struct Token *function_execute(struct Token *statement, struct List *scope){
int header = statement->list->tokens[0]->type;
if( token_is_operator(header) ) return function_operator(statement,scope);
if(header == T_PRINT) return function_print(statement,scope);
if(header == T_IF) return function_if(statement,scope);
if(header == T_EXPRESSION) return function_expression(statement,scope);
if(header == T_STRING) return statement->list->tokens[1];
if(header == T_EQUALS) return function_assignment(statement,scope);
if(header == T_LOOKUP) return function_lookup(statement,scope);
if(header == T_NOT) return function_not(statement,scope);
printf("(ERROR:function_execute) Statement was not a valid function.\n");
return token_create(T_NUMBER,0);
}
static int expr_lex(const char **str, token_t *tok)
{
int n=0;
char c = **str;
const char *s;
int integer_found = 0;
if (c==0) {
tok->type = TOK_END;
return 0;
}
again:
if (isdigit(c)) {
s = *str;
do {
c = (*(++*str));
} while (c && isdigit(c));
n = atoi(s);
integer_found = 1;
if (c!='.' && c!='e') {
tok->i = n;
tok->type = TOK_INT;
return 0;
}
}
switch (c) {
case '.':
c = (*(++*str));
if (!isdigit(c) && c!='e' && integer_found) {
tok->type = TOK_FLOAT;
tok->f = (float)n;
return 0;
}
if (!isdigit(c) && c!='e')
break;
do {
c = (*(++*str));
} while (c && isdigit(c));
if (c!='e') {
tok->f = atof(s);
tok->type = TOK_FLOAT;
return 0;
}
case 'e':
if (!integer_found) {
printf("unexpected `e' outside float\n");
break;
}
c = (*(++*str));
if (c!='-' && !isdigit(c)) {
printf("Incomplete scientific notation `%s'.\n",s);
break;
}
if (c=='-')
c = (*(++*str));
while (c && isdigit(c))
c = (*(++*str));
tok->type = TOK_FLOAT;
tok->f = atof(s);
return 0;
case '+':
case '-':
case '/':
case '*':
case '%':
case '=':
tok->type = TOK_OP;
tok->op = c;
++*str;
return 0;
case '(':
tok->type = TOK_OPEN_PAREN;
++*str;
return 0;
case ')':
tok->type = TOK_CLOSE_PAREN;
++*str;
return 0;
case 'x':
case 'y':
tok->type = TOK_VAR;
tok->var = c;
++*str;
return 0;
case '[':
tok->type = TOK_OPEN_SQUARE;
++*str;
return 0;
case ']':
tok->type = TOK_CLOSE_SQUARE;
++*str;
return 0;
case '{':
tok->type = TOK_OPEN_CURLY;
++*str;
return 0;
case '}':
tok->type = TOK_CLOSE_CURLY;
++*str;
return 0;
case ' ':
case '\t':
case '\r':
case '\n':
c = (*(++*str));
goto again;
case ',':
tok->type = TOK_COMMA;
++*str;
return 0;
default:
if (!isalpha(c)) {
printf("unknown character '%c' in lexer\n", c);
break;
}
s = *str;
while (c && (isalpha(c) || isdigit(c)))
c = (*(++*str));
tok->type = TOK_FUNC;
tok->func = function_lookup(s, *str-s);
return 0;
}
return 1;
}
