loosely translate Python to shellHEAD1.0.0master

3 files changed, 118 insertions, 148 deletions

diff --git a/README.md b/README.md
index 1072dcf..57bde75 100644
--- a/README.md
+++ b/README.md
@@ -1,53 +1,29 @@
-# tex2nix
+# texnix
+
+_texnix is based on [tex2nix](https://github.com/Mic92/tex2nix)._
 
 Generate Texlive environment containing all dependencies for your document
 rather than downloading gigabytes of texlive packages.
 
-## Installation
-
-With stable nix you can do:
-
-``` console
-nix-build && ./result/bin/tex2nix
-```
-
-If you use flakes put the following in your inputs
-
-```nix
-{
-  inputs.tex2nix.url = "github:Mic92/tex2nix";
-  inputs.tex2nix.inputs.utils.follows = "nixpkgs";
-}
-```
-
-or just do:
-
-```console
-$ nix run github:Mic92/tex2nix
-```
-
-
-## USAGE
+## Usage
 
 ```console
-$ tex2nix main.tex
-wrote tex-env.nix
-$ cat tex-env.nix
-# Generated with tex2nix 0.0.0
-{ texlive }:
-(texlive.combine {
-    inherit (texlive) scheme-small;
-    "varwidth" = texlive."varwidth";
-    "tabu" = texlive."tabu";
-
-})
+$ echo '\usepackage{babel}' | texnix -
+# Generated with texnix 1.0.0
+{ texlive, extraTexPackages ? {} }:
+texlive.combine ({
+  inherit (texlive) scheme-small;
+  "babel" = texlive."babel";
+  "ctablestack" = texlive."ctablestack";
+  "luatexbase" = texlive."luatexbase";
+} // extraTexPackages)
 ```
 
-tex2nix does not follow `\input` or `\include`. However you can specify multiple
+texnix does not follow `\input` or `\include`. However you can specify multiple
 texfiles as input
 
 ```console
-$ tex2nix *.tex
+$ texnix *.tex > tex-env.nix
 ```
 
 The resulting expression can be imported like this to in your document directory:
@@ -56,7 +32,7 @@ The resulting expression can be imported like this to in your document directory
 # shell.nix
 with import <nixpkgs> {};
 mkShell {
-  buildInputs = [ (pkgs.callPackage ./tex-env.nix {}) ];
+  buildInputs = [ (callPackage ./tex-env.nix {}) ];
 }
 ```
 
diff --git a/tex2nix/__init__.py b/tex2nix/__init__.py
deleted file mode 100644
index 252895a..0000000
--- a/tex2nix/__init__.py
+++ /dev/null
@@ -1,108 +0,0 @@
-#!/usr/bin/env python3
-
-import re
-import fileinput
-import subprocess
-import json
-import os
-
-from typing import Set, Iterable
-
-
-def get_nix_packages() -> Set[str]:
-    res = subprocess.run(
-        [
-            "nix",
-            "--experimental-features",
-            "nix-command",
-            "eval",
-            "--json",
-            "-f",
-            "<nixpkgs>",
-            "texlive",
-            "--apply",
-            "builtins.attrNames",
-        ],
-        check=True,
-        text=True,
-        stdout=subprocess.PIPE,
-    )
-    return set(json.loads(res.stdout))
-
-
-def get_packages(line: str) -> Set[str]:
-    match = re.match(r"\\(?:usepackage|RequirePackage).*{([^}]+)}", line)
-    if not match:
-        return set()
-    args = match.group(1)
-    packages = set()
-    for arg in args.split(","):
-        packages.add(arg.strip())
-    return packages
-
-
-def _collect_deps(
-    working_set: Set[str], done: Set[str], all_packages: Set[str]
-) -> None:
-    package = working_set.pop()
-    done.add(package)
-    cmd = ["nix-build", "--no-out-link", "<nixpkgs>", "-A", f"texlive.{package}.pkgs"]
-    paths = subprocess.run(cmd, check=True, text=True, stdout=subprocess.PIPE)
-    for dir in paths.stdout.split("\n"):
-        path = os.path.join(dir, "tex")
-        for root, _, files in os.walk(path):
-            for fname in files:
-                path = os.path.join(root, fname)
-                with open(path, "rb") as f:
-                    for line in f:
-                        packages = get_packages(line.decode("utf-8", errors="ignore"))
-                        working_set |= all_packages & (packages - done)
-
-
-def collect_deps(packages: Set[str], all_packages: Set[str]) -> Set[str]:
-    working_set: Set[str] = set(packages)
-    done: Set[str] = set()
-    while working_set:
-        _collect_deps(working_set, done, all_packages)
-
-    return done
-
-
-def write_tex_env(dir: str, packages: Set[str]) -> str:
-    name = os.path.join(dir, "tex-env.nix")
-    with open(name, "w") as f:
-        f.write(
-            """# Generated with tex2nix 0.0.0
-{ texlive, extraTexPackages ? {} }:
-(texlive.combine ({
-    inherit (texlive) scheme-small;
-"""
-        )
-        for package in packages:
-            f.write(f'    "{package}" = texlive."{package}";\n')
-        f.write(
-            """
-} // extraTexPackages))
-"""
-        )
-    print("wrote tex-env.nix...")
-    return name
-
-
-def extract_dependencies(lines: Iterable[str]) -> Set[str]:
-    packages = set()
-    for line in lines:
-        packages |= get_packages(line)
-
-    all_packages = get_nix_packages()
-    nix_packages = packages & all_packages
-    return collect_deps(nix_packages, all_packages)
-
-
-def main() -> None:
-    packages = extract_dependencies(fileinput.input())
-    write_tex_env(os.getcwd(), packages)
-
-
-if __name__ == "__main__":
-    main()
diff --git a/texnix b/texnix
new file mode 100755
index 0000000..1f7cf7e
--- /dev/null
+++ b/texnix
@@ -0,0 +1,102 @@
+#! /bin/sh
+# usage: texnix TEXFILE...
+# Print Nix expression for creating a TeX working environment for a set of
+# TEXFILEs.
+
+set -efu
+
+texnix_version=1.0.0
+
+TMPDIR=$(mktemp --tmpdir -d texnix.XXXXXXXX)
+trap 'rm -R "$TMPDIR"' EXIT
+
+# Export TMPDIR for subsequent calls to mktemp.
+export TMPDIR
+
+# usage: extract_dependencies TEXFILE...
+# Print all (transitive) dependencies of TEXFILEs.
+extract_dependencies() {(
+  all_packages=$TMPDIR/all_packages
+  dependencies=$TMPDIR/dependencies
+  working_set=$TMPDIR/working_set
+
+  get_all_packages > "$all_packages"
+  truncate -s 0 "$dependencies"
+  get_packages "$@" | comm -12 - "$all_packages" > "$working_set"
+
+  while test -s "$working_set"; do
+    package=$(pop "$working_set")
+
+    echo "$package" | add "$dependencies"
+
+    tmp_working_set=$(mktemp working_set.XXXXXXXX)
+    { cat "$working_set"
+      texlive_cat "$package" | get_packages - | comm -2 - "$dependencies"
+    } | sort -u | comm -12 - "$all_packages" > "$tmp_working_set"
+    mv "$tmp_working_set" "$working_set"
+  done
+
+  cat "$dependencies"
+)}
+
+# usage: texlive_cat PACKAGE
+# Concatenate and print all files of a TeX live package.
+texlive_cat() {
+  nix-build --no-out-link '<nixpkgs>' -A texlive."$1".pkgs |
+  while read -r path; do
+    find "$path" -mindepth 1 -maxdepth 1 -name tex -exec find {} -type f \;
+  done |
+  xargs cat
+}
+
+# usage: get_all_packages
+# Print all TeX live packages.
+get_all_packages() {
+  nix-instantiate \
+      --eval \
+      --json \
+      --strict \
+      -E \
+      'builtins.attrNames (import <nixpkgs> {}).texlive' \
+    |
+  jq -r .[] |
+  sort -u
+}
+
+# usage: get_packages TEXFILE...
+# Print all packages used in TEXFILEs.
+get_packages() {
+  sed -rn '
+    s:.*(usepackage|RequirePackage).*\{([^}]+)}:\2:;T
+    s:,:\n:g
+    p
+  ' "$@" |
+  sort -u
+}
+
+# usage: add SETFILE
+# Add lines read from stdin to SETFILE.
+add() {(
+  t=$(mktemp add.XXXXXXXX)
+  sort -u - "$1" > "$t"
+  mv "$t" "$1"
+)}
+
+# usage: pop FILE
+# Remove first line of FILE and print it to stdout.
+pop() {
+  head -1 "$1"
+  sed -i 1d "$1"
+}
+
+cat <<EOF
+# Generated with texnix $texnix_version
+{ texlive, extraTexPackages ? {} }:
+texlive.combine ({
+  inherit (texlive) scheme-small;
+  $(extract_dependencies "$@" | sed '
+    s/.*/"&" = texlive."&";/
+    2,$s/^/  /
+  ')
+} // extraTexPackages)
+EOF