From b0474491d74a47ab675ed0cc4d67bd3e82889ec2 Mon Sep 17 00:00:00 2001
From: Charlotte Thomas <contact@nwa2coco.fr>
Date: Wed, 23 Mar 2022 16:09:16 +0100
Subject: [PATCH] add align, align*, and equation support

---
 lib/htmlgen.ml |  2 +-
 lib/mathgen.ml | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++
 test.txt       |  5 ++++-
 3 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 lib/mathgen.ml

diff --git a/lib/htmlgen.ml b/lib/htmlgen.ml
index e24963a..e1bd4d2 100644
--- a/lib/htmlgen.ml
+++ b/lib/htmlgen.ml
@@ -202,7 +202,7 @@ let prepare_body name str toc =
     in read_preamble p;
     let doc = separate_sections doc
     in let doc = calculate_environments doc 
-    in 
+    in let doc = Mathgen.re_calculate_env doc in 
     (match (Hashtbl.find_opt preamble "glossary") with
       | Some s -> init_glossary s
       | None -> (););
diff --git a/lib/mathgen.ml b/lib/mathgen.ml
new file mode 100644
index 0000000..4c86eb4
--- /dev/null
+++ b/lib/mathgen.ml
@@ -0,0 +1,51 @@
+open Parser
+
+let generate_latex_command s l = 
+  let line = "\\"^s in
+  let args = String.concat "," l in 
+  let line = if args="" then line else Printf.sprintf "%s[%s]" line args in
+  line;;
+  
+
+
+let generate_latex l = 
+  let rec unparse acc l = 
+    match l with 
+      | [] -> String.concat " " acc 
+      | Line s::q -> unparse (s::acc) q 
+      | AtomicCmd (s,l)::q -> 
+        let line = generate_latex_command s l in 
+        unparse (line::acc) q
+      | OneArgCmd (s,l,l2)::q ->
+        let line = generate_latex_command s l in 
+        let line = Printf.sprintf "%s{%s}" line (unparse [] l2) in
+        unparse (line::acc) q 
+      | MultipleArgCmd (s,l,l2)::q ->
+        let line = generate_latex_command s l in
+        let l = List.map (unparse []) l2 in  
+        let line = Printf.sprintf "%s{%s}" line (String.concat "\n" l) in
+        unparse (line::acc) q
+      | _::q -> unparse acc q
+    in unparse [] l;;
+
+let env_de_latexer env = 
+  match env with
+    | e -> e;;
+
+let re_calculate_env ast =
+  let rec aux acc ast = 
+    match ast with
+      | [] -> acc
+      | Env (s,n)::q when s="align" 
+        -> aux (Math(Printf.sprintf "\\begin{align}%s\\end{align}" (generate_latex n))::acc) q 
+      | Env (s,n)::q when s="align*" 
+        -> aux (Math(Printf.sprintf "\\begin{align*}%s\\end{align*}" (generate_latex n))::acc) q
+      | Env (s,n)::q when s="equation" 
+        -> aux (Math(Printf.sprintf "\\begin{equation}%s\\end{equation}" (generate_latex n))::acc) q
+      | Env(s,n)::q 
+        -> let ast = aux [] n in 
+           let ast = List.rev ast
+           in let env = Env(s,ast)
+           in aux (env::acc) q 
+      | e::q -> aux (e::acc) q
+  in List.rev (aux [] ast);;
\ No newline at end of file
diff --git a/test.txt b/test.txt
index 2ad6311..24377ac 100644
--- a/test.txt
+++ b/test.txt
@@ -5,7 +5,10 @@ Hello
 tralalala
 \bigskip
 This is an integral 
-$\int^a_b f(x) \mathrm{d}x$
+\begin{align*}
+2x &= 4 \\
+3y &= 3
+\end{align*}
 \begin{center}
 au center
 \end{center}