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BSD 4.3

/* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1984. */
/* $Header: /var/lib/cvsd/repos/CSRG/43BSD/contrib/B/src/bsmall/b2cmd.c,v 1.1.1.1 2018/04/24 16:12:54 root Exp $ */

/* B commands */
#include "b.h"
#include "b0con.h"
#include "b1obj.h"
#include "b2env.h"
#include "b2scr.h"
#include "b2err.h"
#include "b2key.h"
#include "b2syn.h"
#include "b2sem.h"
#include "b2typ.h"

#define Nex if (!xeq) {tx= ceol; return Yes;}

char rdbuf[RDBUFSIZE];
txptr rdbufend= &rdbuf[RDBUFSIZE];

#define USE_QUIT "\r*** use QUIT or interrupt to abort READ command\n"

Hidden Procedure read_line(l, t, eg) loc l; btype t; bool eg; {
	context c; txptr tx0= tx, rp; intlet k; value r; btype rt;
	envtab svprmnvtab= Vnil; bool must_sv= eg, got;
	sv_context(&c);
	if (active_reads >= MAX_NMB_ACT_READS)
		error("too many READs simultaneously active");
	if (setjmp(reading[active_reads++]) != 0) /* long jump occurred */
		set_context(&c);
	if (cntxt != In_read) sv_context(&read_context);
	if (must_sv) svprmnvtab= prmnvtab == Vnil ? Vnil : prmnv->tab;
	/* save scratch-pad copy because of following setprmnv() */
	if (eg) setprmnv(); must_sv= No;
	cntxt= In_read;
	got= No;
	while (!got) {
		tx= rp= rdbuf;
		if (read_interactive) {
			fprintf(stderr, eg ? eg_prompt : raw_prompt);
		}
		got= Yes;
		while ((k= getchar()) != EOF && k != '\n') {
			*rp++= k;
			if (rp > rdbufend-1) syserr("read buffer overflow");
		}
		if (k == EOF) {
			if (read_interactive) {
				fprintf(stderr, USE_QUIT);
				CLEAR_EOF;
				if (outeractive) at_nwl= Yes;
				got= No;
			} else error("End of file encountered during READ command");
		}
	}
	if (read_interactive && outeractive && k == '\n') at_nwl= Yes;
	*rp= '\n';
	Skipsp(tx);
	if (atkw(QUIT)) int_signal(Yes);
	if (eg) {
		r= expr(rp); rt= valtype(r);
		if (svprmnvtab != Vnil) {
			prmnvtab= prmnv->tab;
			prmnv->tab= svprmnvtab;
		}
		must_sv= Yes;
		set_context(&c);
		must_agree(t, rt,
		    "type of expression does not agree with that of EG sample");
		release(rt);
	} else {
		*rp= '\0';
		r= mk_text(rdbuf);
		set_context(&c);
	}
	put(r, l);
	active_reads--;
	release(r);
	tx= tx0;
}

Hidden Procedure check(o) outcome o; {
	if (o == Fail) checkerr();
}

Hidden bool sim_com() {
	txptr ftx, ttx;
	switch (Char(tx)) {
case 'C': if (atkw(CHECK)) {
		env e0= curnv; outcome o;
		Nex;
		o= test(ceol);
		if (xeq) {
			check(o);
			restore_env(e0);
		}
		return Yes;
	} else if (atkw(CHOOSE)) {
		loc l; value v;
		reqkw(FROM_choose, &ftx, &ttx);
		Nex;
		l= targ(ftx);
		tx= ttx; v= expr(ceol);
		if (xeq) choose(l, v);
		release(v); release(l);
		return Yes;
	  }
	  return No;
case 'D': if (atkw(DELETE)) {
		loc l;
		Nex;
		l= targ(ceol);
		if (xeq) l_delete(l);
		release(l);
		return Yes;
	} else if (atkw(DRAW)) {
		loc l;
		Nex;
		l= targ(ceol);
		if (xeq) draw(l);
		release(l);
		return Yes;
	  }
	  return No;
case 'E': if (atkw(ELSE)) {
	       pprerr("ELSE only allowed as alternative test after SELECT", "");
	  }
	  return No;
case 'I': if (atkw(INSERT)) {
		value v; loc l;
		reqkw(IN_insert, &ftx, &ttx);
		Nex;
		v= expr(ftx);
		tx= ttx; l= targ(ceol);
		if (xeq) l_insert(v, l);
		release(v); release(l);
		return Yes;
	  }
	  return No;
case 'P': if (atkw(PUT)) {
		value v; loc l;
		reqkw(IN_put, &ftx, &ttx);
		Nex;
		v= expr(ftx);
		tx= ttx; l= targ(ceol);
		if (xeq) put(v, l);
		release(v); release(l);
		return Yes;
	  }
	  return No;
case 'R': if (atkw(READ)) {
		value v; loc l; btype vt, lt; bool eg= Yes;
		if (find(RAW, ceol, &ftx, &ttx)) {
			eg= No;
			vt= mk_text("");
		} else reqkw(EG, &ftx, &ttx);
		Nex;
		l= targ(ftx); lt= loctype(l);
		tx= ttx;
		if (eg) {
			v= expr(ceol);
			vt= valtype(v); release(v);
		}
		must_agree(vt, lt,
		    eg ? "this sample could not lawfully be put in the target"
		       : "in READ x RAW, x must be a simple textual target");
		release(lt);
		if (xeq) read_line(l, vt, eg);
		release(l); release(vt);
		return Yes;
	} else if (atkw(REMOVE)) {
		value v; loc l;
		reqkw(FROM_remove, &ftx, &ttx);
		Nex;
		v= expr(ftx);
		tx= ttx; l= targ(ceol);
		if (xeq) l_remove(v, l);
		release(v); release(l);
		return Yes;
	  }
	  return No;
case 'S': if (atkw(SET_RANDOM)) {
		value v;
		Nex;
		v= expr(ceol);
		if (xeq) set_random(v);
		release(v);
		return Yes;
	  } else if (atkw(SHARE)) pprerr(
	  "SHARE only allowed following HOW'TO-, YIELD- or TEST-heading", "");
	  return No;
case 'W': if (atkw(WRITE)) {
		txptr tx0; value v; intlet nwlc;
		Nex;
		Skipsp(tx);
		while (Char(tx) == '/' && (Char(tx+1) == '/')) {
			if (xeq) newline();
			tx++;
		}
		tx0= tx;
	loop:	if (Char(tx++) != '/') {tx= tx0; goto postnl;}
		if (Char(tx++) == '*') goto loop;
		if (xeq) newline();
		tx= tx0+1;
	postnl: ftx= ceol;
		while (Space(Char(ftx-1))) ftx--;
		nwlc= 0;
		while (ftx > tx && Char(ftx-1) == '/') {
			nwlc++;
			ftx--;
		}
		if (ftx > tx) {
			v= expr(ftx);
			if (xeq) writ(v);
			release(v);
		}
		while (nwlc-- > 0) {
			if (xeq) newline();
		}
		return Yes;
	  }
	  return No;
default:  return No;
	}
}

#define Reqcol {req(":", ceol, &utx, &vtx); \
		if (!xeq) {tx= vtx; comm_suite(); return Yes;}}
#define Resetx(tx0) {tx= (tx0); lino= lino0; cur_ilev= cil;}

Hidden bool con_com() {
	intlet lino0= lino, cil= cur_ilev;
	txptr ftx, ttx, utx, vtx;
	switch (Char(tx)) {
case 'I': if (atkw(IF)) {
		env e0= curnv; bool xeq0= xeq;
		outcome o;
		Reqcol;
		o= test(utx);
		xeq= o == Succ;
		tx= vtx; comm_suite();
		xeq= xeq0; restore_env(e0); 
		return Yes;
	  }
	  return No;
case 'S': if (atkw(SELECT)) {
		need(":");
		upto(ceol, "SELECT:");
		alt_suite();
		return Yes;
	  }
	  return No;
case 'W': if (atkw(WHILE)) {
		env e0= curnv; bool xeq0= xeq; txptr tx0= tx;
		outcome o;
		Reqcol;
	loop:	o= test(utx);
		if (xeq0) xeq= o == Succ;
		tx= vtx; comm_suite();
		xeq= xeq0; restore_env(e0);
		if (xeq && o == Succ && !terminated) {
			Resetx(tx0); goto loop;
		}
		return Yes;
	  }
	  return No;
case 'F': if (atkw(FOR)) {
		env e0= curnv; bool xeq0= xeq; loc l; value v, w;
		Reqcol;
		if (find(PARSING, utx, &ftx, &ttx)) {
			tx= ttx; pprerr("PARSING not allowed in FOR ...", "");
		}
		reqkw(IN_for, &ftx, &ttx);
		if (ttx > ceol) {
			tx= ceol;
			parerr("IN after colon", "");
		}
		l= targ(ftx);
		if (!Is_simploc(l) && !Is_compound(l)) /*to bloc.c?*/
			pprerr("inappropriate identifier after FOR", "");
		bind(l);
		tx= ttx; v= expr(utx);
		{value k, k1, len= xeq ? size(v) : copy(one);
			if (compare(len, zero) == 0) {
				xeq= No; release(len); len= copy(one);
			}
			k= copy(one);
			while (!terminated && compare(k, len) <= 0) {
				Resetx(utx);
				if (xeq) {
					w= th_of(k, v);
					put(w, l);
					release(w);
				}
				k= sum(k1= k, one); release(k1);
				tx= vtx; comm_suite();
			}
			release(k); release(len);
		}
		xeq= xeq0; restore_env(e0);
		release(v); release(l);
		return Yes;
	  }
	  return No;
default:  return No;
	}
}

Hidden bool term_com() {
	switch (Char(tx)) {
case 'F': if (atkw(FAIL)) {
		upto(ceol, "FAIL");
		if (xeq) {
			chckvtc(Rep);
			resout= Fail;
			terminated= Yes;
		} else tx= ceol;
		return Yes;
	  }
	  return No;
case 'Q': if (atkw(QUIT)) {
		upto(ceol, "QUIT");
		if (xeq) {
			if (cur_ilev == 0) bye(0);
			chckvtc(Voi);
			terminated= Yes;
		}
		return Yes;
	  }
	  return No;
case 'R': if (atkw(RETURN)) {
		if (xeq) {
			chckvtc(Ret);
			resval= expr(ceol);
			terminated= Yes;
		} else tx= ceol;
		return Yes;
	  } else if (atkw(REPORT)) {
		if (xeq) {
			chckvtc(Rep);
			resout= test(ceol);
			terminated= Yes;
		} else tx= ceol;
		return Yes;
	  }
	  return No;
case 'S': if (atkw(SUCCEED)) {
		upto(ceol, "SUCCEED");
		if (xeq) {
			chckvtc(Rep);
			resout= Succ;
			terminated= Yes;
		} else tx= ceol;
		return Yes;
	  }
	  return No;
default:  return No;
	}
}

Hidden bool secret_com() {
	switch (Char(tx)) {
case 'D': if (atkw("DEBUG")) {
		Nex;
		bugs= Yes;
		return Yes;
	  }
	  return No;
case 'G': if (atkw("GR")) {
		Nex;
		prgr();
		return Yes;
	  }
	  return No;
case 'N': if (atkw("NO'DEBUG")) {
		Nex;
		bugs= No;
		return Yes;
	  } else if (atkw("NO'TRACE")) {
		Nex;
		tracing= No;
		return Yes;
	  }
	  return No;
case 'T': if (atkw("TRACE")) {
		Nex;
		tracing= Yes;
		return Yes;
	  }
	  return No;
default:  return No;
	}
}

Hidden Procedure chckvtc(re) literal re; {
	if (cntxt != In_unit || resexp == Voi) {
		if (re == Ret)
			pprerr("RETURN e only allowed inside YIELD-unit or\n",
			       "    expression-refinement");
		else if (re == Rep)
			pprerr("REPORT t only allowed inside TEST-unit",
			       " or test-refinement");
	}
	if (re != resexp) {
		if (resexp == Ret)
			pprerr(
	"RETURN e must terminate YIELD-unit or expression-refinement", "");
		if (resexp == Rep)
			pprerr(
	"REPORT t must terminate TEST-unit or test-refinement", "");
	}
}

Hidden bool expr_s() {
	char c;
	Skipsp(tx);
	if (tx >= ceol) return No;
	c= Char(tx);
	return Letter(c) || Montormark(c) || Dig(c) || c == '.' || c == 'E' ||
		c == '(' || c == '{' || c == '\'' || c == '"';
}

intlet comcnt= 0;

Visible Procedure command() {
	if (++comcnt > 10000) {
		putprmnv();
		comcnt= 1;
	}
	if (Char(tx) == Eotc) getline();
debug("analyzing command");
	if (tracing) trace();
	if (Ceol(tx));
	else if (sim_com() || con_com() ||
		unit() || term_com() || ref_com() || udc() ||
		secret_com()) skipping= No;
	else if (Char(tx) == ':' || Char(tx) == '=' || Char(tx) == '!') {
		if (!interactive) parerr("special commands only interactively", "");
		if (!(cntxt == In_command && cur_ilev == 0)) parerr(
			"special commands only on outermost level (no indentation)", "");
		special();
	} else if (cntxt == In_command && cur_ilev == 0 && expr_s()) {
		value w= expr(ceol);
		wri(w, Yes, No, No);
		release(w);
	} else {txptr tx0= tx; value uc= keyword(ceol);
		tx= tx0; parerr("you have not told me HOW'TO ", strval(uc));
	}
	To_eol(tx);
debug("command treated");
}

Visible Procedure comm_suite() {
	intlet cil= cur_ilev;
	if (ateol()) {
		txptr tx0= tx; bool xeq0= xeq;
		if (Char(tx+1) == Eotc) xeq= No;
		while (ilev(No) > cil) {
			findceol();
			command();
			if (terminated) return;
			if (cur_ilev <= cil) goto brk1;
		}
		veli();
	brk1:	if (xeq0 && !xeq) {
			tx= tx0; xeq= Yes;
			cur_ilev= cil;
			while (ilev(No) > cil) {
				findceol();
				command();
				if (terminated) return;
				if (cur_ilev <= cil) goto brk2;
			}
			veli();
		brk2:	;
		}
	} else command();
}

Hidden Procedure alt_suite() {
	intlet cil= cur_ilev; env e0= curnv; txptr utx, vtx;
	bool xeq0= xeq, succ= !xeq, Else= No;
	if (!ateol()) syserr("alt_suite not at end of line");
	while (ilev(No) > cil) {
		findceol();
		if (Else)
		parerr("after ELSE: ... no more alternatives are allowed", "");
		req(":", ceol, &utx, &vtx);
		if (atkw(ELSE)) {
			succ= Else= Yes;
			upto(utx, "ELSE");
			tx= vtx; comm_suite();
			if (terminated) return;
		} else {
			if (xeq) succ= test(utx) == Succ;
			xeq= xeq && succ;
			tx= vtx; comm_suite();
			if (terminated) return;
			xeq= !succ;
		}
		if (cur_ilev <= cil) goto brk;
	}
	veli();
brk:	if (!succ) error("none of the alternative tests of SELECT succeeds");
	xeq= xeq0; if (xeq) restore_env(e0);
}

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