use commands::ast::Value;
use commands::ast::AST;
pub struct Plus<'ast> {
lvalue: &'ast AST<'ast>,
rvalue: &'ast AST<'ast>,
}
pub fn new<'ast>(lvalue: &'ast AST<'ast>, rvalue: &'ast AST<'ast>) -> Plus<'ast> {
Plus {
lvalue: lvalue,
rvalue: rvalue,
}
}
impl<'ast> Plus<'ast> {
fn a_a(l: i64, r: i64) -> AST<'ast> {
AST::Value(Value::Number(l + r))
}
fn l_a(l: &'ast AST<'ast>, r: &'ast AST<'ast>) -> AST<'ast> {
AST::Value(Value::Number(1))
}
fn a_l(l: &'ast AST<'ast>, r: &'ast AST<'ast>) -> AST<'ast> {
AST::Value(Value::Number(1))
}
fn v_v(l: &[i64], r: &[i64]) -> AST<'ast> {
let a:Vec<i64> = l.iter().zip(r)
.map(|(l,r)| l+r)
.collect();
AST::Value(Value::VecInt(a))
}
fn v_a(l: &[i64], r: i64) -> AST<'ast> {
let a:Vec<i64> = l.iter()
.map(|x| x+r)
.collect();
AST::Value(Value::VecInt(a))
}
}
impl<'ast> Iterator for Plus<'ast> {
type Item = AST<'ast>;
fn next(&mut self) -> Option<Self::Item> {
match (self.lvalue, self.rvalue) {
(&AST::Value(Value::Number(l)), &AST::Value(Value::Number(r))) => Some(Self::a_a(l, r)),
(&AST::Value(Value::VecInt(ref l)), &AST::Value(Value::VecInt(ref r))) => Some(Self::v_v(l, r)),
(&AST::Value(Value::Number(l)), &AST::Value(Value::VecInt(ref r))) => Some(Self::v_a(r, l)),
(&AST::Value(Value::VecInt(ref r)), &AST::Value(Value::Number(l))) => Some(Self::v_a(r, l)),
_ => None
}
}
}
impl<'a, 'ast> Iterator for &'a Plus<'ast> {
type Item = AST<'ast>;
fn next(&mut self) -> Option<Self::Item> {
None
}
}