You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
61 lines
1.9 KiB
OCaml
61 lines
1.9 KiB
OCaml
(** {1 Micro pre-processor for Heptagon}
|
|
|
|
This module uses camlp4 to replace some fixed strings by string literals at
|
|
compile-time. At the moment, we only replace DATE by the current date and
|
|
STDLIB by "../../lib". Each pseudo-variable can be overriden by the
|
|
environment variable of the same name. *)
|
|
|
|
open Camlp4.PreCast
|
|
open Unix
|
|
|
|
(** {2 Compile-time strings} *)
|
|
|
|
(** [date] is a string denoting the current date. *)
|
|
let date =
|
|
let days = [| "sunday"; "monday"; "tuesday"; "wednesday"; "thursday";
|
|
"friday"; "saturday" |]
|
|
and months = [| "january"; "february"; "march"; "april"; "may"; "june";
|
|
"july"; "august"; "september"; "october"; "november";
|
|
"december" |] in
|
|
|
|
let tm = Unix.localtime (Unix.gettimeofday ()) in
|
|
|
|
let (day, month) =
|
|
let prefix s = String.sub s 0 3 in
|
|
(prefix days.(tm.tm_wday), prefix months.(tm.tm_mon)) in
|
|
|
|
Format.sprintf "%s. %s. %d %d:%d:%d CET %d"
|
|
day month tm.tm_mday tm.tm_hour tm.tm_min tm.tm_sec (1900 + tm.tm_year)
|
|
|
|
|
|
(** [stdlib] is the location of the standard Heptagon library. *)
|
|
let stdlib =
|
|
try
|
|
Unix.getenv "STDLIB"
|
|
with
|
|
| Not_found ->
|
|
let wd = Unix.getcwd () in
|
|
Filename.concat (Filename.dirname (Filename.dirname wd)) "lib"
|
|
|
|
(** Association list defining bindings between constant and our "compile-time
|
|
constants". *)
|
|
let env = [("DATE", date); ("STDLIB", stdlib)]
|
|
|
|
(** {2 Camlp4 hook} *)
|
|
|
|
(** Our home-grown super-duper syntax filter. Looks for string constants present
|
|
in [subst] and replaces them according to the couple found in the
|
|
environment defined above. *)
|
|
let filter =
|
|
object
|
|
inherit Ast.map as super
|
|
method expr e = match e with
|
|
| <:expr< $str:s$ >> when List.mem_assoc s env ->
|
|
let repl = try Sys.getenv s with Not_found -> List.assoc s env in
|
|
<:expr@here< $str:repl$ >>
|
|
| x -> x
|
|
end;;
|
|
|
|
(** Tell Camlp4 about it. *)
|
|
AstFilters.register_str_item_filter filter#str_item
|