diff --git a/src/vim9.h b/src/vim9.h
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+++ b/src/vim9.h
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+/* 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.
+ */
+
+/*
+ * vim9.h: types and globals used for Vim9 script.
+ */
+
+typedef enum {
+    ISN_EXEC,	    // execute Ex command line isn_arg.string
+    ISN_ECHO,	    // echo isn_arg.number items on top of stack
+
+    // get and set variables
+    ISN_LOAD,	    // push local variable isn_arg.number
+    ISN_LOADV,	    // push v: variable isn_arg.number
+    ISN_LOADSCRIPT, // push script-local variable isn_arg.script.
+    ISN_LOADS,	    // push s: variable isn_arg.string
+    ISN_LOADG,	    // push g: variable isn_arg.string
+    ISN_LOADOPT,    // push option isn_arg.string
+    ISN_LOADENV,    // push environment variable isn_arg.string
+    ISN_LOADREG,    // push register isn_arg.number
+
+    ISN_STORE,	    // pop into local variable isn_arg.number
+    ISN_STOREG,	    // pop into global variable isn_arg.string
+    ISN_STORESCRIPT, // pop into scirpt variable isn_arg.script
+    ISN_STOREOPT,   // pop into option isn_arg.string
+    // ISN_STOREOTHER, // pop into other script variable isn_arg.other.
+
+    ISN_STORENR,    // store number into local variable isn_arg.storenr.str_idx
+
+    // constants
+    ISN_PUSHNR,	    // push number isn_arg.number
+    ISN_PUSHBOOL,   // push bool value isn_arg.number
+    ISN_PUSHSPEC,   // push special value isn_arg.number
+    ISN_PUSHF,	    // push float isn_arg.fnumber
+    ISN_PUSHS,	    // push string isn_arg.string
+    ISN_PUSHBLOB,   // push blob isn_arg.blob
+    ISN_NEWLIST,    // push list from stack items, size is isn_arg.number
+    ISN_NEWDICT,    // push dict from stack items, size is isn_arg.number
+
+    // function call
+    ISN_BCALL,	    // call builtin function isn_arg.bfunc
+    ISN_DCALL,	    // call def function isn_arg.dfunc
+    ISN_UCALL,	    // call user function or funcref/partial isn_arg.ufunc
+    ISN_PCALL,	    // call partial, use isn_arg.pfunc
+    ISN_RETURN,	    // return, result is on top of stack
+    ISN_FUNCREF,    // push a function ref to dfunc isn_arg.number
+
+    // expression operations
+    ISN_JUMP,	    // jump if condition is matched isn_arg.jump
+
+    // loop
+    ISN_FOR,	    // get next item from a list, uses isn_arg.forloop
+
+    ISN_TRY,	    // add entry to ec_trystack, uses isn_arg.try
+    ISN_THROW,	    // pop value of stack, store in v:exception
+    ISN_PUSHEXC,    // push v:exception
+    ISN_CATCH,	    // drop v:exception
+    ISN_ENDTRY,	    // take entry off from ec_trystack
+
+    // moreexpression operations
+    ISN_ADDLIST,
+    ISN_ADDBLOB,
+
+    // operation with two arguments; isn_arg.op.op_type is exptype_T
+    ISN_OPNR,
+    ISN_OPFLOAT,
+    ISN_OPANY,
+
+    // comparative operations; isn_arg.op.op_type is exptype_T, op_ic used
+    ISN_COMPAREBOOL,
+    ISN_COMPARESPECIAL,
+    ISN_COMPARENR,
+    ISN_COMPAREFLOAT,
+    ISN_COMPARESTRING,
+    ISN_COMPAREBLOB,
+    ISN_COMPARELIST,
+    ISN_COMPAREDICT,
+    ISN_COMPAREFUNC,
+    ISN_COMPAREPARTIAL,
+    ISN_COMPAREANY,
+
+    // expression operations
+    ISN_CONCAT,
+    ISN_INDEX,	    // [expr] list index
+    ISN_MEMBER,	    // dict.member using isn_arg.string
+    ISN_2BOOL,	    // convert value to bool, invert if isn_arg.number != 0
+    ISN_2STRING,    // convert value to string at isn_arg.number on stack
+    ISN_NEGATENR,   // apply "-" to number
+
+    ISN_CHECKNR,    // check value can be used as a number
+    ISN_CHECKTYPE,  // check value type is isn_arg.type.tc_type
+
+    ISN_DROP	    // pop stack and discard value
+} isntype_T;
+
+
+// arguments to ISN_BCALL
+typedef struct {
+    int	    cbf_idx;	    // index in "global_functions"
+    int	    cbf_argcount;   // number of arguments on top of stack
+} cbfunc_T;
+
+// arguments to ISN_DCALL
+typedef struct {
+    int	    cdf_idx;	    // index in "def_functions" for ISN_DCALL
+    int	    cdf_argcount;   // number of arguments on top of stack
+} cdfunc_T;
+
+// arguments to ISN_PCALL
+typedef struct {
+    int	    cpf_top;	    // when TRUE partial is above the arguments
+    int	    cpf_argcount;   // number of arguments on top of stack
+} cpfunc_T;
+
+// arguments to ISN_UCALL and ISN_XCALL
+typedef struct {
+    char_u  *cuf_name;
+    int	    cuf_argcount;   // number of arguments on top of stack
+} cufunc_T;
+
+typedef enum {
+    JUMP_ALWAYS,
+    JUMP_IF_TRUE,		// pop and jump if true
+    JUMP_IF_FALSE,		// pop and jump if false
+    JUMP_AND_KEEP_IF_TRUE,	// jump if top of stack is true, drop if not
+    JUMP_AND_KEEP_IF_FALSE,	// jump if top of stack is false, drop if not
+} jumpwhen_T;
+
+// arguments to ISN_JUMP
+typedef struct {
+    jumpwhen_T	jump_when;
+    int		jump_where;	    // position to jump to
+} jump_T;
+
+// arguments to ISN_FOR
+typedef struct {
+    int	    for_idx;	    // loop variable index
+    int	    for_end;	    // position to jump to after done
+} forloop_T;
+
+// arguments to ISN_TRY
+typedef struct {
+    int	    try_catch;	    // position to jump to on throw
+    int	    try_finally;    // position to jump to for return
+} try_T;
+
+// arguments to ISN_ECHO
+typedef struct {
+    int	    echo_with_white;    // :echo instead of :echon
+    int	    echo_count;		// number of expressions
+} echo_T;
+
+// arguments to ISN_OPNR, ISN_OPFLOAT, etc.
+typedef struct {
+    exptype_T	op_type;
+    int		op_ic;	    // TRUE with '#', FALSE with '?', else MAYBE
+} opexpr_T;
+
+// arguments to ISN_CHECKTYPE
+typedef struct {
+    vartype_T	ct_type;
+    int		ct_off;	    // offset in stack, -1 is bottom
+} checktype_T;
+
+// arguments to ISN_STORENR
+typedef struct {
+    int		str_idx;
+    varnumber_T	str_val;
+} storenr_T;
+
+// arguments to ISN_STOREOPT
+typedef struct {
+    char_u	*so_name;
+    int		so_flags;
+} storeopt_T;
+
+// arguments to ISN_LOADS
+typedef struct {
+    char_u	*ls_name;	// variable name
+    int		ls_sid;		// script ID
+} loads_T;
+
+// arguments to ISN_LOADSCRIPT
+typedef struct {
+    int		script_sid;	// script ID
+    int		script_idx;	// index in sn_var_vals
+} script_T;
+
+/*
+ * Instruction
+ */
+typedef struct {
+    isntype_T	isn_type;
+    int		isn_lnum;
+    union {
+	char_u		    *string;
+	varnumber_T	    number;
+	blob_T		    *blob;
+#ifdef FEAT_FLOAT
+	float_T		    fnumber;
+#endif
+	jump_T		    jump;
+	forloop_T	    forloop;
+	try_T		    try;
+	cbfunc_T	    bfunc;
+	cdfunc_T	    dfunc;
+	cpfunc_T	    pfunc;
+	cufunc_T	    ufunc;
+	echo_T		    echo;
+	opexpr_T	    op;
+	checktype_T	    type;
+	storenr_T	    storenr;
+	storeopt_T	    storeopt;
+	loads_T		    loads;
+	script_T	    script;
+    } isn_arg;
+} isn_T;
+
+/*
+ * Info about a function defined with :def.  Used in "def_functions".
+ */
+struct dfunc_S {
+    ufunc_T	*df_ufunc;	    // struct containing most stuff
+    int		df_idx;		    // index in def_functions
+    int		df_deleted;	    // if TRUE function was deleted
+
+    garray_T	df_def_args_isn;    // default argument instructions
+    isn_T	*df_instr;	    // function body to be executed
+    int		df_instr_count;
+
+    int		df_varcount;	    // number of local variables
+};
+
+// Number of entries used by stack frame for a function call.
+#define STACK_FRAME_SIZE 3
+
+
+#ifdef DEFINE_VIM9_GLOBALS
+// Functions defined with :def are stored in this growarray.
+// They are never removed, so that they can be found by index.
+// Deleted functions have the df_deleted flag set.
+garray_T def_functions = {0, 0, sizeof(dfunc_T), 50, NULL};
+#else
+extern garray_T def_functions;
+#endif
+