eval: Move get_tv_lnum and get_tv_float to eval/typval.h

Additionally - Rename former tv_get_float to tv_get_float_chk due to name conflict (former get_tv_float is better suited for being tv_get_float). - Add E907 error to get_tv_float() and test that it is being raised when appropriate.
2025-09-15 15:58:17 +00:00 · 2016-08-28 08:09:29 +03:00
parent 949f09bdbb
commit 7ee5cc7429
4 changed files with 236 additions and 173 deletions
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -6498,7 +6498,7 @@ static void float_op_wrapper(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  float_T (*function)(float_T) = (float_T (*)(float_T))fptr;

  rettv->v_type = VAR_FLOAT;
-  if (tv_get_float(argvars, &f)) {
+  if (tv_get_float_chk(argvars, &f)) {
    rettv->vval.v_float = function(f);
  } else {
    rettv->vval.v_float = 0.0;
@@ -6610,7 +6610,7 @@ static void f_append(typval_T *argvars, typval_T *rettv, FunPtr fptr)
    u_sync(TRUE);
  }

-  lnum = get_tv_lnum(argvars);
+  lnum = tv_get_lnum(argvars);
  if (lnum >= 0
      && lnum <= curbuf->b_ml.ml_line_count
      && u_save(lnum, lnum + 1) == OK) {
@@ -6957,7 +6957,7 @@ static void f_atan2(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  float_T fy;

  rettv->v_type = VAR_FLOAT;
-  if (tv_get_float(argvars, &fx) && tv_get_float(&argvars[1], &fy)) {
+  if (tv_get_float_chk(argvars, &fx) && tv_get_float_chk(&argvars[1], &fy)) {
    rettv->vval.v_float = atan2(fx, fy);
  } else {
    rettv->vval.v_float = 0.0;
@@ -7333,7 +7333,7 @@ static void f_cindent(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  linenr_T lnum;

  pos = curwin->w_cursor;
-  lnum = get_tv_lnum(argvars);
+  lnum = tv_get_lnum(argvars);
  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count) {
    curwin->w_cursor.lnum = lnum;
    rettv->vval.v_number = get_c_indent();
@@ -7613,7 +7613,7 @@ static void f_cursor(typval_T *argvars, typval_T *rettv, FunPtr fptr)
      set_curswant = false;
    }
  } else {
-    line = get_tv_lnum(argvars);
+    line = tv_get_lnum(argvars);
    col = get_tv_number_chk(&argvars[1], NULL);
    if (argvars[2].v_type != VAR_UNKNOWN) {
      coladd = get_tv_number_chk(&argvars[2], NULL);
@@ -7808,7 +7808,7 @@ static void f_did_filetype(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_diff_filler(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  rettv->vval.v_number = diff_check_fill(curwin, get_tv_lnum(argvars));
+  rettv->vval.v_number = diff_check_fill(curwin, tv_get_lnum(argvars));
 }

 /*
@@ -7816,7 +7816,7 @@ static void f_diff_filler(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_diff_hlID(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum = get_tv_lnum(argvars);
+  linenr_T lnum = tv_get_lnum(argvars);
  static linenr_T prev_lnum = 0;
  static int changedtick = 0;
  static int fnum = 0;
@@ -8557,7 +8557,7 @@ static void f_float2nr(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
  float_T f;

-  if (tv_get_float(argvars, &f)) {
+  if (tv_get_float_chk(argvars, &f)) {
    if (f < VARNUMBER_MIN) {
      rettv->vval.v_number = VARNUMBER_MIN;
    } else if (f > VARNUMBER_MAX) {
@@ -8577,7 +8577,7 @@ static void f_fmod(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  float_T fy;

  rettv->v_type = VAR_FLOAT;
-  if (tv_get_float(argvars, &fx) && tv_get_float(&argvars[1], &fy)) {
+  if (tv_get_float_chk(argvars, &fx) && tv_get_float_chk(&argvars[1], &fy)) {
    rettv->vval.v_float = fmod(fx, fy);
  } else {
    rettv->vval.v_float = 0.0;
@@ -8629,16 +8629,16 @@ static void f_fnamemodify(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void foldclosed_both(typval_T *argvars, typval_T *rettv, int end)
 {
-  linenr_T lnum;
-  linenr_T first, last;
-
-  lnum = get_tv_lnum(argvars);
+  const linenr_T lnum = tv_get_lnum(argvars);
  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count) {
-    if (hasFoldingWin(curwin, lnum, &first, &last, FALSE, NULL)) {
-      if (end)
+    linenr_T first;
+    linenr_T last;
+    if (hasFoldingWin(curwin, lnum, &first, &last, false, NULL)) {
+      if (end) {
        rettv->vval.v_number = (varnumber_T)last;
-      else
+      } else {
        rettv->vval.v_number = (varnumber_T)first;
+      }
      return;
    }
  }
@@ -8666,12 +8666,11 @@ static void f_foldclosedend(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_foldlevel(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
-
-  lnum = get_tv_lnum(argvars);
-  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count)
+  const linenr_T lnum = tv_get_lnum(argvars);
+  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count) {
    rettv->vval.v_number = foldLevel(lnum);
  }
+}

 /*
 * "foldtext()" function
@@ -8734,7 +8733,6 @@ static void f_foldtext(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_foldtextresult(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
  char_u      *text;
  char_u buf[51];
  foldinfo_T foldinfo;
@@ -8742,10 +8740,11 @@ static void f_foldtextresult(typval_T *argvars, typval_T *rettv, FunPtr fptr)

  rettv->v_type = VAR_STRING;
  rettv->vval.v_string = NULL;
-  lnum = get_tv_lnum(argvars);
-  /* treat illegal types and illegal string values for {lnum} the same */
-  if (lnum < 0)
+  linenr_T lnum = tv_get_lnum(argvars);
+  // Treat illegal types and illegal string values for {lnum} the same.
+  if (lnum < 0) {
    lnum = 0;
+  }
  fold_count = foldedCount(curwin, lnum, &foldinfo);
  if (fold_count > 0) {
    text = get_foldtext(curwin, lnum, lnum + fold_count - 1,
@@ -9782,17 +9781,16 @@ static void f_getftype(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_getline(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
  linenr_T end;
-  int retlist;
+  bool retlist;

-  lnum = get_tv_lnum(argvars);
+  const linenr_T lnum = tv_get_lnum(argvars);
  if (argvars[1].v_type == VAR_UNKNOWN) {
    end = 0;
-    retlist = FALSE;
+    retlist = false;
  } else {
-    end = get_tv_lnum(&argvars[1]);
-    retlist = TRUE;
+    end = tv_get_lnum(&argvars[1]);
+    retlist = true;
  }

  get_buffer_lines(curbuf, lnum, end, retlist, rettv);
@@ -10920,14 +10918,13 @@ static void f_iconv(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_indent(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
-
-  lnum = get_tv_lnum(argvars);
-  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count)
+  const linenr_T lnum = tv_get_lnum(argvars);
+  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count) {
    rettv->vval.v_number = get_indent_lnum(lnum);
-  else
+  } else {
    rettv->vval.v_number = -1;
  }
+}

 /*
 * "index()" function
@@ -11975,15 +11972,15 @@ static void f_line(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_line2byte(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
-
-  lnum = get_tv_lnum(argvars);
-  if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count + 1)
+  const linenr_T lnum = tv_get_lnum(argvars);
+  if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count + 1) {
    rettv->vval.v_number = -1;
-  else
+  } else {
    rettv->vval.v_number = ml_find_line_or_offset(curbuf, lnum, NULL);
-  if (rettv->vval.v_number >= 0)
-    ++rettv->vval.v_number;
+  }
+  if (rettv->vval.v_number >= 0) {
+    rettv->vval.v_number++;
+  }
 }

 /*
@@ -11991,18 +11988,16 @@ static void f_line2byte(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_lispindent(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  pos_T pos;
-  linenr_T lnum;
-
-  pos = curwin->w_cursor;
-  lnum = get_tv_lnum(argvars);
+  const pos_T pos = curwin->w_cursor;
+  const linenr_T lnum = tv_get_lnum(argvars);
  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count) {
    curwin->w_cursor.lnum = lnum;
    rettv->vval.v_number = get_lisp_indent();
    curwin->w_cursor = pos;
-  } else
+  } else {
    rettv->vval.v_number = -1;
  }
+}

 /*
 * "localtime()" function
@@ -12746,14 +12741,15 @@ static void f_nextnonblank(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
  linenr_T lnum;

-  for (lnum = get_tv_lnum(argvars);; ++lnum) {
+  for (lnum = tv_get_lnum(argvars);; lnum++) {
    if (lnum < 0 || lnum > curbuf->b_ml.ml_line_count) {
      lnum = 0;
      break;
    }
-    if (*skipwhite(ml_get(lnum)) != NUL)
+    if (*skipwhite(ml_get(lnum)) != NUL) {
      break;
    }
+  }
  rettv->vval.v_number = lnum;
 }

@@ -12812,7 +12808,7 @@ static void f_pow(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  float_T fy;

  rettv->v_type = VAR_FLOAT;
-  if (tv_get_float(argvars, &fx) && tv_get_float(&argvars[1], &fy)) {
+  if (tv_get_float_chk(argvars, &fx) && tv_get_float_chk(&argvars[1], &fy)) {
    rettv->vval.v_float = pow(fx, fy);
  } else {
    rettv->vval.v_float = 0.0;
@@ -12824,14 +12820,14 @@ static void f_pow(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_prevnonblank(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
-
-  lnum = get_tv_lnum(argvars);
-  if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count)
+  linenr_T lnum = tv_get_lnum(argvars);
+  if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count) {
    lnum = 0;
-  else
-    while (lnum >= 1 && *skipwhite(ml_get(lnum)) == NUL)
-      --lnum;
+  } else {
+    while (lnum >= 1 && *skipwhite(ml_get(lnum)) == NUL) {
+      lnum--;
+    }
+  }
  rettv->vval.v_number = lnum;
 }

@@ -14428,14 +14424,13 @@ static void f_setfperm(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_setline(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  linenr_T lnum;
  char_u      *line = NULL;
  list_T      *l = NULL;
  listitem_T  *li = NULL;
  long added = 0;
  linenr_T lcount = curbuf->b_ml.ml_line_count;

-  lnum = get_tv_lnum(&argvars[0]);
+  linenr_T lnum = tv_get_lnum(&argvars[0]);
  if (argvars[1].v_type == VAR_LIST) {
    l = argvars[1].vval.v_list;
    li = l->lv_first;
@@ -15017,8 +15012,8 @@ static int item_compare(const void *s1, const void *s2, bool keep_zero)
  }

  if (sortinfo->item_compare_float) {
-    float_T v1 = get_tv_float(tv1);
-    float_T v2 = get_tv_float(tv2);
+    const float_T v1 = tv_get_float(tv1);
+    const float_T v2 = tv_get_float(tv2);

    return v1 == v2 ? 0 : v1 > v2 ? 1 : -1;
  }
@@ -15977,19 +15972,18 @@ static void f_substitute(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 /// "synID(lnum, col, trans)" function
 static void f_synID(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  int id = 0;
-  long lnum;
-  long col;
-  int trans;
+  // -1 on type error (both)
+  const linenr_T lnum = tv_get_lnum(argvars);
+  const colnr_T col = (colnr_T)get_tv_number(&argvars[1]) - 1;
+
  bool transerr = false;
+  const int trans = get_tv_number_chk(&argvars[2], &transerr);

-  lnum = get_tv_lnum(argvars);                  /* -1 on type error */
-  col = get_tv_number(&argvars[1]) - 1;         /* -1 on type error */
-  trans = get_tv_number_chk(&argvars[2], &transerr);
-
+  int id = 0;
  if (!transerr && lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count
-      && col >= 0 && col < (long)STRLEN(ml_get(lnum)))
-    id = syn_get_id(curwin, lnum, (colnr_T)col, trans, NULL, FALSE);
+      && col >= 0 && (size_t)col < STRLEN(ml_get(lnum))) {
+    id = syn_get_id(curwin, lnum, col, trans, NULL, false);
+  }

  rettv->vval.v_number = id;
 }
@@ -16090,8 +16084,6 @@ static void f_synIDtrans(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_synconcealed(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  long lnum;
-  long col;
  int syntax_flags = 0;
  int cchar;
  int matchid = 0;
@@ -16100,15 +16092,16 @@ static void f_synconcealed(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  rettv->v_type = VAR_LIST;
  rettv->vval.v_list = NULL;

-  lnum = get_tv_lnum(argvars);                  /* -1 on type error */
-  col = get_tv_number(&argvars[1]) - 1;         /* -1 on type error */
+  // -1 on type error (both)
+  const linenr_T lnum = tv_get_lnum(argvars);
+  const colnr_T col = (colnr_T)get_tv_number(&argvars[1]) - 1;

  memset(str, NUL, sizeof(str));

  tv_list_alloc_ret(rettv);
  if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count && col >= 0
-      && col <= (long)STRLEN(ml_get(lnum)) && curwin->w_p_cole > 0) {
-    (void)syn_get_id(curwin, lnum, col, FALSE, NULL, FALSE);
+      && (size_t)col <= STRLEN(ml_get(lnum)) && curwin->w_p_cole > 0) {
+    (void)syn_get_id(curwin, lnum, col, false, NULL, false);
    syntax_flags = get_syntax_info(&matchid);

    // get the conceal character
@@ -16137,21 +16130,19 @@ static void f_synconcealed(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 */
 static void f_synstack(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  long lnum;
-  long col;
-
  rettv->v_type = VAR_LIST;
  rettv->vval.v_list = NULL;

-  lnum = get_tv_lnum(argvars);                  /* -1 on type error */
-  col = get_tv_number(&argvars[1]) - 1;         /* -1 on type error */
+  // -1 on type error (both)
+  const linenr_T lnum = tv_get_lnum(argvars);
+  const colnr_T col = (colnr_T)get_tv_number(&argvars[1]) - 1;

  if (lnum >= 1
      && lnum <= curbuf->b_ml.ml_line_count
      && col >= 0
-      && col <= (long)STRLEN(ml_get(lnum))) {
+      && (size_t)col <= STRLEN(ml_get(lnum))) {
    tv_list_alloc_ret(rettv);
-    (void)syn_get_id(curwin, lnum, (colnr_T)col, false, NULL, true);
+    (void)syn_get_id(curwin, lnum, col, false, NULL, true);

    int id;
    int i = 0;
@@ -17457,31 +17448,35 @@ static void f_xor(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 }


-/*
- * Translate a String variable into a position.
- * Returns NULL when there is an error.
- */
-static pos_T *
-var2fpos (
-    typval_T *varp,
-    int dollar_lnum,                /* TRUE when $ is last line */
-    int *fnum              /* set to fnum for '0, 'A, etc. */
-)
+/// Translate a VimL object into a position
+///
+/// Accepts VAR_LIST and VAR_STRING objects. Does not give an error for invalid
+/// type.
+///
+/// @param[in]  tv  Object to translate.
+/// @param[in]  dollar_lnum  True when "$" is last line.
+/// @param[out]  ret_fnum  Set to fnum for marks.
+///
+/// @return Pointer to position or NULL in case of error (e.g. invalid type).
+pos_T *var2fpos(const typval_T *const tv, const int dollar_lnum,
+                int *const ret_fnum)
+  FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
 {
  char_u              *name;
  static pos_T pos;
  pos_T               *pp;

-  /* Argument can be [lnum, col, coladd]. */
-  if (varp->v_type == VAR_LIST) {
+  // Argument can be [lnum, col, coladd].
+  if (tv->v_type == VAR_LIST) {
    list_T          *l;
    int len;
    bool error = false;
    listitem_T *li;

-    l = varp->vval.v_list;
-    if (l == NULL)
+    l = tv->vval.v_list;
+    if (l == NULL) {
      return NULL;
+    }

    // Get the line number.
    pos.lnum = tv_list_find_nr(l, 0L, &error);
@@ -17521,20 +17516,24 @@ var2fpos (
    return &pos;
  }

-  name = get_tv_string_chk(varp);
-  if (name == NULL)
+  name = get_tv_string_chk(tv);
+  if (name == NULL) {
    return NULL;
-  if (name[0] == '.')                           /* cursor */
-    return &curwin->w_cursor;
-  if (name[0] == 'v' && name[1] == NUL) {       /* Visual start */
-    if (VIsual_active)
-      return &VIsual;
+  }
+  if (name[0] == '.') {  // Cursor.
    return &curwin->w_cursor;
  }
-  if (name[0] == '\'') {                        /* mark */
-    pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
-    if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
+  if (name[0] == 'v' && name[1] == NUL) {  // Visual start.
+    if (VIsual_active) {
+      return &VIsual;
+    }
+    return &curwin->w_cursor;
+  }
+  if (name[0] == '\'') {  // Mark.
+    pp = getmark_buf_fnum(curbuf, name[1], false, ret_fnum);
+    if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0) {
      return NULL;
+    }
    return pp;
  }

@@ -18465,54 +18464,6 @@ varnumber_T get_tv_number_chk(const typval_T *const varp, bool *const denote)
  return n;
 }

-static float_T get_tv_float(typval_T *varp)
-{
-  switch (varp->v_type) {
-    case VAR_NUMBER:
-      return (float_T)(varp->vval.v_number);
-    case VAR_FLOAT:
-      return varp->vval.v_float;
-      break;
-    case VAR_FUNC:
-    case VAR_PARTIAL:
-      EMSG(_("E891: Using a Funcref as a Float"));
-      break;
-    case VAR_STRING:
-      EMSG(_("E892: Using a String as a Float"));
-      break;
-    case VAR_LIST:
-      EMSG(_("E893: Using a List as a Float"));
-      break;
-    case VAR_DICT:
-      EMSG(_("E894: Using a Dictionary as a Float"));
-      break;
-    default:
-      EMSG2(_(e_intern2), "get_tv_float()");
-      break;
-  }
-  return 0;
-}
-
-/*
- * Get the lnum from the first argument.
- * Also accepts ".", "$", etc., but that only works for the current buffer.
- * Returns -1 on error.
- */
-static linenr_T get_tv_lnum(typval_T *argvars)
-{
-  typval_T rettv;
-  linenr_T lnum;
-
-  lnum = get_tv_number_chk(&argvars[0], NULL);
-  if (lnum == 0) {  /* no valid number, try using line() */
-    rettv.v_type = VAR_NUMBER;
-    f_line(argvars, &rettv, NULL);
-    lnum = rettv.vval.v_number;
-    tv_clear(&rettv);
-  }
-  return lnum;
-}
-
 /*
 * Get the lnum from the first argument.
 * Also accepts "$", then "buf" is used.
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -16,6 +16,7 @@
 #include "nvim/hashtab.h"
 #include "nvim/vim.h"
 #include "nvim/ascii.h"
+#include "nvim/pos.h"
 // TODO(ZyX-I): Move line_breakcheck out of misc1
 #include "nvim/misc1.h"  // For line_breakcheck

@@ -1730,11 +1731,11 @@ static inline void _nothing_conv_dict_end(typval_T *const tv,

 /// Free memory for a variable value and set the value to NULL or 0
 ///
-/// @param[in,out]  varp  Value to free.
-void tv_clear(typval_T *varp)
+/// @param[in,out]  tv  Value to free.
+void tv_clear(typval_T *tv)
 {
-  if (varp != NULL && varp->v_type != VAR_UNKNOWN) {
-    const int evn_ret = encode_vim_to_nothing(varp, varp, "tv_clear argument");
+  if (tv != NULL && tv->v_type != VAR_UNKNOWN) {
+    const int evn_ret = encode_vim_to_nothing(NULL, tv, "tv_clear argument");
    (void)evn_ret;
    assert(evn_ret == OK);
  }
@@ -2017,7 +2018,72 @@ bool tv_check_str_or_nr(const typval_T *const tv)

 //{{{2 Get

-/// Get the string value of a variable
+/// Get the line number from VimL object
+///
+/// @param[in]  tv  Object to get value from. Is expected to be a number or
+///                 a special string like ".", "$", … (works with current buffer
+///                 only).
+///
+/// @return Line number or -1 or 0.
+linenr_T tv_get_lnum(const typval_T *const tv)
+{
+  linenr_T lnum = get_tv_number_chk(tv, NULL);
+  if (lnum == 0) {  // No valid number, try using same function as line() does.
+    int fnum;
+    pos_T *const fp = var2fpos(tv, true, &fnum);
+    if (fp != NULL) {
+      lnum = fp->lnum;
+    }
+  }
+  return lnum;
+}
+
+/// Get the floating-point value of a VimL object
+///
+/// Raises an error if object is not number or floating-point.
+///
+/// @param[in]  tv  Object to get value of.
+///
+/// @return Floating-point value of the variable or zero.
+float_T tv_get_float(const typval_T *const tv)
+{
+  switch (tv->v_type) {
+    case VAR_NUMBER: {
+      return (float_T)(tv->vval.v_number);
+    }
+    case VAR_FLOAT: {
+      return tv->vval.v_float;
+    }
+    case VAR_PARTIAL:
+    case VAR_FUNC: {
+      EMSG(_("E891: Using a Funcref as a Float"));
+      break;
+    }
+    case VAR_STRING: {
+      EMSG(_("E892: Using a String as a Float"));
+      break;
+    }
+    case VAR_LIST: {
+      EMSG(_("E893: Using a List as a Float"));
+      break;
+    }
+    case VAR_DICT: {
+      EMSG(_("E894: Using a Dictionary as a Float"));
+      break;
+    }
+    case VAR_SPECIAL: {
+      EMSG(_("E907: Using a special value as a Float"));
+      break;
+    }
+    case VAR_UNKNOWN: {
+      EMSG2(_(e_intern2), "get_tv_float()");
+      break;
+    }
+  }
+  return 0;
+}
+
+/// Get the string value of a VimL object
 ///
 /// @warning For number and special values it uses a single, static buffer. It
 ///          may be used only once, next call to get_tv_string may reuse it. Use
@@ -2027,38 +2093,38 @@ bool tv_check_str_or_nr(const typval_T *const tv)
 /// @note get_tv_string_chk() and get_tv_string_buf_chk() are similar, but
 ///       return NULL on error.
 ///
-/// @param[in]  varp  Varible to get value of.
+/// @param[in]  tv  Object to get value of.
 ///
-/// @return Variable value if it is VAR_STRING variable, number converted to
+/// @return Object value if it is VAR_STRING object, number converted to
 ///         a string for VAR_NUMBER, v: variable name for VAR_SPECIAL or empty
 ///         string.
-const char *tv_get_string(const typval_T *const varp)
+const char *tv_get_string(const typval_T *const tv)
  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_NONNULL_RET FUNC_ATTR_WARN_UNUSED_RESULT
 {
  static char mybuf[NUMBUFLEN];
-  return tv_get_string_buf((typval_T *)varp, mybuf);
+  return tv_get_string_buf((typval_T *)tv, mybuf);
 }

-/// Get the string value of a variable
+/// Get the string value of a VimL object
 ///
 /// @note get_tv_string_chk() and get_tv_string_buf_chk() are similar, but
 ///       return NULL on error.
 ///
-/// @param[in]  varp  Varible to get value of.
+/// @param[in]  tv  Object to get value of.
 /// @param  buf  Buffer used to hold numbers and special variables converted to
 ///              string. When function encounters one of these stringified value
 ///              will be written to buf and buf will be returned.
 ///
 ///              Buffer must have NUMBUFLEN size.
 ///
-/// @return Variable value if it is VAR_STRING variable, number converted to
+/// @return Object value if it is VAR_STRING object, number converted to
 ///         a string for VAR_NUMBER, v: variable name for VAR_SPECIAL or empty
 ///         string.
-const char *tv_get_string_buf(const typval_T *const varp, char *const buf)
+const char *tv_get_string_buf(const typval_T *const tv, char *const buf)
  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_NONNULL_RET FUNC_ATTR_WARN_UNUSED_RESULT
 {
  const char *const res = (const char *)get_tv_string_buf_chk(
-      (typval_T *)varp, (char_u *)buf);
+      (typval_T *)tv, (char_u *)buf);

  return res != NULL ? res : "";
 }
--- a/src/nvim/eval/typval.h
+++ b/src/nvim/eval/typval.h
@@ -14,6 +14,7 @@
 #include "nvim/profile.h"  // for proftime_T
 #include "nvim/pos.h"      // for linenr_T
 #include "nvim/gettext.h"
+#include "nvim/message.h"

 /// Type used for VimL VAR_NUMBER values
 typedef int varnumber_T;
@@ -373,7 +374,8 @@ extern bool tv_in_free_unref_items;
      } \
    })

-static inline bool tv_get_float(const typval_T *const tv, float_T *const ret_f)
+static inline bool tv_get_float_chk(const typval_T *const tv,
+                                    float_T *const ret_f)
  REAL_FATTR_NONNULL_ALL REAL_FATTR_WARN_UNUSED_RESULT;

 // FIXME circular dependency, cannot import message.h.
@@ -381,11 +383,14 @@ bool emsgf(const char *const fmt, ...);

 /// Get the float value
 ///
+/// Raises an error if object is not number or floating-point.
+///
 /// @param[in]  tv  VimL object to get value from.
 /// @param[out]  ret_f  Location where resulting float is stored.
 ///
 /// @return true in case of success, false if tv is not a number or float.
-static inline bool tv_get_float(const typval_T *const tv, float_T *const ret_f)
+static inline bool tv_get_float_chk(const typval_T *const tv,
+                                    float_T *const ret_f)
 {
  if (tv->v_type == VAR_FLOAT) {
    *ret_f = tv->vval.v_float;
--- a/test/functional/eval/sort_spec.lua
+++ b/test/functional/eval/sort_spec.lua
@@ -0,0 +1,41 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local NIL = helpers.NIL
+local eval = helpers.eval
+local clear = helpers.clear
+local meths = helpers.meths
+local funcs = helpers.funcs
+local command = helpers.command
+local exc_exec = helpers.exc_exec
+
+before_each(clear)
+
+describe('sort()', function()
+  it('errors out when sorting special values', function()
+    eq('Vim(call):E907: Using a special value as a Float',
+       exc_exec('call sort([v:true, v:false], "f")'))
+  end)
+
+  it('sorts “wrong” values between -0.0001 and 0.0001, preserving order',
+  function()
+    meths.set_var('list', {true, false, NIL, {}, {a=42}, 'check',
+                           0.0001, -0.0001})
+    command('call insert(g:list, function("tr"))')
+    local error_lines = funcs.split(
+        funcs.execute('silent! call sort(g:list, "f")'), '\n')
+    local errors = {}
+    for _, err in ipairs(error_lines) do
+      errors[err] = true
+    end
+    eq({
+      ['E891: Using a Funcref as a Float']=true,
+      ['E892: Using a String as a Float']=true,
+      ['E893: Using a List as a Float']=true,
+      ['E894: Using a Dictionary as a Float']=true,
+      ['E907: Using a special value as a Float']=true,
+    }, errors)
+    eq('[-1.0e-4, function(\'tr\'), v:true, v:false, v:null, [], {\'a\': 42}, \'check\', 1.0e-4]',
+       eval('string(g:list)'))
+  end)
+end)