Perhaps the syntax '((' and '()' will be valid one day, but not at the

moment.  This diff works the two checks for them into the main for
parsing loop.

diff --git a/usr.bin/mg/interpreter.c b/usr.bin/mg/interpreter.c
index 1996d81..cef596e 100644 (file)
--- a/usr.bin/mg/interpreter.c
+++ b/usr.bin/mg/interpreter.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: interpreter.c,v 1.30 2021/05/08 09:27:35 lum Exp $   */
+/*      $OpenBSD: interpreter.c,v 1.31 2021/05/08 12:57:41 lum Exp $   */
 /*
  * This file is in the public domain.
  *
@@ -125,7 +125,8 @@ int
 foundparen(char *funstr, int llen, int lnum)
 {
        const char      *lrp = NULL;
-       char            *p, *begp = NULL, *endp = NULL, *regs, *prechr;
+       char            *p, *begp = NULL, *endp = NULL, *prechr;
+       char            *lastchr = NULL;
        int              i, ret, pctr, expctr, blkid, inquote, esc;
        int              elen, spc;
 
@@ -133,18 +134,6 @@ foundparen(char *funstr, int llen, int lnum)
        blkid = 1;
        lnm = lnum;
 
-       /*
-        * Currently can't do () or (( at the moment,
-        * just drop out - stops a segv. TODO.
-        */
-       regs = "[(]+[\t ]*[)]+";
-        if (doregex(regs, funstr))
-               return(dobeep_num("Empty lists not supported at moment line",
-                   lnm));
-       regs = "[(]+[\t ]*[(]+";
-        if (doregex(regs, funstr))
-               return(dobeep_num("Multiple consecutive left parantheses "\
-                   "found line:", lnm));
        /*
         * load expressions into a list called 'expentry', to be processd
         * when all are obtained.
@@ -175,6 +164,9 @@ foundparen(char *funstr, int llen, int lnum)
                if (*p == '\\') {
                        esc = 1;
                } else if (*p == '(') {
+                       if (lastchr != NULL && *lastchr == '(')
+                               return(dobeep_num("Multiple consecutive "\
+                                   "left parantheses line", lnm));
                        if (inquote == 0) {
                                if (begp != NULL) {
                                        if (endp == NULL)
@@ -200,6 +192,9 @@ foundparen(char *funstr, int llen, int lnum)
                        }
                        esc = spc = 0;
                } else if (*p == ')') {
+                       if (lastchr != NULL && *lastchr == '(')
+                               return(dobeep_num("Empty parenthesis "\
+                                   "not supported line", lnm));
                        if (inquote == 0) {
                                if (begp != NULL) {
                                        if (endp == NULL)
@@ -260,6 +255,8 @@ foundparen(char *funstr, int llen, int lnum)
                        }
                        esc = 0;
                }
+               if (*p != '\t' && *p != ' ' && inquote == 0)
+                       lastchr = p;
 
                if (pctr == 0) {
                        blkid++;