chapter9/s_expressions.c
lval lval_num(long x){
    lval v;
    v.type = LVAL_NUM;
    v.num = x;
    return v;
}
/* Create a new number type lval */
Create a new number type lval
Create a new number type lval
lval lval_num(long x){
    lval v;
    v.type = LVAL_NUM;
    v.num = x;
    return v;
}
lval lval_num ( long x ) { lval v ; v . type = LVAL_NUM ; v . num = x ; return v ; }
Create a new number type lval
Create a new number type lval