1 files changed, 132 insertions, 0 deletions
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index f1852f1b6d..13d8f52768 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -3488,6 +3488,138 @@ static void f_index(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 }
 
+/// Evaluate "expr" with the v:key and v:val arguments and return the result.
+/// The expression is expected to return a boolean value.  The caller should set
+/// the VV_KEY and VV_VAL vim variables before calling this function.
+static varnumber_T indexof_eval_expr(typval_T *expr)
+{
+  typval_T argv[3];
+  argv[0] = *get_vim_var_tv(VV_KEY);
+  argv[1] = *get_vim_var_tv(VV_VAL);
+  typval_T newtv;
+  newtv.v_type = VAR_UNKNOWN;
+
+  if (eval_expr_typval(expr, argv, 2, &newtv) == FAIL) {
+    return false;
+  }
+
+  bool error = false;
+  varnumber_T found = tv_get_bool_chk(&newtv, &error);
+  tv_clear(&newtv);
+
+  return error ? false : found;
+}
+
+/// Evaluate "expr" for each byte in the Blob "b" starting with the byte at
+/// "startidx" and return the index of the byte where "expr" is TRUE.  Returns
+/// -1 if "expr" doesn't evaluate to TRUE for any of the bytes.
+static varnumber_T indexof_blob(blob_T *b, varnumber_T startidx, typval_T *expr)
+{
+  if (b == NULL) {
+    return -1;
+  }
+
+  if (startidx < 0) {
+    // negative index: index from the last byte
+    startidx = tv_blob_len(b) + startidx;
+    if (startidx < 0) {
+      startidx = 0;
+    }
+  }
+
+  for (varnumber_T idx = startidx; idx < tv_blob_len(b); idx++) {
+    set_vim_var_nr(VV_KEY, idx);
+    set_vim_var_nr(VV_VAL, tv_blob_get(b, (int)idx));
+
+    if (indexof_eval_expr(expr)) {
+      return idx;
+    }
+  }
+
+  return -1;
+}
+
+/// Evaluate "expr" for each item in the List "l" starting with the item at
+/// "startidx" and return the index of the item where "expr" is TRUE.  Returns
+/// -1 if "expr" doesn't evaluate to TRUE for any of the items.
+static varnumber_T indexof_list(list_T *l, varnumber_T startidx, typval_T *expr)
+{
+  if (l == NULL) {
+    return -1;
+  }
+
+  listitem_T *item;
+  varnumber_T idx = 0;
+  if (startidx == 0) {
+    item = tv_list_first(l);
+  } else {
+    // Start at specified item.
+    idx = tv_list_uidx(l, (int)startidx);
+    if (idx == -1) {
+      item = NULL;
+    } else {
+      item = tv_list_find(l, (int)idx);
+      assert(item != NULL);
+    }
+  }
+
+  for (; item != NULL; item = TV_LIST_ITEM_NEXT(l, item), idx++) {
+    set_vim_var_nr(VV_KEY, idx);
+    tv_copy(TV_LIST_ITEM_TV(item), get_vim_var_tv(VV_VAL));
+
+    bool found = indexof_eval_expr(expr);
+    tv_clear(get_vim_var_tv(VV_VAL));
+
+    if (found) {
+      return idx;
+    }
+  }
+
+  return -1;
+}
+
+/// "indexof()" function
+static void f_indexof(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  rettv->vval.v_number = -1;
+
+  if (tv_check_for_list_or_blob_arg(argvars, 0) == FAIL
+      || tv_check_for_string_or_func_arg(argvars, 1) == FAIL
+      || tv_check_for_opt_dict_arg(argvars, 2) == FAIL) {
+    return;
+  }
+
+  if ((argvars[1].v_type == VAR_STRING && argvars[1].vval.v_string == NULL)
+      || (argvars[1].v_type == VAR_FUNC && argvars[1].vval.v_partial == NULL)) {
+    return;
+  }
+
+  varnumber_T startidx = 0;
+  if (argvars[2].v_type == VAR_DICT) {
+    startidx = tv_dict_get_number_def(argvars[2].vval.v_dict, "startidx", 0);
+  }
+
+  typval_T save_val;
+  typval_T save_key;
+  prepare_vimvar(VV_VAL, &save_val);
+  prepare_vimvar(VV_KEY, &save_key);
+
+  // We reset "did_emsg" to be able to detect whether an error occurred
+  // during evaluation of the expression.
+  const int save_did_emsg = did_emsg;
+  did_emsg = false;
+
+  if (argvars[0].v_type == VAR_BLOB) {
+    rettv->vval.v_number = indexof_blob(argvars[0].vval.v_blob, startidx, &argvars[1]);
+  } else {
+    rettv->vval.v_number = indexof_list(argvars[0].vval.v_list, startidx, &argvars[1]);
+  }
+
+  restore_vimvar(VV_KEY, &save_key);
+  restore_vimvar(VV_VAL, &save_val);
+  did_emsg |= save_did_emsg;
+}
+
 static bool inputsecret_flag = false;
 
 /// "input()" function