Refactored the key binding system and implemented generic procedures (#…

…237)

* Refactored the key binding system and implemented generic procedures
 - vim bindings
 - alternative bindings
 - register cmds before extension cmds
 - add subcommand invocation by name

I took the emacs approach where every functionality is a certain defined
procedure which can, but doesn't have to, be bound to a key. Each can
also be given a name so the future implementation of subcommands should
be very easy. I chose the name 'procedure' as there was already a lot
of ambiguity with the word 'command'.

I kept all the existing key bindings, although I modified some to align
them with vim. I also added a incomplete emacs profile just to showcase
how bindings can be changed.

app/cli.c

@@ -25,6 +25,8 @@
 #include "sheet/sheet_internal.h"
 #include "sheet/handlers_internal.h"
 #endif
+#include "sheet/procedure.h"
+#include "sheet/key-bindings.h"
 
 struct cli_config {
   struct zsv_ext *extensions;
@@ -35,6 +37,9 @@ struct cli_config {
 
 static struct zsv_ext *zsv_ext_new(const char *dl_name, const char *id, char verbose);
 
+zsvsheet_handler_status zsvsheet_ext_prompt(struct zsvsheet_proc_context *ctx, char *buffer, size_t bufsz,
+                                            const char *fmt, ...);
+
 #include "cli_ini.c"
 
 typedef int(cmd_main)(int argc, const char *argv[]);
@@ -141,6 +146,8 @@ struct zsv_execution_data {
   const char **argv;
   char opts_used[ZSV_OPTS_SIZE_MAX];
   void *custom_context; // user-defined
+  void *state;          // program state relevant to the handler, e.g. cursor
+                        // position in zsv sheet.
 };
 
 static const char *ext_opts_used(zsv_execution_context ctx) {
@@ -189,6 +196,16 @@ static void *ext_get_context(zsv_execution_context ctx) {
   return d->custom_context;
 }
 
+static void ext_set_state(zsv_execution_context ctx, void *state) {
+  struct zsv_execution_data *d = ctx;
+  d->state = state;
+}
+
+static void *ext_get_state(zsv_execution_context ctx) {
+  struct zsv_execution_data *d = ctx;
+  return d->state;
+}
+
 static void ext_set_parser(zsv_execution_context ctx, zsv_parser parser) {
   struct zsv_execution_data *d = ctx;
   d->parser = parser;
@@ -367,13 +384,14 @@ static struct zsv_ext_callbacks *zsv_ext_callbacks_init(struct zsv_ext_callbacks
 
 #ifdef ZSVSHEET_BUILD
     e->ext_sheet_handler_key = zsvsheet_handler_key;
-    e->ext_sheet_subcommand_prompt = zsvsheet_subcommand_prompt;
+    e->ext_sheet_prompt = zsvsheet_ext_prompt;
     e->ext_sheet_handler_set_status = zsvsheet_handler_set_status;
     e->ext_sheet_handler_buffer_current = zsvsheet_handler_buffer_current;
     e->ext_sheet_handler_buffer_prior = zsvsheet_handler_buffer_prior;
     e->ext_sheet_handler_buffer_filename = zsvsheet_handler_buffer_filename;
     e->ext_sheet_handler_open_file = zsvsheet_handler_open_file;
-    e->ext_sheet_register_command = zsvsheet_register_command;
+    e->ext_sheet_register_proc = zsvsheet_register_proc;
+    e->ext_sheet_register_proc_key_binding = zsvsheet_register_proc_key_binding;
 #endif
   }
   return e;

app/ext_example/my_extension.c

@@ -7,9 +7,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <assert.h>
 #include <zsv/ext/implementation.h>
 // #include <zsv/ext/sheet.h>
 #include "../../include/zsv/ext/sheet.h"
+#include "../../app/sheet/procedure.h"
 #include <zsv/utils/writer.h>
 
 /**
@@ -72,13 +74,15 @@ static enum zsv_ext_status echo_main(zsv_execution_context ctx, int argc, const
 /**
  * Here we define a custom command for the zsv `sheet` feature
  */
-zsvsheet_handler_status my_sheet_subcommand_handler(zsvsheet_subcommand_handler_context_t ctx) {
-  int ch = zsv_cb.ext_sheet_handler_key(ctx);
-  zsv_cb.ext_sheet_subcommand_prompt(ctx, "You pressed %c. Now enter something here", (char)ch);
-  return zsvsheet_handler_status_ok;
-}
+zsvsheet_handler_status my_test_command_handler(struct zsvsheet_proc_context *ctx) {
+  char result_buffer[256] = {0};
+  assert(ctx->invocation.type == zsvsheet_proc_invocation_type_keypress);
+  zsv_cb.ext_sheet_prompt(ctx, result_buffer, sizeof(result_buffer), "You pressed %c. Now enter something here",
+                          (char)ctx->invocation.u.keypress.ch);
+
+  if (*result_buffer == '\0')
+    return zsvsheet_handler_status_ok;
 
-zsvsheet_handler_status my_sheet_handler(zsvsheet_handler_context_t ctx) {
   const char *temp_filename = "/tmp/zsvsheet_extension_example.csv";
   FILE *f = fopen(temp_filename, "wb");
   if (!f)
@@ -103,7 +107,6 @@ zsvsheet_handler_status my_sheet_handler(zsvsheet_handler_context_t ctx) {
   }
   return zsvsheet_handler_status_ok;
 }
-
 #endif
 
 /**
@@ -134,7 +137,10 @@ enum zsv_ext_status zsv_ext_init(struct zsv_ext_callbacks *cb, zsv_execution_con
   zsv_cb.ext_add_command(ctx, "echo", "print the input data back to stdout", echo_main);
 
 #ifdef ZSVSHEET_BUILD
-  zsv_cb.ext_sheet_register_command('t', "my-test-command", my_sheet_subcommand_handler, my_sheet_handler);
+  int proc_id = zsv_cb.ext_sheet_register_proc("my-test-command", my_test_command_handler);
+  if (proc_id < 0)
+    return zsv_ext_status_error;
+  zsv_cb.ext_sheet_register_proc_key_binding('t', proc_id);
 #endif
   return zsv_ext_status_ok;
 }