Compile LaTeX code using minted without the Python venv

This is a hack, but not a dirty one: a new command `catala pygmentize` is added,
which is just a wrapper around `pygmentize` that calls it with the proper lexers
defined.

The point is that this needs no installation, just a stock `pygmentize`
installation and the `catala` binary.

INSTALL.md

@@ -72,11 +72,10 @@ Next, install all the packages that Catala depends on with
     make dependencies
 
 This should ensure everything is set up for developing on the Catala compiler!
+
 The Python dependencies are installed inside a local virtual environment
-(`venv`). The Makefile rules will use it automatically when building the syntax
-cheat-sheet, for example, but if you need to otherwise colorise Catala code, or
-use generated Python code, you should run the following command once in every
-new shell session:
+(`venv`). To use it, for example to run Python code generated by Catala, you
+should run the following command once in every new shell session:
 
     . _python_venv/bin/activate
 

compiler/catala_utils/cli.ml

@@ -378,6 +378,10 @@ let info =
           "Prints a debugging verbatim of the statement calculus intermediate \
            representation of the Catala program. Use the $(b,-s) option to \
            restrict the output to a particular scope." );
+      `I
+        ( "$(b,pygmentize)",
+          "This special command is a wrapper around the $(b,pygmentize) \
+           command that enables support for colorising Catala code." );
       `S Manpage.s_authors;
       `P "The authors are listed by alphabetical order.";
       `P "Nicolas Chataing <nicolas.chataing@ens.fr>";

compiler/driver.ml

@@ -403,6 +403,10 @@ let driver source_file (options : Cli.options) : int =
     -1
 
 let main () =
+  if
+    Array.length Sys.argv >= 2
+    && String.lowercase_ascii Sys.argv.(1) = "pygmentize"
+  then Literate.Pygmentize.exec ();
   let return_code =
     Cmdliner.Cmd.eval'
       (Cmdliner.Cmd.v Cli.info (Cli.catala_t (fun f -> driver (FileName f))))

compiler/literate/literate_common.ml

@@ -125,6 +125,16 @@ let check_exceeding_lines
                 "%s"
                 String.(sub s max_len (len_s - max_len)))))
 
+let with_pygmentize_lexer lang f =
+  let lexer_py =
+    let lexer_fname = "lexer_" ^ Cli.language_code lang ^ ".py" in
+    match Pygment_lexers.read lexer_fname with
+    | None -> failwith "Pygments lexer not found for this language"
+    | Some lexer -> lexer
+  in
+  File.with_temp_file "pygments_lexer_" ".py" ~contents:lexer_py
+  @@ fun pyg_lexer -> f ["-l"; pyg_lexer; "-x"]
+
 let call_pygmentize ?lang args =
   let cmd = "pygmentize" in
   let check_exit n =
@@ -137,12 +147,5 @@ let call_pygmentize ?lang args =
   match lang with
   | None -> File.process_out ~check_exit cmd args
   | Some lang ->
-    let lexer_py =
-      let lexer_fname = "lexer_" ^ Cli.language_code lang ^ ".py" in
-      match Pygment_lexers.read lexer_fname with
-      | None -> failwith "Pygments lexer not found for this language"
-      | Some lexer -> lexer
-    in
-    File.with_temp_file "pygments_lexer_" ".py" ~contents:lexer_py
-    @@ fun pyg_lexer ->
-    File.process_out ~check_exit cmd ("-l" :: pyg_lexer :: "-x" :: args)
+    with_pygmentize_lexer lang
+    @@ fun lex_args -> File.process_out ~check_exit cmd (lex_args @ args)

compiler/literate/literate_common.mli

@@ -51,3 +51,7 @@ val call_pygmentize : ?lang:Cli.backend_lang -> string list -> string
 (** Calls the [pygmentize] command with the given arguments, and returns the
     results as a string. If [lang] is specified, the proper arguments for the
     Catala lexer are already passed. *)
+
+val with_pygmentize_lexer : Cli.backend_lang -> (string list -> 'a) -> 'a
+(** Creates the required lexer file and returns the corresponding [pygmentize]
+    command-line arguments *)

compiler/literate/pygmentize.ml

@@ -0,0 +1,54 @@
+(* This file is part of the Catala compiler, a specification language for tax
+   and social benefits computation rules. Copyright (C) 2020 Inria, contributor:
+   Louis Gesbert <louis.gesbert@inria.fr>
+
+   Licensed under the Apache License, Version 2.0 (the "License"); you may not
+   use this file except in compliance with the License. You may obtain a copy of
+   the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+   WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+   License for the specific language governing permissions and limitations under
+   the License. *)
+
+open Catala_utils
+open Literate_common
+
+let lang_of_ext s =
+  if String.starts_with ~prefix:"catala_" s then
+    match s with
+    | "catala_en" -> Some Cli.En
+    | "catala_fr" -> Some Cli.Fr
+    | "catala_pl" -> Some Cli.Pl
+    | _ -> failwith "Unknown Catala dialect"
+  else None
+
+let exec () =
+  let args = List.tl (Array.to_list Sys.argv) in
+  let rec find_lang acc = function
+    | "-l" :: lang :: r -> Some lang, List.rev_append acc r
+    | x :: r -> find_lang (x :: acc) r
+    | [] -> None, List.rev acc
+  in
+  let lang, args = find_lang [] args in
+  let catala_lang =
+    match lang with
+    | Some l -> lang_of_ext l
+    | None ->
+      List.find_map
+        (fun s ->
+          match Filename.extension s with
+          | "" -> None
+          | e -> lang_of_ext (String.sub e 1 (String.length e - 1)))
+        args
+  in
+  match catala_lang with
+  | None -> Unix.execvp "pygmentize" (Array.of_list args)
+  | Some lang ->
+    with_pygmentize_lexer lang
+    @@ fun lex_args ->
+    Unix.execvp "pygmentize"
+      (Array.of_list (("pygmentize" :: lex_args) @ List.tl args))

compiler/literate/pygmentize.mli

@@ -0,0 +1,19 @@
+(* This file is part of the Catala compiler, a specification language for tax
+   and social benefits computation rules. Copyright (C) 2020 Inria, contributor:
+   Louis Gesbert <louis.gesbert@inria.fr>
+
+   Licensed under the Apache License, Version 2.0 (the "License"); you may not
+   use this file except in compliance with the License. You may obtain a copy of
+   the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+   WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+   License for the specific language governing permissions and limitations under
+   the License. *)
+
+val exec : unit -> unit
+(** Wrapper around the [pygmentize] binary with support for Catala. Reads the
+    arguments directly from Sys.argv *)

doc/syntax/syntax_en.tex

@@ -26,6 +26,8 @@
 
 \setlist[itemize]{noitemsep, topsep=0pt}
 
+\renewcommand{\MintedPygmentize}{../../_build/default/compiler/catala.exe pygmentize}
+
 % backquote dejavu fix
 \makeatletter
 \chardef\straightquote@code=\catcode`'

doc/syntax/syntax_fr.tex

@@ -26,6 +26,8 @@
 
 \setlist[itemize]{noitemsep, topsep=0pt}
 
+\renewcommand{\MintedPygmentize}{../../_build/default/compiler/catala.exe pygmentize}
+
 % backquote dejavu fix
 \makeatletter
 \chardef\straightquote@code=\catcode`'