parser.c

一个词法分析器程序

      break;
   case L_MATH:
      v[vsp].a.l.x = v[vsp].a.l.y = 0;
      break;
   }
#endif

   if(isdigit(Str[0])
       || (Str[0] == '-' && (isdigit(Str[1]) || Str[1] == '.'))
       || Str[0] == '.') {
      if(o[posp-1].f == StkNeg) {
         posp--;
         Str = Str - 1;
         InitN--;
         v[vsp].len++;
      }
      for(n = 1; isdigit(Str[n]) || Str[n] == '.'; n++);
      if(Str[n] == ',') {
         j = n + SkipWhiteSpace(&Str[n+1]) + 1;
         if(isdigit(Str[j])
             || (Str[j] == '-' && (isdigit(Str[j+1]) || Str[j+1] == '.'))
             || Str[j] == '.') {
            z.y = atof(&Str[j]);
            for(; isdigit(Str[j]) || Str[j] == '.' || Str[j] == '-'; j++);
            v[vsp].len = j;
         }
         else
            z.y = 0.0;
      }
      else
         z.y = 0.0;
      z.x = atof(Str);
      switch(MathType) {
      case D_MATH:
         v[vsp].a.d = z;
         break;
#ifndef XFRACT
      case M_MATH:
         v[vsp].a.m = cmplx2MPC(z);
         break;
      case L_MATH:
         v[vsp].a.l.x = (long)(z.x * fg);
         v[vsp].a.l.y = (long)(z.y * fg);
         break;
#endif
      }
      v[vsp].s = Str;
   }
   return(&v[vsp++]);
}


struct FNCT_LIST {
   char far *s;              /* TIW 03-31-91 added far */
   void (**ptr)(void);
};

/* TIW 03-30-91 START */
void (*StkTrig0)(void) = dStkSin;
void (*StkTrig1)(void) = dStkSqr;
void (*StkTrig2)(void) = dStkSinh;
void (*StkTrig3)(void) = dStkCosh;

char maxfn = 0;
/* TIW 03-30-91 STOP */

struct FNCT_LIST far FnctList[] = {   /* TIW 03-31-91 added far */
   s_sin,   &StkSin,
   s_sinh,  &StkSinh,
   s_cos,   &StkCos,
   s_cosh,  &StkCosh,
   s_sqr,   &StkSqr,
   s_log,   &StkLog,
   s_exp,   &StkExp,
   s_abs,   &StkAbs,
   s_conj,  &StkConj,
   s_real,  &StkReal,
   s_imag,  &StkImag,
   s_fn1,   &StkTrig0,   /* TIW 03-30-91 */
   s_fn2,   &StkTrig1,   /* TIW 03-30-91 */
   s_fn3,   &StkTrig2,   /* TIW 03-30-91 */
   s_fn4,   &StkTrig3,   /* TIW 03-30-91 */
   s_flip,  &StkFlip,    /* MCP 4-9-91 */
   s_tan,   &StkTan,     /* TIW 04-22-91 */
   s_tanh,  &StkTanh,    /* TIW 04-22-91 */
   s_cotan, &StkCoTan,   /* TIW 04-24-91 */
   s_cotanh,&StkCoTanh,  /* TIW 04-24-91 */
   s_cosxx, &StkCosXX,   /* PB  04-28-91 */
   s_srand, &StkSRand,   /* MCP 11-21-91 */
   s_asin,  &StkASin,    /* TIW 11-26-94 */
   s_asinh, &StkASinh,   /* TIW 11-26-94 */
   s_acos,  &StkACos,    /* TIW 11-26-94 */
   s_acosh, &StkACosh,   /* TIW 11-26-94 */
   s_atan,  &StkATan,    /* TIW 11-26-94 */
   s_atanh, &StkATanh,   /* TIW 11-26-94 */
   s_sqrt,  &StkSqrt,    /* TIW 11-26-94 */
   s_cabs,  &StkCAbs,    /* TIW 11-26-94 */
   s_floor, &StkFloor,   /* TIW 06-30-96 */
   s_ceil,  &StkCeil,    /* TIW 06-30-96 */
   s_trunc, &StkTrunc,   /* TIW 06-30-96 */
   s_round, &StkRound,   /* TIW 06-30-96 */
};

void NotAFnct(void) { }
void FnctNotFound(void) { }

/* determine if s names a function and if so which one */
/* TIW 04-22-91 */
whichfn(char *s, int len)
{
   int out;
   if(len != 3)
      out = 0;
   else if(strnicmp(s,"fn",2))
      out = 0;
   else
      out = atoi(s+2);
   if(out < 1 || out > 4)
      out = 0;
   return(out);
}

#ifndef XFRACT
void (far *isfunct(char *Str, int Len))(void)
#else
void (*isfunct(Str, Len))()
char *Str;
int Len;
#endif
{
   unsigned n;
   int functnum;    /* TIW 04-22-91 */

   n = SkipWhiteSpace(&Str[Len]);
   if(Str[Len+n] == '(') {
      for(n = 0; n < sizeof(FnctList) / sizeof(struct FNCT_LIST); n++) {
         if(far_strlen(FnctList[n].s) == Len) {        /* TIW 03-31-91 added far */
            if(!far_strnicmp(FnctList[n].s, Str, Len)) {  /* TIW 03-31-91 added far */
               /* count function variables */
               if((functnum = whichfn(Str, Len)) != 0)    /* TIW 04-22-91 */
                  if(functnum > maxfn)                  /* TIW 04-22-91 */
                     maxfn = (char)functnum;                  /* TIW 04-22-91 */
               return(*FnctList[n].ptr);
            }
         }
      }
      return(FnctNotFound);
   }
   return(NotAFnct);
}

void RecSortPrec(void) {
   int ThisOp = NextOp++;

   while(o[ThisOp].p > o[NextOp].p && NextOp < posp)
      RecSortPrec();
   f[OpPtr++] = o[ThisOp].f;
}

static char *Constants[] = {
   "pixel",        /* v[0] */
   "p1",           /* v[1] */
   "p2",           /* v[2] */
   "z",            /* v[3] */
   "LastSqr",      /* v[4] */
   "pi",           /* v[5] */
   "e",            /* v[6] */
   "rand",         /* v[7] */
   "p3",           /* v[8] */
   "whitesq",      /* v[9] */
   "scrnpix",      /* v[10] */
   "scrnmax",      /* v[11] */
   "maxit",        /* v[12] */
};

struct SYMETRY {
   char *s;
   int n;
} SymStr[] = {
   "NOSYM",         0,
   "XAXIS_NOPARM", -1,
   "XAXIS",         1,
   "YAXIS_NOPARM", -2,
   "YAXIS",         2,
   "XYAXIS_NOPARM",-3,
   "XYAXIS",        3,
   "ORIGIN_NOPARM",-4,
   "ORIGIN",        4,
   "PI_SYM_NOPARM",-5,
   "PI_SYM",        5,
   "XAXIS_NOIMAG", -6,
   "XAXIS_NOREAL",  6,
   "NOPLOT",       99,
   "", 0
};

static int ParseStr(char *Str, int pass) {
   struct ConstArg far *c;
   int ModFlag = 999, Len, Equals = 0, Mod[20], mdstk = 0;
   int NewStatement;
   struct ERROR { int n, s; } far *e;
   double const_pi, const_e;

   SetRandom = Randomized = 0;
   e = (struct ERROR far *)farmemalloc(sizeof(struct ERROR) * 100L);
   /* PB 910417 changed "o" to be a temporary alloc, during ParseStr only */
   if(pass == 0)
      o = (struct PEND_OP far *)
         ((char far *)typespecific_workarea + total_formula_mem-sizeof(struct PEND_OP) * Max_Ops);
   else if(used_extra == 1)
      o = (struct PEND_OP far *)
         ((char far *)typespecific_workarea + total_formula_mem-sizeof(struct PEND_OP) * Max_Ops);
   else
      o = (struct PEND_OP far *)farmemalloc(sizeof(struct PEND_OP) * (long)Max_Ops);
   if(!e || !o || !typespecific_workarea) {
      stopmsg(0,ParseErrs(INSUFFICIENT_MEM_FOR_TYPE_FORMULA));
      return(1);
   }
   switch(MathType) {
   case D_MATH:
      StkAdd = dStkAdd;
      StkSub = dStkSub;
      StkNeg = dStkNeg;
      StkMul = dStkMul;
      StkSin = dStkSin;
      StkSinh = dStkSinh;
      StkLT = dStkLT;
      StkLTE = dStkLTE;
      StkMod = dStkMod;
      StkSqr = dStkSqr;
      StkCos = dStkCos;
      StkCosh = dStkCosh;
      StkLog = dStkLog;
      StkExp = dStkExp;
      StkPwr = dStkPwr;
      StkDiv = dStkDiv;
      StkAbs = dStkAbs;
      StkReal = dStkReal;
      StkImag = dStkImag;
      StkConj = dStkConj;
      StkTrig0 = dtrig0;   /* TIW 03-30-91 */
      StkTrig1 = dtrig1;   /* TIW 03-30-91 */
      StkTrig2 = dtrig2;   /* TIW 03-30-91 */
      StkTrig3 = dtrig3;   /* TIW 03-30-91 */
      StkFlip = dStkFlip;
      StkTan = dStkTan;    /* TIW 04-22-91 */
      StkTanh = dStkTanh;  /* TIW 04-22-91 */
      StkCoTan = dStkCoTan;    /* TIW 04-24-91 */
      StkCoTanh = dStkCoTanh;  /* TIW 04-24-91 */
      StkCosXX = dStkCosXX;    /* PB  04-28-91 */
      StkGT  = dStkGT;         /* MCP 11-3-91 */
      StkGTE = dStkGTE;        /* MCP 11-3-91 */
      StkEQ  = dStkEQ;         /* MCP 11-3-91 */
      StkNE  = dStkNE;         /* MCP 11-3-91 */
      StkAND = dStkAND;        /* MCP 11-3-91 */
      StkOR  = dStkOR ;        /* MCP 11-3-91 */
      StkSRand = dStkSRand;    /* MCP 11-21-91 */
      StkASin = dStkASin;      /* TIW 11-25-94 */
      StkASinh = dStkASinh;    /* TIW 11-25-94 */
      StkACos = dStkACos;      /* TIW 11-25-94 */
      StkACosh = dStkACosh;    /* TIW 11-25-94 */
      StkATan = dStkATan;      /* TIW 11-25-94 */
      StkATanh = dStkATanh;    /* TIW 11-25-94 */
      StkCAbs = dStkCAbs;      /* TIW 11-25-94 */
      StkSqrt = dStkSqrt;      /* TIW 11-25-94 */
      StkZero = dStkZero;      /* JCO 12-31-94 */
      StkFloor = dStkFloor;    /* TIW 06-30-96 */
      StkCeil = dStkCeil;      /* TIW 06-30-96 */
      StkTrunc = dStkTrunc;    /* TIW 06-30-96 */
      StkRound = dStkRound;    /* TIW 06-30-96 */
      break;
#ifndef XFRACT
   case M_MATH:
      StkAdd = mStkAdd;
      StkSub = mStkSub;
      StkNeg = mStkNeg;
      StkMul = mStkMul;
      StkSin = mStkSin;
      StkSinh = mStkSinh;
      StkLT = mStkLT;
      StkLTE = mStkLTE;
      StkMod = mStkMod;
      StkSqr = mStkSqr;
      StkCos = mStkCos;
      StkCosh = mStkCosh;
      StkLog = mStkLog;
      StkExp = mStkExp;
      StkPwr = mStkPwr;
      StkDiv = mStkDiv;
      StkAbs = mStkAbs;
      StkReal = mStkReal;
      StkImag = mStkImag;
      StkConj = mStkConj;
      StkTrig0 = mtrig0;  /* TIW 03-30-91 */
      StkTrig1 = mtrig1;  /* TIW 03-30-91 */
      StkTrig2 = mtrig2;  /* TIW 03-30-91 */
      StkTrig3 = mtrig3;  /* TIW 03-30-91 */
      StkFlip = mStkFlip;
      StkTan  = mStkTan;  /* TIW 04-22-91 */
      StkTanh  = mStkTanh;/* TIW 04-22-91 */
      StkCoTan  = mStkCoTan;  /* TIW 04-24-91 */
      StkCoTanh  = mStkCoTanh;/* TIW 04-24-91 */
      StkCosXX = mStkCosXX;   /* PB  04-28-91 */
      StkGT  = mStkGT;         /* MCP 11-3-91 */
      StkGTE = mStkGTE;        /* MCP 11-3-91 */
      StkEQ  = mStkEQ;         /* MCP 11-3-91 */
      StkNE  = mStkNE;         /* MCP 11-3-91 */
      StkAND = mStkAND;        /* MCP 11-3-91 */
      StkOR  = mStkOR ;        /* MCP 11-3-91 */
      StkSRand = mStkSRand;    /* MCP 11-21-91 */
      StkASin = mStkASin;      /* TIW 11-25-94 */
      StkACos = mStkACos;      /* TIW 11-25-94 */
      StkACosh = mStkACosh;    /* TIW 11-25-94 */
      StkATan = mStkATan;      /* TIW 11-25-94 */
      StkATanh = mStkATanh;    /* TIW 11-25-94 */
      StkCAbs = mStkCAbs;      /* TIW 11-25-94 */
      StkSqrt = mStkSqrt;      /* TIW 11-25-94 */
      StkZero = mStkZero;      /* JCO 12-31-94 */
      StkFloor = mStkFloor;    /* TIW 06-30-96 */
      StkCeil = mStkCeil;      /* TIW 06-30-96 */
      StkTrunc = mStkTrunc;    /* TIW 06-30-96 */
      StkRound = mStkRound;    /* TIW 06-30-96 */
      break;
   case L_MATH:
      Delta16 = bitshift - 16;
      ShiftBack = 32 - bitshift; /* TW 06-18-90 */
      StkAdd = lStkAdd;
      StkSub = lStkSub;
      StkNeg = lStkNeg;
      StkMul = lStkMul;
      StkSin = lStkSin;
      StkSinh = lStkSinh;
      StkLT = lStkLT;
      StkLTE = lStkLTE;
    if (save_release > 1826)
        StkMod = lStkMod;
    else
        StkMod = lStkModOld;
      StkSqr = lStkSqr;
      StkCos = lStkCos;
      StkCosh = lStkCosh;
      StkLog = lStkLog;
      StkExp = lStkExp;
      StkPwr = lStkPwr;
      StkDiv = lStkDiv;
      StkAbs = lStkAbs;
      StkReal = lStkReal;
      StkImag = lStkImag;
      StkConj = lStkConj;
      StkTrig0 = ltrig0;   /* TIW 03-30-91 */
      StkTrig1 = ltrig1;   /* TIW 03-30-91 */
      StkTrig2 = ltrig2;   /* TIW 03-30-91 */
      StkTrig3 = ltrig3;   /* TIW 03-30-91 */
      StkFlip = lStkFlip;
      StkTan  = lStkTan;   /* TIW 04-22-91 */
      StkTanh  = lStkTanh; /* TIW 04-22-91 */
      StkCoTan  = lStkCoTan;   /* TIW 04-24-91 */
      StkCoTanh  = lStkCoTanh; /* TIW 04-24-91 */
      StkCosXX = lStkCosXX;    /* PB  04-28-91 */
      StkGT  = lStkGT;         /* MCP 11-3-91 */
      StkGTE = lStkGTE;        /* MCP 11-3-91 */
      StkEQ  = lStkEQ;         /* MCP 11-3-91 */
      StkNE  = lStkNE;         /* MCP 11-3-91 */
      StkAND = lStkAND;        /* MCP 11-3-91 */
      StkOR  = lStkOR ;        /* MCP 11-3-91 */
      StkSRand = lStkSRand;    /* MCP 11-21-91 */
      StkASin = lStkASin;      /* TIW 11-25-94 */
      StkACos = lStkACos;      /* TIW 11-25-94 */
      StkACosh = lStkACosh;    /* TIW 11-25-94 */
      StkATan = lStkATan;      /* TIW 11-25-94 */
      StkATanh = lStkATanh;    /* TIW 11-25-94 */
      StkCAbs = lStkCAbs;      /* TIW 11-25-94 */
      StkSqrt = lStkSqrt;      /* TIW 11-25-94 */
      StkZero = lStkZero;      /* JCO 12-31-94 */
      StkFloor = lStkFloor;    /* TIW 06-30-96 */
      StkCeil = lStkCeil;      /* TIW 06-30-96 */
      StkTrunc = lStkTrunc;    /* TIW 06-30-96 */
      StkRound = lStkRound;    /* TIW 06-30-96 */
      break;
#endif
   }
   maxfn = 0;   /* TIW 03-30-91 */
   for(vsp = 0; vsp < sizeof(Constants) / sizeof(char*); vsp++) {
      v[vsp].s = Constants[vsp];
      v[vsp].len = strlen(Constants[vsp]);
   }

   const_pi = atan(1.0) * 4;
   const_e  = exp(1.0);
   v[7].a.d.x = v[7].a.d.y = 0.0;
   v[11].a.d.x = (double)xdots;
   v[11].a.d.y = (double)ydots;
   v[12].a.d.x = (double)maxit;
   v[12].a.d.y = 0;

   switch(MathType) {
   case D_MATH:
      v[1].a.d.x = param[0];
      v[1].a.d.y = param[1];
      v[2].a.d.x = param[2];
      v[2].a.d.y = param[3];
      v[5].a.d.x = const_pi;
      v[5].a.d.y = 0.0;
      v[6].a.d.x = const_e;
      v[6].a.d.y = 0.0;
      v[8].a.d.x = param[4];
      v[8].a.d.y = param[5];
      break;
#ifndef XFRACT
   case M_MATH:
      v[1].a.m.x = *d2MP(param[0]);
      v[1].a.m.y = *d2MP(param[1]);
      v[2].a.m.x = *d2MP(param[2]);
      v[2].a.m.y = *d2MP(param[3]);
      v[5].a.m.x = *d2MP(const_pi);
      v[5].a.m.y = *d2MP(0.0);
      v[6].a.m.x = *d2MP(const_e);
      v[6].a.m.y = *d2MP(0.0);
      v[8].a.m.x = *d2MP(param[4]);
      v[8].a.m.y = *d2MP(param[5]);
      v[11].a.m  = cmplx2MPC(v[11].a.d);
      v[12].a.m  = cmplx2MPC(v[12].a.d);
      break;
   case L_MATH:
      v[1].a.l.x = (long)(param[0] * fg);
      v[1].a.l.y = (long)(param[1] * fg);
      v[2].a.l.x = (long)(param[2] * fg);
      v[2].a.l.y = (long)(param[3] * fg);
      v[5].a.l.x = (long)(const_pi * fg);
      v[5].a.l.y = 0L;
      v[6].a.l.x = (long)(const_e * fg);
      v[6].a.l.y = 0L;
      v[8].a.l.x = (long)(param[4] * fg);
      v[8].a.l.y = (long)(param[5] * fg);
      v[11].a.l.x = xdots; v[11].a.l.x <<= bitshift;
      v[11].a.l.y = ydots; v[11].a.l.y <<= bitshift;
      v[12].a.l.x = maxit; v[12].a.l.x <<= bitshift;
      v[12].a.l.y = 0L;
      break;
#endif
   }

   LastInitOp = ErrPtr = paren = OpPtr = LodPtr = StoPtr = posp = 0;
   NewStatement = 1;
   SyntaxErr = -1;
   ExpectingArg = 1;
   for(n = 0; Str[n]; n++) {
      if(!Str[n])
         break;
      InitN = n;
      switch(Str[n]) {
      case ' ':
      case '\t':
      case '\r':
      case '\n':
         break;
      case '(':
         paren++;
         if(!ExpectingArg)
            SyntaxErr = 1;
         break;
      case ')':
         if(paren)
            paren--;
         else
            SyntaxErr = 2;
         if(ExpectingArg) {
            e[ErrPtr].n = InitN;
            e[ErrPtr++].s = 0;
         }
         break;
      case '|':
         if(Str[n+1] == '|') {
            if(ExpectingArg)
               SyntaxErr = 0;
            ExpectingArg = 1;
            n++;
            o[posp].f = StkOR;
            o[posp++].p = 7 - (paren + Equals)*15;
         }
         else if(ModFlag == paren-1) {
            if(ExpectingArg)
               SyntaxErr = 0;
            paren--;
            ModFlag = Mod[--mdstk];
         }
         else {
            if(!ExpectingArg)
               SyntaxErr = 1;
            Mod[mdstk++] = ModFlag;
            o[posp].f = StkMod;
            o[posp++].p = 2 - (paren + Equals)*15;
            ModFlag = paren++;
         }
         break;
      case ',':
      case ';':
         if(paren) {
            e[ErrPtr].n = InitN;
            e[ErrPtr++].s = 3;
         }
         if(!ExpectingArg) {
            NewStatement = 1;
            ExpectingArg = 1;
            o[posp].f = (void(far*)(void))0;
            o[posp++].p = 15;
            o[posp].f = StkClr;
            o[posp++].p = -30000;
            Equals = paren = 0;
         }
         else if(!NewStatement)
            SyntaxErr = 0;
         break;
      case ':':
         if(paren) {
            e[ErrPtr].n = InitN;
            e[ErrPtr++].s = 3;
         }
         if(ExpectingArg)
            SyntaxErr = 0;
         else
            ExpectingArg = 1;