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FAQ

⇐ 12345678910 ⇒



, , SPL. , SPL . SPL , , ( SPL) , , . , SPL , . . , , .

, : , , . , , , . get (), lex. , , , lex lx. exam (). lex lx ( get ()). . exam () .

void exam (int lx)

{

if (lex!=lx)

{

printf ( lex=%i lx=%i nst=%i \n, lex, lx, nst);

exit (1);

}

get ();

return;

}

part2.c , , . part1.c. . main() get(); prog();

get().

while (nch!=EOF)

{

}

if (nch = = EOF)

{

lex = EOF;

return;

}

, get() .

, part2. c part1.c , . , , . , . PROG.

1) PROG → (DCONST |DVARB |DFUNK) * eof

void prog()

{

while (lex!=EOF)

{

switch (lex)

{

case IDEN: dfunc(); break;

case INTL: dvarb(); break;

case CONSTL: dconst(); break;

default: printf( nst=%i. lex=%i \n, nst, lex);

}

}

 

return;

}

, lex!=EOF, lex. lex IDEN, , INTL CONSTL . , : dfunc(), dvarb(), dconst().

 

2) DCONST → constl CONS (, CONS)* ;

 

void dconst()

{

//

// , get();

do

{

get();

cons();

} while (lex = = ,);

exam (;);

return;

}

, constl. , lex constl, prog(). switch (lex) case CONSL dconst(). , CONS, (). , constl . . dconstl - ( get()),

cons(), CONS. lex = =,. , lex==;. exam (;). , exam() get() , , , .

 

 

3) CONS → iden = [ + | - ] numb

 

 

//

void cons()

{

exam (IDEN);

exam (=);

if (lex = = + || lex = = -)

get();

exam (NUMB);

return;

}

, , lex , . exam(). .. , IDEN, =. + - NUNB.

 

4) DVARB → intl iden (, iden) * ;

 

 

// . INTL prog() // switch (lex). dvarb().

void dvarb()

{

do

{

get();

exam(IDEN);

} while(lex = = ,);

exam(;);

return;

}

get(). , IDEN. exam() get(). , do while get() exam(IDEN). , ,, ;.

 

5) DFUNC → iden PARAM BODY

 

 

 

 

// IDEN prog() switch(lex). // get() .

void dfunc()

{

get(); //

param();

body();

return;

}

 

6) PARAM → ( [ iden (, iden) *] )

 

param() dfunc() get(). , .

void param()

{

exam (();

if (lex!=))

{

exan (IDEN);

while (lex = =,)

{

get();

exam (IDEN);

}

}

exam ());

return;

}

, (. exam((). ()). exam() get() . ), IDEN. -, IDEN ,, exam (IDEN). ) .

 

7) BODY → beginl (DCONST |DVARB) * STML endl

 

 

bdy() dfunc() param(). param() exam()). , get(), . BEGINL.

void body()

{

exam (BEGINL);

while(lex = = INTL || lex = = CONSTL)

if (lex = = INTL) dvarb();

else

dconst();

stml();

exam(ENDL);

return;

}

8

 

8) STML → STAT (; STAT)*

 

 

stml() dconst(). exam(;). get(), .

 

void stml()

{

stat();

while (lex = = ;)

{

get();

stat();

}

return;

}

 

9) STAT → iden = EXPR | readl iden | pritl EXPR | retrl EXPR | ifl EXPR thenl STML endl | whilel EXPR dol STML endl

 

 

 

stat() . switch (lex).

void stat()

{

switch (lex)

{

case IDEN: get(); exam (=); expr(); break;

case READL: get(); exam (IDEN); break;

case PRITL: get(); expr(); break;

case RETRL: get(); expr(); break;

case IFL: get(); expr(); exam(THENL); stml(); exam(ENDL); break;

case WHILEL: get(); expr(); exam(DOL); stml(); exam(ENDL); break;

default: printf(. stat nst=%i \n, nst);

}

return;

}

 

10) EXPR → [+|-] TERM ((+|-)TERM)*

 

 

 

//

void expr()

{

if (lex = = + || lex = = -)

get();

term();

while (lex = = + || lex = = -)

{

get();

term();

}

return;

}

 

11)TERM→FACT ((*|/| %)FACT)*

 

 

//

void term();

{

fact();

while(lex = =*||lex = =/||lex = = %)

{

get();

fact();

}

return;

}

 

12) FACT →(EXPR)|numb| iden [([FCTL])]

 

 

void fact()

{

switch(lex)

{

case (: get(); expr();exam()); break;

case NUMB: get(); break;

case IDEN: get(); if(lex = =()

{

get();

if(lex!=))

fctl ();

exam());

}

break;

default: printf ( fact. lex =%d

nst=%d \n,lex, nst);

}

return;

}

 

fact() get(). , . . get(), . .

 

13)FTCL →EXPR(,EXPR)*

 

 

 

//

void fctl()

{

expr();

while(lex = = ,)

{

get();

expr();

}

return;

}

 

9

, SPL - , . .

 

typedef struct

{

int cod;

int opd;

}

cmd;

(int cod) (int opd). , , .

,

cmd TCD[300];

, ,

int st[500]. st[0], st[1], st[2] . . .

int cgv = 0;

Ÿ . main().

- . : () (). main() - -2 -1. main(). main() , main(), . 1, 2 , n, - n, , ( ) , .

. .

: t- (top);

sp - ( ).

sp. st[sp+k], k - ( sp). k<0 - (n+2), , -4,-3.

n .

st[sp-2]- .

st[sp-1]- , st[sp] .

k>0.

 

.

a(x,y,z)

begin

int v,w

end

: x- - (3+2)=-5

y- =-4

z- =-3

v- =1

w- =2

 

, x,y,z,v,w st[sp-5], st[sp-4], st[sp-3], st[sp+1], st[sp+2].

 

 

char TNM [400]

cmd TCD [300]. , int tc=0; tc =0. TCD.

, . - , .

 

.

typedef struct

{

char * name;

int what;

int val;

}

odc;

, TNM.

int what :

1- ;

2- ;

3- - ;

int val k .

odc TOB [100].

pto . TOB.

odc *pto = TOB;

odc *ptol - . TOB.

odc *ptol = TOB;

TOB int out =1. . out =1, , out =0, .

 

 

.

typedef struct

{

char*name

int isd;

int cpt;

int start;

}

fnd;

 

fnd TFN[30]. ptf . .

fnd *ptf=TFN.

- , TNM.

TFN[i].isd , . , TFN[i].isd=1, - . TFN[i].start - .

TFN[i].cpt .

 

10

 

, , .

.. , . , . .

TOB, TFN TCD, . .

 

/*newob - TOB */

void newob(char*nm, int wt, int vl)

{

odc*p,*pe;

pe=out? TOB: ptol;

for(p=pto-1: p>=pe; p - -)

if(strcmp(nm,p→name)= =0)

{

puts( );

exit(1);

}

if(pto>= TOB+100)

{

puts( ”);

exit(1);

}

p→name = nm;

p→what=wt;

p→val=vl;

pto++;

return;

}

out=1, , , out=0, . p>=TOB p>=ptol. , ptol - . , nm , . pto . , , .

/* findob() TOB */

odc *findob(char*nm)

{

odc*p;

for(p=pto-1: p>=TOB; p - -)

if(strcmp(nm,p→name)= =0)

return p;

printf( %s \n, nm);

exit(1);

return p;

}

, , . return p; , - .

 

 

TFN

fnd*newfn(char*nm, int df, int cp, int ps)

{

if(ptf>=TFN+30)

{

puts( TFN);

exit(1);

}

ptf→name = nm;

ptf→isd=df;

ptf→cpt=cp;

ptf→start=ps;

return ptf + +;

}

, ptf fnd TFN[30]. , TFN . , ptf .

 

TFN

fnd*findfn(char*nm)

{

fnd*p;

for(p=ptf-1: p>=TFN; p - -)

if(strcmp(nm,p→name)= =0)

return p;

return NULL;

}

TFN char*nm. , , fnd*p. - .

 

fnd*eval(char*nm, int cp)

. findfn() , . , newfn(nm,0,cp,-1). , . , , TFN. - .

 

fnd*eval(char*nm, int cp)

{

fnd*p;

if(!p=findfn(nm))

return newfn(nm,0,cp,-1);

if(p→cpt= =cp)

return p;

printf( %s \n, nm);

exit(1);

return p;

}

exit(1) return p , - .

 

void defin(char*nm, int cp, int ad)

{

fnd*p;

int c1,c2;

p=findfn(nm);

if(p)

{

if(p→isd)

{

printf( %s \n,nm);

exit(1);

}

if(p→cpt!=cp)

{

printf( %s \n,nm);

exit(1);

}

p→isd=1;

for(c1=p→start;c1!=-1;c1=c2)

{

c2=TCD[c1].opd;

TCD[c1].opd=ad;

}

p→start=ad;

}// if(p)

else

newfn(nm,1,cp,ad);

return;

}

nm, cp, ad , .

nm TFN. , , . , p→isd=1. , . , TFN[i].start , ,, . 3 , SUM, n .

 

TNM

 

3

 

defin() for(). p→start TCD, . g en(CAL, p→start).

1. , 1≠-1 . p→start=ad.

, findfn(nm) TFN nm, newfn(nm,1,cp,ad). TFN , .

 

main()

 

fnd*fmain()

{

static har nm[]=main;

fnd*pm=NULL;

fnd*p;

for(p=ptf-1;p>=TFN; p - -)

{

if(!p→isd)

{

printf( %s \n, p→name);

exit(1);

}

if(strcmp(nm, p → name)= = 0)

pm=p;

}// for()

if(pm)

return pm;

puts( main);

exit(1);

return pm;

}

 

r eturn pm; exit(1) , . main() , e xit(1); return pm; .

 

11

SPL

 

, , SPL , TCD. . - . 10 . . . - . . , .

enum{OPR,LIT,LDE,LDI,STE,STI,CAL,INI,JMC, JMP};

, OPR .

LIT -, LDE - . .

 

OPR .

1) OPR 1 - stdin ( ).

OPR 2 - ( stdout).

OPR 3, OPR 4, OPR 5, OPR 6, OPR 7 - +, -,*, /, % . t-1, - t. .

OPR 8 - .

OPR 9 - (return). , . main(), p=-1, . .

OPR 10 .

2) LIT - t.

3) LDE - . - .

4) LDI - .

5) STE - , . , , st [a], .

6) STI - , . st[sp+a], sp- , .

7) CAL - TCD.

8) INI ( ).

9) JMC - TCD.

10) JMP - .

, . - . , .

 

SPL

 

, , TFN, TCD.

TNM .

TCD , +b < ><b>+.

val {LIT val}. d {LDE a} {LDI a}. , t.

f(e1,e2,en) TCD <e1><e2><en> {LIT n } {CAL a}, <ei> - ei. {LIT n } . <e>{OPR 8}.

e1 e2 < e1>< e2>{OPR }, =3,4,5,6,7 +,-, *, /, %. e1. - e2. e1 t -1. {OPR }.

SPL d e, d , , <e>{STE a}. <e>{STI a}.

read d {OPR 1}{STE a } d {OPR 1}{STI a} . - .

print e, return e d <e>{OPR 2},<e>{OPR 9 }. e, t, .

if e then s end e . , s , then end. if . ≤0, . TCD <e>{JMC l} <s> l, l- s TCD.

 

while e do s end lb:<e>{JMC l}<s>{JMP lb} l. lb - TCD, . l - TCD, {JMP lb}. . , s , do end. lb TCD. .. ≤0, l TCD ( .)

, . SPL

f()

begin

;

end

a:{ INI m} <s> {OPR 10}

a - ( TCD );

m - .

s - , begin and.

. SPL

 

main(x,y)

begin

int c;

read c;

c=x-y/c;

if c then return c

end

 

, .

main() x y .

n.

x (n+2)=-4. y -3. 1.

, x,y, c st[sp-4], st[sp-3], st[sp+1].

, .

TCD
  INI 1
  OPR 1 stdin (stdin→t)
  STI 1 c=t.
  LDI -4 x
  LDL -3 y t. x t -1
  LDI 1 c t, x t -2, y - t -1
  OPR 6 y c, t
  OPR 4 x-y/c. t
  STI 1 t
  LDI 1 c=x-y/c. c . , .
  JMC 13 ≤0, 13. - , .. 11
  LDI 1 , .. t
  OPR 9 return. main(). - t
  OPR 10

 

, TCD cmd TCD [300].

( ) ( ). , TCD .

 

i TCD[i].cod TCD[i].opd
     
     
     
    -4
    -3
     
     
     
     
     
     
     
     
     

 

, , SPL.

 

12

 

body(), stat(), expr(), term(), fact(). gen()/.

:

int cgv=0, clv=0; //

int tc=0; // , TCD

int out=1 // out=1, . out=0, -

 

 

int gen(int co, int op)

{

if (tc>=300)

{

puts( TCD);

exit(1);

}

TCD[tc].cod=co;

TCD[tc].opd=op;

return tc + +;

}

return tc + +. TCD, .

 

 

body()

 

int body()

{

int st; //

exam(BEGINL);

clv=0;// .

while(lex = = INTL|| lex = = CONSTL)

if (lex = = CONSTL)

dconst();

else

dvarb();// clv

st = gen(INI, clv); // TCD

stml();

exam(ENDL);

gen(OPR, 10); //

return st;// .

}

body() gen() TCD .

 

stat()

 

void stat()

{

int t1, t2;

odc*p;

switch(lex)

{

case IDEN: p= findob((char*)lval); get();

exam(=); expr();

if(p→what = =1);

{

printf(%s- . \n,p→name);

exit(1)

}

gen (p->what == 2? STE: STI, p->val); break;

case READL:

get(); p = findob ((char *)lval); gen (OPR, 1);

if (p->what == 1)

{

printf ("%s \n", p->name);

exit(1);

}

gen (p->what == 2? STE: STI, p->val);

exam (IDEN); break;

case IFL:

get(); expr(); exam (THENL);

t1 = gen (JMC, 0); stml(); exam (ENDL);

TCD[t1].opd = tc; break;

case WHILEL:

get(); t1 = tc; expr();

exam (DOL); t2 = gen (JMC, 0); stml();

gen (JMP, t1); TCD[t2].opd = tc;

exam (ENDL); break;

case PRITL:

get(); expr(); gen (OPR, 2); break;

case RETRL:

get(); expr(); gen (OPR, 9); break;

default:

printf( lex=%i nst=%i \n, lex, nst);

}

return;

}

 

 

case IDEN TOB (char*) lval. , lval - . , TNM. int lval (char*,) findob(char*name) char*. odc*p. →what 1, , , . xit(1) . →what 2, . gen (ST, p->val).

gen (STI, p->val). , p->val . , c 1. c gen (STI, 1).

case READL , TCD

OPR 1 stdin, , . - .

case IFL (get()) expr() thenl. t1 tc TCD, gen (JMC,0)- 0 TCD. stml() TCD . , tc. tc , t1 TCD

TCD[t1].opd=tc.

case WHILEL. get() TCD, . , :

lb:<e>{JMC l}<s>{JMP lb} l.

t1=tc lb <e>.

t2=gen(JMC,0) - JMC0 TCD. <s>, stml(), (JMP,t1)- , <e> . case IFL, TCD[t2].opd=tc (JMC,0) (JMC,tc).

 

13

expr ()

 

void expr ()

{

int neg = (lex == ' - ');

if (lex == '+' || lex == '-')

get();

term();

if (neg)

gen (OPR, 8);

while (lex == '+' || lex == '-')

{

neg = (lex == ' - '? 4: 3);

get();

term();

gen (OPR, neg);

}

return;

}

expr () lex -, .. 1. OPR 8 .

g + - OPR 3 OPR 4.

 

term()

void term ()

{

int op;

fact();

while (lex == '*' || lex == '/' || lex == '%')

{

op = (lex == '*'? 5: (lex == '/'? 6: 7));

get();

fact();

gen (OPR, op);

}

return;

}

op 5 6, 7 . OPR 5 OPR 6, OPR 7.

 

fact()

void fact ()

{

char *nm;

int cp; //

odc *p;

fnd *p1;

switch (lex)

{

 

case IDEN: nm = (char *)lval; get();

if (lex == '(')

{

get();

cp = (lex == ')'? 0: fctl()); // FCTL

exam(')');

p1 = eval (nm, cp); // nm cp

gen (LIT, cp);//

cp = gen (CAL, p1->start); // TCD

if (!p1->isd)

p1->start = cp;/* , p1->start TCD */

}

else

{

p = findob (nm);

gen (p->what == 1? LIT: (p->what == 2? LDE: LDI), p->val);

}

break;

case '(': get(); expr(); exam(')');

break;

case NUMB: gen (LIT, lval); get();

break;

default: printf (" fact() lex=%i nst=%i \n", lex, nst);

exit(1);

}

return;

}

 

case IDEN. , , , .

.

, . , {LIT, lval},{LDE, lval} {LDI, lval } , , .

 

fctl()

int fctl ()

{

int cf = 1; // , .

expr();

while (lex == ',')

{

get();

expr();

cf++;

}

return cf;

}

fctl() , cf.

 

14

 

, TFN.

 

 

newob(). cons(), dvarb(), param(). newob() exam(IDEN) exam(NUMB) get().

 

cons()

void cons ()

{

char *nm = (char *)lval; //

int s;

exam (IDEN);

exam('=');

s = (lex == '-'? -1: 1);

if (lex == '-' || lex == '+')

get();

newob (nm, 1, s*lval); // .

exam (NUMB);

return;

}

 

 

dvarb()

 

void dvarb ()

{

do

{

get();

newob ((char *)lval, (out? 2: 3), (out? cgv++: ++clv));

exam (IDEN);

} while (lex == ',');

exam (';');

return;

}

out , . , odc what 2, val ( )- cgv+ +. - what 3, val - + +clv. , . int cgv=0 . st[0]. cgv 1 , st[1] ..

.

clv , , clv (++clv).

out , dfunc() out=0, out=1.

dfunc()

void dfunc ()

{

int cp; //

int st; //

char *nm = (char *)lval; //

get();

out = 0; // ,

cp = param(); //

st = body(); //

out = 1; // out.

ptol = pto; // ,

defin (nm, cp, st); //

return;

}

 

param ()

 

int param ()

{

odc *p;

int cp = 0; //

exam('(');

if (lex!= ')')

{

newob ((char *)lval, 3, ++cp);

exam (IDEN);

while (lex == ',')

{

get();

newob ((char *)lval, 3, ++cp);

exam (IDEN);

}

}

exam (')');

for (p = ptol; p < pto; p++)

p->val -= cp+3;

return cp;

}

 

ptol . ptol pto- . ( : ). for(), p→val +3. , f(x,y,z) . for x 1, y 2, z 3. for() x -5, y - -4,

z --3.

 

prog()

SPL , main(). SPL. , , ( TCD) . :

 

int adrnm; // main()

int cpnm; // main()

 

prog()

 

void prog ()

{

fnd *p;

while (lex!= EOF)

switch (lex)

{

case CONSTL: dconst(); break;

case INTL: dvarb(); break;

case IDEN: dfunc(); break;

default: printf ( prog lex=%i

nst=%i\n,lex, nst);

}

p = fmain();

adrnm = p->start;// main() TCD

cpnm = p->cpt;/ main()

return;

}

, fmain() .

 

  ,
  newob(char*nm, int wt, int vl) cons(), dvarb(), param()
  findob(char*nm) stat(), fact
  newfn(char*nm, int df, int cp, int ps) eval(char*nm, int cp); define(char*nm, int cp, int ad)
  findfn(char*nm) eval(char*nm, int cp); defin(char*nm, int cp, int ad)
  eval(char*nm, int cp) fact()
  defin(char*nm, int cp, int ad) dfunc()
  fmain() prog()

 

 

15

SPL-

:

int t; //st[t]- ;

int sp; //st[sp]- ;

int p; // , TCD.

main() get();, prog(); interp();. interp(); SPL - , TC D. : comman()- , TCD[p], - ;

operat(a)- OPR a;

push(a)- ;

reader()- (stdin→t).

 

interp()

void interp ()

{

int i;

t = -1; /* st[t] -1, push() st[+ +t]= st[0] */

puts(SPL- \n);

for (i = 0; i < cgv; i++)

push(0); /* ,

cqv ,

*/

 

if (cpnm)

{

printf ("%d>", cpnm);

fflush (stdin);

for (i = 0; i < cpnm; i++)

push (reader());

}/* cpnm main() ,

for() */

push (cpnm); /* main()*/

push(-2);/* =-2 */

push(-1);/* = -1 - st[t]*/

sp = t; /* t.

sp - */

p = adrnm; /* ( )

main() .

,

TCD* /

 

do

{

comman(); // TCD[p]

p++; //

} while (p >= 0);

if (p == -1)

printf ("%d\n", st[t]);/* <0 = = -1,

st[t]*/

return;

}

void comman ()

{

int a = TCD[p].opd; //

 

switch (TCD[p].cod)

{

case OPR: operat(a); break;

case LIT: push(a); break;//{LIT a}

case LDE: push(st[a]); break;//{LDE a}

case LDI: push(st[sp+a]); break;//{LDI a}

case STE: st[a] = st[t--]; break; /* , st[a] t, t */

case STI: st[sp+a] = st[t--]; break;

case CAL: push(p); push(sp);sp = t; p = a-1; break;/* p sp. sp=t. . -1. interp()

+ +. . , {CAL a }*/

case INI: for (i =0; i<a; i++)

push(0); /* . */

break;

case JMP: p = a-1;

break;/* TCD, */

case JMC: if (st[t--] <= 0)

p = a-1;/* ≤0, -1. , t , */

}

return;

}

 

void operat (int a)

{

int j = t-1;

switch (a)

{

case 1: printf ("1>");

fflush (stdin);

push (reader()); /* */

break;

case 2: printf ("%d\n", st[t--]); break;

case 3: st[j] += st[t--]; break; /* t=10, j=10-1=9 st[9]=st[9]+ st[10]. <

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