;;; guile-syntax-highlight --- General-purpose syntax highlighter
;;; Copyright © 2023 David Thompson <davet@gnu.org>
;;;
;;; Guile-syntax-highlight is free software; you can redistribute it
;;; and/or modify it under the terms of the GNU Lesser General Public
;;; License as published by the Free Software Foundation; either
;;; version 3 of the License, or (at your option) any later version.
;;;
;;; Guile-syntax-highlight is distributed in the hope that it will be
;;; useful, but WITHOUT ANY WARRANTY; without even the implied
;;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
;;; See the GNU Lesser General Public License for more details.
;;;
;;; You should have received a copy of the GNU Lesser General Public
;;; License along with guile-syntax-highlight.  If not, see
;;; <http://www.gnu.org/licenses/>.

;;; Commentary:
;;
;; Syntax highlighting for WebAssembly text format.
;;
;;; Code:

(define-module (syntax-highlight wat)
  #:use-module (ice-9 match)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-26)
  #:use-module (syntax-highlight lexers)
  #:export (%default-special-symbols
            %default-special-prefixes
            make-wat-lexer
            lex-wat))

(define char-set:wat-delimiters
  (char-set-union char-set:whitespace
                  (char-set #\( #\))))

(define char-set:wat-symbol
  (char-set-complement char-set:wat-delimiters))

(define %keywords
  '("i31" "i32" "i64" "f32" "f64" "eq" "string" "module" "type" "func"
    "array" "struct" "mut" "ref" "extern" "null" "field" "sub" "import"
    "export" "param" "result" "block" "loop" "local" "rec"))

;; TODO: WAT has some weird commenting syntax that this doesn't
;; support, among probably other missing things.
(define lex-wat
  (lex-consume
   (lex-any (lex-char-set char-set:whitespace)
            (lex-tag 'open (lex-string "("))
            (lex-tag 'close (lex-string ")"))
            (lex-tag 'comment (lex-delimited ";" #:until "\n"))
            (lex-tag 'special
                     (lex-filter (lambda (str)
                                   (any (cut string=? <> str) %keywords))
                                 (lex-char-set char-set:wat-symbol)))
            (lex-tag 'string (lex-delimited "\""))
            (lex-tag 'symbol (lex-char-set char-set:wat-symbol)))))