vim-patch:8.2.0918: duplicate code for evaluating expression argument

Problem:    Duplicate code for evaluating expression argument.
Solution:   Merge the code and make the use more flexible.
https://github.com/vim/vim/commit/a9c010494767e43a51c443cac35ebc80d0831d0b

3 files changed, 18 insertions, 96 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 2d8d1694d1..4b83bda804 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -766,6 +766,15 @@ static int eval1_emsg(char_u **arg, typval_T *rettv, bool evaluate)
   return ret;
 }
 
+/// @return whether a typval is a valid expression to pass to eval_expr_typval()
+/// or eval_expr_to_bool().  An empty string returns false;
+bool eval_expr_valid_arg(const typval_T *const tv)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_CONST
+{
+  return tv->v_type != VAR_UNKNOWN
+         && (tv->v_type != VAR_STRING || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
+}
+
 int eval_expr_typval(const typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
   FUNC_ATTR_NONNULL_ARG(1, 2, 4)
 {
@@ -3381,67 +3390,6 @@ static int eval_func(char_u **const arg, char_u *const name, const int name_len,
   return ret;
 }
 
-/// Process a function argument that can be a string expression or a function
-/// reference.
-/// "tv" must remain valid until calling evalarg_clean()!
-/// @return false when the argument is invalid.
-bool evalarg_get(typval_T *const tv, evalarg_T *const eva)
-  FUNC_ATTR_NONNULL_ALL
-{
-  if (tv->v_type == VAR_STRING || tv->v_type == VAR_NUMBER || tv->v_type == VAR_BOOL
-      || tv->v_type == VAR_SPECIAL) {
-    char numbuf[NUMBUFLEN];
-    eva->eva_string = tv_get_string_buf(tv, numbuf);
-    return true;
-  }
-
-  return callback_from_typval(&eva->eva_callback, tv);
-}
-
-/// @return whether "eva" has a valid expression or callback.
-bool evalarg_valid(const evalarg_T *const eva)
-  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_CONST
-{
-  return eva->eva_string != NULL || eva->eva_callback.type != kCallbackNone;
-}
-
-/// Invoke the expression or callback "eva" and return the result in "tv".
-/// @return false if something failed
-bool evalarg_call(evalarg_T *const eva, typval_T *const tv)
-  FUNC_ATTR_NONNULL_ALL
-{
-  if (eva->eva_string != NULL) {
-    return eval0((char_u *)eva->eva_string, tv, NULL, true);
-  }
-
-  typval_T argv[1];
-  argv[0].v_type = VAR_UNKNOWN;
-  return callback_call(&eva->eva_callback, 0, argv, tv);
-}
-
-/// Like evalarg_call(), but just return true or false.
-/// Sets "error" to true if evaluation failed.
-bool evalarg_call_bool(evalarg_T *const eva, bool *const error)
-  FUNC_ATTR_NONNULL_ALL
-{
-  typval_T tv;
-  if (!evalarg_call(eva, &tv)) {
-    *error = true;
-    return false;
-  }
-
-  const bool r = tv_get_number(&tv);
-  tv_clear(&tv);
-  *error = false;
-  return r;
-}
-
-void evalarg_clean(evalarg_T *const eva)
-  FUNC_ATTR_NONNULL_ALL
-{
-  callback_free(&eva->eva_callback);
-}
-
 // TODO(ZyX-I): move to eval/expressions
 
 /*
diff --git a/src/nvim/eval.h b/src/nvim/eval.h
index f74f23d084..a9ec5d47a6 100644
--- a/src/nvim/eval.h
+++ b/src/nvim/eval.h
@@ -272,22 +272,6 @@ typedef int (*ex_unletlock_callback)(lval_T *, char_u *, exarg_T *, int);
 // Used for checking if local variables or arguments used in a lambda.
 extern bool *eval_lavars_used;
 
-/// Function argument that can be a string, funcref or partial.
-/// - declare:  evalarg_T name;
-/// - init:     name = EVALARG_INIT;
-/// - set:      evalarg_get(&argvars[3], &name);
-/// - use:      if (evalarg_valid(&name)) res = evalarg_call(&name);
-/// - cleanup:  evalarg_clean(&name);
-typedef struct {
-  const char *eva_string;
-  Callback eva_callback;
-} evalarg_T;
-
-#define EVALARG_INIT (evalarg_T) { \
-  .eva_string = NULL, \
-  .eva_callback = CALLBACK_NONE, \
-}
-
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "eval.h.generated.h"
 #endif
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 8004c1d32e..8beacc9988 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -8237,7 +8237,7 @@ static int search_cmn(typval_T *argvars, pos_T *match_pos, int *flagsp)
   int options = SEARCH_KEEP;
   int subpatnum;
   searchit_arg_T sia;
-  evalarg_T skip = EVALARG_INIT;
+  bool use_skip = false;
 
   const char *const pat = tv_get_string(&argvars[0]);
   dir = get_search_arg(&argvars[1], flagsp);  // May set p_ws.
@@ -8266,9 +8266,7 @@ static int search_cmn(typval_T *argvars, pos_T *match_pos, int *flagsp)
       if (time_limit < 0) {
         goto theend;
       }
-      if (argvars[4].v_type != VAR_UNKNOWN && !evalarg_get(&argvars[4], &skip)) {
-        goto theend;
-      }
+      use_skip = eval_expr_valid_arg(&argvars[4]);
     }
   }
 
@@ -8303,19 +8301,19 @@ static int search_cmn(typval_T *argvars, pos_T *match_pos, int *flagsp)
       subpatnum = FAIL;
     }
 
-    if (subpatnum == FAIL || !evalarg_valid(&skip)) {
+    if (subpatnum == FAIL || !use_skip) {
       // didn't find it or no skip argument
       break;
     }
     firstpos = pos;
 
-    // If the skip pattern matches, ignore this match.
+    // If the skip expression matches, ignore this match.
     {
-      bool err;
       const pos_T save_pos = curwin->w_cursor;
 
       curwin->w_cursor = pos;
-      const bool do_skip = evalarg_call_bool(&skip, &err);
+      bool err = false;
+      const bool do_skip = eval_expr_to_bool(&argvars[4], &err);
       curwin->w_cursor = save_pos;
       if (err) {
         // Evaluating {skip} caused an error, break here.
@@ -8356,7 +8354,6 @@ static int search_cmn(typval_T *argvars, pos_T *match_pos, int *flagsp)
   }
 theend:
   p_ws = save_p_ws;
-  evalarg_clean(&skip);
 
   return retval;
 }
@@ -8788,13 +8785,9 @@ static int searchpair_cmn(typval_T *argvars, pos_T *match_pos)
       || argvars[4].v_type == VAR_UNKNOWN) {
     skip = NULL;
   } else {
+    // Type is checked later.
     skip = &argvars[4];
-    if (skip->v_type != VAR_FUNC
-        && skip->v_type != VAR_PARTIAL
-        && skip->v_type != VAR_STRING) {
-      semsg(_(e_invarg2), tv_get_string(&argvars[4]));
-      goto theend;  // Type error.
-    }
+
     if (argvars[5].v_type != VAR_UNKNOWN) {
       lnum_stop = tv_get_number_chk(&argvars[5], NULL);
       if (lnum_stop < 0) {
@@ -8905,10 +8898,7 @@ long do_searchpair(const char *spat, const char *mpat, const char *epat, int dir
   }
 
   if (skip != NULL) {
-    // Empty string means to not use the skip expression.
-    if (skip->v_type == VAR_STRING || skip->v_type == VAR_FUNC) {
-      use_skip = skip->vval.v_string != NULL && *skip->vval.v_string != NUL;
-    }
+    use_skip = eval_expr_valid_arg(skip);
   }
 
   save_cursor = curwin->w_cursor;