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reduce.c
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/* MIRANDA REDUCE */
/* new SK reduction machine - installed Oct 86 */
/**************************************************************************
* Copyright (C) Research Software Limited 1985-90. All rights reserved. *
* The Miranda system is distributed as free software under the terms in *
* the file "COPYING" which is included in the distribution. *
* *
* Revised to C11 standard and made 64bit compatible, January 2020 *
*------------------------------------------------------------------------*/
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
struct stat buf; /* used only by code for FILEMODE, FILESTAT in reduce */
#include "data.h"
#include "big.h"
#include "lex.h"
extern int debug, UTF8, UTF8OUT;
#define FST HD
#define SND TL
#define BSDCLOCK
/* POSIX clock wraps around after c. 72 mins */
#ifdef RYU
char* d2s(double);
word d2s_buffered(double, char*);
#endif
double fa,fb;
long long cycles=0;
word stdinuse=0;
/* int lasthead=0; /* DEBUG */
static void apfile(word);
static void closefile(word);
static void div_error(void);
static void fn_error(char *);
static void getenv_error(char *);
static word g_residue(word);
static void lexfail(word);
static word lexstate(word);
static int memclass(int,word);
static word numplus(word,word);
static void outf(word);
static word piperrmess(word);
static void print(word);
static word reduce(word);
static void stdin_error(int);
static void subs_error(void);
static void int_error(char *);
#define constr_tag(x) hd[x]
#define idconstr_tag(x) hd[id_val(x)]
#define constr_name(x) (tag[tl[x]]==ID?get_id(tl[x]):get_id(pn_val(tl[x])))
#define suppressed(x) (tag[tl[x]]==STRCONS&&tag[pn_val(tl[x])]!=ID)
/* suppressed constructor */
#define isodigit(x) ('0'<=(x) && (x)<='7')
#define sign(x) (x)
#define fsign(x) ((d=(x))<0?-1:d>0)
/* ### */ /* functions marked ### contain possibly recursive calls
to reduce - fix later */
int compare(a,b) /* returns -1, 0, 1 as a is less than equal to or greater than
b in the ordering imposed on all data types by the miranda
language -- a and b already reduced */
/* used by MATCH, EQ, NEQ, GR, GRE */
word a,b;
{ double d;
L: switch(tag[a])
{ case DOUBLE:
if(tag[b]==DOUBLE)return(fsign(get_dbl(a)-get_dbl(b)));
else return(fsign(get_dbl(a)-bigtodbl(b)));
case INT:
if(tag[b]==INT)return(bigcmp(a,b));
else return(fsign(bigtodbl(a)-get_dbl(b)));
case UNICODE: return sign(get_char(a)-get_char(b));
case ATOM:
if(tag[b]==UNICODE) return sign(get_char(a)-get_char(b));
if(S<=a&&a<=ERROR||S<=b&&b<=ERROR)
fn_error("attempt to compare functions");
/* what about constructors - FIX LATER */
if(tag[b]==ATOM)return(sign(a-b)); /* order of declaration */
else return(-1); /* atomic object always less than non-atomic */
case CONSTRUCTOR:
if(tag[b]==CONSTRUCTOR)
return(sign(constr_tag(a)-constr_tag(b))); /*order of declaration*/
else return(-1); /* atom less than non-atom */
case CONS: case AP:
if(tag[a]==tag[b])
{ word temp;
hd[a]=reduce(hd[a]);
hd[b]=reduce(hd[b]);
if((temp=compare(hd[a],hd[b]))!=0)return(temp);
a=tl[a]=reduce(tl[a]);
b=tl[b]=reduce(tl[b]);
goto L; }
else if(S<=b&&b<=ERROR)fn_error("attempt to compare functions");
else return(1); /* non-atom greater than atom */
default: fprintf(stderr,"\nghastly error in compare\n");
}
return(0);
}
void force(x) /* ensures that x is evaluated "all the way" */
word x; /* x is already reduced */ /* ### */
{ word h;
switch(tag[x])
{ case AP: h=hd[x];
while(tag[h]==AP)h=hd[h];
if(S<=h&&h<=ERROR)return; /* don't go inside functions */
/* what about unsaturated constructors? fix later */
while(tag[x]==AP)
{ tl[x]=reduce(tl[x]);
force(tl[x]);
x=hd[x]; }
return;
case CONS: while(tag[x]==CONS)
{ hd[x]=reduce(hd[x]);
force(hd[x]);
x=tl[x]=reduce(tl[x]); }
}
return;
}
word head(x) /* finds the function part of x */
word x;
{ while(tag[x]==AP)x= hd[x];
return(x);
}
extern char linebuf[]; /* used as workspace in various places */
/* ### */ /* opposite is str_conv - see lex.c */
char *getstring(x,cmd) /* collect Miranda string - x is already reduced */
word x;
char *cmd; /* context, for error message */
{ word x1=x,n=0;
char *p=linebuf;
while(tag[x]==CONS&&n<BUFSIZE)
n++, hd[x] = reduce(hd[x]), x=tl[x]=reduce(tl[x]);
x=x1;
while(tag[x]==CONS&&n--)
*p++ = hd[x], x=tl[x];
*p++ ='\0';
if(p-linebuf>BUFSIZE)
{ if(cmd)fprintf(stderr,
"\n%s, argument string too long (limit=%d chars): %s...\n",
cmd,BUFSIZE,linebuf),
outstats(),
exit(1);
else return(linebuf); /* see G_CLOSE */ }
return(linebuf); /* very inefficient to keep doing this for filenames etc.
CANNOT WE SUPPORT A PACKED REPRESENTATION OF STRINGS? */
} /* call keep(linebuf) if you want to save the string */
FILE *s_out=NULL; /* destination of current output message */
/* initialised in main() */
#define Stdout 0
#define Stderr 1
#define Tofile 2
#define Closefile 3
#define Appendfile 4
#define System 5
#define Exit 6
#define Stdoutb 7
#define Tofileb 8
#define Appendfileb 9
/* order of declaration of constructors of these names in sys_message */
/* ### */
void output(e) /* "output" is called by YACC (see rules.y) to print the
value of an expression - output then calls "reduce" - so the
whole reduction process is driven by the need to print */
/* the value of the whole expression is a list of `messages' */
word e;
{
extern word *cstack;
cstack = &e; /* don't follow C stack below this in gc */
L:e= reduce(e);
while(tag[e]==CONS)
{ word d;
hd[e]= reduce(hd[e]);
switch(constr_tag(head(hd[e])))
{ case Stdout: print(tl[hd[e]]);
break;
case Stdoutb: UTF8OUT=0;
print(tl[hd[e]]);
UTF8OUT=UTF8;
break;
case Stderr: s_out=stderr; print(tl[hd[e]]); s_out=stdout;
break;
case Tofile: outf(hd[e]);
break;
case Tofileb: UTF8OUT=0;
outf(hd[e]);
UTF8OUT=UTF8;
break;
case Closefile: closefile(tl[hd[e]]=reduce(tl[hd[e]]));
break;
case Appendfile: apfile(tl[hd[e]]=reduce(tl[hd[e]]));
break;
case Appendfileb: UTF8OUT=0;
apfile(tl[hd[e]]=reduce(tl[hd[e]]));
UTF8OUT=UTF8;
break;
case System: system(getstring(tl[hd[e]]=reduce(tl[hd[e]]),"System"));
break;
case Exit: { word n=reduce(tl[hd[e]]);
if(tag[n]==INT)n=digit0(n);
else int_error("Exit");
outstats(); exit(n); }
default: fprintf(stderr,"\n<impossible event in output list: ");
out(stderr,hd[e]);
fprintf(stderr,">\n"); }
e= tl[e]= reduce(tl[e]);
}
if(e==NIL)return;
fprintf(stderr,"\nimpossible event in output\n"),
putc('<',stderr),out(stderr,e),fprintf(stderr,">\n");
exit(1);
}
/* ### */
void print(e) /* evaluate list of chars and send to s_out */
word e;
{ e= reduce(e);
while(tag[e]==CONS && is_char(hd[e]=reduce(hd[e])))
{ unsigned c=get_char(hd[e]);
if(UTF8)outUTF8(c,s_out); else
if(c<256) putc(c,s_out);
else fprintf(stderr,"\n warning: non Latin1 char \%x in print, ignored\n",c);
e= tl[e]= reduce(tl[e]); }
if(e==NIL)return;
fprintf(stderr,"\nimpossible event in print\n"),
putc('<',stderr),out(stderr,e),fprintf(stderr,">\n"),
exit(1);
}
word outfilq=NIL; /* list of opened-for-output files */
/* note that this will be automatically reset to NIL and all files on it
closed at end of expression evaluation, because of the fork-exit structure */
/* ### */
void outf(e) /* e is of the form (Tofile f x) */
word e;
{ word p=outfilq; /* have we already opened this file for output? */
char *f=getstring(tl[hd[e]]=reduce(tl[hd[e]]),"Tofile");
while(p!=NIL && strcmp((char *)hd[hd[p]],f)!=0)p=tl[p];
if(p==NIL) /* new output file */
{ s_out= fopen(f,"w");
if(s_out==NULL)
{ fprintf(stderr,"\nTofile: cannot write to \"%s\"\n",f);
s_out=stdout;
return;
/* outstats(); exit(1); /* release one policy */
}
if(isatty(fileno(s_out)))setbuf(s_out,NULL); /*for unbuffered tty output*/
outfilq= cons(datapair(keep(f),s_out),outfilq); }
else s_out= (FILE *)tl[hd[p]];
print(tl[e]);
s_out= stdout;
}
void apfile(f) /* open file of name f for appending and add to outfilq */
word f;
{ word p=outfilq; /* is it already open? */
char *fil=getstring(f,"Appendfile");
while(p!=NIL && strcmp((char *)hd[hd[p]],fil)!=0)p=tl[p];
if(p==NIL) /* no, so open in append mode */
{ FILE *s=fopen(fil,"a");
if(s==NULL)
fprintf(stderr,"\nAppendfile: cannot write to \"%s\"\n",fil);
else outfilq= cons(datapair(keep(fil),s),outfilq);
}
/* if already there do nothing */
}
void closefile(f) /* remove file of name "f" from outfilq and close stream */
word f;
{ word *p= &outfilq; /* is this file open for output? */
char *fil=getstring(f,"Closefile");
while(*p!=NIL && strcmp((char *)hd[hd[*p]],fil)!=0)p= &tl[*p];
if(*p!=NIL) /* yes */
{ fclose((FILE *)tl[hd[*p]]);
*p=tl[*p]; /* remove link from outfilq */}
/* otherwise ignore closefile request (harmless??) */
}
static word errtrap=0; /* to prevent error cycles - see ERROR below */
word waiting=NIL;
/* list of terminated child processes with exit_status - see Exec/EXEC */
/* pointer-reversing SK reduction machine - based on code written Sep 83 */
#define READY(x) (x)
#define RESTORE(x)
/* in this machine the above two are no-ops, alternate definitions are, eg
#define READY(x) (x+1)
#define RESTORE(x) x--
(if using this method each strict comb needs next opcode unallocated)
see comment before "ready" switch */
#define mktlptr(x) x |= tlptrbit
#define mk1tlptr x |= tlptrbits
#define mknormal(x) x &= ~tlptrbits
#define abnormal(x) ((x)<0)
/* covers x is tlptr and x==BACKSTOP */
/* control abstractions */
#define setcell(t,a,b) tag[e]=t,hd[e]=a,tl[e]=b
#define DOWNLEFT hold=s, s=e, e=hd[e], hd[s]=hold
#define DOWNRIGHT hold=hd[s], hd[s]=e, e=tl[s], tl[s]=hold, mktlptr(s)
#define downright if(abnormal(s))goto DONE; DOWNRIGHT
#define UPLEFT hold=s, s=hd[s], hd[hold]=e, e=hold
#define upleft if(abnormal(s))goto DONE; UPLEFT
#define GETARG(a) UPLEFT, a=tl[e]
#define getarg(a) upleft; a=tl[e]
#define UPRIGHT mknormal(s), hold=tl[s], tl[s]=e, e=hd[s], hd[s]=hold
#define lastarg tl[e]
word reds=0;
/* IMPORTANT WARNING - the macro's
`downright;' `upleft;' `getarg;'
MUST BE ENCLOSED IN BRACES when they occur as the body of a control
structure (if, while etc.) */
#define simpl(r) hd[e]=I, e=tl[e]=r
#ifdef DEBUG
word maxrdepth=0,rdepth=0;
#endif
#define fails(x) (x==NIL)
#define FAILURE NIL
/* used by grammar combinators */
/* reduce e to hnf, note that a function in hnf will have head h with
S<=h<=ERROR all combinators lie in this range see combs.h */
word reduce(e)
word e;
{ word s=BACKSTOP,hold,arg1,arg2,arg3;
#ifdef DEBUG
if(++rdepth>maxrdepth)maxrdepth=rdepth;
if(debug&02)
printf("reducing: "),out(stdout,e),putchar('\n');
#endif
NEXTREDEX:
while(!abnormal(e)&&tag[e]==AP)DOWNLEFT;
#ifdef HISTO
histo(e);
#endif
#ifdef DEBUG
if(debug&02)
{ printf("head= ");
if(e==BACKSTOP)printf("BACKSTOP");
else out(stdout,e);
putchar('\n'); }
#endif
OPDECODE:
/*lasthead=e; /* DEBUG */
cycles++;
switch(e)
{
case S: /* S f g x => f x(g x) */
getarg(arg1);
getarg(arg2);
upleft;
hd[e]=ap(arg1,lastarg); tl[e]=ap(arg2,lastarg);
DOWNLEFT;
DOWNLEFT;
goto NEXTREDEX;
case B: /* B f g x => f(g z) */
getarg(arg1);
getarg(arg2);
upleft;
hd[e]=arg1; tl[e]=ap(arg2,lastarg);
DOWNLEFT;
goto NEXTREDEX;
case CB: /* CB f g x => g(f z) */
getarg(arg1);
getarg(arg2);
upleft;
hd[e]=arg2; tl[e]=ap(arg1,lastarg);
DOWNLEFT;
goto NEXTREDEX;
case C: /* C f g x => f x g */
getarg(arg1);
getarg(arg2);
upleft;
hd[e]=ap(arg1,lastarg); tl[e]=arg2;
DOWNLEFT;
DOWNLEFT;
goto NEXTREDEX;
case Y: /* Y h => self where self=(h self) */
upleft;
hd[e]=tl[e]; tl[e]=e;
DOWNLEFT;
goto NEXTREDEX;
L_K:
case K: /* K x y => x */
getarg(arg1);
upleft;
hd[e]=I; e=tl[e]=arg1;
goto NEXTREDEX; /* could make eager in first arg */
L_KI:
case KI: /* KI x y => y */
upleft; /* lose first arg */
upleft;
hd[e]=I; e=lastarg; /* ?? */
goto NEXTREDEX; /* could make eager in 2nd arg */
case S1: /* S1 k f g x => k(f x)(g x) */
getarg(arg1);
getarg(arg2);
getarg(arg3);
upleft;
hd[e]=ap(arg2,lastarg);
hd[e]=ap(arg1,hd[e]);
tl[e]=ap(arg3,lastarg);
DOWNLEFT;
DOWNLEFT;
goto NEXTREDEX;
case B1: /* B1 k f g x => k(f(g x)) */
getarg(arg1); /* Mark Scheevel's new B1 */
getarg(arg2);
getarg(arg3);
upleft;
hd[e]=arg1;
tl[e]=ap(arg3,lastarg);
tl[e]=ap(arg2,tl[e]);
DOWNLEFT;
goto NEXTREDEX;
case C1: /* C1 k f g x => k(f x)g */
getarg(arg1);
getarg(arg2);
getarg(arg3);
upleft;
hd[e]=ap(arg2,lastarg);
hd[e]=ap(arg1,hd[e]);
tl[e]=arg3;
DOWNLEFT;
goto NEXTREDEX;
case S_p: /* S_p f g x => (f x) : (g x) */
getarg(arg1);
getarg(arg2);
upleft;
setcell(CONS,ap(arg1,lastarg),ap(arg2,lastarg));
goto DONE;
case B_p: /* B_p f g x => f : (g x) */
getarg(arg1);
getarg(arg2);
upleft;
setcell(CONS,arg1,ap(arg2,lastarg));
goto DONE;
case C_p: /* C_p f g x => (f x) : g */
getarg(arg1);
getarg(arg2);
upleft;
setcell(CONS,ap(arg1,lastarg),arg2);
goto DONE;
case ITERATE: /* ITERATE f x => x:ITERATE f (f x) */
getarg(arg1);
upleft;
hold=ap(hd[e],ap(arg1,lastarg));
setcell(CONS,lastarg,hold);
goto DONE;
case ITERATE1: /* ITERATE1 f x => [], x=FAIL
=> x:ITERATE1 f (f x), otherwise */
getarg(arg1);
upleft;
if((lastarg=reduce(lastarg))==FAIL) /* ### */
{ hd[e]=I; e=tl[e]=NIL; }
else
{ hold=ap(hd[e],ap(arg1,lastarg));
setcell(CONS,lastarg,hold); }
goto DONE;
case G_RULE:
case P: /* P x y => x:y */
getarg(arg1);
upleft;
setcell(CONS,arg1,lastarg);
goto DONE;
case U: /* U f x => f (HD x) (TL x)
non-strict uncurry */
getarg(arg1);
upleft;
hd[e]=ap(arg1,ap(HD,lastarg));
tl[e]=ap(TL,lastarg);
DOWNLEFT;
DOWNLEFT;
goto NEXTREDEX;
case Uf: /* Uf f x => f (BODY x) (LAST x)
version of non-strict U for
arbitrary constructors */
getarg(arg1);
upleft;
if(tag[head(lastarg)]==CONSTRUCTOR) /* be eager if safe */
hd[e]=ap(arg1,hd[lastarg]),
tl[e]=tl[lastarg];
else
hd[e]=ap(arg1,ap(BODY,lastarg)),
tl[e]=ap(LAST,lastarg);
DOWNLEFT;
DOWNLEFT;
goto NEXTREDEX;
case ATLEAST: /* ATLEAST k f x => f(x-k), isnat x & x>=k
=> FAIL, otherwise */
/* for matching n+k patterns */
getarg(arg1);
getarg(arg2);
upleft;
lastarg= reduce(lastarg); /* ### */
if(tag[lastarg]==INT)
{ hold = bigsub(lastarg,arg1);
if(poz(hold))hd[e]=arg2,tl[e]=hold;
else hd[e]=I,e=tl[e]=FAIL; }
else hd[e]=I,e=tl[e]=FAIL;
goto NEXTREDEX;
case U_: /* U_ f (a:b) => f a b
U_ f other => FAIL
U_ is a strict version of U(see above) */
getarg(arg1);
upleft;
lastarg= reduce(lastarg); /* ### */
if(lastarg==NIL)
{ hd[e]=I;
e=tl[e]=FAIL;
goto NEXTREDEX; }
hd[e]=ap(arg1,hd[lastarg]);
tl[e]=tl[lastarg];
goto NEXTREDEX;
case Ug: /* Ug k f (k x1 ... xn) => f x1 ... xn, n>=0
Ug k f other => FAIL
Ug is a strict version of U for arbitrary constructor k */
getarg(arg1);
getarg(arg2);
upleft;
lastarg= reduce(lastarg); /* ### */
if(constr_tag(arg1)!=constr_tag(head(lastarg)))
{ hd[e]=I;
e=tl[e]=FAIL;
goto NEXTREDEX; }
if(tag[lastarg]==CONSTRUCTOR) /* case n=0 */
{ hd[e]=I; e=tl[e]=arg2; goto NEXTREDEX; }
hd[e]=hd[lastarg];
tl[e]=tl[lastarg];
while(tag[hd[e]]!=CONSTRUCTOR)
/* go back to head of arg3, copying spine */
{ hd[e]=ap(hd[hd[e]],tl[hd[e]]);
DOWNLEFT; }
hd[e]=arg2; /* replace k with f */
goto NEXTREDEX;
case MATCH: /* MATCH a f a => f
MATCH a f b => FAIL */
upleft;
arg1=lastarg=reduce(lastarg); /* ### */
/* note that MATCH evaluates arg1, usually needless, could have second
version - MATCHEQ, say */
getarg(arg2);
upleft;
lastarg=reduce(lastarg); /* ### */
hd[e]=I;
e=tl[e]=compare(arg1,lastarg)?FAIL:arg2;
goto NEXTREDEX;
case MATCHINT: /* same but 1st arg is integer literal */
getarg(arg1);
getarg(arg2);
upleft;
lastarg=reduce(lastarg); /* ### */
hd[e]=I;
e=tl[e]=(tag[lastarg]!=INT||bigcmp(arg1,lastarg))?FAIL:arg2;
/* note no coercion from INT to DOUBLE here */
goto NEXTREDEX;
case GENSEQ: /* GENSEQ (i,NIL) a => a:GENSEQ (i,NIL) (a+i)
GENSEQ (i,b) a => [], a>b=sign
=> a:GENSEQ (i,b) (a+i), otherwise
where
sign = 1, i>=0
= -1, otherwise */
GETARG(arg1);
UPLEFT;
if(tl[arg1]!=NIL&&
(tag[arg1]==AP?compare(lastarg,tl[arg1]):compare(tl[arg1],lastarg))>0)
hd[e]=I, e=tl[e]=NIL;
else hold=ap(hd[e],numplus(lastarg,hd[arg1])),
setcell(CONS,lastarg,hold);
goto DONE;
/* efficiency hack - tag of arg1 encodes sign of step */
case MAP: /* MAP f [] => []
MAP f (a:x) => f a : MAP f x */
getarg(arg1);
upleft;
lastarg=reduce(lastarg); /* ### */
if(lastarg==NIL)
hd[e]=I, e=tl[e]=NIL;
else hold=ap(hd[e],tl[lastarg]),
setcell(CONS,ap(arg1,hd[lastarg]),hold);
goto DONE;
case FLATMAP: /* funny version of map for compiling zf exps
FLATMAP f [] => []
FLATMAP f (a:x) => FLATMAP f x, f a=FAIL
=> f a ++ FLATMAP f x
(FLATMAP was formerly called MAP1) */
getarg(arg1);
getarg(arg2);
L1:arg2=reduce(arg2); /* ### */
if(arg2==NIL)
{ hd[e]=I;
e=tl[e]=NIL;
goto DONE; }
hold=reduce(hold=ap(arg1,hd[arg2]));
if(hold==FAIL||hold==NIL){ arg2=tl[arg2]; goto L1; }
tl[e]=ap(hd[e],tl[arg2]);
hd[e]=ap(APPEND,hold);
goto NEXTREDEX;
case FILTER: /* FILTER f [] => []
FILTER f (a:x) => a : FILTER f x, f a
=> FILTER f x, otherwise */
getarg(arg1);
upleft;
lastarg=reduce(lastarg); /* ### */
while(lastarg!=NIL&&reduce(ap(arg1,hd[lastarg]))==False) /* ### */
lastarg=reduce(tl[lastarg]); /* ### */
if(lastarg==NIL)
hd[e]=I, e=tl[e]=NIL;
else hold=ap(hd[e],tl[lastarg]),
setcell(CONS,hd[lastarg],hold);
goto DONE;
case LIST_LAST: /* LIST_LAST x => x!(#x-1) */
upleft;
if((lastarg=reduce(lastarg))==NIL)fn_error("last []"); /* ### */
while((tl[lastarg]=reduce(tl[lastarg]))!=NIL) /* ### */
lastarg=tl[lastarg];
hd[e]=I; e=tl[e]=hd[lastarg];
goto NEXTREDEX;
case LENGTH: /* takes length of a list */
upleft;
{ long long n=0; /* problem - may be followed by gc */
/* cannot make static because of ### below */
while((lastarg=reduce(lastarg))!=NIL) /* ### */
lastarg=tl[lastarg],n++;
simpl(sto_int(n)); }
goto DONE;
case DROP:
getarg(arg1);
upleft;
arg1=tl[hd[e]]=reduce(tl[hd[e]]); /* ### */
if(tag[arg1]!=INT)int_error("drop");
{ long long n=get_int(arg1);
while(n-- >0)
if((lastarg=reduce(lastarg))==NIL) /* ### */
{ simpl(NIL); goto DONE; }
else lastarg=tl[lastarg]; }
simpl(lastarg);
goto NEXTREDEX;
case SUBSCRIPT: /* SUBSCRIPT i x => x!i */
upleft;
upleft;
arg1=tl[hd[e]]=reduce(tl[hd[e]]); /* ### */
lastarg=reduce(lastarg); /* ### */
if(lastarg==NIL)subs_error();
{ long long indx;
if(tag[arg1]==ATOM)indx=arg1;/* small indexes represented directly */
else if(tag[arg1]==INT)indx=get_int(arg1);
else int_error("!");
/* problem, indx may be followed by gc
- cannot make static, because of ### below */
if(indx<0)subs_error();
while(indx)
{ lastarg= tl[lastarg]= reduce(tl[lastarg]); /* ### */
if(lastarg==NIL)subs_error();
indx--; }
hd[e]= I;
e=tl[e]=hd[lastarg]; /* could be eager in tl[e] */
goto NEXTREDEX; }
case FOLDL1: /* FOLDL1 op (a:x) => FOLDL op a x */
getarg(arg1);
upleft;
if((lastarg=reduce(lastarg))!=NIL) /* ### */
{ hd[e]=ap2(FOLDL,arg1,hd[lastarg]);
tl[e]=tl[lastarg];
goto NEXTREDEX; }
else fn_error("foldl1 applied to []");
case FOLDL: /* FOLDL op r [] => r
FOLDL op r (a:x) => FOLDL op (op r a)^ x
^ (FOLDL op) is made strict in 1st param */
getarg(arg1);
getarg(arg2);
upleft;
while((lastarg=reduce(lastarg))!=NIL) /* ### */
arg2=reduce(ap2(arg1,arg2,hd[lastarg])), /* ^ ### */
lastarg=tl[lastarg];
hd[e]=I, e=tl[e]=arg2;
goto NEXTREDEX;
case FOLDR: /* FOLDR op r [] => r
FOLDR op r (a:x) => op a (FOLDR op r x) */
getarg(arg1);
getarg(arg2);
upleft;
lastarg=reduce(lastarg); /* ### */
if(lastarg==NIL)
hd[e]=I, e=tl[e]=arg2;
else hold=ap(hd[e],tl[lastarg]),
hd[e]=ap(arg1,hd[lastarg]), tl[e]=hold;
goto NEXTREDEX;
L_READBIN:
case READBIN: /* READBIN streamptr => nextchar : READBIN streamptr
if end of file, READBIN file => NIL
READBIN does no UTF-8 conversion */
UPLEFT; /* gc insecurity - arg is not a heap object */
if(lastarg==0) /* special case created by $:- */
{ if(stdinuse=='-')stdin_error(':');
if(stdinuse)
{ hd[e]=I; e=tl[e]=NIL; goto DONE; }
stdinuse=':';
tl[e]=(word)stdin; }
hold= getc((FILE *)lastarg);
if(hold==EOF)
{ fclose((FILE *)lastarg);
hd[e]=I;
e=tl[e]= NIL;
goto DONE; }
setcell(CONS,hold,ap(READBIN,lastarg));
goto DONE;
L_READ:
case READ: /* READ streamptr => nextchar : READ streamptr
if end of file, READ file => NIL
does UTF-8 conversion where appropriate */
UPLEFT; /* gc insecurity - arg is not a heap object */
if(lastarg==0) /* special case created by $- */
{ if(stdinuse==':')stdin_error('-');
if(stdinuse)
{ hd[e]=I; e=tl[e]=NIL; goto DONE; }
stdinuse='-';
tl[e]=(word)stdin; }
hold=UTF8?sto_char(fromUTF8((FILE *)lastarg)):getc((FILE *)lastarg);
if(hold==EOF)
{ fclose((FILE *)lastarg);
hd[e]=I;
e=tl[e]= NIL;
goto DONE; }
setcell(CONS,hold,ap(READ,lastarg));
goto DONE;
L_READVALS:
case READVALS: /* READVALS (t:fil) f => [], EOF from FILE *f
=> val : READVALS t f, otherwise
where val is obtained by parsing lines of
f, and taking next legal expr of type t */
GETARG(arg1);
upleft;
hold=parseline(hd[arg1],(FILE *)lastarg,tl[arg1]);
if(hold==EOF)
{ fclose((FILE *)lastarg);
hd[e]=I;
e=tl[e]= NIL;
goto DONE; }
arg2=ap(hd[e],lastarg);
setcell(CONS,hold,arg2);
goto DONE;
case BADCASE: /* BADCASE cons(oldn,here_info) => BOTTOM */
UPLEFT;
{ word subject= hd[lastarg];
/* either datapair(oldn,0) or 0 */
fprintf(stderr,"\nprogram error: missing case in definition");
if(subject) /* cannot do patterns - FIX LATER */
fprintf(stderr," of %s",(char *)hd[subject]);
putc('\n',stderr);
out_here(stderr,tl[lastarg],1);
/* if(nargs>1)
{ int i=2;
fprintf(stderr,"arg%s = ",nargs>2?"s":"");
while(i<=nargs)out(stderr,tl[stackp[-(i++)]]),putc(' ',stderr);
putc('\n',stderr); } /* fix later */
}
outstats();
exit(1);
case GETARGS: /* GETARGS 0 => argv ||`$*' = command line args */
UPLEFT;
simpl(conv_args());
goto DONE;
case CONFERROR: /* CONFERROR error_info => BOTTOM */
/* if(nargs<1)fprintf(stderr,"\nimpossible event in reduce\n"),
exit(1); */
UPLEFT;
fprintf(stderr,"\nprogram error: lhs of definition doesn't match rhs");
/*fprintf(stderr," OF ");
out_formal1(stderr,hd[lastarg]); /* omit - names may have been aliased */
putc('\n',stderr);
out_here(stderr,tl[lastarg],1);
outstats();
exit(1);
case ERROR: /* ERROR error_info => BOTTOM */
upleft;
if(errtrap)fprintf(stderr,"\n(repeated error)\n");
else { errtrap=1;
fprintf(stderr,"\nprogram error: ");
s_out=stderr;
print(lastarg); /* ### */
putc('\n',stderr); }
outstats();
exit(1);
case WAIT: /* WAIT pid => <exit_status of child process pid> */
UPLEFT;
{ word *w= &waiting; /* list of terminated pid's and their exit statuses */
while(*w!=NIL&&hd[*w]!=lastarg)w= &tl[tl[*w]];
if(*w!=NIL)hold=hd[tl[*w]],
*w=tl[tl[*w]]; /* remove entry */
else { int status;
while((hold=wait(&status))!=lastarg&&hold!= -1)
waiting=cons(hold,cons(WEXITSTATUS(status),waiting));
if(hold!= -1)hold=WEXITSTATUS(status); }}
simpl(stosmallint(hold));
goto DONE;
L_I:
/* case MONOP: (all strict monadic operators share this code) */
case I: /* we treat I as strict to avoid I-chains (MOD1) */
case SEQ:
case FORCE:
case HD:
case TL:
case BODY:
case LAST:
case EXEC:
case FILEMODE:
case FILESTAT:
case GETENV:
case INTEGER:
case NUMVAL:
case TAKE:
case STARTREAD:
case STARTREADBIN:
case NB_STARTREAD:
case COND:
case APPEND:
case AND:
case OR:
case NOT:
case NEG:
case CODE:
case DECODE:
case SHOWNUM:
case SHOWHEX:
case SHOWOCT:
case ARCTAN_FN: /* ...FN are strict functions of one numeric arg */
case EXP_FN:
case ENTIER_FN:
case LOG_FN:
case LOG10_FN:
case SIN_FN:
case COS_FN:
case SQRT_FN:
downright; /* subtask -- reduce arg */
goto NEXTREDEX;
case TRY: /* TRY f g x => TRY(f x)(g x) */
getarg(arg1);
getarg(arg2);
while(!abnormal(s))
{ UPLEFT;
hd[e]=ap(TRY,arg1=ap(arg1,lastarg));
arg2=tl[e]=ap(arg2,lastarg); }
DOWNLEFT;
/* DOWNLEFT; DOWNRIGHT; equivalent to:*/
hold=s,s=e,e=tl[e],tl[s]=hold,mktlptr(s); /* now be strict in arg1 */
goto NEXTREDEX;
case FAIL: /* FAIL x => FAIL */
while(!abnormal(s))hold=s,s=hd[s],hd[hold]=FAIL,tl[hold]=0;
goto DONE;
/* case DIOP: (all strict diadic operators share this code) */
case ZIP:
case STEP:
case EQ:
case NEQ:
case PLUS:
case MINUS:
case TIMES:
case INTDIV:
case FDIV:
case MOD:
case GRE:
case GR:
case POWER:
case SHOWSCALED:
case SHOWFLOAT:
case MERGE:
upleft;
downright; /* first subtask -- reduce arg2 */
goto NEXTREDEX;
case Ush: /* strict in three args */
case STEPUNTIL:
upleft;
upleft;
downright;
goto NEXTREDEX; /* first subtask -- reduce arg3 */
case Ush1: /* non-strict version of Ush */
/* Ush1 (k f1...fn) p stuff
=> "k"++' ':f1 x1 ...++' ':fn xn, p='\0'
=> "(k"++' ':f1 x1 ...++' ':fn xn++")", p='\1'
where xi = LAST(BODY^(n-i) stuff) */
getarg(arg1);
arg1=reduce(arg1); /* ### */
getarg(arg2);
arg2=reduce(arg2); /* ### */
getarg(arg3);
if(tag[arg1]==CONSTRUCTOR) /* don't parenthesise atom */
{ hd[e]=I;
if(suppressed(arg1))
e=tl[e]=str_conv("<unprintable>");
else e=tl[e]=str_conv(constr_name(arg1));
goto DONE; }
hold=arg2?cons(')',NIL):NIL;
while(tag[arg1]!=CONSTRUCTOR)
hold=cons(' ',ap2(APPEND,ap(tl[arg1],ap(LAST,arg3)),hold)),
arg1=hd[arg1],arg3=ap(BODY,arg3);
if(suppressed(arg1))
{ hd[e]=I; e=tl[e]=str_conv("<unprintable>"); goto DONE; }
hold=ap2(APPEND,str_conv(constr_name(arg1)),hold);
if(arg2)
{ setcell(CONS,'(',hold); goto DONE; }
else { hd[e]=I; e=tl[e]=hold; goto NEXTREDEX; }
case MKSTRICT: /* MKSTRICT k f x1 ... xk => f x1 ... xk, xk~=BOT */
GETARG(arg1);
getarg(arg2);
{ word i=arg1;
while(i--) { upleft; } }
lastarg=reduce(lastarg); /* ### */
while(--arg1) /* go back towards head, copying spine */
{ hd[e]=ap(hd[hd[e]],tl[hd[e]]);
DOWNLEFT;}
hd[e]=arg2; /* overwrite (MKSTRICT k f) with f */
goto NEXTREDEX;
case G_ERROR: /* G_ERROR f g toks = (g residue):[], fails(f toks)
= f toks, otherwise */
GETARG(arg1);
GETARG(arg2);
upleft;
hold=ap(arg1,lastarg);
hold=reduce(hold); /* ### */
if(!fails(hold))
{ hd[e]=I; e=tl[e]=hold; goto DONE; }
hold=g_residue(lastarg);
setcell(CONS,ap(arg2,hold),NIL);
goto DONE;
case G_ALT: /* G_ALT f g toks = f toks, !fails(f toks)
= g toks, otherwise */
GETARG(arg1);
GETARG(arg2);
upleft;