runtime: move value formatting functionality to a dedicated api

bshell.runtime/format/format.c

@@ -21,17 +21,10 @@ static void format_value_fallback(const fx_value *value, fx_stream *dest)
 
 enum bshell_status format_value_default(const fx_value *value, fx_stream *dest)
 {
-	if (fx_type_is_value_type(value->v_type)) {
-		format_value_fallback(value, dest);
-		return BSHELL_SUCCESS;
-	}
-
-	fx_object *object = NULL;
-	fx_value_get_object(value, &object);
-	enum bshell_status status = format_object_table(object, dest);
-	if (status != BSHELL_SUCCESS) {
-		format_value_fallback(value, dest);
-	}
+	struct bshell_value_writer writer;
+	bshell_value_writer_init(&writer, dest);
+	bshell_value_writer_write(&writer, value);
+	bshell_value_writer_cleanup(&writer);
 
 	return BSHELL_SUCCESS;
 }

bshell.runtime/format/value-writer.c

@@ -0,0 +1,85 @@
+#include <bshell/format.h>
+#include <fx/collections/array.h>
+#include <fx/string.h>
+#include <fx/type.h>
+#include <fx/value-type.h>
+
+static void initialise_table(
+	struct bshell_value_writer *w,
+	const fx_value *first_record)
+{
+	bshell_table_ctx_init(&w->w_table_ctx, w->w_dest);
+	const fx_type *ty = fx_type_get_by_id(first_record->v_type);
+	bshell_table_ctx_prepare_columns_from_format(&w->w_table_ctx, ty, NULL);
+	bshell_table_ctx_print_headers(&w->w_table_ctx);
+	w->w_table_initialised = true;
+}
+
+static void write_iterable(struct bshell_value_writer *w, const fx_value *value)
+{
+	fx_array *array = NULL;
+	fx_value_get_object(value, &array);
+
+	const fx_iterator *it = fx_iterator_begin(array);
+	fx_foreach(v, it)
+	{
+		bshell_value_writer_write(w, v);
+	}
+	fx_iterator_unref(it);
+}
+
+static void write_string(struct bshell_value_writer *w, const fx_value *value)
+{
+	const char *str = NULL;
+	fx_value_get_cstr(value, &str);
+	fx_stream_write_cstr(w->w_dest, str, NULL);
+	fx_stream_write_char(w->w_dest, '\n');
+}
+
+static void write_value(struct bshell_value_writer *w, const fx_value *value)
+{
+	const fx_type *ty = fx_type_get_by_id(value->v_type);
+	if (fx_value_is_type(value, FX_TYPE_STRING)) {
+		write_string(w, value);
+		return;
+	}
+
+	if (fx_type_get_interface(ty, FX_TYPE_ITERABLE)) {
+		write_iterable(w, value);
+		return;
+	}
+
+	if (fx_type_is_value_type(value->v_type)) {
+		fx_value_to_string(value, w->w_dest, NULL);
+		fx_stream_write_char(w->w_dest, '\n');
+		return;
+	}
+
+	if (!w->w_table_initialised) {
+		initialise_table(w, value);
+	}
+
+	bshell_table_ctx_print_record(&w->w_table_ctx, value);
+}
+
+void bshell_value_writer_init(struct bshell_value_writer *w, fx_stream *dest)
+{
+	memset(w, 0x00, sizeof *w);
+	w->w_dest = dest;
+}
+
+void bshell_value_writer_write(
+	struct bshell_value_writer *w,
+	const fx_value *value)
+{
+	write_value(w, value);
+}
+
+void bshell_value_writer_cleanup(struct bshell_value_writer *w)
+{
+	if (w->w_table_initialised) {
+		bshell_table_ctx_cleanup(&w->w_table_ctx);
+	}
+
+	w->w_table_initialised = false;
+}