X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/math/qdparse.c

diff --git a/math/qdparse.c b/math/qdparse.c
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+/* -*-c-*-
+ *
+ * Quick-and-dirty parser
+ *
+ * (c) 2004 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb 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 Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <ctype.h>
+#include <string.h>
+
+#include "qdparse.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @qd_skipspc@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = context
+ *
+ * Returns:	---
+ *
+ * Use:		Skips spaces in the string.  No errors.
+ */
+
+void qd_skipspc(qd_parse *qd)
+{
+  while (isspace((unsigned char)*qd->p))
+    qd->p++;
+}
+
+/* --- @qd_delim@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = context
+ *		@int ch@ = character to compare with
+ *
+ * Returns:	Nonzero if it was, zero if it wasn't.
+ *
+ * Use:		Checks the next (non-whitespace) character is what we
+ *		expect.  If it is, the character is eaten; otherwise it's no
+ *		big deal.
+ */
+
+int qd_delim(qd_parse *qd, int ch)
+{
+  qd_skipspc(qd);
+  if (*qd->p != ch)
+    return (0);
+  qd->p++;
+  return (1);
+}
+
+/* --- @qd_enum@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = context
+ *		@const char *e@ = list of enum strings, space separated
+ *
+ * Returns:	Index of the string matched, or @-1@.
+ *
+ * Use:		Matches a keyword.
+ */
+
+int qd_enum(qd_parse *qd, const char *e)
+{
+  size_t n;
+  int i = 0;
+
+  qd_skipspc(qd);
+  for (;;) {
+    e += strspn(e, ", ");
+    if (!*e) break;
+    n = strcspn(e, ", ");
+    if (strncmp(qd->p, e, n) == 0 && !isalnum((unsigned char)qd->p[n])) {
+      qd->p += n;
+      return (i);
+    }
+    i++; e += n;
+  }
+  qd->e = "unrecognized keyword";
+  return (-1);
+}
+
+/* --- @qd_getmp@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = context
+ *
+ * Returns:	The integer extracted, or null.
+ *
+ * Use:		Parses a multiprecision integer from a string.
+ */
+
+mp *qd_getmp(qd_parse *qd)
+{
+  char *q;
+  mp *m;
+
+  qd_skipspc(qd);
+  m = mp_readstring(MP_NEW, qd->p, &q, 0);
+  if (m && !isalnum((unsigned char)*q))
+    qd->p = q;
+  else {
+    mp_drop(m);
+    qd->e = "bad number";
+  }
+  return (m);
+}
+
+/* --- @qd_eofp@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = context
+ *
+ * Returns:	Nonzero if at EOF, zero otherwise.
+ */
+
+int qd_eofp(qd_parse *qd)
+{
+  qd_skipspc(qd);
+  return (!*qd->p);
+}
+
+/*----- That's all, folks -------------------------------------------------*/