Add structured output formatter for JSON and plain text (but don't use them yet).

Using the new structured printer support in sprinter.h, implement
sprinter_json_create, which returns a new JSON structured output
formatter. The formatter prints output similar to the existing JSON, but
with differences in whitespace (mostly newlines, --output=summary prints
the entire message summary on one line, not split across multiple lines).

Also implement a "structured" formatter for plain text that prints
prefixed strings, to be used with notmuch-search.c plain text output.

1 files changed, 10 insertions, 0 deletions

diff --git a/sprinter.h b/sprinter.h
index 77dc26f3..6680d419 100644
--- a/sprinter.h
+++ b/sprinter.h
@@ -55,4 +55,14 @@ typedef struct sprinter {
     notmuch_bool_t is_text_printer;
 } sprinter_t;
 
+
+/* Create a new unstructured printer that emits the default text format
+ * for "notmuch search". */
+struct sprinter *
+sprinter_text_create (const void *ctx, FILE *stream);
+
+/* Create a new structure printer that emits JSON. */
+struct sprinter *
+sprinter_json_create (const void *ctx, FILE *stream);
+
 #endif // NOTMUCH_SPRINTER_H