util: Function to parse boolean term queries

[notmuch] / util / string-util.c

diff --git a/util/string-util.c b/util/string-util.c
index 7a71049a098d70d7788e13098ac6c28c3d33f6e3..aba9aa836e6522c7c51be56458dfee6fd48618cb 100644 (file)
--- a/util/string-util.c
+++ b/util/string-util.c
@@ -22,6 +22,7 @@
 #include "string-util.h"
 #include "talloc.h"
 
+#include <ctype.h>
 #include <errno.h>
 
 char *
@@ -107,3 +108,84 @@ make_boolean_term (void *ctx, const char *prefix, const char *term,
 
     return 0;
 }
+
+static const char*
+skip_space (const char *str)
+{
+    while (*str && isspace ((unsigned char) *str))
+       ++str;
+    return str;
+}
+
+int
+parse_boolean_term (void *ctx, const char *str,
+                   char **prefix_out, char **term_out)
+{
+    int err = EINVAL;
+    *prefix_out = *term_out = NULL;
+
+    /* Parse prefix */
+    str = skip_space (str);
+    const char *pos = strchr (str, ':');
+    if (! pos)
+       goto FAIL;
+    *prefix_out = talloc_strndup (ctx, str, pos - str);
+    if (! *prefix_out) {
+       err = ENOMEM;
+       goto FAIL;
+    }
+    ++pos;
+
+    /* Implement de-quoting compatible with make_boolean_term. */
+    if (*pos == '"') {
+       char *out = talloc_array (ctx, char, strlen (pos));
+       int closed = 0;
+       if (! out) {
+           err = ENOMEM;
+           goto FAIL;
+       }
+       *term_out = out;
+       /* Skip the opening quote, find the closing quote, and
+        * un-double doubled internal quotes. */
+       for (++pos; *pos; ) {
+           if (*pos == '"') {
+               ++pos;
+               if (*pos != '"') {
+                   /* Found the closing quote. */
+                   closed = 1;
+                   pos = skip_space (pos);
+                   break;
+               }
+           }
+           *out++ = *pos++;
+       }
+       /* Did the term terminate without a closing quote or is there
+        * trailing text after the closing quote? */
+       if (!closed || *pos)
+           goto FAIL;
+       *out = '\0';
+    } else {
+       const char *start = pos;
+       /* Check for text after the boolean term. */
+       while (! is_unquoted_terminator (*pos))
+           ++pos;
+       if (*skip_space (pos)) {
+           err = EINVAL;
+           goto FAIL;
+       }
+       /* No trailing text; dup the string so the caller can free
+        * it. */
+       *term_out = talloc_strndup (ctx, start, pos - start);
+       if (! *term_out) {
+           err = ENOMEM;
+           goto FAIL;
+       }
+    }
+    return 0;
+
+ FAIL:
+    talloc_free (*prefix_out);
+    talloc_free (*term_out);
+    errno = err;
+    return -1;
+}