/flake.lock

@@ -0,0 +1,99 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1726560853,
+        "narHash": "sha256-X6rJYSESBVr3hBoH0WbKE5KvhPU5bloyZ2L4K60/fPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c1dfcf08411b08f6b8615f7d8971a2bfa81d5e8a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1729256560,
+        "narHash": "sha256-/uilDXvCIEs3C9l73JTACm4quuHUsIHcns1c+cHUJwA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4c2fcb090b1f3e5b47eaa7bd33913b574a11e0a0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "typix": "typix",
+        "typst-packages": "typst-packages"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "typix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1728290750,
+        "narHash": "sha256-piLZT8398O69hy0e3gX8hUWqSzbCslMCt10pT8d6c8E=",
+        "owner": "loqusion",
+        "repo": "typix",
+        "rev": "62d032735ad32a9a90225c06cb0857677fc753ee",
+        "type": "github"
+      },
+      "original": {
+        "owner": "loqusion",
+        "repo": "typix",
+        "type": "github"
+      }
+    },
+    "typst-packages": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1729252723,
+        "narHash": "sha256-xdaQYNw1GApaJnXJO4WnUTNuYeRXisxIUSuAzVXFEW4=",
+        "owner": "typst",
+        "repo": "packages",
+        "rev": "9bcf190c85da91be6df9f5fc25a93ce5812489cc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "typst",
+        "repo": "packages",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

2024/flake.nix

@@ -0,0 +1,92 @@
+{
+  description = "Compiling work in 2024 in a reproducible manner";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+    typix = {
+      url = "github:loqusion/typix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    flake-utils.url = "github:numtide/flake-utils";
+
+    typst-packages = {
+      url = "github:typst/packages";
+      flake = false;
+    };
+
+    # Example of downloading icons from a non-flake source
+    # font-awesome = {
+    #   url = "github:FortAwesome/Font-Awesome";
+    #   flake = false;
+    # };
+  };
+
+  outputs =
+    inputs@{
+      nixpkgs,
+      typix,
+      flake-utils,
+      ...
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      let
+        typstPackagesSrc = "${inputs.typst-packages}/packages";
+
+        typstPackagesCache = pkgs.stdenv.mkDerivation {
+          name = "typst-packages-cache";
+          src = typstPackagesSrc;
+          dontBuild = true;
+          installPhase = ''
+            mkdir -p "$out/typst/packages"
+            cp -LR --reflink=auto --no-preserve=mode -t "$out/typst/packages" "$src"/*
+          '';
+        };
+        typixLib = typix.lib.${system};
+      in
+      let
+        alexandriaLib = import ./nix/lib {
+          inherit pkgs typixLib typstPackagesCache;
+        };
+
+      in
+      {
+        # checks = {
+        #   inherit build-drv build-script watch-script;
+        # };
+
+        legacyPackages = {
+          phil-1 = {
+            paper-1 = alexandriaLib.callTypstProject (import ./documents/by-course/phil-1/paper-1/package.nix);
+          };
+          digression-linear-algebra = alexandriaLib.callTypstProject (import ./documents/by-name/digression-linear-algebra/package.nix);
+        };
+        #   apps = rec {
+        #     default = watch;
+        #     build = flake-utils.lib.mkApp {
+        #       drv = build-script;
+        #     };
+        #     watch = flake-utils.lib.mkApp {
+        #       drv = watch-script;
+        #     };
+        #   };
+        #
+        #   devShells.default = typixLib.devShell {
+        #     inherit (commonArgs) fontPaths virtualPaths;
+        #     packages = [
+        #       # WARNING: Don't run `typst-build` directly, instead use `nix run .#build`
+        #       # See https://github.com/loqusion/typix/issues/2
+        #       # build-script
+        #       watch-script
+        #       # More packages can be added here, like typstfmt
+        #       pkgs.typstyle
+        #     ];
+        #   };
+      }
+    );
+}

2024/nix/lib/callTypstProject.nix

@@ -0,0 +1,16 @@
+{
+  pkgs,
+  typixLib,
+  typstPackagesCache,
+  cleanTypstSource,
+  ...
+}:
+package:
+package {
+  inherit
+    pkgs
+    typixLib
+    typstPackagesCache
+    cleanTypstSource
+    ;
+}

2024/nix/lib/cleanTypstSource.nix

@@ -0,0 +1,18 @@
+{ pkgs, ... }:
+src:
+let
+  inherit (pkgs) lib;
+in
+lib.cleanSourceWith {
+  src = lib.cleanSource src;
+  filter =
+    path: type:
+    let
+      isTypstSource = lib.hasSuffix ".typ" path || lib.hasSuffix ".bib" path;
+      isImage = lib.hasSuffix ".png" path || lib.hasSuffix ".jpeg" path || lib.hasSuffix ".jpg" path;
+      isSpecialFile = builtins.elem (builtins.baseNameOf path) [
+        "typst.toml"
+      ];
+    in
+    type == "directory" || isTypstSource || isSpecialFile || isImage;
+}

2024/nix/lib/default.nix

@@ -0,0 +1,19 @@
+{
+  pkgs,
+  typstPackagesCache,
+  typixLib,
+}:
+let
+  defaultArgs = {
+    inherit pkgs typstPackagesCache typixLib;
+  };
+in
+rec {
+  cleanTypstSource = (import ./cleanTypstSource.nix) defaultArgs;
+  callTypstProject = (import ./callTypstProject.nix) (
+    defaultArgs
+    // {
+      inherit cleanTypstSource;
+    }
+  );
+}

2024/notes/math-4a/week-2/main.typ

@@ -0,0 +1,165 @@
+#import "@preview/unequivocal-ams:0.1.1": ams-article, theorem, proof
+
+#show: ams-article.with(
+  title: [A Digression on Abstract Linear Algebra],
+  authors: (
+    (
+      name: "Youwen Wu",
+      organization: [University of California, Santa Barbara],
+      email: "youwen@ucsb.edu",
+      url: "https://youwen.dev",
+    ),
+  ),
+  bibliography: bibliography("refs.bib"),
+)
+
+= Introduction
+
+Many introductory linear algebra classes focus on _application_. In general,
+this is a red herring and is engineer-speak for "we will teach you how to
+crunch numbers with no regard for conceptual understanding."
+
+If you are a math major (or math-adjacent, such as Computer Science), this
+class is essentially useless for you. You will learn how to perform trivial
+numerical operations such as the _matrix multiplication_, _matrix-vector
+multiplication_, _row reduction_, and other trite tasks better suited for
+computers.
+
+If you are taking this course, you might as well learn linear algebra properly.
+Otherwise, you will have to re-learn it later on, anyways. Completing a math
+course without gaining a theoretical appreciation for the topics at hand is an
+unequivocal waste of time. I have prepared this brief crash course designed to
+fill in the theoretical gaps left by this class.
+
+= Basic Notions
+
+== Vector spaces
+
+Before we can understand vectors, we need to first discuss _vector spaces_. Thus
+far, you have likely encountered vectors primarily in physics classes,
+generally in the two-dimensional plane. You may conceptualize them as arrows in
+space. For vectors of size $>3$, a hand waving argument is made that they are
+essentially just arrows in higher dimensional spaces.
+
+It is helpful to take a step back from this primitive geometric understanding
+of the vector. Let us build up a rigorous idea of vectors from first
+principles.
+
+=== Vector axioms
+
+The so-called _axioms_ of a _vector space_ (which we'll call the vector space
+$V$) are as follows:
+
+#enum[
+  Commutativity: $u + v = v + u, " " forall u,v in V$
+][
+  Associativity: $(u + v) + w = u + (v + w), " " forall u,v,w in V$
+][
+  Zero vector: $exists$ a special vector, denoted $0$, such that $v + 0 = v, " " forall v in V$
+][
+  Additive inverse: $forall v in V, " " exists w in V "such that" v + w = 0$. Such an additive inverse is generally denoted $-v$
+][
+  Multiplicative identity: $1 v = v, " " forall v in V$
+][
+  Multiplicative associativity: $(alpha beta) v = alpha (beta v) " " forall v in V, "scalars" alpha, beta$
+][
+  Distributive property for vectors: $alpha (u + v) = alpha u + alpha v " " forall u,v in V, "scalars" alpha$
+][
+  Distributive property for scalars: $(alpha + beta) v = alpha v + beta v " " forall v in V, " scalars" alpha, beta$
+]
+
+It is easy to show that the zero vector $0$ and the additive inverse $-v$ are
+_unique_. We leave the proof of this fact as an exercise.
+
+These may seem difficult to memorize, but they are essentially the same
+familiar algebraic properties of numbers you know from high school. The
+important thing to remember is which operations are valid for what objects. For
+example, you cannot add a vector and scalar, as it does not make sense.
+
+_Remark_. For those of you versed in computer science, you may recognize this
+as essentially saying that you must ensure your operations are _type-safe_.
+Adding a vector and scalar is not just false, it is an _invalid question_
+entirely because vectors and scalars and different types of mathematical
+objects. See #cite(<chen2024digression>, form: "prose") for more.
+
+=== Vectors big and small
+
+In order to begin your descent into what mathematicians colloquially recognize
+as _abstract vapid nonsense_, let's discuss which fields constitute a vector space. We
+have the familiar space where all scalars are real numbers, or $RR$. We
+generally discuss 2-D or 3-D vectors, corresponding to vectors of length 2 or
+3; in our case, $RR^2$ and $RR^3$.
+
+However, vectors in $RR$ can really be of any length. Discard your primitive
+conception of vectors as arrows in space. Vectors are simply arbitrary length
+lists of numbers (for the computer science folk: think C++ `std::vector`).
+
+_Example_. $ vec(1,2,3,4,5,6,7,8,9) $
+
+Moreover, vectors need not be in $RR$ at all. Recall that a vector space need
+only satisfy the aforementioned _axioms of a vector space_.
+
+_Example_. The vector space $CC$ is similar to $RR$, except it includes complex
+numbers. All complex vector spaces are real vector spaces (as you can simply
+restrict them to only use the real numbers), but not the other way around.
+
+In general, we can have a vector space where the scalars are in an arbitrary
+field $FF$, as long as the axioms are satisfied.
+
+_Example_. The vector space of all polynomials of degree 3, or $PP^3$. It is
+not yet clear what this vector may look like. We shall return to this example
+once we discuss _basis_.
+
+== Vector addition. Multiplication
+
+Vector addition, represented by $+$, and multiplication, represented by the
+$dot$ (dot) operator, can be done entrywise.
+
+_Example._
+
+$
+  vec(1,2,3) + vec(4,5,6) = vec(1 + 4, 2 + 5, 3 + 6) = vec(5,7,9)
+$
+$
+  vec(1,2,3) dot vec(4,5,6) = vec(1 dot 4, 2 dot 5, 3 dot 6) = vec(4,10,18)
+$
+
+This is simple enough to understand. Again, the difficulty is simply ensuring
+that you always perform operations with the correct _types_. For example, once
+we introduce matrices, it doesn't make sense to multiply or add vectors and
+matrices in this fashion.
+
+== Vector-scalar multiplication
+
+Multiplying a vector by a scalar simply results in each entry of the vector
+being multiplied by the scalar.
+
+_Example_.
+
+$ beta vec(a, b, c) = vec(beta dot a, beta dot b, beta dot c) $
+
+== Matrices
+
+Before discussing any properties of matrices, let's simply reiterate what we
+learned in class about their notation. We say a matrix with rows of length $m$,
+and columns of size $n$ (in less precise terms, a matrix with length $m$ and
+height $n$) is a $m times n$ matrix.
+
+Given a matrix
+
+$ A = mat(1,2,3;4,5,6;7,8,9) $
+
+we refer to the entry in row $j$ and column $k$ as $A_(j,k)$ .
+
+=== Matrix transpose
+
+A formalism that is useful later on is called the _transpose_, and we obtain it
+from a matrix $A$ by switching all the rows and columns. More precisely, each
+row becomes a column instead. We use the notation $A^T$ to represent the
+transpose of $A$.
+
+$
+  mat(1,2,3;4,5,6)^T = mat(1,4;2,5;3,6)
+$
+
+Formally, we can say $(A_(j,k))^T = A_(k,j)$.

2024/notes/math-4a/week-2/refs.bib

@@ -0,0 +1,6 @@
+@misc{chen2024digression,
+  author       = {Evan Chen},
+  title        = {Digression on Type Safety},
+  year         = {2024},
+  howpublished = {\url{https://web.evanchen.cc/upload/1802/tsafe-1802.pdf}},
+}

2024/result

@@ -0,0 +1 @@
+/nix/store/fv6y2dqv26lw4gzb2pf6ms5hyikpbkm9-typst