patch 8.2.1744: Vim9: using ":const!" is weird
Problem: Vim9: using ":const!" is weird.
Solution: Use "var" - "final" - "const" like Dart. "let" still works for
now.
diff --git a/src/evalvars.c b/src/evalvars.c
index 5ceaca4..087a0cb 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -669,6 +669,25 @@
}
/*
+ * Vim9 variable declaration:
+ * ":var name"
+ * ":var name: type"
+ * ":var name = expr"
+ * ":var name: type = expr"
+ * etc.
+ */
+ void
+ex_var(exarg_T *eap)
+{
+ if (!in_vim9script())
+ {
+ semsg(_(e_str_cannot_be_used_in_legacy_vim_script), ":var");
+ return;
+ }
+ ex_let(eap);
+}
+
+/*
* ":let" list all variable values
* ":let var1 var2" list variable values
* ":let var = expr" assignment command.
@@ -683,6 +702,9 @@
* ":let var =<< ..." heredoc
* ":let var: string" Vim9 declaration
*
+ * ":final var = expr" assignment command.
+ * ":final [var1, var2] = expr" unpack list.
+ *
* ":const" list all variable values
* ":const var1 var2" list variable values
* ":const var = expr" assignment command.
@@ -702,14 +724,22 @@
int first = TRUE;
int concat;
int has_assign;
- int flags = eap->cmdidx == CMD_const ? LET_IS_CONST : 0;
+ int flags = eap->cmdidx == CMD_const ? ASSIGN_CONST : 0;
int vim9script = in_vim9script();
+ if (eap->cmdidx == CMD_final && !vim9script)
+ {
+ // In legacy Vim script ":final" is short for ":finally".
+ ex_finally(eap);
+ return;
+ }
+ if (eap->cmdidx == CMD_const && !vim9script && !eap->forceit)
+ // In legacy Vim script ":const" works like ":final".
+ eap->cmdidx = CMD_final;
+
// detect Vim9 assignment without ":let" or ":const"
if (eap->arg == eap->cmd)
- flags |= LET_NO_COMMAND;
- if (eap->forceit)
- flags |= LET_FORCEIT;
+ flags |= ASSIGN_NO_DECL;
argend = skip_var_list(arg, TRUE, &var_count, &semicolon, FALSE);
if (argend == NULL)
@@ -787,7 +817,7 @@
op[1] = NUL;
if (*expr != '=')
{
- if (vim9script && (flags & LET_NO_COMMAND) == 0)
+ if (vim9script && (flags & ASSIGN_NO_DECL) == 0)
{
// +=, /=, etc. require an existing variable
semsg(_(e_cannot_use_operator_on_new_variable), eap->arg);
@@ -860,7 +890,7 @@
int copy, // copy values from "tv", don't move
int semicolon, // from skip_var_list()
int var_count, // from skip_var_list()
- int flags, // LET_IS_CONST, LET_FORCEIT, LET_NO_COMMAND
+ int flags, // ASSIGN_CONST, ASSIGN_NO_DECL
char_u *op)
{
char_u *arg = arg_start;
@@ -1215,7 +1245,7 @@
char_u *arg, // points to variable name
typval_T *tv, // value to assign to variable
int copy, // copy value from "tv"
- int flags, // LET_IS_CONST, LET_FORCEIT, LET_NO_COMMAND
+ int flags, // ASSIGN_CONST, ASSIGN_NO_DECL
char_u *endchars, // valid chars after variable name or NULL
char_u *op) // "+", "-", "." or NULL
{
@@ -1227,7 +1257,7 @@
int opt_flags;
char_u *tofree = NULL;
- if (in_vim9script() && (flags & LET_NO_COMMAND) == 0
+ if (in_vim9script() && (flags & ASSIGN_NO_DECL) == 0
&& vim_strchr((char_u *)"$@&", *arg) != NULL)
{
vim9_declare_error(arg);
@@ -1237,7 +1267,7 @@
// ":let $VAR = expr": Set environment variable.
if (*arg == '$')
{
- if (flags & LET_IS_CONST)
+ if (flags & ASSIGN_CONST)
{
emsg(_("E996: Cannot lock an environment variable"));
return NULL;
@@ -1289,7 +1319,7 @@
// ":let &g:option = expr": Set global option value.
else if (*arg == '&')
{
- if (flags & LET_IS_CONST)
+ if (flags & ASSIGN_CONST)
{
emsg(_(e_const_option));
return NULL;
@@ -1373,7 +1403,7 @@
// ":let @r = expr": Set register contents.
else if (*arg == '@')
{
- if (flags & LET_IS_CONST)
+ if (flags & ASSIGN_CONST)
{
emsg(_("E996: Cannot lock a register"));
return NULL;
@@ -2926,7 +2956,7 @@
typval_T *tv,
int copy) // make copy of value in "tv"
{
- set_var_const(name, NULL, tv, copy, LET_NO_COMMAND);
+ set_var_const(name, NULL, tv, copy, ASSIGN_NO_DECL);
}
/*
@@ -2940,7 +2970,7 @@
type_T *type,
typval_T *tv_arg,
int copy, // make copy of value in "tv"
- int flags) // LET_IS_CONST, LET_FORCEIT, LET_NO_COMMAND
+ int flags) // ASSIGN_CONST, ASSIGN_NO_DECL
{
typval_T *tv = tv_arg;
typval_T bool_tv;
@@ -2960,7 +2990,7 @@
if (vim9script
&& !is_script_local
- && (flags & LET_NO_COMMAND) == 0
+ && (flags & ASSIGN_NO_DECL) == 0
&& name[1] == ':')
{
vim9_declare_error(name);
@@ -2990,7 +3020,7 @@
{
if ((di->di_flags & DI_FLAGS_RELOAD) == 0)
{
- if (flags & LET_IS_CONST)
+ if (flags & ASSIGN_CONST)
{
emsg(_(e_cannot_mod));
goto failed;
@@ -2998,7 +3028,7 @@
if (is_script_local && vim9script)
{
- if ((flags & LET_NO_COMMAND) == 0)
+ if ((flags & ASSIGN_NO_DECL) == 0)
{
semsg(_(e_redefining_script_item_str), name);
goto failed;
@@ -3094,7 +3124,7 @@
goto failed;
}
di->di_flags = DI_FLAGS_ALLOC;
- if (flags & LET_IS_CONST)
+ if (flags & ASSIGN_CONST)
di->di_flags |= DI_FLAGS_LOCK;
if (is_script_local && vim9script)
@@ -3113,7 +3143,7 @@
sv->sv_type = typval2type(tv, &si->sn_type_list);
else
sv->sv_type = type;
- sv->sv_const = (flags & LET_IS_CONST);
+ sv->sv_const = (flags & ASSIGN_CONST);
sv->sv_export = is_export;
++si->sn_var_vals.ga_len;
@@ -3132,8 +3162,8 @@
init_tv(tv);
}
- // ":const var = val" locks the value; in Vim9 script only with ":const!"
- if ((flags & LET_IS_CONST) && (!vim9script || (flags & LET_FORCEIT)))
+ // ":const var = val" locks the value
+ if (flags & ASSIGN_CONST)
// Like :lockvar! name: lock the value and what it contains, but only
// if the reference count is up to one. That locks only literal
// values.