shithub: libnate

Download patch

ref: aab184987c79fc7a8e5467200f9ac448700b797f
parent: 855a60a7698acb993b68f8e64448bd2fc3ff86da
author: sirjofri <sirjofri@sirjofri.de>
date: Sun Mar 30 11:31:01 EDT 2025 

remove accessor pointers from Nelems


--- a/n_box.c
+++ b/n_box.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_box.h"
 
@@ -147,26 +148,30 @@
 	.getname = box_getname,
 };
 
-DEF_SLOTFUNC(NBox, box_slot);
+#define NTYPE NBox
+#define NACCS NBoxAccessors
 
-DEF_ACCESSOR_TwoParams(NBox, box_border, int, borderwidth, Image*, bordercolor);
-DEF_ACCESSOR_OneParam(NBox, box_autosize, int, autosize);
-DEF_ACCESSOR_OneParam(NBox, box_size, Point, size);
-DEF_ACCESSOR_OneParam(NBox, box_padding, Nmargin, padding);
-DEF_ACCESSOR_TwoParams(NBox, box_onclick, OnclickHandler, hitfunc, void*, hitaux);
+DEF_SLOTFUNC(box_slot);
+DEF_ACCESSOR_TwoParams(box_border, int, borderwidth, Image*, bordercolor);
+DEF_ACCESSOR_OneParam(box_autosize, int, autosize);
+DEF_ACCESSOR_OneParam(box_size, Point, size);
+DEF_ACCESSOR_TwoParams(box_onclick, OnclickHandler, hitfunc, void*, hitaux);
+DEF_ACCESSOR_OneParam(box_padding, Nmargin, padding);
 
-NBox*
+static NBoxAccessors accs = {
+	.Slot = box_slot,
+	.Border = box_border,
+	.AutoSize = box_autosize,
+	.Size = box_size,
+	.OnClick = box_onclick,
+	.Padding = box_padding,
+};
+
+NBoxAccessors*
 New_Box(char *name)
 {
-	NBox *b = MakeNelem(NBox, NBox_Type, &Nboxfunctions, name, 1);
+	NBox *b = MakeNelem(NBox, NBox_Type, &Nboxfunctions, &accs, name, 1);
 	
-	b->Slot = box_slot;
-	b->Border = box_border;
-	b->AutoSize = box_autosize;
-	b->Size = box_size;
-	b->OnClick = box_onclick;
-	b->Padding = box_padding;
-	
 	b->autosize = 0;
 	b->size = Pt(-1, -1);
 	b->hitfunc = nil;
@@ -174,5 +179,5 @@
 	b->borderwidth = 0;
 	b->bordercolor = display->black;
 	nc_push(b);
-	return b;
+	return &accs;
 }
--- a/n_box.h
+++ b/n_box.h
@@ -1,14 +1,23 @@
 extern char* NBox_Type;
 
+#define NTYPE NBox
+#define NACCS NBoxAccessors
+
+typedef struct NBoxAccessors NBoxAccessors;
+struct NBoxAccessors {
+	Nelemaccessors;
+	
+	DECL_SLOTFUNC(Slot);
+	DECL_ACCESSOR_TwoParams(Border, int, Image*);
+	DECL_ACCESSOR_OneParam(AutoSize, int);
+	DECL_ACCESSOR_OneParam(Size, Point);
+	DECL_ACCESSOR_TwoParams(OnClick, OnclickHandler, void*);
+	DECL_ACCESSOR_OneParam(Padding, Nmargin);
+};
+
 typedef struct NBox NBox;
 struct NBox {
 	Nelem;
-	DECL_SLOTFUNC(NBox, Slot);
-	DECL_ACCESSOR_TwoParams(NBox, Border, int, Image*);
-	DECL_ACCESSOR_OneParam(NBox, AutoSize, int);
-	DECL_ACCESSOR_OneParam(NBox, Size, Point);
-	DECL_ACCESSOR_TwoParams(NBox, OnClick, OnclickHandler, void*);
-	DECL_ACCESSOR_OneParam(NBox, Padding, Nmargin);
 	
 	// private members
 	Point size;
@@ -21,4 +30,7 @@
 	int ishit;
 };
 
-NBox* New_Box(char*);
+#undef NTYPE
+#undef NACCS
+
+NBoxAccessors* New_Box(char*);
--- a/n_button.c
+++ b/n_button.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_box.h"
 #include "n_label.h"
@@ -75,95 +76,126 @@
 	.getchildren = button_getchildren,
 };
 
-static NButton*
-button_slot(Nslot info, Nelem* child)
+#define NTYPE NButton
+#define NACCS NButtonAccessors
+
+static NACCS*
+button_slot(Nslot info, Nelemaccessors *a)
 {
-	if (child == nc_get())
-		nc_pop();
-	NButton *c = (NButton*)nc_get();
+	NButton *c;
+	Nelem *child = nc_get();
+	if (a->type != child->type)
+		sysfatal("invalid child type in slot");
+	nc_pop();
+	c = (NButton*)nc_get();
 	GUARD(c);
 	nc_push(c->box);
-	c->box->Slot(info, child);
+	NCACCS(NBoxAccessors, c->box)->Slot(info, a);
 	nc_pop();
-	return c;
+	return (NACCS*)c->accs;
 }
 
-static NButton*
+static NACCS*
 button_border(int w, Image *i)
 {
 	NButton *c = (NButton*)nc_get();
 	GUARD(c);
 	nc_push(c->box);
-	c->box->Border(w, i);
+	NCACCS(NBoxAccessors, c->box)->Border(w, i);
 	nc_pop();
-	return c;
+	return (NACCS*)c->accs;
 }
 
-static NButton*
+static NACCS*
 button_autosize(int n)
 {
 	NButton *c = (NButton*)nc_get();
 	GUARD(c);
 	nc_push(c->box);
-	c->box->AutoSize(n);
+	NCACCS(NBoxAccessors, c->box)->AutoSize(n);
 	nc_pop();
-	return c;
+	return (NACCS*)c->accs;
 }
 
-static NButton*
+static NACCS*
 button_onclick(OnclickHandler f, void *aux)
 {
 	NButton *c = (NButton*)nc_get();
 	GUARD(c);
 	nc_push(c->box);
-	c->box->OnClick(f, aux);
+	NCACCS(NBoxAccessors, c->box)->OnClick(f, aux);
 	nc_pop();
-	return c;
+	return NCACCS(NACCS, c);
 }
 
-static NButton*
+static NACCS*
 button_label(char *l)
 {
 	NButton *c = (NButton*)nc_get();
 	GUARD(c);
 	nc_push(c->label);
-	c->label->Label(l);
+	NCACCS(NLabelAccessors, c->label)->Label(l);
 	nc_pop();
-	return c;
+	return (NACCS*)c->accs;
 }
 
-static NButton*
+static NACCS*
 button_labelfunc(StringGetter f)
 {
 	NButton *c = (NButton*)nc_get();
 	GUARD(c);
 	nc_push(c->label);
-	c->label->LabelFunc(f);
+	NCACCS(NLabelAccessors, c->label)->LabelFunc(f);
 	nc_pop();
-	return c;
+	return (NACCS*)c->accs;
 }
 
-NButton*
+static NACCS*
+button_font(Font *f)
+{
+	NButton *c = (NButton*)nc_get();
+	GUARD(c);
+	nc_push(c->label);
+	NCACCS(NLabelAccessors, c->label)->Font(f);
+	nc_pop();
+	return (NACCS*)c->accs;
+}
+
+static NACCS*
+button_color(Image *i)
+{
+	NButton *c = (NButton*)nc_get();
+	GUARD(c);
+	nc_push(c->label);
+	NCACCS(NLabelAccessors, c->label)->Color(i);
+	nc_pop();
+	return (NACCS*)c->accs;
+}
+
+static NACCS accs = {
+	.Slot = button_slot,
+	.Border = button_border,
+	.AutoSize = button_autosize,
+	.OnClick = button_onclick,
+	.Label = button_label,
+	.LabelFunc = button_labelfunc,
+	.Font = button_font,
+	.Color = button_color,
+};
+
+NACCS*
 New_Button(char *name)
 {
-	NButton *b = MakeNelem(NButton, NButton_Type, &Nbuttonfunctions, name, 0);
+	NButton *b = MakeNelem(NButton, NButton_Type, &Nbuttonfunctions, &accs, name, 0);
 	
-	b->box = New_Box(name)
+	NAssign(NBoxAccessors, &b->box, New_Box(name))
 		->Slot(NSlot(),
-			NAssign(NLabel, &b->label, New_Label(nil))
+			NAssign(NLabelAccessors, &b->label, New_Label(nil))
 			->Margin(NMargin2(5, 2))
 		);
 	/* pop box from stack */
 	nc_pop();
 	
-	b->Slot = button_slot;
-	b->Border = button_border;
-	b->AutoSize = button_autosize;
-	b->OnClick = button_onclick;
-	
-	b->Label = button_label;
-	b->LabelFunc = button_labelfunc;
-	
 	nc_push(b);
-	return b;
+	return &accs;
 }
--- a/n_button.h
+++ b/n_button.h
@@ -1,21 +1,31 @@
 extern char* NButton_Type;
 
+#define NTYPE NButton
+#define NACCS NButtonAccessors
+
+typedef struct NACCS NACCS;
+struct NACCS {
+	Nelemaccessors;
+	DECL_SLOTFUNC(Slot);
+	DECL_ACCESSOR_TwoParams(Border, int, Image*);
+	DECL_ACCESSOR_OneParam(AutoSize, int);
+	DECL_ACCESSOR_TwoParams(OnClick, OnclickHandler, void*);
+	
+	DECL_ACCESSOR_OneParam(Label, char*);
+	DECL_ACCESSOR_OneParam(LabelFunc, char* (*f)(void));
+	DECL_ACCESSOR_OneParam(Font, Font*);
+	DECL_ACCESSOR_OneParam(Color, Image*);
+};
+
 typedef struct NButton NButton;
 struct NButton {
 	Nelem;
-	DECL_SLOTFUNC(NButton, Slot);
-	DECL_ACCESSOR_TwoParams(NButton, Border, int, Image*);
-	DECL_ACCESSOR_OneParam(NButton, AutoSize, int);
-	DECL_ACCESSOR_TwoParams(NButton, OnClick, OnclickHandler, void*);
 	
-	DECL_ACCESSOR_OneParam(NButton, Label, char*);
-	DECL_ACCESSOR_OneParam(NButton, LabelFunc, char* (*f)(void));
-	DECL_ACCESSOR_OneParam(NButton, Font, Font*);
-	DECL_ACCESSOR_OneParam(NButton, Color, Image*);
-	
 	// private members
 	NBox *box;
 	NLabel *label;
 };
 
-NButton* New_Button(char*);
+NACCS* New_Button(char*);
+#undef NTYPE
+#undef NACCS
--- a/n_hbox.c
+++ b/n_hbox.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_hbox.h"
 
@@ -136,9 +137,12 @@
 	.draw = hbox_draw,
 };
 
-DEF_SLOTFUNC(NHBox, hbox_slot);
+#define NTYPE NHBox
+#define NACCS NHBoxAccessors
 
-static NHBox*
+DEF_SLOTFUNC(hbox_slot);
+
+static NACCS*
 hbox_autoheight(int h)
 {
 	NHBox *b = (NHBox*)nc_get();
@@ -148,19 +152,21 @@
 	else
 		if (b->slot.fill & FILLX)
 			b->slot.fill -= FILLX;
-	return b;
+	return (NACCS*)b->accs;
 }
 
-NHBox*
+static NACCS accs = {
+	.Slot = hbox_slot,
+	.AutoHeight = hbox_autoheight,
+};
+
+NACCS*
 New_HBox(char *name)
 {
-	NHBox *b = MakeNelem(NHBox, NHBox_Type, &Nhboxfunctions, name, -1);
+	NHBox *b = MakeNelem(NHBox, NHBox_Type, &Nhboxfunctions, &accs, name, -1);
 	
-	b->Slot = hbox_slot;
-	b->AutoHeight = hbox_autoheight;
-	
 	linit(&b->children);
 	b->autoheight = 0;
 	nc_push(b);
-	return b;
+	return (NACCS*)b->accs;
 }
--- a/n_hbox.h
+++ b/n_hbox.h
@@ -1,13 +1,24 @@
 extern char* NHBox_Type;
 
+#define NTYPE NHBox
+#define NACCS NHBoxAccessors
+
+typedef struct NACCS NACCS;
+struct NACCS {
+	Nelemaccessors;
+	DECL_SLOTFUNC(Slot);
+	DECL_ACCESSOR_OneParam(AutoHeight, int);
+};
+
 typedef struct NHBox NHBox;
 struct NHBox {
 	Nelem;
-	DECL_SLOTFUNC(NHBox, Slot);
-	DECL_ACCESSOR_OneParam(NHBox, AutoHeight, int);
 	
 	// private members
 	int autoheight;
 };
 
-NHBox* New_HBox(char*);
+NACCS* New_HBox(char*);
+
+#undef NACCS
+#undef NTYPE
--- a/n_image.c
+++ b/n_image.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_image.h"
 
@@ -58,21 +59,26 @@
 	.draw = image_draw,
 };
 
-DEF_ACCESSOR_OneParam(NImage, image_image, Image*, image);
-DEF_ACCESSOR_OneParam(NImage, image_offset, Point, offset);
-DEF_ACCESSOR_OneParam(NImage, image_autosize, int, autosize);
+#define NTYPE NImage
+#define NACCS NImageAccessors
 
-NImage*
+DEF_ACCESSOR_OneParam(image_image, Image*, image);
+DEF_ACCESSOR_OneParam(image_offset, Point, offset);
+DEF_ACCESSOR_OneParam(image_autosize, int, autosize);
+
+static NACCS accs = {
+	.Image = image_image,
+	.Offset = image_offset,
+	.AutoSize = image_autosize,
+};
+
+NACCS*
 New_Image(char *name)
 {
-	NImage *i = MakeNelem(NImage, NImage_Type, &Nimagefunctions, name, 0);
+	NImage *i = MakeNelem(NImage, NImage_Type, &Nimagefunctions, &accs, name, 0);
 	
 	i->image = nil;
 	i->offset = ZP;
-	
-	i->Image = image_image;
-	i->Offset = image_offset;
-	i->AutoSize = image_autosize;
 	nc_push(i);
-	return i;
+	return &accs;
 }
--- a/n_image.h
+++ b/n_image.h
@@ -1,11 +1,19 @@
 extern char* NImage_Type;
 
+#define NTYPE NImage
+#define NACCS NImageAccessors
+
+typedef struct NACCS NACCS;
+struct NACCS {
+	Nelemaccessors;
+	DECL_ACCESSOR_OneParam(Image, Image*);
+	DECL_ACCESSOR_OneParam(Offset, Point);
+	DECL_ACCESSOR_OneParam(AutoSize, int);
+};
+
 typedef struct NImage NImage;
 struct NImage {
 	Nelem;
-	DECL_ACCESSOR_OneParam(NImage, Image, Image*);
-	DECL_ACCESSOR_OneParam(NImage, Offset, Point);
-	DECL_ACCESSOR_OneParam(NImage, AutoSize, int);
 	
 	// private members
 	Image *image;
@@ -13,4 +21,7 @@
 	int autosize;
 };
 
-NImage* New_Image(char*);
+NACCS* New_Image(char*);
+
+#undef NTYPE
+#undef NACCS
--- a/n_label.c
+++ b/n_label.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_label.h"
 
@@ -55,6 +56,9 @@
 	r = l->slot.r;
 	sz = stringsize(l->font, str);
 	
+	// TODO: background color for text?
+	draw(img, r, display->white, nil, ZP);
+	
 	switch (l->align) {
 	case TOPLEFT:
 		p.x = r.min.x + l->margin.left;
@@ -112,29 +116,34 @@
 	.getname = label_getname,
 };
 
-DEF_ACCESSOR_OneParam(NLabel, label, char*, label);
-DEF_ACCESSOR_OneParam(NLabel, labelfunc, StringGetter, labelfunc);
-DEF_ACCESSOR_OneParam(NLabel, lfont, Font*, font);
-DEF_ACCESSOR_OneParam(NLabel, lcolor, Image*, color);
-DEF_ACCESSOR_OneParam(NLabel, lmargin, Nmargin, margin);
-DEF_ACCESSOR_OneParam(NLabel, lalign, Nalign, align);
+#define NTYPE NLabel
+#define NACCS NLabelAccessors
 
-NLabel*
+DEF_ACCESSOR_OneParam(label, char*, label);
+DEF_ACCESSOR_OneParam(labelfunc, StringGetter, labelfunc);
+DEF_ACCESSOR_OneParam(lfont, Font*, font);
+DEF_ACCESSOR_OneParam(lcolor, Image*, color);
+DEF_ACCESSOR_OneParam(lmargin, Nmargin, margin);
+DEF_ACCESSOR_OneParam(lalign, Nalign, align);
+
+static NACCS accs = {
+	.Label = label,
+	.LabelFunc = labelfunc,
+	.Font = lfont,
+	.Color = lcolor,
+	.Margin = lmargin,
+	.Align = lalign,
+};
+
+NACCS*
 New_Label(char *name)
 {
-	NLabel *e = MakeNelem(NLabel, NLabel_Type, &Nlabelfunctions, name, 0);
+	NLabel *e = MakeNelem(NLabel, NLabel_Type, &Nlabelfunctions, &accs, name, 0);
 	
-	e->Label = label;
-	e->LabelFunc = labelfunc;
-	e->Font = lfont;
-	e->Color = lcolor;
-	e->Margin = lmargin;
-	e->Align = lalign;
-	
 	e->label = nil;
 	e->labelfunc = nil;
 	e->font = display->defaultfont;
 	e->color = display->black;
 	nc_push(e);
-	return e;
+	return &accs;
 }
--- a/n_label.h
+++ b/n_label.h
@@ -1,14 +1,22 @@
 extern char* NLabel_Type;
 
+#define NTYPE NLabel
+#define NACCS NLabelAccessors
+
+typedef struct NACCS NACCS;
+struct NACCS {
+	Nelemaccessors;
+	DECL_ACCESSOR_OneParam(Label, char*);
+	DECL_ACCESSOR_OneParam(LabelFunc, StringGetter);
+	DECL_ACCESSOR_OneParam(Font, Font*);
+	DECL_ACCESSOR_OneParam(Color, Image*);
+	DECL_ACCESSOR_OneParam(Margin, Nmargin);
+	DECL_ACCESSOR_OneParam(Align, Nalign);
+};
+
 typedef struct NLabel NLabel;
 struct NLabel {
 	Nelem;
-	DECL_ACCESSOR_OneParam(NLabel, Label, char*);
-	DECL_ACCESSOR_OneParam(NLabel, LabelFunc, StringGetter);
-	DECL_ACCESSOR_OneParam(NLabel, Font, Font*);
-	DECL_ACCESSOR_OneParam(NLabel, Color, Image*);
-	DECL_ACCESSOR_OneParam(NLabel, Margin, Nmargin);
-	DECL_ACCESSOR_OneParam(NLabel, Align, Nalign);
 	
 	// private members
 	char* label;
@@ -19,4 +27,7 @@
 	Nalign align;
 };
 
-NLabel* New_Label(char*);
+NACCS* New_Label(char*);
+
+#undef NTYPE
+#undef NACCS
--- a/n_vbox.c
+++ b/n_vbox.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_vbox.h"
 
@@ -138,20 +139,24 @@
 	.draw = vbox_draw,
 };
 
-DEF_SLOTFUNC(NVBox, vbox_slot);
+#define NTYPE NVBox
+#define NACCS NVBoxAccessors
 
-DEF_ACCESSOR_OneParam(NVBox, vbox_autowidth, int, autowidth);
+DEF_SLOTFUNC(vbox_slot);
+DEF_ACCESSOR_OneParam(vbox_autowidth, int, autowidth);
 
-NVBox*
+static NACCS accs = {
+	.Slot = vbox_slot,
+	.AutoWidth = vbox_autowidth,
+};
+
+NACCS*
 New_VBox(char *name)
 {
-	NVBox *b = MakeNelem(NVBox, NVBox_Type, &Nvboxfunctions, name, -1);
+	NVBox *b = MakeNelem(NVBox, NVBox_Type, &Nvboxfunctions, &accs, name, -1);
 	
-	b->Slot = vbox_slot;
-	b->AutoWidth = vbox_autowidth;
-	
 	linit(&b->children);
 	b->autowidth = 0;
 	nc_push(b);
-	return b;
+	return &accs;
 }
--- a/n_vbox.h
+++ b/n_vbox.h
@@ -1,13 +1,24 @@
 extern char* NVBox_Type;
 
+#define NTYPE NVBox
+#define NACCS NVBoxAccessors
+
+typedef struct NACCS NACCS;
+struct NACCS {
+	Nelemaccessors;
+	DECL_SLOTFUNC(Slot);
+	DECL_ACCESSOR_OneParam(AutoWidth, int);
+};
+
 typedef struct NVBox NVBox;
 struct NVBox {
 	Nelem;
-	DECL_SLOTFUNC(NVBox, Slot);
-	DECL_ACCESSOR_OneParam(NVBox, AutoWidth, int);
 	
 	// private members
 	int autowidth;
 };
 
-NVBox* New_VBox(char*);
+NACCS* New_VBox(char*);
+
+#undef NTYPE
+#undef NACCS
--- a/n_window.c
+++ b/n_window.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 #include "n_window.h"
 
@@ -46,25 +47,30 @@
 	.free = wfree,
 };
 
-DEF_SLOTFUNC(NWindow, wslot);
+#define NTYPE NWindow
+#define NACCS NWindowAccessors
 
-static NWindow*
+DEF_SLOTFUNC(wslot);
+
+static NWindowAccessors*
 makeroot(void)
 {
 	NWindow* w = (NWindow*)nc_get();
 	GUARD(w);
 	nregroot(w);
-	return w;
+	return (NACCS*)w->accs;
 }
 
-NWindow*
+static NWindowAccessors accs = {
+	.Slot = wslot,
+	.MakeRoot = makeroot,
+};
+
+NWindowAccessors*
 New_Window(char *name)
 {
-	NWindow *e = MakeNelem(NWindow, NWindow_Type, &Nwindowfunctions, name, 1);
+	NWindow *e = MakeNelem(NWindow, NWindow_Type, &Nwindowfunctions, &accs, name, 1);
 	
-	e->Slot = wslot;
-	e->MakeRoot = makeroot;
-	
 	nc_push(e);
-	return e;
+	return &accs;
 }
--- a/n_window.h
+++ b/n_window.h
@@ -1,10 +1,21 @@
 extern char* NWindow_Type;
 
+#define NTYPE NWindow
+#define NACCS NWindowAccessors
+
+typedef struct NACCS NACCS;
+struct NACCS {
+	Nelemaccessors;
+	DECL_SLOTFUNC(Slot);
+	DECL_ACCESSOR(MakeRoot);
+};
+
 typedef struct NWindow NWindow;
 struct NWindow {
 	Nelem;
-	DECL_SLOTFUNC(NWindow, Slot);
-	DECL_ACCESSOR(NWindow, MakeRoot);
 };
 
-NWindow* New_Window(char*);
+#undef NTYPE
+#undef NACCS
+
+NWindowAccessors* New_Window(char*);
--- a/nate.c
+++ b/nate.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 
 int nateborders = 0;
@@ -265,11 +266,13 @@
 	return nil;
 }
 
-Nelem*
-nassign(Nelem** dst, Nelem* src)
+Nelemaccessors*
+nassign(Nelem** dst, Nelemaccessors* src)
 {
-	assert(dst && src);
-	*dst = src;
+	Nelem *nel = nc_get();
+	assert(dst && src && nel);
+	assert(nel->type == src->type);
+	*dst = nel;
 	return src;
 }
 
--- a/nate.h
+++ b/nate.h
@@ -2,6 +2,7 @@
 
 typedef struct Nelem Nelem;
 typedef struct Nslot Nslot;
+typedef struct Nelemaccessors Nelemaccessors;
 typedef struct Nelemfunctions Nelemfunctions;
 typedef struct Nlist Nlist;
 typedef struct Nlistelem Nlistelem;
@@ -64,7 +65,7 @@
 int natemouseevent(Mouse);
 
 #define NAssign(T, A, B) ((T*)(nassign((Nelem**)A, B)))
-Nelem* nassign(Nelem**, Nelem*);
+Nelemaccessors* nassign(Nelem**, Nelemaccessors*);
 
 extern int nateborders;
 extern int natetracehit;
@@ -94,6 +95,9 @@
 Nslot NSlot(void);
 Nslot NSlotx(Nalign, int);
 
+struct Nelemaccessors {
+	char *type;
+};
 struct Nelem {
 	char *type;
 	char *name;
@@ -100,7 +104,8 @@
 	Nslot slot;
 	Nlist children;
 	int nchildren; /* -1=inf, 0=none, n otherwise */
-	Nelemfunctions* funcs;
+	Nelemaccessors *accs;
+	Nelemfunctions *funcs;
 };
 struct Nelemfunctions {
 	Rectangle (*calcrect)(Nelem*, Image*, Rectangle);
@@ -165,8 +170,8 @@
 /* more syntactic sugar */
 /************************/
 
-#define DECL_SLOTFUNC(Type, Acc) Type* (*Acc)(Nslot, Nelem*)
-#define DECL_ACCESSOR(Type, Acc) Type* (*Acc)(void)
-#define DECL_ACCESSOR_OneParam(Type, Acc, T1) Type* (*Acc)(T1)
-#define DECL_ACCESSOR_TwoParams(Type, Acc, T1, T2) Type* (*Acc)(T1, T2)
-#define DECL_ACCESSOR_ThreeParams(Type, Acc, T1, T2, T3) Type* (*Acc)(T1, T2, T3)
+#define DECL_SLOTFUNC(Acc) NACCS* (*Acc)(Nslot, Nelemaccessors*)
+#define DECL_ACCESSOR(Acc) NACCS* (*Acc)(void)
+#define DECL_ACCESSOR_OneParam(Acc, T1) NACCS* (*Acc)(T1)
+#define DECL_ACCESSOR_TwoParams(Acc, T1, T2) NACCS* (*Acc)(T1, T2)
+#define DECL_ACCESSOR_ThreeParams(Acc, T1, T2, T3) NACCS* (*Acc)(T1, T2, T3)
--- a/nate_construct.c
+++ b/nate_construct.c
@@ -2,6 +2,7 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
+#include "nate.h"
 #include "nate_construct.h"
 
 typedef struct NCelem NCelem;
@@ -106,14 +107,16 @@
 }
 
 Nelem*
-makenelem(long size, char *type, Nelemfunctions *funcs, char *name, int nchildren)
+makenelem(long size, char *type, Nelemfunctions *funcs, Nelemaccessors *accs, char *name, int nchildren)
 {
 	Nelem *nel = mallocz(size, 1);
 	if (!nel)
 		sysfatal("oom: creating nelem %s", type);
+	accs->type = type;
 	nel->type = type;
 	nel->name = name;
 	nel->funcs = funcs;
+	nel->accs = accs;
 	nel->nchildren = nchildren;
 	linit(&nel->children);
 	return nel;
--- a/nate_construct.h
+++ b/nate_construct.h
@@ -1,5 +1,3 @@
-#include "nate.h"
-
 void nc_push(Nelem*);
 void nc_pop(void);
 Nelem* nc_get(void);
@@ -6,11 +4,11 @@
 
 // #define N_TYPE in your implementation
 #define COND(N) (N->type == N_TYPE)
-#define GUARD(N) assert(COND(N))
+#define GUARD(N) assert(N->type == N_TYPE)
 
 // create with benefits
-Nelem *makenelem(long size, char *type, Nelemfunctions *funcs, char *name, int nchildren);
-#define MakeNelem(Type, Char, F, N, NUM) ((Type*)makenelem(sizeof(Type), Char, F, N, NUM));
+Nelem *makenelem(long size, char *type, Nelemfunctions *funcs, Nelemaccessors*, char *name, int nchildren);
+#define MakeNelem(Type, Char, F, ACCS, N, NUM) ((Type*)makenelem(sizeof(Type), Char, F, ACCS, N, NUM));
 
 void nc_addchild(Nelem*, Nelem*);
 
@@ -25,50 +23,54 @@
 Nelem* nd_checkhit(Nelem* nelem, Image* screen, Mouse m);
 void nd_free(Nelem *nelem);
 
+// syntactic sugar: get accessor of type
+#define NCACCS(Type, nel) ((Type*)(nel->accs))
+
 // syntactic sugar: default slot
-#define DEF_SLOTFUNC(Type, Func) \
-	static Type* \
-	Func(Nslot info, Nelem *el) \
+#define DEF_SLOTFUNC(Func) \
+	static NACCS* \
+	Func(Nslot info, Nelemaccessors *elaccs) \
 	{ \
-		if (el == nc_get()) \
-			nc_pop(); \
-		Type *b = (Type*)nc_get(); \
+		Nelem *el = nc_get(); \
+		nc_pop(); \
+		assert(el->type == elaccs->type); \
+		NTYPE *b = (NTYPE*)nc_get(); \
 		GUARD(b); \
 		el->slot = info; \
 		nc_addchild(b, el); \
-		return b; \
+		return (NACCS*)b->accs; \
 	}
 
 // syntactic sugar: default accessors
-#define DEF_ACCESSOR_OneParam(Type, Func, T1, N1) \
-	static Type* \
+#define DEF_ACCESSOR_OneParam(Func, T1, N1) \
+	static NACCS* \
 	Func(T1 N1) \
 	{ \
-		Type *b = (Type*)nc_get(); \
+		NTYPE *b = (NTYPE*)nc_get(); \
 		GUARD(b); \
 		b->N1 = N1; \
-		return b; \
+		return (NACCS*)b->accs; \
 	}
 
-#define DEF_ACCESSOR_TwoParams(Type, Func, T1, N1, T2, N2) \
-	static Type* \
+#define DEF_ACCESSOR_TwoParams(Func, T1, N1, T2, N2) \
+	static NACCS* \
 	Func(T1 N1, T2 N2) \
 	{ \
-		Type *b = (Type*)nc_get(); \
+		NTYPE *b = (NTYPE*)nc_get(); \
 		GUARD(b); \
 		b->N1 = N1; \
 		b->N2 = N2; \
-		return b; \
+		return (NACCS*)b->accs; \
 	}
 
-#define DEF_ACCESSOR_ThreeParams(Type, Func, T1, N1, T2, N2, T3, N3) \
-	static Type* \
+#define DEF_ACCESSOR_ThreeParams(Func, T1, N1, T2, N2, T3, N3) \
+	static NACCS* \
 	Func(T1 N1, T2 N2, T3 N3) \
 	{ \
-		Type *b = (Type*)nc_get(); \
+		NTYPE *b = (NTYPE*)nc_get(); \
 		GUARD(b); \
 		b->N1 = N1; \
 		b->N2 = N2; \
 		b->N3 = N3; \
-		return b; \
+		return (NACCS*)b->accs; \
 	}
--- a/test/ntest.c
+++ b/test/ntest.c
@@ -82,7 +82,7 @@
 	Image* blue = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, DBlue);
 	
 #ifdef T_VBOX
-	NAssign(NWindow, &mainwindow, New_Window("window"))
+	NAssign(NWindowAccessors, &mainwindow, New_Window("window"))
 	->MakeRoot()
 	->Slot(NSlot(),
 		New_VBox("vbox")
@@ -98,7 +98,7 @@
 #endif
 
 #ifdef T_HBOX
-	NAssign(NWindow, &mainwindow, New_Window("window"))
+	NAssign(NWindowAccessors, &mainwindow, New_Window("window"))
 	->MakeRoot()
 	->Slot(NSlot(),
 		New_HBox("hbox")
@@ -114,7 +114,7 @@
 #endif
 
 #ifdef T_GRID
-	NAssign(NWindow, &mainwindow, New_Window("window"))
+	NAssign(NWindowAccessors, &mainwindow, New_Window("window"))
 	->MakeRoot()
 	->Slot(NSlot(),
 		New_VBox("vbox")
@@ -144,7 +144,7 @@
 #endif
 
 #ifdef T_BOX
-	NAssign(NWindow, &mainwindow, New_Window("window"))
+	NAssign(NWindowAccessors, &mainwindow, New_Window("window"))
 	->MakeRoot()
 	->Slot(NSlot(),
 		New_HBox("hbox")
-- 
⑨