Compiler.l

%{
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <time.h>
    #include "data_struct.h"
    #include "Compiler.tab.h"
    void yyerror(char*);
    int symLookup(char *s);    
    
    // Declaration of variable
    int START_ID = 100;                  // ID 0-99 is reserved for keyword
    int current_id;                      // Store the index of current usable id to store the variable        
    SymbolTable *list_name = NULL;       // pointer that point to the last node in the linked_list
    SymbolTable *start_list_name = NULL; // pointer that point to the start of list_name
    
%}

%%
0                   {
                        yylval.dValue = atof(yytext);
                        return DOUBLE;
                    }
[1-9][0-9]*         {
                        yylval.dValue = atof(yytext);
                        return DOUBLE;
                    } 

[0-9]+[.][0-9]*     {  
                        yylval.dValue = atof(yytext);
                        return DOUBLE;
                    }

[-^()=+*{}/;,.\n]   { return *yytext; }
"["                 { return *yytext; }
"]"                 { return *yytext; }
[a-zA-Z][A-Za-z0-9]* {  
                        if (list_name == NULL){  // If it is NULL, declared it
                            list_name = malloc(sizeof(SymbolTable));
                            list_name->nextSymbol = NULL;
                            start_list_name = list_name;
                            current_id = START_ID;
                        }
                        yylval.id = symLookup(yytext);
                        return IDENTIFIER;
                    }
[ \t]               { ; }                           // ignore whitespace 
.                   yyerror("Unknown character");   // All other character is considered as unknown

%%

int yywrap(){ return 1; }

int symLookup(char *s){
    /* 
        range [0 ,25 ) is function with 1 argument
        range [25,35 ) is function with 2 arguments
        range [35,40 ) is function with 3 arguments
        range [40,100) is function with 0 argument 
    */
    if (strcmp(s, "sin") == 0)           return 0;
    else if(strcmp(s, "cos") == 0)       return 1;
    else if(strcmp(s, "tan") == 0)       return 2;
    else if (strcmp(s, "asin") == 0)     return 3;
    else if(strcmp(s, "acos") == 0)      return 4;
    else if(strcmp(s, "atan") == 0)      return 5;
    else if(strcmp(s, "round") == 0)     return 6;
    else if(strcmp(s, "ceil") == 0)      return 7;
    else if(strcmp(s, "floor") == 0)     return 8;
    else if(strcmp(s, "exp") == 0)       return 9;
    else if(strcmp(s, "log") == 0)       return 10;
    else if(strcmp(s, "log10") == 0)     return 11;
    else if(strcmp(s, "sqrt") == 0)      return 12;
    else if(strcmp(s, "length") ==0)     return 13;
    else if(strcmp(s, "size") ==0)       return 14;
    else if(strcmp(s, "ndims") ==0)      return 15;
    else if(strcmp(s, "numel") ==0)      return 16;
    else if(strcmp(s, "transpose") == 0) return 17;
    else if(strcmp(s, "det") == 0)       return 18;
    else if(strcmp(s, "trace") == 0)     return 19;
    else if(strcmp(s, "inverse")==0)     return 20;
    
    else if(strcmp(s, "mod") == 0)       return 25;
    else if(strcmp(s, "horzat") == 0)    return 26;
    else if(strcmp(s, "verzat") == 0)    return 27;
    else if(strcmp(s, "zeros") ==0)      return 28;
    else if(strcmp(s, "ones") ==0)       return 29;
    else if(strcmp(s, "cross") ==0)      return 30;
    else if(strcmp(s, "scamulmat") ==0)  return 31;
    else if(strcmp(s, "matmulsca") ==0)  return 32;

    else if(strcmp(s, "reshape") == 0)   return 35;
    else if(strcmp(s, "linspace") ==0)   return 36;
    else if(strcmp(s, "logspace") ==0)   return 37;

    else if(strcmp(s, "clear") ==0)      return 40;
    else if(strcmp(s, "ans") ==0)        return 41;
}