shithub: lpa

ref: 5af5764e62f81ec4057e99a3bd03902b723cd7b8
dir: /prim.c/

#include <u.h>
#include <libc.h>
#include <thread.h>

#include "dat.h"
#include "fns.h"

/* NOTE: In LPA, system functions are treated as primitives as well */

/* monadic functions */
static Array *primfn_same(Array *);

/* dyadic functions */
static Array *primfn_left(Array *, Array *);
static Array *primfn_right(Array *, Array *);

struct {
	char *spelling;
	int nameclass;
	Array *(*nilad)(void);
	Array *(*monad)(Array *);
	Array *(*dyad)(Array *, Array *);
} primspecs[] = {
	"⊢", NameclassFunc, nil, primfn_same, primfn_right,
	"⊣", NameclassFunc, nil, primfn_same, primfn_left,
	"+", NameclassFunc, nil, nil, nil,
	"-", NameclassFunc, nil, nil, nil,
};

char *
primsymb(int id)
{
	return primspecs[id].spelling;
}

int
primclass(int id)
{
	return primspecs[id].nameclass;
}

int
primvalence(int id)
{
	int valence = 0;
	if(primspecs[id].monad)
		valence |= Monadic;
	if(primspecs[id].dyad)
		valence |= Dyadic;
	return valence;
}

int
primid(char *s)
{
	for(int i = 0; i < nelem(primspecs); i++){
		char *x = primspecs[i].spelling;
		if(strncmp(s, x, strlen(x)) == 0)
			return i;
	}
	return -1;
}

Array *
primnilad(int id)
{
	if(primspecs[id].nilad)
		return primspecs[id].nilad();
	else
		error(EInternal, "primitive %s has no niladic definition", primsymb(id));
}

Array *
primmonad(int id, Array *y)
{
	if(primspecs[id].monad)
		return primspecs[id].monad(y);
	else
		error(EInternal, "primitive %s has no monadic definition", primsymb(id));
}

Array *
primdyad(int id, Array *x, Array *y)
{
	if(primspecs[id].dyad)
		return primspecs[id].dyad(x, y);
	else
		error(EInternal, "primitive %s has no dyadic definition", primsymb(id));
}

/* monadic functions */
static Array *
primfn_same(Array *a)
{
	return a;
}

/* dyadic functions */
static Array *
primfn_left(Array *x, Array *)
{
	return x;
}

static Array *
primfn_right(Array *, Array *y)
{
	return y;
}