added stubs for patsubst

src/m4-builtin.lisp

@@ -358,3 +358,5 @@
     (progn
       (m4-warn "too few arguments to builtin `translit'")
       (macro-return string))))
+
+; (defm4macro "patsubst" (string &optional regexp replacement) (:minimum-arguments 1)) ; TODO

src/m4-util.lisp

@@ -204,3 +204,19 @@ searched additionally passing ARGS."
                *m4-quote-start*
                (funcall (macro-token-m4macro token) nil :expansion)
                *m4-quote-end*))
+
+;; (defmacro with-regex-search-handler (regexp string startpos registers &body body)
+;;   `(if regexp
+;;     (handler-case
+;;      (multiple-value-bind (startpos registers)
+;;          (regex-search regexp string)
+;;        ,@body
+;;      (regex-compilation-failure (condition)
+;;        (m4-warn (format nil "bad regular expression: `~a': ~a"
+;;                         regexp condition))
+;;        "0")
+;;      (regex-internal-error ()
+;;        (m4-warn (format nil "error matching regular expression `~a'" regexp))
+;;        "0"))
+;;     (prog1 "0" (m4-warn "too few arguments to builtin `regexp'")))) ; TODO
+

test/m4-macros.lisp

@@ -1505,3 +1505,30 @@ m4
 m4eof
 
 :depends (list "translit")))
+
+
+;; 11.6 Substituting text by regular expression
+(deftest gnu-m4-11.6-1 ()
+  (m4-test
+#>m4>
+patsubst(`GNUs not Unix', `^', `OBS: ')
+patsubst(`GNUs not Unix', `\<', `OBS: ')
+patsubst(`GNUs not Unix', `\w*', `(\&)')
+patsubst(`GNUs not Unix', `\w+', `(\&)')
+patsubst(`GNUs not Unix', `[A-Z][a-z]+')
+patsubst(`GNUs not Unix', `not', `NOT\')
+m4
+
+#>m4>
+OBS: GNUs not Unix
+OBS: GNUs OBS: not OBS: Unix
+(GNUs)() (not)() (Unix)()
+(GNUs) (not) (Unix)
+GN not
+GNUs NOT Unix
+m4
+
+:error #>m4eof>cl-m4:2:15: Warning: trailing \ ignored in replacement
+m4eof
+
+:depends (list "patsubst")))