lexer: Reimplement for better testability and internationalization.

[pspp] / src / data / identifier2.c

diff --git a/src/data/identifier2.c b/src/data/identifier2.c
new file mode 100644 (file)
index 0000000..3b6458f
--- /dev/null
+++ b/src/data/identifier2.c
@@ -0,0 +1,133 @@
+/* PSPP - a program for statistical analysis.
+   Copyright (C) 1997-9, 2000, 2005, 2009, 2010, 2011 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+/* This file implements parts of identifier.h that call the msg() function.
+   This allows test programs that do not use those functions to avoid linking
+   additional object files. */
+
+#include <config.h>
+
+#include "data/identifier.h"
+
+#include <string.h>
+#include <unistr.h>
+
+#include "libpspp/cast.h"
+#include "libpspp/i18n.h"
+#include "libpspp/message.h"
+
+#include "gl/c-ctype.h"
+
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
+/* Returns true if UTF-8 string ID is an acceptable identifier in encoding
+   DICT_ENCODING (UTF-8 if null), false otherwise.  If ISSUE_ERROR is true,
+   issues an explanatory error message on failure. */
+bool
+id_is_valid (const char *id, const char *dict_encoding, bool issue_error)
+{
+  size_t dict_len;
+
+  if (!id_is_plausible (id, issue_error))
+    return false;
+
+  if (dict_encoding != NULL)
+    {
+      /* XXX need to reject recoded strings that contain the fallback
+         character. */
+      dict_len = recode_string_len (dict_encoding, "UTF-8", id, -1);
+    }
+  else
+    dict_len = strlen (id);
+
+  if (dict_len > ID_MAX_LEN)
+    {
+      if (issue_error)
+        msg (SE, _("Identifier `%s' exceeds %d-byte limit."),
+             id, ID_MAX_LEN);
+      return false;
+    }
+
+  return true;
+}
+
+/* Returns true if UTF-8 string ID is an plausible identifier, false
+   otherwise.  If ISSUE_ERROR is true, issues an explanatory error message on
+   failure.  */
+bool
+id_is_plausible (const char *id, bool issue_error)
+{
+  const uint8_t *bad_unit;
+  const uint8_t *s;
+  char ucname[16];
+  int mblen;
+  ucs4_t uc;
+
+  /* ID cannot be the empty string. */
+  if (id[0] == '\0')
+    {
+      if (issue_error)
+        msg (SE, _("Identifier cannot be empty string."));
+      return false;
+    }
+
+  /* ID cannot be a reserved word. */
+  if (lex_id_to_token (ss_cstr (id)) != T_ID)
+    {
+      if (issue_error)
+        msg (SE, _("`%s' may not be used as an identifier because it "
+                   "is a reserved word."), id);
+      return false;
+    }
+
+  bad_unit = u8_check (CHAR_CAST (const uint8_t *, id), strlen (id));
+  if (bad_unit != NULL)
+    {
+      /* If this message ever appears, it probably indicates a PSPP bug since
+         it shouldn't be possible to get invalid UTF-8 this far. */
+      if (issue_error)
+        msg (SE, _("`%s' may not be used as an identifier because it "
+                   "contains ill-formed UTF-8 at byte offset %tu."),
+             id, CHAR_CAST (const char *, bad_unit) - id);
+      return false;
+    }
+
+  /* Check that it is a valid identifier. */
+  mblen = u8_strmbtouc (&uc, CHAR_CAST (uint8_t *, id));
+  if (!lex_uc_is_id1 (uc))
+    {
+      if (issue_error)
+        msg (SE, _("Character %s (in `%s') may not appear "
+                   "as the first character in a identifier."),
+             uc_name (uc, ucname), id);
+      return false;
+    }
+
+  for (s = CHAR_CAST (uint8_t *, id + mblen);
+       (mblen = u8_strmbtouc (&uc, s)) != 0;
+        s += mblen)
+    if (!lex_uc_is_idn (uc))
+      {
+        if (issue_error)
+          msg (SE, _("Character %s (in `%s') may not appear in an "
+                     "identifier."),
+               uc_name (uc, ucname), id);
+        return false;
+      }
+
+  return true;
+}