Add WAT lexer.

1 files changed, 60 insertions, 0 deletions

diff --git a/syntax-highlight/wat.scm b/syntax-highlight/wat.scm
new file mode 100644
index 0000000..4966d05
--- /dev/null
+++ b/syntax-highlight/wat.scm
@@ -0,0 +1,60 @@
+;;; 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)))))