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Annotation of capa/capa51/pProj/capaFormulaLexer.c, revision 1.2

1.2     ! albertel    1: /* Lexer for formula answers
        !             2:    Copyright (C) 1992-2000 Michigan State University
        !             3: 
        !             4:    The CAPA system is free software; you can redistribute it and/or
        !             5:    modify it under the terms of the GNU Library General Public License as
        !             6:    published by the Free Software Foundation; either version 2 of the
        !             7:    License, or (at your option) any later version.
        !             8: 
        !             9:    The CAPA system is distributed in the hope that it will be useful,
        !            10:    but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            11:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
        !            12:    Library General Public License for more details.
        !            13: 
        !            14:    You should have received a copy of the GNU Library General Public
        !            15:    License along with the CAPA system; see the file COPYING.  If not,
        !            16:    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
        !            17:    Boston, MA 02111-1307, USA.  */
1.1       albertel   18: 
                     19: /* =========================================================== */
                     20: /*      capaFormulaLexer.c  created by Isaac Tsai @ Feb 1999   */
                     21: /* =========================================================== */
                     22: 
                     23: #include <ctype.h>    /* isspace() */
                     24: #include <stdio.h>    /* sscanf()  */
                     25: #include "capaParser.h"
1.2     ! albertel   26: #define YYSTYPE  Symbol_p
1.1       albertel   27: #include "capaFormula.h"
                     28: #include "capaToken.h"
                     29: 
                     30: /* ---------------  Global variables ------------------------- */
                     31: extern      int         Func_idx;
                     32: extern      Symbol      FuncStack[MAX_FUNC_NEST];
                     33: 
                     34: 
                     35: extern      char        Fbuf[ONE_K];          /* lexer input buffer */
                     36: extern      int         Fidx;                 /* lexer input char index */
                     37: 
                     38: extern      Symbol_p    fml_lval;  /* lexical variable used in parser */
                     39: 
                     40: /* ---- Token value returned from this lexer ---------------- */
                     41: 
                     42: /* ---------------  Global variables ------------------------ */
                     43: 
                     44: 
                     45: /* scan a F_NUMBER token */
                     46: double
                     47: f_get_float()
                     48: {
                     49:   double   num; 
                     50:   int      ii=0, len;
                     51:   char     num_str[QUARTER_K];
                     52:   
                     53:   num_str[ii]=0;
                     54:   while( isspace(Fbuf[Fidx]) ) { Fidx++; }
                     55:   if( Fbuf[Fidx] == '+' || Fbuf[Fidx] == '-' ) {
                     56:     num_str[ii++] = Fbuf[Fidx++];
                     57:   }
                     58:   while( isdigit(Fbuf[Fidx]) || Fbuf[Fidx] == '.' ) {
                     59:       num_str[ii++] = Fbuf[Fidx++];
                     60:   }
                     61:   if( Fbuf[Fidx] == 'E' || Fbuf[Fidx] == 'e' ) {  /* a number followed immediately by e or E */
                     62:     if( Fbuf[Fidx+1] == '+' || Fbuf[Fidx+1] == '-' || isdigit(Fbuf[Fidx+1]) ) {  
                     63:     /* e or E followed immediately by a digit */
                     64:       num_str[ii++] = Fbuf[Fidx++];
                     65:       num_str[ii++] = Fbuf[Fidx++];
                     66:       while( isdigit(Fbuf[Fidx]) ) {
                     67:         num_str[ii++] = Fbuf[Fidx++];
                     68:       }
                     69:     }
                     70:   }
                     71:   num_str[ii] = 0; /* terminate the str */
                     72:   len = strlen(num_str);
                     73:   if(len > 0 ) {
                     74:     sscanf(num_str,"%lg", &num);
                     75:   } else {
                     76:     num = 1.0;
                     77:   }
                     78:   return (num);
                     79: }
                     80: 
                     81: char *
                     82: f_get_id()
                     83: {
                     84:   char    *var_p; 
                     85:   int      ii=0, len;
                     86:   char     id_str[QUARTER_K];
                     87:   
                     88:   id_str[ii]=0;
                     89:   while( isspace(Fbuf[Fidx]) ) { Fidx++; }
                     90:   if( isalpha( Fbuf[Fidx] ) ) {
                     91:     id_str[ii++] = Fbuf[Fidx++];
                     92:   }
                     93:   while( isalnum(Fbuf[Fidx]) || Fbuf[Fidx] == '_' ) {
                     94:       id_str[ii++] = Fbuf[Fidx++];
                     95:   }
                     96:   id_str[ii] = 0; /* terminate the str */
                     97:   len = strlen(id_str);
                     98:   var_p = (char *)capa_malloc( (len+1), sizeof(char));
                     99:   strcpy(var_p,id_str);
                    100:   return (var_p);
                    101: }
                    102: 
                    103: int
                    104: f_peek_next_token()
                    105: {
                    106:   int   idx;
                    107:   
                    108:   idx = Fidx;
                    109:   while( isspace(Fbuf[idx]) ) { idx++; }
                    110:   return (Fbuf[idx]); 
                    111: }
                    112: 
                    113: 
                    114: /* ======================================================= */
                    115: 
                    116: int
                    117: fml_lex()
                    118: {
                    119:   char    *id_p;
                    120:   int      c;
                    121:   
                    122:   if( Fbuf[Fidx] == 0 )  { /* printf("EoI\n"); */ return (EOF); }
                    123:   while( isspace(Fbuf[Fidx]) ) { Fidx++; }
                    124:   if( isalpha(Fbuf[Fidx]) ) {
                    125:     id_p = f_get_id();
                    126:     c = f_peek_next_token();
                    127:     if( c == '(' ) {
                    128:       (FuncStack[Func_idx]).s_type = FUNCTION_ID;
                    129:       (FuncStack[Func_idx]).s_name = id_p;
                    130:        Func_idx++;
                    131:        
                    132:        return (F_ID);
                    133:     } else {
                    134:       fml_lval = find_formula_id(id_p); capa_mfree((char *)id_p);
                    135:       if( fml_lval == NULL) {
                    136:         return (F_ERROR);
                    137:       } else {
                    138:         return (V_ID);
                    139:       }
                    140:     } 
                    141:   }
                    142:   if( isdigit(Fbuf[Fidx]) || Fbuf[Fidx] == '.' ) {
                    143:     
                    144:     fml_lval = (Symbol *) capa_malloc(1, sizeof(Symbol)); /* *** */
                    145:     fml_lval->s_real = f_get_float();
                    146:     fml_lval->s_type = R_CONSTANT;
                    147:     
                    148:     return (F_NUMBER);
                    149:   }
                    150:   if( Fbuf[Fidx] == '(' ) {
                    151:     Fidx++;
                    152:     return (F_LPAR);
                    153:   }
                    154:   if( Fbuf[Fidx] == ')' ) {
                    155:     Fidx++;
                    156:     return (F_RPAR);
                    157:   }
                    158:   if( Fbuf[Fidx] == '+' ) {
                    159:     Fidx++;
                    160:     return (F_PLUS);
                    161:   }
                    162:   if( Fbuf[Fidx] == '-' ) {
                    163:     Fidx++;
                    164:     return (F_MINUS);
                    165:   }
                    166:   if( Fbuf[Fidx] == '*' ) {
                    167:     Fidx++;
                    168:     return (F_MULT);
                    169:   }
                    170:   if( Fbuf[Fidx] == '/' ) {
                    171:     Fidx++;
                    172:     return (F_DIV);
                    173:   }
                    174:   if( Fbuf[Fidx] == '%' ) {
                    175:     Fidx++;
                    176:     return (F_MOD);
                    177:   }
                    178:   if( Fbuf[Fidx] == '^' ) {
                    179:     Fidx++;
                    180:     return (F_POW);
                    181:   }
                    182:   if( Fbuf[Fidx] == ',' ) {
                    183:     Fidx++;
                    184:     return (F_COMMA);
                    185:   }
                    186:   return (F_ERROR);
                    187:   
                    188: }