c - Making calculator in yacc and lex char array -

i'm working yacc , lex, , have problem something.

i working on caluclator. calculator can :

example:

user: = 1+3 user: calc: 4 

problem is, can 1 character. want maximum 3 characters.

example:

user: abc = 1+3 user: abc calc: 4 

also want add more.

my code works :

user: abc = 1+3 user: abc calc: 4 user: ab calc: 4     /* because scan first character */ user: calc: 4     /* because scan first character */ 

part of code connecting problem :

-yacc

%{  int symbolval(char symbol); void updatesymbolval(char symbol, int val);  %}  %union {double num; char id;} %token <id> identifier %type <id> assignment  %%  assignment : identifier equals exp { updatesymbolval($1, $3); }  term   : /*something */        | identifier { $$ = symbolval($1); }  %%  /* c code */  int symbolval(char symbol) {     int bucker = computesymbolindex(symbol);     return symbols[bucket]; }  void updatesymbolval(char symbol,int val) {     int bucket = computesymbolindex(symbol);     symbols[bucket] = val; }  int computesymbolindex(char token) {     int idx = 0;     idx = token - 'a' + 26;     return idx; } 

i want code is correct.

but want maximum 3 characters.

maybe can array or pointers, don't know how.

my guess in lex returning single character token. way return token representing variable, , actual name it's yyval. here's code snippets of go code make work - though can't further without seeing lex file.

lex:

[a-za-z]+   { yylval.s = new std::string(yytext); return tvariable; } 

yacc:

%union {   str s;    /* symbol name */ } %token<s> tvariable  ...  // on grammar: identifier: tvariable { $$ = $1; }