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use super::*;
pub(super) fn optimize_functions(
input: Vec<ExprIR>,
function: IRFunctionExpr,
options: FunctionOptions,
expr_arena: &mut Arena<AExpr>,
) -> PolarsResult<Option<AExpr>> {
let out = match function {
// is_null().any() -> null_count() > 0
// is_not_null().any() -> ~is_empty(ignore_nulls=True)
// CORRECTNESS: we can ignore 'ignore_nulls' since is_null/is_not_null never produces NULLS
IRFunctionExpr::Boolean(IRBooleanFunction::Any { ignore_nulls: _ }) => {
let input_node = expr_arena.get(input[0].node());
match input_node {
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNull),
options: _,
} => Some(AExpr::BinaryExpr {
left: expr_arena.add(new_null_count(input)),
op: Operator::Gt,
right: expr_arena.add(AExpr::Literal(LiteralValue::new_idxsize(0))),
}),
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNotNull),
options: _,
} => Some(
AExprBuilder::new_from_node(input[0].node())
.is_empty(true, expr_arena)
.not(expr_arena)
.build(expr_arena),
),
_ => None,
}
},
// is_null().all() -> null_count() == len()
// is_not_null().all() -> null_count() == 0
IRFunctionExpr::Boolean(IRBooleanFunction::All { ignore_nulls: _ }) => {
let input_node = expr_arena.get(input[0].node());
match input_node {
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNull),
options: _,
} => {
// we should perform optimization only if the original expression is a column
// so in case of disabled CSE, we will not suffer from performance regression
if input.len() == 1 {
let is_null_input_node = input[0].node();
match expr_arena.get(is_null_input_node) {
AExpr::Column(_) => Some(AExpr::BinaryExpr {
op: Operator::Eq,
right: expr_arena.add(new_null_count(input)),
left: expr_arena.add(AExpr::Agg(IRAggExpr::Count {
input: is_null_input_node,
include_nulls: true,
})),
}),
_ => None,
}
} else {
None
}
},
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNotNull),
options: _,
} => Some(AExpr::BinaryExpr {
left: expr_arena.add(new_null_count(input)),
op: Operator::Eq,
right: expr_arena.add(AExpr::Literal(LiteralValue::new_idxsize(0))),
}),
_ => None,
}
},
// sort().reverse() -> sort(reverse)
// sort_by().reverse() -> sort_by(reverse)
IRFunctionExpr::Reverse => {
let input = expr_arena.get(input[0].node());
match input {
AExpr::Sort { expr, options } => {
let mut options = *options;
options.descending = !options.descending;
Some(AExpr::Sort {
expr: *expr,
options,
})
},
AExpr::SortBy {
expr,
by,
sort_options,
} => {
let mut sort_options = sort_options.clone();
let reversed_descending = sort_options.descending.iter().map(|x| !*x).collect();
sort_options.descending = reversed_descending;
Some(AExpr::SortBy {
expr: *expr,
by: by.clone(),
sort_options,
})
},
// TODO: add support for cum_sum and other operation that allow reversing.
_ => None,
}
},
// flatten nested concat_str calls
#[cfg(all(feature = "strings", feature = "concat_str"))]
ref function @ IRFunctionExpr::StringExpr(IRStringFunction::ConcatHorizontal {
delimiter: ref sep,
ignore_nulls,
}) if sep.is_empty() => {
if input
.iter()
.any(|e| is_string_concat(expr_arena.get(e.node()), ignore_nulls))
{
let mut new_inputs = Vec::with_capacity(input.len() * 2);
for e in input {
match get_string_concat_input(e.node(), expr_arena, ignore_nulls) {
Some(inp) => new_inputs.extend_from_slice(inp),
None => new_inputs.push(e.clone()),
}
}
Some(AExpr::Function {
input: new_inputs,
function: function.clone(),
options,
})
} else {
None
}
},
IRFunctionExpr::Boolean(IRBooleanFunction::Not) => {
let y = expr_arena.get(input[0].node());
match y {
// not(a and b) => not(a) or not(b)
AExpr::BinaryExpr {
left,
op: Operator::And | Operator::LogicalAnd,
right,
} => {
let left = *left;
let right = *right;
Some(AExpr::BinaryExpr {
left: expr_arena.add(AExpr::Function {
input: vec![ExprIR::from_node(left, expr_arena)],
function: IRFunctionExpr::Boolean(IRBooleanFunction::Not),
options,
}),
op: Operator::Or,
right: expr_arena.add(AExpr::Function {
input: vec![ExprIR::from_node(right, expr_arena)],
function: IRFunctionExpr::Boolean(IRBooleanFunction::Not),
options,
}),
})
},
// not(a or b) => not(a) and not(b)
AExpr::BinaryExpr {
left,
op: Operator::Or | Operator::LogicalOr,
right,
} => {
let left = *left;
let right = *right;
Some(AExpr::BinaryExpr {
left: expr_arena.add(AExpr::Function {
input: vec![ExprIR::from_node(left, expr_arena)],
function: IRFunctionExpr::Boolean(IRBooleanFunction::Not),
options,
}),
op: Operator::And,
right: expr_arena.add(AExpr::Function {
input: vec![ExprIR::from_node(right, expr_arena)],
function: IRFunctionExpr::Boolean(IRBooleanFunction::Not),
options,
}),
})
},
// not(not x) => x
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::Not),
..
} => Some(expr_arena.get(input[0].node()).clone()),
// not(lit x) => !x
AExpr::Literal(lv) if lv.bool().is_some() => {
Some(AExpr::Literal(Scalar::from(!lv.bool().unwrap()).into()))
},
// not(x.is_null) => x.is_not_null
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNull),
options,
} => Some(AExpr::Function {
input: input.clone(),
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNotNull),
options: *options,
}),
// not(x.is_not_null) => x.is_null
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNotNull),
options,
} => Some(AExpr::Function {
input: input.clone(),
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsNull),
options: *options,
}),
// not(a == b) => a != b
AExpr::BinaryExpr {
left,
op: Operator::Eq,
right,
} => Some(AExpr::BinaryExpr {
left: *left,
op: Operator::NotEq,
right: *right,
}),
// not(a != b) => a == b
AExpr::BinaryExpr {
left,
op: Operator::NotEq,
right,
} => Some(AExpr::BinaryExpr {
left: *left,
op: Operator::Eq,
right: *right,
}),
// not(a < b) => a >= b
AExpr::BinaryExpr {
left,
op: Operator::Lt,
right,
} => Some(AExpr::BinaryExpr {
left: *left,
op: Operator::GtEq,
right: *right,
}),
// not(a <= b) => a > b
AExpr::BinaryExpr {
left,
op: Operator::LtEq,
right,
} => Some(AExpr::BinaryExpr {
left: *left,
op: Operator::Gt,
right: *right,
}),
// not(a > b) => a <= b
AExpr::BinaryExpr {
left,
op: Operator::Gt,
right,
} => Some(AExpr::BinaryExpr {
left: *left,
op: Operator::LtEq,
right: *right,
}),
// not(a >= b) => a < b
AExpr::BinaryExpr {
left,
op: Operator::GtEq,
right,
} => Some(AExpr::BinaryExpr {
left: *left,
op: Operator::Lt,
right: *right,
}),
#[cfg(feature = "is_between")]
// not(col('x').is_between(a,b)) => col('x') < a || col('x') > b
AExpr::Function {
input,
function: IRFunctionExpr::Boolean(IRBooleanFunction::IsBetween { closed }),
..
} => {
if !matches!(expr_arena.get(input[0].node()), AExpr::Column(_)) {
None
} else {
let left_cmp_op = match closed {
ClosedInterval::Both | ClosedInterval::Left => Operator::Lt,
ClosedInterval::None | ClosedInterval::Right => Operator::LtEq,
};
let right_cmp_op = match closed {
ClosedInterval::Both | ClosedInterval::Right => Operator::Gt,
ClosedInterval::None | ClosedInterval::Left => Operator::GtEq,
};
let left_left = input[0].node();
let right_left = input[1].node();
let left_right = left_left;
let right_right = input[2].node();
// input[0] is between input[1] and input[2]
Some(AExpr::BinaryExpr {
// input[0] (<,<=) input[1]
left: expr_arena.add(AExpr::BinaryExpr {
left: left_left,
op: left_cmp_op,
right: right_left,
}),
// OR
op: Operator::Or,
// input[0] (>,>=) input[2]
right: expr_arena.add(AExpr::BinaryExpr {
left: left_right,
op: right_cmp_op,
right: right_right,
}),
})
}
},
_ => None,
}
},
IRFunctionExpr::GatherEvery { n: 1, offset: 0 } => {
Some(expr_arena.get(input[0].node()).clone())
},
IRFunctionExpr::GatherEvery { n: 1, offset } => {
let offset_i64: i64 = offset.try_into().unwrap_or(i64::MAX);
let offset_node =
expr_arena.add(AExpr::Literal(LiteralValue::Scalar(offset_i64.into())));
let length_node = expr_arena.add(AExpr::Literal(LiteralValue::Scalar(
(usize::MAX as u64).into(),
)));
Some(AExpr::Slice {
input: input[0].node(),
offset: offset_node,
length: length_node,
})
},
_ => None,
};
Ok(out)
}
#[cfg(all(feature = "strings", feature = "concat_str"))]
fn is_string_concat(ae: &AExpr, ignore_nulls: bool) -> bool {
matches!(ae, AExpr::Function {
function:IRFunctionExpr::StringExpr(
IRStringFunction::ConcatHorizontal{delimiter: sep, ignore_nulls: func_inore_nulls},
),
..
} if sep.is_empty() && *func_inore_nulls == ignore_nulls)
}
#[cfg(all(feature = "strings", feature = "concat_str"))]
fn get_string_concat_input(
node: Node,
expr_arena: &Arena<AExpr>,
ignore_nulls: bool,
) -> Option<&[ExprIR]> {
match expr_arena.get(node) {
AExpr::Function {
input,
function:
IRFunctionExpr::StringExpr(IRStringFunction::ConcatHorizontal {
delimiter: sep,
ignore_nulls: func_ignore_nulls,
}),
..
} if sep.is_empty() && *func_ignore_nulls == ignore_nulls => Some(input),
_ => None,
}
}