updated for version 7.0006

1 files changed, 2244 insertions, 0 deletions

diff --git a/src/if_mzsch.c b/src/if_mzsch.c
new file mode 100644
index 0000000000..377b5f755b
--- /dev/null
+++ b/src/if_mzsch.c
@@ -0,0 +1,2244 @@
+/* vi:set ts=8 sts=4 sw=4:
+ *
+ * MzScheme interface by Sergey Khorev <khorev@softlab.ru>
+ * Original work by Brent Fulgham <bfulgham@debian.org>
+ * (Based on lots of help from Matthew Flatt)
+ *
+ * This consists of six parts:
+ * 1. MzScheme interpreter main program
+ * 2. Routines that handle the external interface between MzScheme and
+ *    Vim.
+ * 3. MzScheme input/output handlers: writes output via [e]msg().
+ * 4. Implementation of the Vim Features for MzScheme
+ * 5. Vim Window-related Manipulation Functions.
+ * 6. Vim Buffer-related Manipulation Functions
+ *
+ * NOTES
+ * 1. Memory, allocated with scheme_malloc*, need not to be freed explicitly,
+ *    garbage collector will do it self
+ * 2. Requires at least NORMAL features. I can't imagine why one may want
+ *    to build with SMALL or TINY features but with MzScheme interface.
+ * 3. I don't use K&R-style functions. Anyway, MzScheme headers are ANSI.
+ */
+
+/* TODO
+ * way to catch Vim errors (incl. verbose messages)
+ * libmzscheme.dll dynamic loading
+ * macros to pass modifiers (e.g. (browse edit))
+ * opportunity to use shared mzscheme libraries on Unix
+ * event on-change-mode
+ * Scheme-driven coloring
+ * global exn-handler
+ * embed Read-Eval-Print-Loop
+ */
+
+#include "vim.h"
+#include "if_mzsch.h"
+
+/* Base data structures */
+#define SCHEME_VIMBUFFERP(obj)  SAME_TYPE(SCHEME_TYPE(obj), mz_buffer_type)
+#define SCHEME_VIMWINDOWP(obj)  SAME_TYPE(SCHEME_TYPE(obj), mz_window_type)
+
+typedef struct
+{
+    Scheme_Type	    tag;
+    Scheme_Env	    *env;
+    buf_T	    *buf;
+    Scheme_Object   *text_objects;
+} vim_mz_buffer;
+
+#define INVALID_BUFFER_VALUE ((buf_T *)(-1))
+
+typedef struct
+{
+    Scheme_Type	    tag;
+    struct window   *win;
+} vim_mz_window;
+
+#define INVALID_WINDOW_VALUE ((win_T *)(-1))
+
+/*
+ * Prims that form MzScheme Vim interface
+ */
+typedef struct
+{
+    Scheme_Closed_Prim	*prim;
+    char	*name;
+    int		mina;	/* arity information */
+    int		maxa;
+} Vim_Prim;
+
+typedef struct
+{
+    char	    *name;
+    Scheme_Object   *port;
+} Port_Info;
+
+/* info for closed prim */
+/*
+ * data have different means:
+ * for do_eval it is char*
+ * for do_apply is Apply_Onfo*
+ * for do_load is Port_Info*
+ */
+typedef struct
+{
+    void	*data;
+    Scheme_Env	*env;
+} Cmd_Info;
+
+/* info for do_apply */
+typedef struct
+{
+    Scheme_Object   *proc;
+    int		    argc;
+    Scheme_Object   **argv;
+} Apply_Info;
+
+/*
+ *========================================================================
+ *  Vim-Control Commands
+ *========================================================================
+ */
+/*
+ *========================================================================
+ *  Utility functions for the vim/mzscheme interface
+ *========================================================================
+ */
+/*  Buffer-related commands */
+static Scheme_Object *buffer_new(buf_T *buf);
+static Scheme_Object *get_buffer_by_name(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_by_num(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_count(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_line(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_line_list(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_name(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_num(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_size(void *, int, Scheme_Object **);
+static Scheme_Object *get_curr_buffer(void *, int, Scheme_Object **);
+static Scheme_Object *get_next_buffer(void *, int, Scheme_Object **);
+static Scheme_Object *get_prev_buffer(void *, int, Scheme_Object **);
+static Scheme_Object *mzscheme_open_buffer(void *, int, Scheme_Object **);
+static Scheme_Object *set_buffer_line(void *, int, Scheme_Object **);
+static Scheme_Object *set_buffer_line_list(void *, int, Scheme_Object **);
+static Scheme_Object *insert_buffer_line_list(void *, int, Scheme_Object **);
+static Scheme_Object *get_range_start(void *, int, Scheme_Object **);
+static Scheme_Object *get_range_end(void *, int, Scheme_Object **);
+static Scheme_Object *get_buffer_namespace(void *, int, Scheme_Object **);
+static vim_mz_buffer *get_vim_curr_buffer(void);
+
+/*  Window-related commands */
+static Scheme_Object *window_new(win_T *win);
+static Scheme_Object *get_curr_win(void *, int, Scheme_Object **);
+static Scheme_Object *get_window_count(void *, int, Scheme_Object **);
+static Scheme_Object *get_window_by_num(void *, int, Scheme_Object **);
+static Scheme_Object *get_window_num(void *, int, Scheme_Object **);
+static Scheme_Object *get_window_buffer(void *, int, Scheme_Object **);
+static Scheme_Object *get_window_height(void *, int, Scheme_Object **);
+static Scheme_Object *set_window_height(void *, int, Scheme_Object **);
+#ifdef FEAT_VERTSPLIT
+static Scheme_Object *get_window_width(void *, int, Scheme_Object **);
+static Scheme_Object *set_window_width(void *, int, Scheme_Object **);
+#endif
+static Scheme_Object *get_cursor(void *, int, Scheme_Object **);
+static Scheme_Object *set_cursor(void *, int, Scheme_Object **);
+static Scheme_Object *get_window_list(void *, int, Scheme_Object **);
+static vim_mz_window *get_vim_curr_window(void);
+
+/*  Vim-related commands */
+static Scheme_Object *mzscheme_beep(void *, int, Scheme_Object **);
+static Scheme_Object *get_option(void *, int, Scheme_Object **);
+static Scheme_Object *set_option(void *, int, Scheme_Object **);
+static Scheme_Object *vim_command(void *, int, Scheme_Object **);
+static Scheme_Object *vim_eval(void *, int, Scheme_Object **);
+static Scheme_Object *vim_bufferp(void *data, int, Scheme_Object **);
+static Scheme_Object *vim_windowp(void *data, int, Scheme_Object **);
+static Scheme_Object *vim_buffer_validp(void *data, int, Scheme_Object **);
+static Scheme_Object *vim_window_validp(void *data, int, Scheme_Object **);
+
+/*
+ *========================================================================
+ *  Internal Function Prototypes
+ *========================================================================
+ */
+static int vim_error_check(void);
+static int do_mzscheme_command(exarg_T *, void *, Scheme_Closed_Prim *what);
+static void startup_mzscheme(void);
+static char *string_to_line(Scheme_Object *obj);
+static int mzscheme_io_init(void);
+static void mzscheme_interface_init(vim_mz_buffer *self);
+static void do_output(char *mesg, long len);
+static void do_printf(char *format, ...);
+static void do_flush(void);
+static Scheme_Object *_apply_thunk_catch_exceptions(
+	Scheme_Object *, Scheme_Object **);
+static Scheme_Object *extract_exn_message(Scheme_Object *v);
+static Scheme_Object *do_eval(void *, int noargc, Scheme_Object **noargv);
+static Scheme_Object *do_load(void *, int noargc, Scheme_Object **noargv);
+static Scheme_Object *do_apply(void *, int noargc, Scheme_Object **noargv);
+static void register_vim_exn(Scheme_Env *env);
+static vim_mz_buffer *get_buffer_arg(const char *fname, int argnum,
+	int argc, Scheme_Object **argv);
+static vim_mz_window *get_window_arg(const char *fname, int argnum,
+	int argc, Scheme_Object **argv);
+static void add_vim_exn(Scheme_Env *env);
+static int line_in_range(linenr_T, buf_T *);
+static void check_line_range(linenr_T, buf_T *);
+static void mz_fix_cursor(int lo, int hi, int extra);
+
+static int eval_in_namespace(void *, Scheme_Closed_Prim *, Scheme_Env *,
+		Scheme_Object **ret);
+static void make_modules(Scheme_Env *);
+
+/*
+ *========================================================================
+ *  1. MzScheme interpreter startup
+ *========================================================================
+ */
+
+static Scheme_Type mz_buffer_type;
+static Scheme_Type mz_window_type;
+
+static int initialized = 0;
+
+/* global environment */
+static Scheme_Env    *environment = NULL;
+/* output/error handlers */
+static Scheme_Object *curout = NULL;
+static Scheme_Object *curerr = NULL;
+/* vim:exn exception */
+static Scheme_Object *exn_catching_apply = NULL;
+static Scheme_Object *exn_p = NULL;
+static Scheme_Object *exn_message = NULL;
+static Scheme_Object *vim_exn = NULL; /* Vim Error exception */
+ /* values for exn:vim - constructor, predicate, accessors etc */
+static Scheme_Object *vim_exn_names = NULL;
+static Scheme_Object *vim_exn_values = NULL;
+
+static long range_start;
+static long range_end;
+
+/* MzScheme threads scheduling stuff */
+static int mz_threads_allow = 0;
+#ifdef FEAT_GUI
+static void setup_timer(void);
+static void remove_timer(void);
+#endif
+
+#if defined(FEAT_GUI_W32)
+static void CALLBACK timer_proc(HWND, UINT, UINT, DWORD);
+static UINT timer_id = 0;
+#elif defined(FEAT_GUI_GTK)
+static gint timer_proc(gpointer);
+static guint timer_id = 0;
+#elif defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA)
+static void timer_proc(XtPointer, XtIntervalId *);
+static XtIntervalId timer_id = (XtIntervalId)0;
+#elif defined(FEAT_GUI_MAC)
+pascal void timer_proc(EventLoopTimerRef, void *);
+static EventLoopTimerRef timer_id = NULL;
+static EventLoopTimerUPP timerUPP;
+#endif
+
+#ifndef FEAT_GUI_W32 /* Win32 console and Unix */
+    void
+mzvim_check_threads(void)
+{
+    /* Last time MzScheme threads were scheduled */
+    static time_t mz_last_time = 0;
+
+    if (mz_threads_allow && p_mzq > 0)
+    {
+	time_t now = time(NULL);
+
+	if ((now - mz_last_time) * 1000 > p_mzq)
+	{
+	    mz_last_time = now;
+	    scheme_check_threads();
+	}
+    }
+}
+#endif
+
+#ifdef FEAT_GUI
+/* timers are presented in GUI only */
+# if defined(FEAT_GUI_W32)
+    static void CALLBACK
+timer_proc(HWND hwnd, UINT uMsg, UINT idEvent, DWORD dwTime)
+# elif defined(FEAT_GUI_GTK)
+/*ARGSUSED*/
+    static gint
+timer_proc(gpointer data)
+# elif defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA)
+/* ARGSUSED */
+    static void
+timer_proc(XtPointer timed_out, XtIntervalId *interval_id)
+# elif defined(FEAT_GUI_MAC)
+    pascal void
+timer_proc(EventLoopTimerRef theTimer, void *userData)
+# endif
+{
+    scheme_check_threads();
+# if defined(FEAT_GUI_GTK)
+    return TRUE; /* continue receiving notifications */
+# elif defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA)
+    /* renew timeout */
+    if (mz_threads_allow && p_mzq > 0)
+	timer_id = XtAppAddTimeOut(app_context, p_mzq,
+		timer_proc, NULL);
+# endif
+}
+
+    static void
+setup_timer(void)
+{
+# if defined(FEAT_GUI_W32)
+    timer_id = SetTimer(NULL, 0, p_mzq, timer_proc);
+# elif defined(FEAT_GUI_GTK)
+    timer_id = gtk_timeout_add((guint32)p_mzq, (GtkFunction)timer_proc, NULL);
+# elif defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA)
+    timer_id = XtAppAddTimeOut(app_context, p_mzq, timer_proc, NULL);
+# elif defined(FEAT_GUI_MAC)
+    timerUPP = NewEventLoopTimerUPP(timer_proc);
+    InstallEventLoopTimer(GetMainEventLoop(), p_mzq * kEventDurationMillisecond,
+		p_mzq * kEventDurationMillisecond, timerUPP, NULL, &timer_id);
+# endif
+}
+
+    static void
+remove_timer(void)
+{
+# if defined(FEAT_GUI_W32)
+    KillTimer(NULL, timer_id);
+# elif defined(FEAT_GUI_GTK)
+    gtk_timeout_remove(timer_id);
+# elif defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA)
+    XtRemoveTimeOut(timer_id);
+# elif defined(FEAT_GUI_MAC)
+    RemoveEventLoopTimer(timer_id);
+    DisposeEventLoopTimerUPP(timerUPP);
+# endif
+    timer_id = 0;
+}
+
+    void
+mzvim_reset_timer(void)
+{
+    if (timer_id != 0)
+	remove_timer();
+    if (mz_threads_allow && p_mzq > 0 && gui.in_use)
+	setup_timer();
+}
+
+#endif
+
+    static void
+notify_multithread(int on)
+{
+    mz_threads_allow = on;
+#ifdef FEAT_GUI
+    if (on && timer_id == 0 && p_mzq > 0 && gui.in_use)
+	setup_timer();
+    if (!on && timer_id != 0)
+	remove_timer();
+#endif
+}
+
+    int
+mzscheme_enabled(int verbose)
+{
+    return initialized;
+}
+
+    void
+mzscheme_end(void)
+{
+}
+
+    static void
+startup_mzscheme(void)
+{
+    scheme_set_stack_base(NULL, 1);
+
+    MZ_REGISTER_STATIC(environment);
+    MZ_REGISTER_STATIC(curout);
+    MZ_REGISTER_STATIC(curerr);
+    MZ_REGISTER_STATIC(exn_catching_apply);
+    MZ_REGISTER_STATIC(exn_p);
+    MZ_REGISTER_STATIC(exn_message);
+    MZ_REGISTER_STATIC(vim_exn);
+    MZ_REGISTER_STATIC(vim_exn_names);
+    MZ_REGISTER_STATIC(vim_exn_values);
+
+    environment = scheme_basic_env();
+
+    /* redirect output */
+    scheme_console_output = do_output;
+    scheme_console_printf = do_printf;
+
+#ifdef MZSCHEME_COLLECTS
+    /* setup 'current-library-collection-paths' parameter */
+    scheme_set_param(scheme_config, MZCONFIG_COLLECTION_PATHS,
+	    scheme_make_pair(scheme_make_string(MZSCHEME_COLLECTS),
+		scheme_null));
+#endif
+
+    /* Create buffer and window types for use in Scheme code */
+    mz_buffer_type = scheme_make_type("<vim-buffer>");
+    mz_window_type = scheme_make_type("<vim-window>");
+
+    register_vim_exn(environment);
+    make_modules(environment);
+
+    /*
+     * setup callback to receive notifications
+     * whether thread scheduling is (or not) required
+     */
+    scheme_notify_multithread = notify_multithread;
+    initialized = 1;
+}
+
+/*
+ * This routine is called for each new invocation of MzScheme
+ * to make sure things are properly initialized.
+ */
+    static int
+mzscheme_init(void)
+{
+    int do_require = FALSE;
+
+    if (!initialized)
+    {
+	do_require = TRUE;
+        startup_mzscheme();
+
+	if (mzscheme_io_init())
+	    return -1;
+
+    }
+    /* recreate ports each call effectivelly clearing these ones */
+    curout = scheme_make_string_output_port();
+    curerr = scheme_make_string_output_port();
+    scheme_set_param(scheme_config, MZCONFIG_OUTPUT_PORT, curout);
+    scheme_set_param(scheme_config, MZCONFIG_ERROR_PORT, curerr);
+
+    if (do_require)
+    {
+	/* auto-instantiate in basic env */
+	eval_in_namespace("(require (prefix vimext: vimext))", do_eval,
+		environment, NULL);
+    }
+
+    return 0;
+}
+
+/*
+ * This routine fills the namespace with various important routines that can
+ * be used within MzScheme.
+ */
+    static void
+mzscheme_interface_init(vim_mz_buffer *mzbuff)
+{
+    Scheme_Object   *attach;
+
+    mzbuff->env = (Scheme_Env *)scheme_make_namespace(0, NULL);
+
+    /*
+     * attach instantiated modules from global namespace
+     * so they can be easily instantiated in the buffer namespace
+     */
+    attach = scheme_lookup_global(
+	    scheme_intern_symbol("namespace-attach-module"),
+	    environment);
+
+    if (attach != NULL)
+    {
+	Scheme_Object   *ret;
+	Scheme_Object	*args[2];
+
+	args[0] = (Scheme_Object *)environment;
+	args[1] = scheme_intern_symbol("vimext");
+
+	ret = (Scheme_Object *)mzvim_apply(attach, 2, args);
+    }
+
+    add_vim_exn(mzbuff->env);
+}
+
+/*
+ *========================================================================
+ *  2.  External Interface
+ *========================================================================
+ */
+
+/*
+ * Evaluate command in namespace with exception handling
+ */
+    static int
+eval_in_namespace(void *data, Scheme_Closed_Prim *what, Scheme_Env *env,
+		Scheme_Object **ret)
+{
+    Scheme_Object   *value;
+    Scheme_Object   *exn;
+    Cmd_Info	    info;   /* closure info */
+
+    info.data = data;
+    info.env = env;
+
+    scheme_set_param(scheme_config, MZCONFIG_ENV,
+	    (Scheme_Object *) env);
+    /*
+     * ensure all evaluations will be in current buffer namespace,
+     * the second argument to scheme_eval_string isn't enough!
+     */
+    value = _apply_thunk_catch_exceptions(
+	    scheme_make_closed_prim_w_arity(what, &info, "mzvim", 0, 0),
+	    &exn);
+
+    if (!value)
+    {
+	value = extract_exn_message(exn);
+        /* Got an exn? */
+	if (value)
+	{
+	    scheme_display(value, curerr);  /*  Send to stderr-vim */
+	    do_flush();
+	}
+	/* `raise' was called on some arbitrary value */
+	return FAIL;
+    }
+
+    if (ret != NULL)	/* if pointer to retval supported give it up */
+	*ret = value;
+    /* Print any result, as long as it's not a void */
+    else if (!SCHEME_VOIDP(value))
+	scheme_display(value, curout);  /* Send to stdout-vim */
+
+    do_flush();
+    return OK;
+}
+
+/* :mzscheme */
+    static int
+do_mzscheme_command(exarg_T *eap, void *data, Scheme_Closed_Prim *what)
+{
+    if (mzscheme_init())
+	return FAIL;
+
+    range_start = eap->line1;
+    range_end = eap->line2;
+
+    return eval_in_namespace(data, what, get_vim_curr_buffer()->env, NULL);
+}
+
+/*
+ * Routine called by VIM when deleting a buffer
+ */
+    void
+mzscheme_buffer_free(buf_T *buf)
+{
+    if (buf->mzscheme_ref)
+    {
+        vim_mz_buffer *bp;
+	bp = buf->mzscheme_ref;
+	bp->buf = INVALID_BUFFER_VALUE;
+	buf->mzscheme_ref = NULL;
+	scheme_gc_ptr_ok(bp);
+    }
+}
+
+/*
+ * Routine called by VIM when deleting a Window
+ */
+    void
+mzscheme_window_free(win_T *win)
+{
+    if (win->mzscheme_ref)
+    {
+	vim_mz_window *wp;
+	wp = win->mzscheme_ref;
+	wp->win = INVALID_WINDOW_VALUE;
+	win->mzscheme_ref = NULL;
+	scheme_gc_ptr_ok(wp);
+    }
+}
+
+/*
+ * ":mzscheme" (or ":mz")
+ */
+    void
+ex_mzscheme(exarg_T *eap)
+{
+    char_u	*script;
+
+    script = script_get(eap, eap->arg);
+    if (!eap->skip)
+    {
+	if (script == NULL)
+	    do_mzscheme_command(eap, eap->arg, do_eval);
+	else
+	{
+	    do_mzscheme_command(eap, script, do_eval);
+	    vim_free(script);
+	}
+    }
+}
+
+/* eval MzScheme string */
+    void *
+mzvim_eval_string(char_u *str)
+{
+    Scheme_Object *ret = NULL;
+    if (mzscheme_init())
+	return FAIL;
+
+    eval_in_namespace(str, do_eval, get_vim_curr_buffer()->env, &ret);
+    return ret;
+}
+
+/*
+ * apply MzScheme procedure with arguments,
+ * handling errors
+ */
+    Scheme_Object *
+mzvim_apply(Scheme_Object *proc, int argc, Scheme_Object **argv)
+{
+    Apply_Info	data;
+    Scheme_Object *ret = NULL;
+
+    if (mzscheme_init())
+	return FAIL;
+
+    data.proc = proc;
+    data.argc = argc;
+    data.argv = argv;
+
+    eval_in_namespace(&data, do_apply, get_vim_curr_buffer()->env, &ret);
+    return ret;
+}
+
+    static Scheme_Object *
+do_load(void *data, int noargc, Scheme_Object **noargv)
+{
+    Cmd_Info	    *info = (Cmd_Info *)data;
+    Scheme_Object   *result = scheme_void;
+    Scheme_Object   *expr;
+    char_u	    *file = scheme_malloc_fail_ok(
+					  scheme_malloc_atomic, MAXPATHL + 1);
+    Port_Info	    *pinfo = (Port_Info *)(info->data);
+
+    /* make Vim expansion */
+    expand_env((char_u *)pinfo->name, file, MAXPATHL);
+    /* scheme_load looks strange working with namespaces and error handling*/
+    pinfo->port = scheme_open_input_file(file, "mzfile");
+    scheme_count_lines(pinfo->port); /* to get accurate read error location*/
+
+    /* Like REPL but print only last result */
+    while (!SCHEME_EOFP(expr = scheme_read(pinfo->port)))
+	result = scheme_eval(expr, info->env);
+
+    /* errors will be caught in do_mzscheme_comamnd and ex_mzfile */
+    scheme_close_input_port(pinfo->port);
+    pinfo->port = NULL;
+    return result;
+}
+
+/* :mzfile */
+    void
+ex_mzfile(exarg_T *eap)
+{
+    Port_Info	pinfo;
+
+    pinfo.name = (char *)eap->arg;
+    pinfo.port = NULL;
+    if (do_mzscheme_command(eap, &pinfo, do_load) != OK
+	    && pinfo.port != NULL)	/* looks like port was not closed */
+	scheme_close_input_port(pinfo.port);
+}
+
+
+/*
+ *========================================================================
+ * Exception handling code -- cribbed form the MzScheme sources and
+ * Matthew Flatt's "Inside PLT MzScheme" document.
+ *========================================================================
+ */
+    static void
+init_exn_catching_apply(void)
+{
+    if (!exn_catching_apply)
+    {
+	char *e =
+	    "(lambda (thunk) "
+	        "(with-handlers ([void (lambda (exn) (cons #f exn))]) "
+		"(cons #t (thunk))))";
+
+        /* make sure we have a namespace with the standard syntax: */
+	Scheme_Env *env = (Scheme_Env *)scheme_make_namespace(0, NULL);
+	add_vim_exn(env);
+
+        exn_catching_apply = scheme_eval_string(e, env);
+	exn_p = scheme_lookup_global(scheme_intern_symbol("exn?"), env);
+        exn_message = scheme_lookup_global(
+		scheme_intern_symbol("exn-message"), env);
+    }
+}
+
+/*
+ * This function applies a thunk, returning the Scheme value if there's
+ * no exception, otherwise returning NULL and setting *exn to the raised
+ * value (usually an exn structure).
+ */
+    static Scheme_Object *
+_apply_thunk_catch_exceptions(Scheme_Object *f, Scheme_Object **exn)
+{
+    Scheme_Object *v;
+
+    init_exn_catching_apply();
+
+    v = _scheme_apply(exn_catching_apply, 1, &f);
+    /* v is a pair: (cons #t value) or (cons #f exn) */
+
+    if (SCHEME_TRUEP(SCHEME_CAR(v)))
+	return SCHEME_CDR(v);
+    else
+    {
+	*exn = SCHEME_CDR(v);
+	return NULL;
+    }
+}
+
+    static Scheme_Object *
+extract_exn_message(Scheme_Object *v)
+{
+    init_exn_catching_apply();
+
+    if (SCHEME_TRUEP(_scheme_apply(exn_p, 1, &v)))
+	return _scheme_apply(exn_message, 1, &v);
+    else
+	return NULL; /* Not an exn structure */
+}
+
+    static Scheme_Object *
+do_eval(void *s, int noargc, Scheme_Object **noargv)
+{
+    Cmd_Info	*info = (Cmd_Info *)s;
+
+    return scheme_eval_string_all((char *)(info->data), info->env, TRUE);
+}
+
+    static Scheme_Object *
+do_apply(void *a, int noargc, Scheme_Object **noargv)
+{
+    Apply_Info	*info = (Apply_Info *)(((Cmd_Info *)a)->data);
+
+    return scheme_apply(info->proc, info->argc, info->argv);
+}
+
+/*
+ *========================================================================
+ *  3.  MzScheme I/O Handlers
+ *========================================================================
+ */
+    static void
+do_intrnl_output(char *mesg, long len, int error)
+{
+    char *p, *prev;
+
+    prev = mesg;
+    p = strchr(prev, '\n');
+    while (p)
+    {
+	*p = '\0';
+	if (error)
+	    EMSG(prev);
+	else
+	    MSG(prev);
+	prev = p + 1;
+	p = strchr(prev, '\n');
+    }
+
+    if (error)
+	EMSG(prev);
+    else
+	MSG(prev);
+}
+
+    static void
+do_output(char *mesg, long len)
+{
+    do_intrnl_output(mesg, len, 0);
+}
+
+    static void
+do_err_output(char *mesg, long len)
+{
+    do_intrnl_output(mesg, len, 1);
+}
+
+    static void
+do_printf(char *format, ...)
+{
+    do_intrnl_output(format, STRLEN(format), 1);
+}
+
+    static void
+do_flush(void)
+{
+    char *buff;
+    long length;
+
+    buff = scheme_get_sized_string_output(curerr, &length);
+    if (length)
+    {
+	do_err_output(buff, length);
+	return;
+    }
+
+    buff = scheme_get_sized_string_output(curout, &length);
+    if (length)
+	do_output(buff, length);
+}
+
+    static int
+mzscheme_io_init(void)
+{
+    /* Nothing needed so far... */
+    return 0;
+}
+
+/*
+ *========================================================================
+ *  4. Implementation of the Vim Features for MzScheme
+ *========================================================================
+ */
+
+/* (command {command-string}) */
+    static Scheme_Object *
+vim_command(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	*prim = (Vim_Prim *)data;
+    char	*cmd = SCHEME_STR_VAL(GUARANTEE_STRING(prim->name, 0));
+
+    /* may be use do_cmdline_cmd? */
+    do_cmdline((char_u *)cmd, NULL, NULL, DOCMD_NOWAIT|DOCMD_VERBOSE);
+    update_screen(VALID);
+
+    raise_if_error();
+    return scheme_void;
+}
+
+/* (eval {expr-string}) */
+    static Scheme_Object *
+vim_eval(void *data, int argc, Scheme_Object **argv)
+{
+#ifdef FEAT_EVAL
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    char	    *expr;
+    char	    *str;
+    Scheme_Object   *result;
+
+    expr = SCHEME_STR_VAL(GUARANTEE_STRING(prim->name, 0));
+
+    str = (char *)eval_to_string((char_u *)expr, NULL);
+
+    if (str == NULL)
+	raise_vim_exn(_("invalid expression"));
+
+    result = scheme_make_string(str);
+
+    vim_free(str);
+
+    return result;
+#else
+    raise_vim_exn(_("expressions disabled at compile time"));
+    /* unreachable */
+    return scheme_false;
+#endif
+}
+
+/* (range-start) */
+    static Scheme_Object *
+get_range_start(void *data, int argc, Scheme_Object **argv)
+{
+    return scheme_make_integer(range_start);
+}
+
+/* (range-end) */
+    static Scheme_Object *
+get_range_end(void *data, int argc, Scheme_Object **argv)
+{
+    return scheme_make_integer(range_end);
+}
+
+/* (beep) */
+    static Scheme_Object *
+mzscheme_beep(void *data, int argc, Scheme_Object **argv)
+{
+    vim_beep();
+    return scheme_void;
+}
+
+static Scheme_Object *M_global = NULL;
+
+/* (get-option {option-name}) [buffer/window] */
+    static Scheme_Object *
+get_option(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    char_u	    *name;
+    long	    value;
+    char_u	    *strval;
+    int		    rc;
+    Scheme_Object   *rval;
+    int		    opt_flags = 0;
+    buf_T	    *save_curb = curbuf;
+    win_T	    *save_curw = curwin;
+
+    name = (char_u *)SCHEME_STR_VAL(GUARANTEE_STRING(prim->name, 0));
+
+    if (argc > 1)
+    {
+	if (M_global == NULL)
+	{
+	    MZ_REGISTER_STATIC(M_global);
+	    M_global = scheme_intern_symbol("global");
+	}
+
+	if (argv[1] == M_global)
+	    opt_flags = OPT_GLOBAL;
+	else if (SCHEME_VIMBUFFERP(argv[1]))
+	{
+	    curbuf = get_valid_buffer(argv[1]);
+	    opt_flags = OPT_LOCAL;
+	}
+	else if (SCHEME_VIMWINDOWP(argv[1]))
+	{
+	    win_T *win = get_valid_window(argv[1]);
+
+	    curwin = win;
+	    curbuf = win->w_buffer;
+	    opt_flags = OPT_LOCAL;
+	}
+	else
+	    scheme_wrong_type(prim->name, "vim-buffer/window", 1, argc, argv);
+    }
+
+    rc = get_option_value(name, &value, &strval, opt_flags);
+    curbuf = save_curb;
+    curwin = save_curw;
+
+    switch (rc)
+    {
+    case 1:
+	return scheme_make_integer_value(value);
+    case 0:
+        rval = scheme_make_string(strval);
+	vim_free(strval);
+	return rval;
+    case -1:
+    case -2:
+        raise_vim_exn(_("hidden option"));
+    case -3:
+        raise_vim_exn(_("unknown option"));
+    }
+    /* unreachable */
+    return scheme_void;
+}
+
+/* (set-option {option-changing-string} [buffer/window]) */
+    static Scheme_Object *
+set_option(void *data, int argc, Scheme_Object **argv)
+{
+    char_u	*cmd;
+    int		opt_flags = 0;
+    buf_T	*save_curb = curbuf;
+    win_T	*save_curw = curwin;
+    Vim_Prim	*prim = (Vim_Prim *)data;
+
+    GUARANTEE_STRING(prim->name, 0);
+    if (argc > 1)
+    {
+	if (M_global == NULL)
+	{
+	    MZ_REGISTER_STATIC(M_global);
+	    M_global = scheme_intern_symbol("global");
+	}
+
+	if (argv[1] == M_global)
+	    opt_flags = OPT_GLOBAL;
+	else if (SCHEME_VIMBUFFERP(argv[1]))
+	{
+	    curbuf = get_valid_buffer(argv[1]);
+	    opt_flags = OPT_LOCAL;
+	}
+	else if (SCHEME_VIMWINDOWP(argv[1]))
+	{
+	    win_T *win = get_valid_window(argv[1]);
+	    curwin = win;
+	    curbuf = win->w_buffer;
+	    opt_flags = OPT_LOCAL;
+	}
+	else
+	    scheme_wrong_type(prim->name, "vim-buffer/window", 1, argc, argv);
+    }
+
+    /* do_set can modify cmd, make copy */
+    cmd = vim_strsave((char_u *)SCHEME_STR_VAL(argv[0]));
+    do_set(cmd, opt_flags);
+    vim_free(cmd);
+    update_screen(NOT_VALID);
+    curbuf = save_curb;
+    curwin = save_curw;
+    raise_if_error();
+    return scheme_void;
+}
+
+/*
+ *===========================================================================
+ *  5. Vim Window-related Manipulation Functions
+ *===========================================================================
+ */
+
+/* (curr-win) */
+    static Scheme_Object *
+get_curr_win(void *data, int argc, Scheme_Object **argv)
+{
+    return (Scheme_Object *)get_vim_curr_window();
+}
+
+/* (win-count) */
+    static Scheme_Object *
+get_window_count(void *data, int argc, Scheme_Object **argv)
+{
+    win_T   *w;
+    int	    n = 0;
+
+    for (w = firstwin; w; w = w->w_next) ++n;
+    return scheme_make_integer(n);
+}
+
+/* (get-win-list [buffer]) */
+    static Scheme_Object *
+get_window_list(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    vim_mz_buffer   *buf;
+    Scheme_Object   *list;
+    win_T	    *w;
+
+    buf = get_buffer_arg(prim->name, 0, argc, argv);
+    list = scheme_null;
+
+    for (w = firstwin; w; w = w->w_next)
+        if (w->w_buffer == buf->buf)
+	    list = scheme_make_pair(window_new(w), list);
+
+    return list;
+}
+
+    static Scheme_Object *
+window_new(win_T *win)
+{
+    vim_mz_window *self;
+
+    /* We need to handle deletion of windows underneath us.
+     * If we add a "mzscheme_ref" field to the win_T structure,
+     * then we can get at it in win_free() in vim.
+     *
+     * On a win_free() we set the Scheme object's win_T *field
+     * to an invalid value. We trap all uses of a window
+     * object, and reject them if the win_T *field is invalid.
+     */
+    if (win->mzscheme_ref)
+	return win->mzscheme_ref;
+
+    self = scheme_malloc_fail_ok(scheme_malloc, sizeof(vim_mz_window));
+
+    vim_memset(self, 0, sizeof(vim_mz_window));
+    scheme_dont_gc_ptr(self);	/* because win isn't visible to GC */
+    win->mzscheme_ref = self;
+    self->win = win;
+    self->tag = mz_window_type;
+
+    return (Scheme_Object *)(self);
+}
+
+/* (get-win-num [window]) */
+    static Scheme_Object *
+get_window_num(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	*prim = (Vim_Prim *)data;
+    win_T	*win = get_window_arg(prim->name, 0, argc, argv)->win;
+    int		nr = 1;
+    win_T	*wp;
+
+    for (wp = firstwin; wp != win; wp = wp->w_next)
+	++nr;
+
+    return scheme_make_integer(nr);
+}
+
+/* (get-win-by-num {windownum}) */
+    static Scheme_Object *
+get_window_by_num(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	*prim = (Vim_Prim *)data;
+    win_T	*win;
+    int		fnum;
+
+    fnum = SCHEME_INT_VAL(GUARANTEE_INTEGER(prim->name, 0));
+    if (fnum < 1)
+	scheme_signal_error(_("window index is out of range"));
+
+    for (win = firstwin; win; win = win->w_next, --fnum)
+        if (fnum == 1)	    /* to be 1-based */
+	    return window_new(win);
+
+    return scheme_false;
+}
+
+/* (get-win-buffer [window]) */
+    static Scheme_Object *
+get_window_buffer(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    vim_mz_window   *win = get_window_arg(prim->name, 0, argc, argv);
+
+    return buffer_new(win->win->w_buffer);
+}
+
+/* (get-win-height [window]) */
+    static Scheme_Object *
+get_window_height(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    vim_mz_window   *win = get_window_arg(prim->name, 0, argc, argv);
+
+    return scheme_make_integer(win->win->w_height);
+}
+
+/* (set-win-height {height} [window]) */
+    static Scheme_Object *
+set_window_height(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    vim_mz_window   *win;
+    win_T	    *savewin;
+    int		    height;
+
+    win = get_window_arg(prim->name, 1, argc, argv);
+    height = SCHEME_INT_VAL(GUARANTEE_INTEGER(prim->name, 0));
+
+#ifdef FEAT_GUI
+    need_mouse_correct = TRUE;
+#endif
+
+    savewin = curwin;
+    curwin = win->win;
+    win_setheight(height);
+    curwin = savewin;
+
+    raise_if_error();
+    return scheme_void;
+}
+
+#ifdef FEAT_VERTSPLIT
+/* (get-win-width [window]) */
+    static Scheme_Object *
+get_window_width(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    vim_mz_window   *win = get_window_arg(prim->name, 0, argc, argv);
+
+    return scheme_make_integer(W_WIDTH(win->win));
+}
+
+/* (set-win-width {width} [window]) */
+    static Scheme_Object *
+set_window_width(void *data, int argc, Scheme_Object **argv)
+{
+    Vim_Prim	    *prim = (Vim_Prim *)data;
+    vim_mz_window   *win;
+    win_T	    *savewin;
+    int		    width = 0;
+
+    win = get_window_arg(prim->name, 1, argc, argv);
+    width = SCHEME_INT_VAL(GUARANTEE_INTEGER(prim->name, 0));
+
+# ifdef FEAT_GUI
+    need_mouse_correct = TRUE;
+# endif
+
+    savewin = curwin;
+    curwin = win->win;
+    win_setwidth(width);
+    curwin = savewin;
+
+    raise_if_error();
+    return scheme_void;
+}
+#endif
+
+/* (ge