+/* Return pointer to dewrapped string, with enclosing specified chars removed.
+The given string is modified on return. Leading whitespace is skipped while
+looking for the opening wrap character, then the rest is scanned for the trailing
+(non-escaped) wrap character. A backslash in the string will act as an escape.
+
+A nul is written over the trailing wrap, and a pointer to the char after the
+leading wrap is returned.
+
+Arguments:
+ s String for de-wrapping
+ wrap Two-char string, the first being the opener, second the closer wrapping
+ character
+Return:
+ Pointer to de-wrapped string, or NULL on error (with expand_string_message set).
+*/
+
+static uschar *
+dewrap(uschar * s, const uschar * wrap)
+{
+uschar * p = s;
+unsigned depth = 0;
+BOOL quotesmode = wrap[0] == wrap[1];
+
+while (isspace(*p)) p++;
+
+if (*p == *wrap)
+ {
+ s = ++p;
+ wrap++;
+ while (*p)
+ {
+ if (*p == '\\') p++;
+ else if (!quotesmode && *p == wrap[-1]) depth++;
+ else if (*p == *wrap)
+ if (depth == 0)
+ {
+ *p = '\0';
+ return s;
+ }
+ else
+ depth--;
+ p++;
+ }
+ }
+expand_string_message = string_sprintf("missing '%c'", *wrap);
+return NULL;
+}
+
+
+/* Pull off the leading array or object element, returning
+a copy in an allocated string. Update the list pointer.
+
+The element may itself be an abject or array.
+Return NULL when the list is empty.
+*/
+
+static uschar *
+json_nextinlist(const uschar ** list)
+{
+unsigned array_depth = 0, object_depth = 0;
+const uschar * s = *list, * item;
+
+while (isspace(*s)) s++;
+
+for (item = s;
+ *s && (*s != ',' || array_depth != 0 || object_depth != 0);
+ s++)
+ switch (*s)
+ {
+ case '[': array_depth++; break;
+ case ']': array_depth--; break;
+ case '{': object_depth++; break;
+ case '}': object_depth--; break;
+ }
+*list = *s ? s+1 : s;
+if (item == s) return NULL;
+item = string_copyn(item, s - item);
+DEBUG(D_expand) debug_printf_indent(" json ele: '%s'\n", item);
+return US item;
+}
+
+
+
+/************************************************/
+/* Return offset in ops table, or -1 if not found.
+Repoint to just after the operator in the string.
+
+Argument:
+ ss string representation of operator
+ opname split-out operator name
+*/
+
+static int
+identify_operator(const uschar ** ss, uschar ** opname)
+{
+const uschar * s = *ss;
+uschar name[256];
+
+/* Numeric comparisons are symbolic */
+
+if (*s == '=' || *s == '>' || *s == '<')
+ {
+ int p = 0;
+ name[p++] = *s++;
+ if (*s == '=')
+ {
+ name[p++] = '=';
+ s++;
+ }
+ name[p] = 0;
+ }
+
+/* All other conditions are named */
+
+else
+ s = read_name(name, sizeof(name), s, US"_");
+*ss = s;
+
+/* If we haven't read a name, it means some non-alpha character is first. */
+
+if (!name[0])
+ {
+ expand_string_message = string_sprintf("condition name expected, "
+ "but found \"%.16s\"", s);
+ return -1;
+ }
+if (opname)
+ *opname = string_copy(name);
+
+return chop_match(name, cond_table, nelem(cond_table));
+}
+
+