The R Project SVN R

/*
 *  R : A Computer Langage for Statistical Data Analysis
 *  Copyright (C) 1995, 1996  Robert Gentleman and Ross Ihaka
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "Defn.h"

/*-----------------------*/
/* Basic List Constructs */
/*-----------------------*/

/* cons - return a dotted pair with the given car and cdr */
SEXP cons(SEXP car, SEXP cdr)
{
    SEXP e;
    PROTECT(car);
    PROTECT(cdr);
    e = allocSExp(LISTSXP);
    UNPROTECT(2);
    CAR(e) = car;
    SETCDR(e, cdr);
#ifdef oldmem
    TAG(e) = R_NilValue;
#endif
    return e;
}

SEXP list1(SEXP s)
{
    return CONS(s, R_NilValue);
}

SEXP list2(SEXP s, SEXP t)
{
    PROTECT(s);
    s = CONS(s, list1(t));
    UNPROTECT(1);
    return s;
}

SEXP list3(SEXP s, SEXP t, SEXP u)
{
    PROTECT(s);
    s = CONS(s, list2(t, u));
    UNPROTECT(1);
    return s;
}

SEXP list4(SEXP s, SEXP t, SEXP u, SEXP v)
{
    PROTECT(s);
    s = CONS(s, list3(t, u, v));
    UNPROTECT(1);
    return s;
}

/* listAppend - Destructive list append */
/* See also ``append'' */
SEXP listAppend(SEXP s, SEXP t)
{
    SEXP r;
    if (s == R_NilValue)
        return t;
    r = s;
    while (CDR(r) != R_NilValue)
        r = CDR(r);
    SETCDR(r, t);
    return s;
}


/*--------------------------------*/
/* Language based list constructs */
/*--------------------------------*/

/* lcons - return a (language) dotted pair with the given car and cdr */
SEXP lcons(SEXP car, SEXP cdr)
{
    SEXP e;
    PROTECT(car);
    PROTECT(cdr);
    e = allocSExp(LANGSXP);
    UNPROTECT(2);
    CAR(e) = car;
    SETCDR(e, cdr);
    TAG(e) = R_NilValue;
    return e;
}

SEXP lang1(SEXP s)
{
    return LCONS(s, R_NilValue);
}

SEXP lang2(SEXP s, SEXP t)
{
    PROTECT(s);
    s = LCONS(s, list1(t));
    UNPROTECT(1);
    return s;
}

SEXP lang3(SEXP s, SEXP t, SEXP u)
{
    PROTECT(s);
    s = LCONS(s, list2(t, u));
    UNPROTECT(1);
    return s;
}

SEXP lang4(SEXP s, SEXP t, SEXP u, SEXP v)
{
    PROTECT(s);
    s = LCONS(s, list3(t, u, v));
    UNPROTECT(1);
    return s;
}

static SEXP ans;
static int  UniqueNames;
static int  IncludeFunctions;
static int  StoreValues;
static int  ItemCount;
static int  MaxCount;

static void namewalk(SEXP s)
{
    int i, j, n;
    switch(TYPEOF(s)) {
    case SYMSXP:
        if(ItemCount < MaxCount) {
            if(StoreValues) {
                if(UniqueNames) {
                    for(j=0 ; j<ItemCount ; j++) {
                        if(STRING(ans)[j] == PRINTNAME(s))
                            goto ignore;
                    }
                }
                STRING(ans)[ItemCount] = PRINTNAME(s);
            }
            ItemCount += 1;
        }
    ignore:
        break;
    case LANGSXP:
        if(!IncludeFunctions) s = CDR(s);
        while(s != R_NilValue) {
            namewalk(CAR(s));
            s = CDR(s);
        }
        break;
    case EXPRSXP:
        n = length(s);
        for(i=0 ; i<n ; i++)
            namewalk(VECTOR(s)[i]);
        break;
    }
}

SEXP do_allnames(SEXP call, SEXP op, SEXP args, SEXP env)
{
    SEXP expr;
    int i, savecount;

    checkArity(op, args);

    expr = CAR(args);
    args = CDR(args);

    IncludeFunctions = asLogical(CAR(args));
    if(IncludeFunctions == NA_LOGICAL)
        IncludeFunctions = 0;
    args = CDR(args);

    MaxCount = asInteger(CAR(args));
    if(MaxCount < 0 || MaxCount == NA_INTEGER)
        MaxCount = 0;
    args = CDR(args);

    UniqueNames = asLogical(CAR(args));
    if(UniqueNames == NA_LOGICAL)
        UniqueNames = 1;

    StoreValues = 0;
    ItemCount = 0;
    namewalk(expr);
    savecount = ItemCount;

    ans = allocVector(STRSXP, ItemCount);

    StoreValues = 1;
    ItemCount = 0;
    namewalk(expr);

    if(ItemCount != savecount) {
        PROTECT(expr = ans);
        ans = allocVector(STRSXP, ItemCount);
        for(i=0 ; i<ItemCount ; i++)
            STRING(ans)[i] = STRING(expr)[i];
        UNPROTECT(1);
    }

    return ans;
}