Adding upstream version 2:9.0.1378.upstream/2%9.0.1378upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2741 insertions, 0 deletions

diff --git a/src/typval.c b/src/typval.c
new file mode 100644
index 0000000..4033c07
--- /dev/null
+++ b/src/typval.c
@@ -0,0 +1,2741 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * typval.c: functions that deal with a typval
+ */
+
+#include "vim.h"
+
+#if defined(FEAT_EVAL) || defined(PROTO)
+
+/*
+ * Allocate memory for a variable type-value, and make it empty (0 or NULL
+ * value).
+ */
+    typval_T *
+alloc_tv(void)
+{
+    return ALLOC_CLEAR_ONE(typval_T);
+}
+
+/*
+ * Allocate memory for a variable type-value, and assign a string to it.
+ * The string "s" must have been allocated, it is consumed.
+ * Return NULL for out of memory, the variable otherwise.
+ */
+    typval_T *
+alloc_string_tv(char_u *s)
+{
+    typval_T	*rettv;
+
+    rettv = alloc_tv();
+    if (rettv != NULL)
+    {
+	rettv->v_type = VAR_STRING;
+	rettv->vval.v_string = s;
+    }
+    else
+	vim_free(s);
+    return rettv;
+}
+
+/*
+ * Free the memory for a variable type-value.
+ */
+    void
+free_tv(typval_T *varp)
+{
+    if (varp == NULL)
+	return;
+
+    switch (varp->v_type)
+    {
+	case VAR_FUNC:
+	    func_unref(varp->vval.v_string);
+	    // FALLTHROUGH
+	case VAR_STRING:
+	    vim_free(varp->vval.v_string);
+	    break;
+	case VAR_PARTIAL:
+	    partial_unref(varp->vval.v_partial);
+	    break;
+	case VAR_BLOB:
+	    blob_unref(varp->vval.v_blob);
+	    break;
+	case VAR_LIST:
+	    list_unref(varp->vval.v_list);
+	    break;
+	case VAR_DICT:
+	    dict_unref(varp->vval.v_dict);
+	    break;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    job_unref(varp->vval.v_job);
+	    break;
+#endif
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    channel_unref(varp->vval.v_channel);
+	    break;
+#endif
+	case VAR_CLASS:
+	    class_unref(varp->vval.v_class);
+	    break;
+	case VAR_OBJECT:
+	    object_unref(varp->vval.v_object);
+	    break;
+
+	case VAR_NUMBER:
+	case VAR_FLOAT:
+	case VAR_ANY:
+	case VAR_UNKNOWN:
+	case VAR_VOID:
+	case VAR_BOOL:
+	case VAR_SPECIAL:
+	case VAR_INSTR:
+	    break;
+    }
+    vim_free(varp);
+}
+
+/*
+ * Free the memory for a variable value and set the value to NULL or 0.
+ */
+    void
+clear_tv(typval_T *varp)
+{
+    if (varp == NULL)
+	return;
+
+    switch (varp->v_type)
+    {
+	case VAR_FUNC:
+	    func_unref(varp->vval.v_string);
+	    // FALLTHROUGH
+	case VAR_STRING:
+	    VIM_CLEAR(varp->vval.v_string);
+	    break;
+	case VAR_PARTIAL:
+	    partial_unref(varp->vval.v_partial);
+	    varp->vval.v_partial = NULL;
+	    break;
+	case VAR_BLOB:
+	    blob_unref(varp->vval.v_blob);
+	    varp->vval.v_blob = NULL;
+	    break;
+	case VAR_LIST:
+	    list_unref(varp->vval.v_list);
+	    varp->vval.v_list = NULL;
+	    break;
+	case VAR_DICT:
+	    dict_unref(varp->vval.v_dict);
+	    varp->vval.v_dict = NULL;
+	    break;
+	case VAR_NUMBER:
+	case VAR_BOOL:
+	case VAR_SPECIAL:
+	    varp->vval.v_number = 0;
+	    break;
+	case VAR_FLOAT:
+	    varp->vval.v_float = 0.0;
+	    break;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    job_unref(varp->vval.v_job);
+	    varp->vval.v_job = NULL;
+#endif
+	    break;
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    channel_unref(varp->vval.v_channel);
+	    varp->vval.v_channel = NULL;
+#endif
+	    break;
+	case VAR_INSTR:
+	    VIM_CLEAR(varp->vval.v_instr);
+	    break;
+	case VAR_CLASS:
+	    class_unref(varp->vval.v_class);
+	    varp->vval.v_class = NULL;
+	    break;
+	case VAR_OBJECT:
+	    object_unref(varp->vval.v_object);
+	    varp->vval.v_object = NULL;
+	    break;
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	case VAR_VOID:
+	    break;
+    }
+    varp->v_lock = 0;
+}
+
+/*
+ * Set the value of a variable to NULL without freeing items.
+ */
+    void
+init_tv(typval_T *varp)
+{
+    if (varp != NULL)
+	CLEAR_POINTER(varp);
+}
+
+    static varnumber_T
+tv_get_bool_or_number_chk(typval_T *varp, int *denote, int want_bool)
+{
+    varnumber_T	n = 0L;
+
+    switch (varp->v_type)
+    {
+	case VAR_NUMBER:
+	    if (in_vim9script() && want_bool && varp->vval.v_number != 0
+						   && varp->vval.v_number != 1)
+	    {
+		semsg(_(e_using_number_as_bool_nr), varp->vval.v_number);
+		break;
+	    }
+	    return varp->vval.v_number;
+	case VAR_FLOAT:
+	    emsg(_(e_using_float_as_number));
+	    break;
+	case VAR_FUNC:
+	case VAR_PARTIAL:
+	    emsg(_(e_using_funcref_as_number));
+	    break;
+	case VAR_STRING:
+	    if (in_vim9script())
+	    {
+		emsg_using_string_as(varp, !want_bool);
+		break;
+	    }
+	    if (varp->vval.v_string != NULL)
+		vim_str2nr(varp->vval.v_string, NULL, NULL,
+					    STR2NR_ALL, &n, NULL, 0, FALSE);
+	    return n;
+	case VAR_LIST:
+	    emsg(_(e_using_list_as_number));
+	    break;
+	case VAR_DICT:
+	    emsg(_(e_using_dictionary_as_number));
+	    break;
+	case VAR_BOOL:
+	case VAR_SPECIAL:
+	    if (!want_bool && in_vim9script())
+	    {
+		if (varp->v_type == VAR_BOOL)
+		    emsg(_(e_using_bool_as_number));
+		else
+		    emsg(_(e_using_special_as_number));
+		break;
+	    }
+	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    emsg(_(e_using_job_as_number));
+	    break;
+#endif
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    emsg(_(e_using_channel_as_number));
+	    break;
+#endif
+	case VAR_BLOB:
+	    emsg(_(e_using_blob_as_number));
+	    break;
+	case VAR_CLASS:
+	    emsg(_(e_using_class_as_number));
+	    break;
+	case VAR_OBJECT:
+	    emsg(_(e_using_object_as_number));
+	    break;
+	case VAR_VOID:
+	    emsg(_(e_cannot_use_void_value));
+	    break;
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	case VAR_INSTR:
+	    internal_error_no_abort("tv_get_number(UNKNOWN)");
+	    break;
+    }
+    if (denote == NULL)		// useful for values that must be unsigned
+	n = -1;
+    else
+	*denote = TRUE;
+    return n;
+}
+
+/*
+ * Get the number value of a variable.
+ * If it is a String variable, uses vim_str2nr().
+ * For incompatible types, return 0.
+ * tv_get_number_chk() is similar to tv_get_number(), but informs the
+ * caller of incompatible types: it sets *denote to TRUE if "denote"
+ * is not NULL or returns -1 otherwise.
+ */
+    varnumber_T
+tv_get_number(typval_T *varp)
+{
+    int		error = FALSE;
+
+    return tv_get_number_chk(varp, &error);	// return 0L on error
+}
+
+    varnumber_T
+tv_get_number_chk(typval_T *varp, int *denote)
+{
+    return tv_get_bool_or_number_chk(varp, denote, FALSE);
+}
+
+/*
+ * Get the boolean value of "varp".  This is like tv_get_number_chk(),
+ * but in Vim9 script accepts Number (0 and 1) and Bool/Special.
+ */
+    varnumber_T
+tv_get_bool(typval_T *varp)
+{
+    return tv_get_bool_or_number_chk(varp, NULL, TRUE);
+}
+
+/*
+ * Get the boolean value of "varp".  This is like tv_get_number_chk(),
+ * but in Vim9 script accepts Number and Bool.
+ */
+    varnumber_T
+tv_get_bool_chk(typval_T *varp, int *denote)
+{
+    return tv_get_bool_or_number_chk(varp, denote, TRUE);
+}
+
+    static float_T
+tv_get_float_chk(typval_T *varp, int *error)
+{
+    switch (varp->v_type)
+    {
+	case VAR_NUMBER:
+	    return (float_T)(varp->vval.v_number);
+	case VAR_FLOAT:
+	    return varp->vval.v_float;
+	case VAR_FUNC:
+	case VAR_PARTIAL:
+	    emsg(_(e_using_funcref_as_float));
+	    break;
+	case VAR_STRING:
+	    emsg(_(e_using_string_as_float));
+	    break;
+	case VAR_LIST:
+	    emsg(_(e_using_list_as_float));
+	    break;
+	case VAR_DICT:
+	    emsg(_(e_using_dictionary_as_float));
+	    break;
+	case VAR_BOOL:
+	    emsg(_(e_using_boolean_value_as_float));
+	    break;
+	case VAR_SPECIAL:
+	    emsg(_(e_using_special_value_as_float));
+	    break;
+	case VAR_JOB:
+# ifdef FEAT_JOB_CHANNEL
+	    emsg(_(e_using_job_as_float));
+	    break;
+# endif
+	case VAR_CHANNEL:
+# ifdef FEAT_JOB_CHANNEL
+	    emsg(_(e_using_channel_as_float));
+	    break;
+# endif
+	case VAR_BLOB:
+	    emsg(_(e_using_blob_as_float));
+	    break;
+	case VAR_CLASS:
+	    emsg(_(e_using_class_as_float));
+	    break;
+	case VAR_OBJECT:
+	    emsg(_(e_using_object_as_float));
+	    break;
+	case VAR_VOID:
+	    emsg(_(e_cannot_use_void_value));
+	    break;
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	case VAR_INSTR:
+	    internal_error_no_abort("tv_get_float(UNKNOWN)");
+	    break;
+    }
+    if (error != NULL)
+	*error = TRUE;
+    return 0;
+}
+
+    float_T
+tv_get_float(typval_T *varp)
+{
+    return tv_get_float_chk(varp, NULL);
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is unknown
+ */
+    int
+check_for_unknown_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_UNKNOWN)
+    {
+	semsg(_(e_too_many_arguments), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string.
+ */
+    int
+check_for_string_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING)
+    {
+	semsg(_(e_string_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a non-empty string.
+ */
+    int
+check_for_nonempty_string_arg(typval_T *args, int idx)
+{
+    if (check_for_string_arg(args, idx) == FAIL)
+	return FAIL;
+    if (args[idx].vval.v_string == NULL || *args[idx].vval.v_string == NUL)
+    {
+	semsg(_(e_non_empty_string_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional string argument at 'idx'
+ */
+    int
+check_for_opt_string_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_string_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a number.
+ */
+    int
+check_for_number_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_NUMBER)
+    {
+	semsg(_(e_number_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional number argument at 'idx'
+ */
+    int
+check_for_opt_number_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_number_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a float or a number.
+ */
+    int
+check_for_float_or_nr_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_FLOAT && args[idx].v_type != VAR_NUMBER)
+    {
+	semsg(_(e_float_or_number_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a bool.
+ */
+    int
+check_for_bool_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_BOOL
+	    && !(args[idx].v_type == VAR_NUMBER
+		&& (args[idx].vval.v_number == 0
+		    || args[idx].vval.v_number == 1)))
+    {
+	semsg(_(e_bool_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional bool argument at 'idx'.
+ * Return FAIL if the type is wrong.
+ */
+    int
+check_for_opt_bool_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type == VAR_UNKNOWN)
+	return OK;
+    return check_for_bool_arg(args, idx);
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a blob.
+ */
+    int
+check_for_blob_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_BLOB)
+    {
+	semsg(_(e_blob_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a list.
+ */
+    int
+check_for_list_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_LIST)
+    {
+	    semsg(_(e_list_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a non-NULL list.
+ */
+    int
+check_for_nonnull_list_arg(typval_T *args, int idx)
+{
+    if (check_for_list_arg(args, idx) == FAIL)
+	return FAIL;
+
+    if (args[idx].vval.v_list == NULL)
+    {
+	semsg(_(e_non_null_list_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional list argument at 'idx'
+ */
+    int
+check_for_opt_list_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_list_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a dict.
+ */
+    int
+check_for_dict_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_DICT)
+    {
+	semsg(_(e_dict_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a non-NULL dict.
+ */
+    int
+check_for_nonnull_dict_arg(typval_T *args, int idx)
+{
+    if (check_for_dict_arg(args, idx) == FAIL)
+	return FAIL;
+
+    if (args[idx].vval.v_dict == NULL)
+    {
+	semsg(_(e_non_null_dict_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional dict argument at 'idx'
+ */
+    int
+check_for_opt_dict_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_dict_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+#if defined(FEAT_JOB_CHANNEL) || defined(PROTO)
+/*
+ * Give an error and return FAIL unless "args[idx]" is a channel or a job.
+ */
+    int
+check_for_chan_or_job_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_CHANNEL && args[idx].v_type != VAR_JOB)
+    {
+	semsg(_(e_chan_or_job_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is an optional channel or a
+ * job.
+ */
+    int
+check_for_opt_chan_or_job_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_chan_or_job_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a job.
+ */
+    int
+check_for_job_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_JOB)
+    {
+	semsg(_(e_job_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional job argument at 'idx'.
+ */
+    int
+check_for_opt_job_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_job_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+#else
+/*
+ * Give an error and return FAIL unless "args[idx]" is an optional channel or a
+ * job.  Used without the +channel feature, thus only VAR_UNKNOWN is accepted.
+ */
+    int
+check_for_opt_chan_or_job_arg(typval_T *args, int idx)
+{
+    return args[idx].v_type == VAR_UNKNOWN ? OK : FAIL;
+}
+#endif
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or
+ * a number.
+ */
+    int
+check_for_string_or_number_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING && args[idx].v_type != VAR_NUMBER)
+    {
+	semsg(_(e_string_or_number_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional string or number argument at 'idx'.
+ */
+    int
+check_for_opt_string_or_number_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_string_or_number_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a buffer number.
+ * Buffer number can be a number or a string.
+ */
+    int
+check_for_buffer_arg(typval_T *args, int idx)
+{
+    return check_for_string_or_number_arg(args, idx);
+}
+
+/*
+ * Check for an optional buffer argument at 'idx'
+ */
+    int
+check_for_opt_buffer_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_buffer_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a line number.
+ * Line number can be a number or a string.
+ */
+    int
+check_for_lnum_arg(typval_T *args, int idx)
+{
+    return check_for_string_or_number_arg(args, idx);
+}
+
+/*
+ * Check for an optional line number argument at 'idx'
+ */
+    int
+check_for_opt_lnum_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_lnum_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+#if defined(FEAT_JOB_CHANNEL) || defined(PROTO)
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or a blob.
+ */
+    int
+check_for_string_or_blob_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING && args[idx].v_type != VAR_BLOB)
+    {
+	semsg(_(e_string_or_blob_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+#endif
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or a list.
+ */
+    int
+check_for_string_or_list_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING && args[idx].v_type != VAR_LIST)
+    {
+	semsg(_(e_string_or_list_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string, a list or a
+ * blob.
+ */
+    int
+check_for_string_or_list_or_blob_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING
+	    && args[idx].v_type != VAR_LIST
+	    && args[idx].v_type != VAR_BLOB)
+    {
+	semsg(_(e_string_list_or_blob_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Check for an optional string or list argument at 'idx'
+ */
+    int
+check_for_opt_string_or_list_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_string_or_list_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or a dict.
+ */
+    int
+check_for_string_or_dict_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING && args[idx].v_type != VAR_DICT)
+    {
+	semsg(_(e_string_or_dict_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or a number
+ * or a list.
+ */
+    int
+check_for_string_or_number_or_list_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING
+	    && args[idx].v_type != VAR_NUMBER
+	    && args[idx].v_type != VAR_LIST)
+    {
+	semsg(_(e_string_number_or_list_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is an optional string
+ * or number or a list
+ */
+    int
+check_for_opt_string_or_number_or_list_arg(typval_T *args, int idx)
+{
+    return (args[idx].v_type == VAR_UNKNOWN
+	    || check_for_string_or_number_or_list_arg(args, idx)
+							!= FAIL) ? OK : FAIL;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or a number
+ * or a list or a blob.
+ */
+    int
+check_for_string_or_number_or_list_or_blob_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING
+	    && args[idx].v_type != VAR_NUMBER
+	    && args[idx].v_type != VAR_LIST
+	    && args[idx].v_type != VAR_BLOB)
+    {
+	semsg(_(e_string_number_list_or_blob_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string or a list
+ * or a dict.
+ */
+    int
+check_for_string_or_list_or_dict_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_STRING
+	    && args[idx].v_type != VAR_LIST
+	    && args[idx].v_type != VAR_DICT)
+    {
+	semsg(_(e_string_list_or_dict_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a string
+ * or a function reference.
+ */
+    int
+check_for_string_or_func_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_PARTIAL
+	    && args[idx].v_type != VAR_FUNC
+	    && args[idx].v_type != VAR_STRING)
+    {
+	semsg(_(e_string_or_function_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a list or a blob.
+ */
+    int
+check_for_list_or_blob_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_LIST && args[idx].v_type != VAR_BLOB)
+    {
+	semsg(_(e_list_or_blob_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a list or dict
+ */
+    int
+check_for_list_or_dict_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_LIST
+	    && args[idx].v_type != VAR_DICT)
+    {
+	semsg(_(e_list_or_dict_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a list or dict or a
+ * blob.
+ */
+    int
+check_for_list_or_dict_or_blob_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_LIST
+	    && args[idx].v_type != VAR_DICT
+	    && args[idx].v_type != VAR_BLOB)
+    {
+	semsg(_(e_list_dict_or_blob_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is a list or dict or a
+ * blob or a string.
+ */
+    int
+check_for_list_or_dict_or_blob_or_string_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_LIST
+	    && args[idx].v_type != VAR_DICT
+	    && args[idx].v_type != VAR_BLOB
+	    && args[idx].v_type != VAR_STRING)
+    {
+	semsg(_(e_list_dict_blob_or_string_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Give an error and return FAIL unless "args[idx]" is an optional buffer
+ * number or a dict.
+ */
+    int
+check_for_opt_buffer_or_dict_arg(typval_T *args, int idx)
+{
+    if (args[idx].v_type != VAR_UNKNOWN
+	    && args[idx].v_type != VAR_STRING
+	    && args[idx].v_type != VAR_NUMBER
+	    && args[idx].v_type != VAR_DICT)
+    {
+	semsg(_(e_string_required_for_argument_nr), idx + 1);
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Get the string value of a variable.
+ * If it is a Number variable, the number is converted into a string.
+ * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
+ * tv_get_string_buf() uses a given buffer.
+ * If the String variable has never been set, return an empty string.
+ * Never returns NULL;
+ * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
+ * NULL on error.
+ */
+    char_u *
+tv_get_string(typval_T *varp)
+{
+    static char_u   mybuf[NUMBUFLEN];
+
+    return tv_get_string_buf(varp, mybuf);
+}
+
+/*
+ * Like tv_get_string() but don't allow number to string conversion for Vim9.
+ */
+    char_u *
+tv_get_string_strict(typval_T *varp)
+{
+    static char_u   mybuf[NUMBUFLEN];
+    char_u	    *res =  tv_get_string_buf_chk_strict(
+						 varp, mybuf, in_vim9script());
+
+    return res != NULL ? res : (char_u *)"";
+}
+
+    char_u *
+tv_get_string_buf(typval_T *varp, char_u *buf)
+{
+    char_u	*res = tv_get_string_buf_chk(varp, buf);
+
+    return res != NULL ? res : (char_u *)"";
+}
+
+/*
+ * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
+ */
+    char_u *
+tv_get_string_chk(typval_T *varp)
+{
+    static char_u   mybuf[NUMBUFLEN];
+
+    return tv_get_string_buf_chk(varp, mybuf);
+}
+
+    char_u *
+tv_get_string_buf_chk(typval_T *varp, char_u *buf)
+{
+    return tv_get_string_buf_chk_strict(varp, buf, FALSE);
+}
+
+    char_u *
+tv_get_string_buf_chk_strict(typval_T *varp, char_u *buf, int strict)
+{
+    switch (varp->v_type)
+    {
+	case VAR_NUMBER:
+	    if (strict)
+	    {
+		emsg(_(e_using_number_as_string));
+		break;
+	    }
+	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
+					    (varnumber_T)varp->vval.v_number);
+	    return buf;
+	case VAR_FUNC:
+	case VAR_PARTIAL:
+	    emsg(_(e_using_funcref_as_string));
+	    break;
+	case VAR_LIST:
+	    emsg(_(e_using_list_as_string));
+	    break;
+	case VAR_DICT:
+	    emsg(_(e_using_dictionary_as_string));
+	    break;
+	case VAR_FLOAT:
+	    if (strict)
+	    {
+		emsg(_(e_using_float_as_string));
+		break;
+	    }
+	    vim_snprintf((char *)buf, NUMBUFLEN, "%g", varp->vval.v_float);
+	    return buf;
+	case VAR_STRING:
+	    if (varp->vval.v_string != NULL)
+		return varp->vval.v_string;
+	    return (char_u *)"";
+	case VAR_BOOL:
+	case VAR_SPECIAL:
+	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
+	    return buf;
+	case VAR_BLOB:
+	    emsg(_(e_using_blob_as_string));
+	    break;
+	case VAR_CLASS:
+	    emsg(_(e_using_class_as_string));
+	    break;
+	case VAR_OBJECT:
+	    emsg(_(e_using_object_as_string));
+	    break;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    if (in_vim9script())
+	    {
+		semsg(_(e_using_invalid_value_as_string_str), "job");
+		break;
+	    }
+	    return job_to_string_buf(varp, buf);
+#endif
+	    break;
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    if (in_vim9script())
+	    {
+		semsg(_(e_using_invalid_value_as_string_str), "channel");
+		break;
+	    }
+	    return channel_to_string_buf(varp, buf);
+#endif
+	    break;
+	case VAR_VOID:
+	    emsg(_(e_cannot_use_void_value));
+	    break;
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	case VAR_INSTR:
+	    semsg(_(e_using_invalid_value_as_string_str),
+						  vartype_name(varp->v_type));
+	    break;
+    }
+    return NULL;
+}
+
+/*
+ * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
+ * string() on Dict, List, etc.
+ */
+    char_u *
+tv_stringify(typval_T *varp, char_u *buf)
+{
+    if (varp->v_type == VAR_LIST
+	    || varp->v_type == VAR_DICT
+	    || varp->v_type == VAR_BLOB
+	    || varp->v_type == VAR_FUNC
+	    || varp->v_type == VAR_PARTIAL
+	    || varp->v_type == VAR_FLOAT)
+    {
+	typval_T tmp;
+
+	f_string(varp, &tmp);
+	tv_get_string_buf(&tmp, buf);
+	clear_tv(varp);
+	*varp = tmp;
+	return tmp.vval.v_string;
+    }
+    return tv_get_string_buf(varp, buf);
+}
+
+/*
+ * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
+ * Also give an error message, using "name" or _("name") when use_gettext is
+ * TRUE.
+ */
+    int
+tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
+{
+    int	lock = 0;
+
+    switch (tv->v_type)
+    {
+	case VAR_BLOB:
+	    if (tv->vval.v_blob != NULL)
+		lock = tv->vval.v_blob->bv_lock;
+	    break;
+	case VAR_LIST:
+	    if (tv->vval.v_list != NULL)
+		lock = tv->vval.v_list->lv_lock;
+	    break;
+	case VAR_DICT:
+	    if (tv->vval.v_dict != NULL)
+		lock = tv->vval.v_dict->dv_lock;
+	    break;
+	default:
+	    break;
+    }
+    return value_check_lock(tv->v_lock, name, use_gettext)
+		   || (lock != 0 && value_check_lock(lock, name, use_gettext));
+}
+
+/*
+ * Copy the values from typval_T "from" to typval_T "to".
+ * When needed allocates string or increases reference count.
+ * Does not make a copy of a list, blob or dict but copies the reference!
+ * It is OK for "from" and "to" to point to the same item.  This is used to
+ * make a copy later.
+ */
+    void
+copy_tv(typval_T *from, typval_T *to)
+{
+    to->v_type = from->v_type;
+    to->v_lock = 0;
+    switch (from->v_type)
+    {
+	case VAR_NUMBER:
+	case VAR_BOOL:
+	case VAR_SPECIAL:
+	    to->vval.v_number = from->vval.v_number;
+	    break;
+	case VAR_FLOAT:
+	    to->vval.v_float = from->vval.v_float;
+	    break;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    to->vval.v_job = from->vval.v_job;
+	    if (to->vval.v_job != NULL)
+		++to->vval.v_job->jv_refcount;
+	    break;
+#endif
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    to->vval.v_channel = from->vval.v_channel;
+	    if (to->vval.v_channel != NULL)
+		++to->vval.v_channel->ch_refcount;
+	    break;
+#endif
+	case VAR_INSTR:
+	    to->vval.v_instr = from->vval.v_instr;
+	    break;
+
+	case VAR_CLASS:
+	    copy_class(from, to);
+	    break;
+
+	case VAR_OBJECT:
+	    copy_object(from, to);
+	    break;
+
+	case VAR_STRING:
+	case VAR_FUNC:
+	    if (from->vval.v_string == NULL)
+		to->vval.v_string = NULL;
+	    else
+	    {
+		to->vval.v_string = vim_strsave(from->vval.v_string);
+		if (from->v_type == VAR_FUNC)
+		    func_ref(to->vval.v_string);
+	    }
+	    break;
+	case VAR_PARTIAL:
+	    if (from->vval.v_partial == NULL)
+		to->vval.v_partial = NULL;
+	    else
+	    {
+		to->vval.v_partial = from->vval.v_partial;
+		++to->vval.v_partial->pt_refcount;
+	    }
+	    break;
+	case VAR_BLOB:
+	    if (from->vval.v_blob == NULL)
+		to->vval.v_blob = NULL;
+	    else
+	    {
+		to->vval.v_blob = from->vval.v_blob;
+		++to->vval.v_blob->bv_refcount;
+	    }
+	    break;
+	case VAR_LIST:
+	    if (from->vval.v_list == NULL)
+		to->vval.v_list = NULL;
+	    else
+	    {
+		to->vval.v_list = from->vval.v_list;
+		++to->vval.v_list->lv_refcount;
+	    }
+	    break;
+	case VAR_DICT:
+	    if (from->vval.v_dict == NULL)
+		to->vval.v_dict = NULL;
+	    else
+	    {
+		to->vval.v_dict = from->vval.v_dict;
+		++to->vval.v_dict->dv_refcount;
+	    }
+	    break;
+	case VAR_VOID:
+	    emsg(_(e_cannot_use_void_value));
+	    break;
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	    internal_error_no_abort("copy_tv(UNKNOWN)");
+	    break;
+    }
+}
+
+/*
+ * Compare "tv1" and "tv2".
+ * Put the result in "tv1".  Caller should clear "tv2".
+ */
+    int
+typval_compare(
+    typval_T	*tv1,	// first operand
+    typval_T	*tv2,	// second operand
+    exprtype_T	type,   // operator
+    int		ic)     // ignore case
+{
+    varnumber_T	n1, n2;
+    int		res = 0;
+    int		type_is = type == EXPR_IS || type == EXPR_ISNOT;
+
+    if (type_is && tv1->v_type != tv2->v_type)
+    {
+	// For "is" a different type always means FALSE, for "isnot"
+	// it means TRUE.
+	n1 = (type == EXPR_ISNOT);
+    }
+    else if (((tv1->v_type == VAR_SPECIAL && tv1->vval.v_number == VVAL_NULL)
+		|| (tv2->v_type == VAR_SPECIAL
+					   && tv2->vval.v_number == VVAL_NULL))
+	    && tv1->v_type != tv2->v_type
+	    && (type == EXPR_EQUAL || type == EXPR_NEQUAL))
+    {
+	n1 = typval_compare_null(tv1, tv2);
+	if (n1 == MAYBE)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	if (type == EXPR_NEQUAL)
+	    n1 = !n1;
+    }
+    else if (tv1->v_type == VAR_BLOB || tv2->v_type == VAR_BLOB)
+    {
+	if (typval_compare_blob(tv1, tv2, type, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+    else if (tv1->v_type == VAR_LIST || tv2->v_type == VAR_LIST)
+    {
+	if (typval_compare_list(tv1, tv2, type, ic, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+    else if (tv1->v_type == VAR_CLASS || tv2->v_type == VAR_CLASS)
+    {
+	if (typval_compare_class(tv1, tv2, type, ic, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+    else if (tv1->v_type == VAR_OBJECT || tv2->v_type == VAR_OBJECT)
+    {
+	if (typval_compare_object(tv1, tv2, type, ic, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+    else if (tv1->v_type == VAR_DICT || tv2->v_type == VAR_DICT)
+    {
+	if (typval_compare_dict(tv1, tv2, type, ic, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+    else if (tv1->v_type == VAR_FUNC || tv2->v_type == VAR_FUNC
+	|| tv1->v_type == VAR_PARTIAL || tv2->v_type == VAR_PARTIAL)
+    {
+	if (typval_compare_func(tv1, tv2, type, ic, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+
+    // If one of the two variables is a float, compare as a float.
+    // When using "=~" or "!~", always compare as string.
+    else if ((tv1->v_type == VAR_FLOAT || tv2->v_type == VAR_FLOAT)
+	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
+    {
+	float_T f1, f2;
+	int	error = FALSE;
+
+	f1 = tv_get_float_chk(tv1, &error);
+	if (!error)
+	    f2 = tv_get_float_chk(tv2, &error);
+	if (error)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = FALSE;
+	switch (type)
+	{
+	    case EXPR_IS:
+	    case EXPR_EQUAL:    n1 = (f1 == f2); break;
+	    case EXPR_ISNOT:
+	    case EXPR_NEQUAL:   n1 = (f1 != f2); break;
+	    case EXPR_GREATER:  n1 = (f1 > f2); break;
+	    case EXPR_GEQUAL:   n1 = (f1 >= f2); break;
+	    case EXPR_SMALLER:  n1 = (f1 < f2); break;
+	    case EXPR_SEQUAL:   n1 = (f1 <= f2); break;
+	    case EXPR_UNKNOWN:
+	    case EXPR_MATCH:
+	    default:  break;  // avoid gcc warning
+	}
+    }
+
+    // If one of the two variables is a number, compare as a number.
+    // When using "=~" or "!~", always compare as string.
+    else if ((tv1->v_type == VAR_NUMBER || tv2->v_type == VAR_NUMBER)
+	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
+    {
+	int error = FALSE;
+
+	n1 = tv_get_number_chk(tv1, &error);
+	if (!error)
+	    n2 = tv_get_number_chk(tv2, &error);
+	if (error)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	switch (type)
+	{
+	    case EXPR_IS:
+	    case EXPR_EQUAL:    n1 = (n1 == n2); break;
+	    case EXPR_ISNOT:
+	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
+	    case EXPR_GREATER:  n1 = (n1 > n2); break;
+	    case EXPR_GEQUAL:   n1 = (n1 >= n2); break;
+	    case EXPR_SMALLER:  n1 = (n1 < n2); break;
+	    case EXPR_SEQUAL:   n1 = (n1 <= n2); break;
+	    case EXPR_UNKNOWN:
+	    case EXPR_MATCH:
+	    default:  break;  // avoid gcc warning
+	}
+    }
+    else if (in_vim9script() && (tv1->v_type == VAR_BOOL
+				    || tv2->v_type == VAR_BOOL
+				    || (tv1->v_type == VAR_SPECIAL
+					      && tv2->v_type == VAR_SPECIAL)))
+    {
+	if (tv1->v_type != tv2->v_type)
+	{
+	    semsg(_(e_cannot_compare_str_with_str),
+		       vartype_name(tv1->v_type), vartype_name(tv2->v_type));
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = tv1->vval.v_number;
+	n2 = tv2->vval.v_number;
+	switch (type)
+	{
+	    case EXPR_IS:
+	    case EXPR_EQUAL:    n1 = (n1 == n2); break;
+	    case EXPR_ISNOT:
+	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
+	    default:
+		semsg(_(e_invalid_operation_for_str),
+						   vartype_name(tv1->v_type));
+		clear_tv(tv1);
+		return FAIL;
+	}
+    }
+#ifdef FEAT_JOB_CHANNEL
+    else if (tv1->v_type == tv2->v_type
+	    && (tv1->v_type == VAR_CHANNEL || tv1->v_type == VAR_JOB)
+	    && (type == EXPR_NEQUAL || type == EXPR_EQUAL))
+    {
+	if (tv1->v_type == VAR_CHANNEL)
+	    n1 = tv1->vval.v_channel == tv2->vval.v_channel;
+	else
+	    n1 = tv1->vval.v_job == tv2->vval.v_job;
+	if (type == EXPR_NEQUAL)
+	    n1 = !n1;
+    }
+#endif
+    else
+    {
+	if (typval_compare_string(tv1, tv2, type, ic, &res) == FAIL)
+	{
+	    clear_tv(tv1);
+	    return FAIL;
+	}
+	n1 = res;
+    }
+    clear_tv(tv1);
+    if (in_vim9script())
+    {
+	tv1->v_type = VAR_BOOL;
+	tv1->vval.v_number = n1 ? VVAL_TRUE : VVAL_FALSE;
+    }
+    else
+    {
+	tv1->v_type = VAR_NUMBER;
+	tv1->vval.v_number = n1;
+    }
+
+    return OK;
+}
+
+/*
+ * Compare "tv1" to "tv2" as lists according to "type" and "ic".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_list(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type,
+	int	    ic,
+	int	    *res)
+{
+    int	    val = 0;
+
+    if (type == EXPR_IS || type == EXPR_ISNOT)
+    {
+	val = (tv1->v_type == tv2->v_type
+				      && tv1->vval.v_list == tv2->vval.v_list);
+	if (type == EXPR_ISNOT)
+	    val = !val;
+    }
+    else if (tv1->v_type != tv2->v_type
+	    || (type != EXPR_EQUAL && type != EXPR_NEQUAL))
+    {
+	if (tv1->v_type != tv2->v_type)
+	    emsg(_(e_can_only_compare_list_with_list));
+	else
+	    emsg(_(e_invalid_operation_for_list));
+	return FAIL;
+    }
+    else
+    {
+	val = list_equal(tv1->vval.v_list, tv2->vval.v_list,
+							ic, FALSE);
+	if (type == EXPR_NEQUAL)
+	    val = !val;
+    }
+    *res = val;
+    return OK;
+}
+
+/*
+ * Compare v:null with another type.  Return TRUE if the value is NULL.
+ */
+    int
+typval_compare_null(typval_T *tv1, typval_T *tv2)
+{
+    if ((tv1->v_type == VAR_SPECIAL && tv1->vval.v_number == VVAL_NULL)
+	    || (tv2->v_type == VAR_SPECIAL && tv2->vval.v_number == VVAL_NULL))
+    {
+	typval_T	*tv = tv1->v_type == VAR_SPECIAL ? tv2 : tv1;
+
+	switch (tv->v_type)
+	{
+	    case VAR_BLOB: return tv->vval.v_blob == NULL;
+#ifdef FEAT_JOB_CHANNEL
+	    case VAR_CHANNEL: return tv->vval.v_channel == NULL;
+#endif
+	    case VAR_DICT: return tv->vval.v_dict == NULL;
+	    case VAR_FUNC: return tv->vval.v_string == NULL;
+#ifdef FEAT_JOB_CHANNEL
+	    case VAR_JOB: return tv->vval.v_job == NULL;
+#endif
+	    case VAR_LIST: return tv->vval.v_list == NULL;
+	    case VAR_PARTIAL: return tv->vval.v_partial == NULL;
+	    case VAR_STRING: return tv->vval.v_string == NULL;
+
+	    case VAR_NUMBER: if (!in_vim9script())
+				 return tv->vval.v_number == 0;
+			     break;
+	    case VAR_FLOAT: if (!in_vim9script())
+				 return tv->vval.v_float == 0.0;
+			     break;
+	    default: break;
+	}
+    }
+    // although comparing null with number, float or bool is not very useful
+    // we won't give an error
+    return FALSE;
+}
+
+/*
+ * Compare "tv1" to "tv2" as blobs according to "type".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_blob(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type,
+	int	    *res)
+{
+    int	    val = 0;
+
+    if (type == EXPR_IS || type == EXPR_ISNOT)
+    {
+	val = (tv1->v_type == tv2->v_type
+			&& tv1->vval.v_blob == tv2->vval.v_blob);
+	if (type == EXPR_ISNOT)
+	    val = !val;
+    }
+    else if (tv1->v_type != tv2->v_type
+	    || (type != EXPR_EQUAL && type != EXPR_NEQUAL))
+    {
+	if (tv1->v_type != tv2->v_type)
+	    emsg(_(e_can_only_compare_blob_with_blob));
+	else
+	    emsg(_(e_invalid_operation_for_blob));
+	return FAIL;
+    }
+    else
+    {
+	val = blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
+	if (type == EXPR_NEQUAL)
+	    val = !val;
+    }
+    *res = val;
+    return OK;
+}
+
+/*
+ * Compare "tv1" to "tv2" as classes according to "type".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_class(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type UNUSED,
+	int	    ic UNUSED,
+	int	    *res)
+{
+    // TODO: use "type"
+    *res = tv1->vval.v_class == tv2->vval.v_class;
+    return OK;
+}
+
+/*
+ * Compare "tv1" to "tv2" as objects according to "type".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_object(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type,
+	int	    ic,
+	int	    *res)
+{
+    int res_match = type == EXPR_EQUAL || type == EXPR_IS ? TRUE : FALSE;
+
+    if (tv1->vval.v_object == NULL && tv2->vval.v_object == NULL)
+    {
+	*res = res_match;
+	return OK;
+    }
+    if (tv1->vval.v_object == NULL || tv2->vval.v_object == NULL)
+    {
+	*res = !res_match;
+	return OK;
+    }
+
+    class_T *cl1 = tv1->vval.v_object->obj_class;
+    class_T *cl2 = tv2->vval.v_object->obj_class;
+    if (cl1 != cl2 || cl1 == NULL || cl2 == NULL)
+    {
+	*res = !res_match;
+	return OK;
+    }
+
+    object_T *obj1 = tv1->vval.v_object;
+    object_T *obj2 = tv2->vval.v_object;
+    if (type == EXPR_IS || type == EXPR_ISNOT)
+    {
+	*res = obj1 == obj2 ? res_match : !res_match;
+	return OK;
+    }
+
+    for (int i = 0; i < cl1->class_obj_member_count; ++i)
+	if (!tv_equal((typval_T *)(obj1 + 1) + i,
+				 (typval_T *)(obj2 + 1) + i, ic, TRUE))
+	{
+	    *res = !res_match;
+	    return OK;
+	}
+    *res = res_match;
+    return OK;
+}
+
+/*
+ * Compare "tv1" to "tv2" as dictionaries according to "type" and "ic".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_dict(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type,
+	int	    ic,
+	int	    *res)
+{
+    int	    val;
+
+    if (type == EXPR_IS || type == EXPR_ISNOT)
+    {
+	val = (tv1->v_type == tv2->v_type
+			&& tv1->vval.v_dict == tv2->vval.v_dict);
+	if (type == EXPR_ISNOT)
+	    val = !val;
+    }
+    else if (tv1->v_type != tv2->v_type
+		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
+    {
+	if (tv1->v_type != tv2->v_type)
+	    emsg(_(e_can_only_compare_dictionary_with_dictionary));
+	else
+	    emsg(_(e_invalid_operation_for_dictionary));
+	return FAIL;
+    }
+    else
+    {
+	val = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, FALSE);
+	if (type == EXPR_NEQUAL)
+	    val = !val;
+    }
+    *res = val;
+    return OK;
+}
+
+/*
+ * Compare "tv1" to "tv2" as funcrefs according to "type" and "ic".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_func(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type,
+	int	    ic,
+	int	    *res)
+{
+    int	    val = 0;
+
+    if (type != EXPR_EQUAL && type != EXPR_NEQUAL
+	    && type != EXPR_IS && type != EXPR_ISNOT)
+    {
+	emsg(_(e_invalid_operation_for_funcrefs));
+	return FAIL;
+    }
+    if ((tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial == NULL)
+	    || (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial == NULL))
+	// When both partials are NULL, then they are equal.
+	// Otherwise they are not equal.
+	val = (tv1->vval.v_partial == tv2->vval.v_partial);
+    else if (type == EXPR_IS || type == EXPR_ISNOT)
+    {
+	if (tv1->v_type == VAR_FUNC && tv2->v_type == VAR_FUNC)
+	    // strings are considered the same if their value is
+	    // the same
+	    val = tv_equal(tv1, tv2, ic, FALSE);
+	else if (tv1->v_type == VAR_PARTIAL && tv2->v_type == VAR_PARTIAL)
+	    val = (tv1->vval.v_partial == tv2->vval.v_partial);
+	else
+	    val = FALSE;
+    }
+    else
+	val = tv_equal(tv1, tv2, ic, FALSE);
+    if (type == EXPR_NEQUAL || type == EXPR_ISNOT)
+	val = !val;
+    *res = val;
+    return OK;
+}
+
+/*
+ * Compare "tv1" to "tv2" as strings according to "type" and "ic".
+ * Put the result, false or true, in "res".
+ * Return FAIL and give an error message when the comparison can't be done.
+ */
+    int
+typval_compare_string(
+	typval_T    *tv1,
+	typval_T    *tv2,
+	exprtype_T  type,
+	int	    ic,
+	int	    *res)
+{
+    int		i = 0;
+    int		val = FALSE;
+    char_u	*s1, *s2;
+    char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
+
+    if (in_vim9script()
+	  && ((tv1->v_type != VAR_STRING && tv1->v_type != VAR_SPECIAL)
+	   || (tv2->v_type != VAR_STRING && tv2->v_type != VAR_SPECIAL)))
+    {
+	semsg(_(e_cannot_compare_str_with_str),
+		   vartype_name(tv1->v_type), vartype_name(tv2->v_type));
+	return FAIL;
+    }
+    s1 = tv_get_string_buf(tv1, buf1);
+    s2 = tv_get_string_buf(tv2, buf2);
+    if (type != EXPR_MATCH && type != EXPR_NOMATCH)
+	i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
+    switch (type)
+    {
+	case EXPR_IS:	    if (in_vim9script())
+			    {
+				// Really check it is the same string, not just
+				// the same value.
+				val = tv1->vval.v_string == tv2->vval.v_string;
+				break;
+			    }
+			    // FALLTHROUGH
+	case EXPR_EQUAL:    val = (i == 0); break;
+	case EXPR_ISNOT:    if (in_vim9script())
+			    {
+				// Really check it is not the same string, not
+				// just a different value.
+				val = tv1->vval.v_string != tv2->vval.v_string;
+				break;
+			    }
+			    // FALLTHROUGH
+	case EXPR_NEQUAL:   val = (i != 0); break;
+	case EXPR_GREATER:  val = (i > 0); break;
+	case EXPR_GEQUAL:   val = (i >= 0); break;
+	case EXPR_SMALLER:  val = (i < 0); break;
+	case EXPR_SEQUAL:   val = (i <= 0); break;
+
+	case EXPR_MATCH:
+	case EXPR_NOMATCH:
+		val = pattern_match(s2, s1, ic);
+		if (type == EXPR_NOMATCH)
+		    val = !val;
+		break;
+
+	default:  break;  // avoid gcc warning
+    }
+    *res = val;
+    return OK;
+}
+/*
+ * Convert any type to a string, never give an error.
+ * When "quotes" is TRUE add quotes to a string.
+ * Returns an allocated string.
+ */
+    char_u *
+typval_tostring(typval_T *arg, int quotes)
+{
+    char_u	*tofree;
+    char_u	numbuf[NUMBUFLEN];
+    char_u	*ret = NULL;
+
+    if (arg == NULL)
+	return vim_strsave((char_u *)"(does not exist)");
+    if (!quotes && arg->v_type == VAR_STRING)
+    {
+	ret = vim_strsave(arg->vval.v_string == NULL ? (char_u *)""
+							 : arg->vval.v_string);
+    }
+    else
+    {
+	ret = tv2string(arg, &tofree, numbuf, 0);
+	// Make a copy if we have a value but it's not in allocated memory.
+	if (ret != NULL && tofree == NULL)
+	    ret = vim_strsave(ret);
+    }
+    return ret;
+}
+
+/*
+ * Return TRUE if typeval "tv" is locked: Either that value is locked itself
+ * or it refers to a List or Dictionary that is locked.
+ */
+    int
+tv_islocked(typval_T *tv)
+{
+    return (tv->v_lock & VAR_LOCKED)
+	|| (tv->v_type == VAR_LIST
+		&& tv->vval.v_list != NULL
+		&& (tv->vval.v_list->lv_lock & VAR_LOCKED))
+	|| (tv->v_type == VAR_DICT
+		&& tv->vval.v_dict != NULL
+		&& (tv->vval.v_dict->dv_lock & VAR_LOCKED));
+}
+
+    static int
+func_equal(
+    typval_T *tv1,
+    typval_T *tv2,
+    int	     ic)	    // ignore case
+{
+    char_u	*s1, *s2;
+    dict_T	*d1, *d2;
+    int		a1, a2;
+    int		i;
+
+    // empty and NULL function name considered the same
+    s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
+					   : partial_name(tv1->vval.v_partial);
+    if (s1 != NULL && *s1 == NUL)
+	s1 = NULL;
+    s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
+					   : partial_name(tv2->vval.v_partial);
+    if (s2 != NULL && *s2 == NUL)
+	s2 = NULL;
+    if (s1 == NULL || s2 == NULL)
+    {
+	if (s1 != s2)
+	    return FALSE;
+    }
+    else if (STRCMP(s1, s2) != 0)
+	return FALSE;
+
+    // empty dict and NULL dict is different
+    d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
+    d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
+    if (d1 == NULL || d2 == NULL)
+    {
+	if (d1 != d2)
+	    return FALSE;
+    }
+    else if (!dict_equal(d1, d2, ic, TRUE))
+	return FALSE;
+
+    // empty list and no list considered the same
+    a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
+    a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
+    if (a1 != a2)
+	return FALSE;
+    for (i = 0; i < a1; ++i)
+	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
+		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
+	    return FALSE;
+
+    return TRUE;
+}
+
+/*
+ * Return TRUE if "tv1" and "tv2" have the same value.
+ * Compares the items just like "==" would compare them, but strings and
+ * numbers are different.  Floats and numbers are also different.
+ */
+    int
+tv_equal(
+    typval_T *tv1,
+    typval_T *tv2,
+    int	     ic,	    // ignore case
+    int	     recursive)	    // TRUE when used recursively
+{
+    char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
+    char_u	*s1, *s2;
+    static int  recursive_cnt = 0;	    // catch recursive loops
+    int		r;
+    static int	tv_equal_recurse_limit;
+
+    // Catch lists and dicts that have an endless loop by limiting
+    // recursiveness to a limit.  We guess they are equal then.
+    // A fixed limit has the problem of still taking an awful long time.
+    // Reduce the limit every time running into it. That should work fine for
+    // deeply linked structures that are not recursively linked and catch
+    // recursiveness quickly.
+    if (!recursive)
+	tv_equal_recurse_limit = 1000;
+    if (recursive_cnt >= tv_equal_recurse_limit)
+    {
+	--tv_equal_recurse_limit;
+	return TRUE;
+    }
+
+    // For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
+    // arguments.
+    if ((tv1->v_type == VAR_FUNC
+		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
+	    && (tv2->v_type == VAR_FUNC
+		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
+    {
+	++recursive_cnt;
+	r = func_equal(tv1, tv2, ic);
+	--recursive_cnt;
+	return r;
+    }
+
+    if (tv1->v_type != tv2->v_type
+	    && ((tv1->v_type != VAR_BOOL && tv1->v_type != VAR_SPECIAL)
+		|| (tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)))
+	return FALSE;
+
+    switch (tv1->v_type)
+    {
+	case VAR_LIST:
+	    ++recursive_cnt;
+	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
+	    --recursive_cnt;
+	    return r;
+
+	case VAR_DICT:
+	    ++recursive_cnt;
+	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
+	    --recursive_cnt;
+	    return r;
+
+	case VAR_BLOB:
+	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
+
+	case VAR_NUMBER:
+	case VAR_BOOL:
+	case VAR_SPECIAL:
+	    return tv1->vval.v_number == tv2->vval.v_number;
+
+	case VAR_STRING:
+	    s1 = tv_get_string_buf(tv1, buf1);
+	    s2 = tv_get_string_buf(tv2, buf2);
+	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
+
+	case VAR_FLOAT:
+	    return tv1->vval.v_float == tv2->vval.v_float;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    return tv1->vval.v_job == tv2->vval.v_job;
+#endif
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    return tv1->vval.v_channel == tv2->vval.v_channel;
+#endif
+	case VAR_INSTR:
+	    return tv1->vval.v_instr == tv2->vval.v_instr;
+
+	case VAR_CLASS:
+	    // A class only exists once, equality is identity.
+	    return tv1->vval.v_class == tv2->vval.v_class;
+
+	case VAR_OBJECT:
+	    (void)typval_compare_object(tv1, tv2, EXPR_EQUAL, ic, &r);
+	    return r;
+
+	case VAR_PARTIAL:
+	    return tv1->vval.v_partial == tv2->vval.v_partial;
+
+	case VAR_FUNC:
+	    return tv1->vval.v_string == tv2->vval.v_string;
+
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	case VAR_VOID:
+	    break;
+    }
+
+    // VAR_UNKNOWN can be the result of a invalid expression, let's say it
+    // does not equal anything, not even itself.
+    return FALSE;
+}
+
+/*
+ * Get an option value.
+ * "arg" points to the '&' or '+' before the option name.
+ * "arg" is advanced to character after the option name.
+ * Return OK or FAIL.
+ */
+    int
+eval_option(
+    char_u	**arg,
+    typval_T	*rettv,	// when NULL, only check if option exists
+    int		evaluate)
+{
+    char_u	*option_end;
+    long	numval;
+    char_u	*stringval;
+    getoption_T	opt_type;
+    int		c;
+    int		working = (**arg == '+');    // has("+option")
+    int		ret = OK;
+    int		scope;
+
+    // Isolate the option name and find its value.
+    option_end = find_option_end(arg, &scope);
+    if (option_end == NULL)
+    {
+	if (rettv != NULL)
+	    semsg(_(e_option_name_missing_str), *arg);
+	return FAIL;
+    }
+
+    if (!evaluate)
+    {
+	*arg = option_end;
+	return OK;
+    }
+
+    c = *option_end;
+    *option_end = NUL;
+    opt_type = get_option_value(*arg, &numval,
+			       rettv == NULL ? NULL : &stringval, NULL, scope);
+
+    if (opt_type == gov_unknown)
+    {
+	if (rettv != NULL)
+	    semsg(_(e_unknown_option_str), *arg);
+	ret = FAIL;
+    }
+    else if (rettv != NULL)
+    {
+	rettv->v_lock = 0;
+	if (opt_type == gov_hidden_string)
+	{
+	    rettv->v_type = VAR_STRING;
+	    rettv->vval.v_string = NULL;
+	}
+	else if (opt_type == gov_hidden_bool || opt_type == gov_hidden_number)
+	{
+	    rettv->v_type = in_vim9script() && opt_type == gov_hidden_bool
+						       ? VAR_BOOL : VAR_NUMBER;
+	    rettv->vval.v_number = 0;
+	}
+	else if (opt_type == gov_bool || opt_type == gov_number)
+	{
+	    if (in_vim9script() && opt_type == gov_bool)
+	    {
+		rettv->v_type = VAR_BOOL;
+		rettv->vval.v_number = numval ? VVAL_TRUE : VVAL_FALSE;
+	    }
+	    else
+	    {
+		rettv->v_type = VAR_NUMBER;
+		rettv->vval.v_number = numval;
+	    }
+	}
+	else				// string option
+	{
+	    rettv->v_type = VAR_STRING;
+	    rettv->vval.v_string = stringval;
+	}
+    }
+    else if (working && (opt_type == gov_hidden_bool
+			|| opt_type == gov_hidden_number
+			|| opt_type == gov_hidden_string))
+	ret = FAIL;
+
+    *option_end = c;		    // put back for error messages
+    *arg = option_end;
+
+    return ret;
+}
+
+/*
+ * Allocate a variable for a number constant.  Also deals with "0z" for blob.
+ * Return OK or FAIL.
+ */
+    int
+eval_number(
+	char_u	    **arg,
+	typval_T    *rettv,
+	int	    evaluate,
+	int	    want_string UNUSED)
+{
+    int		len;
+    int		skip_quotes = !in_old_script(4);
+    char_u	*p;
+    int		get_float = FALSE;
+
+    // We accept a float when the format matches
+    // "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
+    // strict to avoid backwards compatibility problems.
+    // With script version 2 and later the leading digit can be
+    // omitted.
+    // Don't look for a float after the "." operator, so that
+    // ":let vers = 1.2.3" doesn't fail.
+    if (**arg == '.')
+	p = *arg;
+    else
+    {
+	p = *arg + 1;
+	if (skip_quotes)
+	    for (;;)
+	    {
+		if (*p == '\'')
+		    ++p;
+		if (!vim_isdigit(*p))
+		    break;
+		p = skipdigits(p);
+	    }
+	else
+	    p = skipdigits(p);
+    }
+    if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
+    {
+	get_float = TRUE;
+	p = skipdigits(p + 2);
+	if (*p == 'e' || *p == 'E')
+	{
+	    ++p;
+	    if (*p == '-' || *p == '+')
+		++p;
+	    if (!vim_isdigit(*p))
+		get_float = FALSE;
+	    else
+		p = skipdigits(p + 1);
+	}
+	if (ASCII_ISALPHA(*p) || *p == '.')
+	    get_float = FALSE;
+    }
+    if (get_float)
+    {
+	float_T	f;
+
+	*arg += string2float(*arg, &f, skip_quotes);
+	if (evaluate)
+	{
+	    rettv->v_type = VAR_FLOAT;
+	    rettv->vval.v_float = f;
+	}
+    }
+    else
+    if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
+    {
+	char_u  *bp;
+	blob_T  *blob = NULL;  // init for gcc
+
+	// Blob constant: 0z0123456789abcdef
+	if (evaluate)
+	    blob = blob_alloc();
+	for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
+	{
+	    if (!vim_isxdigit(bp[1]))
+	    {
+		if (blob != NULL)
+		{
+		    emsg(_(e_blob_literal_should_have_an_even_number_of_hex_characters));
+		    ga_clear(&blob->bv_ga);
+		    VIM_CLEAR(blob);
+		}
+		return FAIL;
+	    }
+	    if (blob != NULL)
+		ga_append(&blob->bv_ga,
+			     (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
+	    if (bp[2] == '.' && vim_isxdigit(bp[3]))
+		++bp;
+	}
+	if (blob != NULL)
+	    rettv_blob_set(rettv, blob);
+	*arg = bp;
+    }
+    else
+    {
+	varnumber_T	n;
+
+	// decimal, hex or octal number
+	vim_str2nr(*arg, NULL, &len, skip_quotes
+		      ? STR2NR_NO_OCT + STR2NR_QUOTE
+		      : STR2NR_ALL, &n, NULL, 0, TRUE);
+	if (len == 0)
+	{
+	    if (evaluate)
+		semsg(_(e_invalid_expression_str), *arg);
+	    return FAIL;
+	}
+	*arg += len;
+	if (evaluate)
+	{
+	    rettv->v_type = VAR_NUMBER;
+	    rettv->vval.v_number = n;
+	}
+    }
+    return OK;
+}
+
+/*
+ * Evaluate a string constant and put the result in "rettv".
+ * "*arg" points to the double quote or to after it when "interpolate" is TRUE.
+ * When "interpolate" is TRUE reduce "{{" to "{", reduce "}}" to "}" and stop
+ * at a single "{".
+ * Return OK or FAIL.
+ */
+    int
+eval_string(char_u **arg, typval_T *rettv, int evaluate, int interpolate)
+{
+    char_u	*p;
+    char_u	*end;
+    int		extra = interpolate ? 1 : 0;
+    int		off = interpolate ? 0 : 1;
+    int		len;
+
+    // Find the end of the string, skipping backslashed characters.
+    for (p = *arg + off; *p != NUL && *p != '"'; MB_PTR_ADV(p))
+    {
+	if (*p == '\\' && p[1] != NUL)
+	{
+	    ++p;
+	    // A "\<x>" form occupies at least 4 characters, and produces up
+	    // to 9 characters (6 for the char and 3 for a modifier):
+	    // reserve space for 5 extra.
+	    if (*p == '<')
+	    {
+		int		modifiers = 0;
+		int		flags = FSK_KEYCODE | FSK_IN_STRING;
+
+		extra += 5;
+
+		// Skip to the '>' to avoid using '{' inside for string
+		// interpolation.
+		if (p[1] != '*')
+		    flags |= FSK_SIMPLIFY;
+		if (find_special_key(&p, &modifiers, flags, NULL) != 0)
+		    --p;  // leave "p" on the ">"
+	    }
+	}
+	else if (interpolate && (*p == '{' || *p == '}'))
+	{
+	    if (*p == '{' && p[1] != '{') // start of expression
+		break;
+	    ++p;
+	    if (p[-1] == '}' && *p != '}') // single '}' is an error
+	    {
+		semsg(_(e_stray_closing_curly_str), *arg);
+		return FAIL;
+	    }
+	    --extra;  // "{{" becomes "{", "}}" becomes "}"
+	}
+    }
+
+    if (*p != '"' && !(interpolate && *p == '{'))
+    {
+	semsg(_(e_missing_double_quote_str), *arg);
+	return FAIL;
+    }
+
+    // If only parsing, set *arg and return here
+    if (!evaluate)
+    {
+	*arg = p + off;
+	return OK;
+    }
+
+    // Copy the string into allocated memory, handling backslashed
+    // characters.
+    rettv->v_type = VAR_STRING;
+    len = (int)(p - *arg + extra);
+    rettv->vval.v_string = alloc(len);
+    if (rettv->vval.v_string == NULL)
+	return FAIL;
+    end = rettv->vval.v_string;
+
+    for (p = *arg + off; *p != NUL && *p != '"'; )
+    {
+	if (*p == '\\')
+	{
+	    switch (*++p)
+	    {
+		case 'b': *end++ = BS; ++p; break;
+		case 'e': *end++ = ESC; ++p; break;
+		case 'f': *end++ = FF; ++p; break;
+		case 'n': *end++ = NL; ++p; break;
+		case 'r': *end++ = CAR; ++p; break;
+		case 't': *end++ = TAB; ++p; break;
+
+		case 'X': // hex: "\x1", "\x12"
+		case 'x':
+		case 'u': // Unicode: "\u0023"
+		case 'U':
+			  if (vim_isxdigit(p[1]))
+			  {
+			      int	n, nr;
+			      int	c = toupper(*p);
+
+			      if (c == 'X')
+				  n = 2;
+			      else if (*p == 'u')
+				  n = 4;
+			      else
+				  n = 8;
+			      nr = 0;
+			      while (--n >= 0 && vim_isxdigit(p[1]))
+			      {
+				  ++p;
+				  nr = (nr << 4) + hex2nr(*p);
+			      }
+			      ++p;
+			      // For "\u" store the number according to
+			      // 'encoding'.
+			      if (c != 'X')
+				  end += (*mb_char2bytes)(nr, end);
+			      else
+				  *end++ = nr;
+			  }
+			  break;
+
+			  // octal: "\1", "\12", "\123"
+		case '0':
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7': *end = *p++ - '0';
+			  if (*p >= '0' && *p <= '7')
+			  {
+			      *end = (*end << 3) + *p++ - '0';
+			      if (*p >= '0' && *p <= '7')
+				  *end = (*end << 3) + *p++ - '0';
+			  }
+			  ++end;
+			  break;
+
+			  // Special key, e.g.: "\<C-W>"
+		case '<':
+			  {
+			      int flags = FSK_KEYCODE | FSK_IN_STRING;
+
+			      if (p[1] != '*')
+				  flags |= FSK_SIMPLIFY;
+			      extra = trans_special(&p, end, flags, FALSE, NULL);
+			      if (extra != 0)
+			      {
+				  end += extra;
+				  if (end >= rettv->vval.v_string + len)
+				      iemsg("eval_string() used more space than allocated");
+				  break;
+			      }
+			  }
+			  // FALLTHROUGH
+
+		default: MB_COPY_CHAR(p, end);
+			  break;
+	    }
+	}
+	else
+	{
+	    if (interpolate && (*p == '{' || *p == '}'))
+	    {
+		if (*p == '{' && p[1] != '{') // start of expression
+		    break;
+		++p;  // reduce "{{" to "{" and "}}" to "}"
+	    }
+	    MB_COPY_CHAR(p, end);
+	}
+    }
+    *end = NUL;
+    if (*p == '"' && !interpolate)
+	++p;
+    *arg = p;
+
+    return OK;
+}
+
+/*
+ * Allocate a variable for a 'str''ing' constant.
+ * When "interpolate" is TRUE reduce "{{" to "{" and stop at a single "{".
+ * Return OK when a "rettv" was set to the string.
+ * Return FAIL on error, "rettv" is not set.
+ */
+    int
+eval_lit_string(char_u **arg, typval_T *rettv, int evaluate, int interpolate)
+{
+    char_u	*p;
+    char_u	*str;
+    int		reduce = interpolate ? -1 : 0;
+    int		off = interpolate ? 0 : 1;
+
+    // Find the end of the string, skipping ''.
+    for (p = *arg + off; *p != NUL; MB_PTR_ADV(p))
+    {
+	if (*p == '\'')
+	{
+	    if (p[1] != '\'')
+		break;
+	    ++reduce;
+	    ++p;
+	}
+	else if (interpolate)
+	{
+	    if (*p == '{')
+	    {
+		if (p[1] != '{')
+		    break;
+		++p;
+		++reduce;
+	    }
+	    else if (*p == '}')
+	    {
+		++p;
+		if (*p != '}')
+		{
+		    semsg(_(e_stray_closing_curly_str), *arg);
+		    return FAIL;
+		}
+		++reduce;
+	    }
+	}
+    }
+
+    if (*p != '\'' && !(interpolate && *p == '{'))
+    {
+	semsg(_(e_missing_single_quote_str), *arg);
+	return FAIL;
+    }
+
+    // If only parsing return after setting "*arg"
+    if (!evaluate)
+    {
+	*arg = p + off;
+	return OK;
+    }
+
+    // Copy the string into allocated memory, handling '' to ' reduction and
+    // any expressions.
+    str = alloc((p - *arg) - reduce);
+    if (str == NULL)
+	return FAIL;
+    rettv->v_type = VAR_STRING;
+    rettv->vval.v_string = str;
+
+    for (p = *arg + off; *p != NUL; )
+    {
+	if (*p == '\'')
+	{
+	    if (p[1] != '\'')
+		break;
+	    ++p;
+	}
+	else if (interpolate && (*p == '{' || *p == '}'))
+	{
+	    if (*p == '{' && p[1] != '{')
+		break;
+	    ++p;
+	}
+	MB_COPY_CHAR(p, str);
+    }
+    *str = NUL;
+    *arg = p + off;
+
+    return OK;
+}
+
+/*
+ * Evaluate a single or double quoted string possibly containing expressions.
+ * "arg" points to the '$'.  The result is put in "rettv".
+ * Returns OK or FAIL.
+ */
+    int
+eval_interp_string(char_u **arg, typval_T *rettv, int evaluate)
+{
+    typval_T	tv;
+    int		ret = OK;
+    int		quote;
+    garray_T	ga;
+    char_u	*p;
+
+    ga_init2(&ga, 1, 80);
+
+    // *arg is on the '$' character, move it to the first string character.
+    ++*arg;
+    quote = **arg;
+    ++*arg;
+
+    for (;;)
+    {
+	// Get the string up to the matching quote or to a single '{'.
+	// "arg" is advanced to either the quote or the '{'.
+	if (quote == '"')
+	    ret = eval_string(arg, &tv, evaluate, TRUE);
+	else
+	    ret = eval_lit_string(arg, &tv, evaluate, TRUE);
+	if (ret == FAIL)
+	    break;
+	if (evaluate)
+	{
+	    ga_concat(&ga, tv.vval.v_string);
+	    clear_tv(&tv);
+	}
+
+	if (**arg != '{')
+	{
+	    // found terminating quote
+	    ++*arg;
+	    break;
+	}
+	p = eval_one_expr_in_str(*arg, &ga, evaluate);
+	if (p == NULL)
+	{
+	    ret = FAIL;
+	    break;
+	}
+	*arg = p;
+    }
+
+    rettv->v_type = VAR_STRING;
+    if (ret == FAIL || !evaluate || ga_append(&ga, NUL) == FAIL)
+    {
+	ga_clear(&ga);
+	rettv->vval.v_string = NULL;
+	return ret;
+    }
+
+    rettv->vval.v_string = ga.ga_data;
+    return OK;
+}
+
+/*
+ * Return a string with the string representation of a variable.
+ * If the memory is allocated "tofree" is set to it, otherwise NULL.
+ * "numbuf" is used for a number.
+ * Puts quotes around strings, so that they can be parsed back by eval().
+ * May return NULL.
+ */
+    char_u *
+tv2string(
+    typval_T	*tv,
+    char_u	**tofree,
+    char_u	*numbuf,
+    int		copyID)
+{
+    return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
+}
+
+/*
+ * Get the value of an environment variable.
+ * "arg" is pointing to the '$'.  It is advanced to after the name.
+ * If the environment variable was not set, silently assume it is empty.
+ * Return FAIL if the name is invalid.
+ */
+    int
+eval_env_var(char_u **arg, typval_T *rettv, int evaluate)
+{
+    char_u	*string = NULL;
+    int		len;
+    int		cc;
+    char_u	*name;
+    int		mustfree = FALSE;
+
+    ++*arg;
+    name = *arg;
+    len = get_env_len(arg);
+    if (evaluate)
+    {
+	if (len == 0)
+	    return FAIL; // invalid empty name
+
+	cc = name[len];
+	name[len] = NUL;
+	// first try vim_getenv(), fast for normal environment vars
+	string = vim_getenv(name, &mustfree);
+	if (string != NULL && *string != NUL)
+	{
+	    if (!mustfree)
+		string = vim_strsave(string);
+	}
+	else
+	{
+	    if (mustfree)
+		vim_free(string);
+
+	    // next try expanding things like $VIM and ${HOME}
+	    string = expand_env_save(name - 1);
+	    if (string != NULL && *string == '$')
+		VIM_CLEAR(string);
+	}
+	name[len] = cc;
+
+	rettv->v_type = VAR_STRING;
+	rettv->vval.v_string = string;
+	rettv->v_lock = 0;
+    }
+
+    return OK;
+}
+
+/*
+ * Get the lnum from the first argument.
+ * Also accepts ".", "$", etc., but that only works for the current buffer.
+ * Returns -1 on error.
+ */
+    linenr_T
+tv_get_lnum(typval_T *argvars)
+{
+    linenr_T	lnum = -1;
+    int		did_emsg_before = did_emsg;
+
+    if (argvars[0].v_type != VAR_STRING || !in_vim9script())
+	lnum = (linenr_T)tv_get_number_chk(&argvars[0], NULL);
+    if (lnum <= 0 && did_emsg_before == did_emsg
+					    && argvars[0].v_type != VAR_NUMBER)
+    {
+	int	fnum;
+	pos_T	*fp;
+
+	// no valid number, try using arg like line()
+	fp = var2fpos(&argvars[0], TRUE, &fnum, FALSE);
+	if (fp != NULL)
+	    lnum = fp->lnum;
+    }
+    return lnum;
+}
+
+/*
+ * Get the lnum from the first argument.
+ * Also accepts "$", then "buf" is used.
+ * Returns 0 on error.
+ */
+    linenr_T
+tv_get_lnum_buf(typval_T *argvars, buf_T *buf)
+{
+    if (argvars[0].v_type == VAR_STRING
+	    && argvars[0].vval.v_string != NULL
+	    && argvars[0].vval.v_string[0] == '$'
+	    && argvars[0].vval.v_string[1] == NUL
+	    && buf != NULL)
+	return buf->b_ml.ml_line_count;
+    return (linenr_T)tv_get_number_chk(&argvars[0], NULL);
+}
+
+/*
+ * Get buffer by number or pattern.
+ */
+    buf_T *
+tv_get_buf(typval_T *tv, int curtab_only)
+{
+    char_u	*name = tv->vval.v_string;
+    buf_T	*buf;
+
+    if (tv->v_type == VAR_NUMBER)
+	return buflist_findnr((int)tv->vval.v_number);
+    if (tv->v_type != VAR_STRING)
+	return NULL;
+    if (name == NULL || *name == NUL)
+	return curbuf;
+    if (name[0] == '$' && name[1] == NUL)
+	return lastbuf;
+
+    buf = buflist_find_by_name(name, curtab_only);
+
+    // If not found, try expanding the name, like done for bufexists().
+    if (buf == NULL)
+	buf = find_buffer(tv);
+
+    return buf;
+}
+
+/*
+ * Like tv_get_buf() but give an error message is the type is wrong.
+ */
+    buf_T *
+tv_get_buf_from_arg(typval_T *tv)
+{
+    buf_T *buf;
+
+    ++emsg_off;
+    buf = tv_get_buf(tv, FALSE);
+    --emsg_off;
+    if (buf == NULL
+	    && tv->v_type != VAR_NUMBER
+	    && tv->v_type != VAR_STRING)
+	// issue errmsg for type error
+	(void)tv_get_number(tv);
+    return buf;
+}
+
+#endif // FEAT_EVAL