Merge pull request #12507 from tjdevries/tjdevries/viml_lua_callbacks

[RFC] Allow passing lua functions and closures into vim functions.

4 files changed, 67 insertions, 4 deletions

diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 1071e75c06..99014d1a09 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -824,9 +824,12 @@ static void f_call(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   } else if (argvars[0].v_type == VAR_PARTIAL) {
     partial = argvars[0].vval.v_partial;
     func = partial_name(partial);
+  } else if (nlua_is_table_from_lua(&argvars[0])) {
+    func = nlua_register_table_as_callable(&argvars[0]);
   } else {
     func = (char_u *)tv_get_string(&argvars[0]);
   }
+
   if (*func == NUL) {
     return;             // type error or empty name
   }
diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index 0daaf6c878..89ca2db59b 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -16,6 +16,7 @@
 #include "nvim/eval/typval_encode.h"
 #include "nvim/eval.h"
 #include "nvim/eval/userfunc.h"
+#include "nvim/lua/executor.h"
 #include "nvim/types.h"
 #include "nvim/assert.h"
 #include "nvim/memory.h"
@@ -301,6 +302,7 @@ void tv_list_free_list(list_T *const l)
   }
   list_log(l, NULL, NULL, "freelist");
 
+  nlua_free_typval_list(l);
   xfree(l);
 }
 
@@ -1374,6 +1376,7 @@ void tv_dict_free_dict(dict_T *const d)
     d->dv_used_next->dv_used_prev = d->dv_used_prev;
   }
 
+  nlua_free_typval_dict(d);
   xfree(d);
 }
 
diff --git a/src/nvim/eval/typval.h b/src/nvim/eval/typval.h
index 343dd205ff..503a32a81e 100644
--- a/src/nvim/eval/typval.h
+++ b/src/nvim/eval/typval.h
@@ -180,6 +180,8 @@ struct listvar_S {
   int lv_idx;  ///< Index of a cached item, used for optimising repeated l[idx].
   int lv_copyID;  ///< ID used by deepcopy().
   VarLockStatus lv_lock;  ///< Zero, VAR_LOCKED, VAR_FIXED.
+
+  LuaRef lua_table_ref;
 };
 
 // Static list with 10 items. Use tv_list_init_static10() to initialize.
@@ -245,6 +247,8 @@ struct dictvar_S {
   dict_T *dv_used_next;   ///< Next dictionary in used dictionaries list.
   dict_T *dv_used_prev;   ///< Previous dictionary in used dictionaries list.
   QUEUE watchers;         ///< Dictionary key watchers set by user code.
+
+  LuaRef lua_table_ref;
 };
 
 /// Type used for script ID
@@ -271,6 +275,12 @@ typedef struct {
 /// Number of fixed variables used for arguments
 #define FIXVAR_CNT 12
 
+/// Callback interface for C function reference>
+///     Used for managing functions that were registered with |register_cfunc|
+typedef int (*cfunc_T)(int argcount, typval_T *argvars, typval_T *rettv, void *state);  // NOLINT
+/// Callback to clear cfunc_T and any associated state.
+typedef void (*cfunc_free_T)(void *state);
+
 // Structure to hold info for a function that is currently being executed.
 typedef struct funccall_S funccall_T;
 
@@ -307,6 +317,10 @@ struct ufunc {
   garray_T     uf_lines;         ///< function lines
   int          uf_profiling;     ///< true when func is being profiled
   int          uf_prof_initialized;
+  // Managing cfuncs
+  cfunc_T      uf_cb;            ///< C function extension callback
+  cfunc_free_T uf_cb_free;       ///< C function extesion free callback
+  void        *uf_cb_state;      ///< State of C function extension.
   // Profiling the function as a whole.
   int          uf_tm_count;      ///< nr of calls
   proftime_T   uf_tm_total;      ///< time spent in function + children
diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 4d658498c1..229f0e8dde 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -32,6 +32,7 @@
 #define FC_DELETED  0x10          // :delfunction used while uf_refcount > 0
 #define FC_REMOVED  0x20          // function redefined while uf_refcount > 0
 #define FC_SANDBOX  0x40          // function defined in the sandbox
+#define FC_CFUNC    0x80          // C function extension
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 #include "eval/userfunc.c.generated.h"
@@ -162,6 +163,17 @@ static void register_closure(ufunc_T *fp)
     [current_funccal->fc_funcs.ga_len++] = fp;
 }
 
+
+/// Get a name for a lambda.  Returned in static memory.
+char_u * get_lambda_name(void)
+{
+    static char_u   name[30];
+    static int      lambda_no = 0;
+
+    snprintf((char *)name, sizeof(name), "<lambda>%d", ++lambda_no);
+    return name;
+}
+
 /// Parse a lambda expression and get a Funcref from "*arg".
 ///
 /// @return OK or FAIL.  Returns NOTDONE for dict or {expr}.
@@ -175,7 +187,6 @@ int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
   int        ret;
   char_u     *start = skipwhite(*arg + 1);
   char_u     *s, *e;
-  static int lambda_no = 0;
   bool       *old_eval_lavars = eval_lavars_used;
   bool       eval_lavars = false;
 
@@ -219,11 +230,9 @@ int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
   if (evaluate) {
     int len, flags = 0;
     char_u *p;
-    char_u name[20];
     garray_T newlines;
 
-    lambda_no++;
-    snprintf((char *)name, sizeof(name), "<lambda>%d", lambda_no);
+    char_u *name = get_lambda_name();
 
     fp = xcalloc(1, offsetof(ufunc_T, uf_name) + STRLEN(name) + 1);
     pt = xcalloc(1, sizeof(partial_T));
@@ -700,6 +709,11 @@ static void func_clear_items(ufunc_T *fp)
   ga_clear_strings(&(fp->uf_args));
   ga_clear_strings(&(fp->uf_lines));
 
+  if (fp->uf_cb_free != NULL) {
+    fp->uf_cb_free(fp->uf_cb_state);
+    fp->uf_cb_free = NULL;
+  }
+
   XFREE_CLEAR(fp->uf_tml_count);
   XFREE_CLEAR(fp->uf_tml_total);
   XFREE_CLEAR(fp->uf_tml_self);
@@ -1408,6 +1422,9 @@ call_func(
 
       if (fp != NULL && (fp->uf_flags & FC_DELETED)) {
         error = ERROR_DELETED;
+      } else if (fp != NULL && (fp->uf_flags & FC_CFUNC)) {
+        cfunc_T cb = fp->uf_cb;
+        error = (*cb)(argcount, argvars, rettv, fp->uf_cb_state);
       } else if (fp != NULL) {
         if (argv_func != NULL) {
           // postponed filling in the arguments, do it now
@@ -3435,3 +3452,29 @@ bool set_ref_in_func(char_u *name, ufunc_T *fp_in, int copyID)
   xfree(tofree);
   return abort;
 }
+
+/// Registers a C extension user function.
+char_u *register_cfunc(cfunc_T cb, cfunc_free_T cb_free, void *state)
+{
+  char_u *name = get_lambda_name();
+  ufunc_T *fp = NULL;
+
+  fp = xcalloc(1, offsetof(ufunc_T, uf_name) + STRLEN(name) + 1);
+  if (fp == NULL) {
+    return NULL;
+  }
+
+  fp->uf_refcount = 1;
+  fp->uf_varargs = true;
+  fp->uf_flags = FC_CFUNC;
+  fp->uf_calls = 0;
+  fp->uf_script_ctx = current_sctx;
+  fp->uf_cb = cb;
+  fp->uf_cb_free = cb_free;
+  fp->uf_cb_state = state;
+
+  STRCPY(fp->uf_name, name);
+  hash_add(&func_hashtab, UF2HIKEY(fp));
+
+  return fp->uf_name;
+}