risingwave_frontend/expr/
mod.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use enum_as_inner::EnumAsInner;
16use fixedbitset::FixedBitSet;
17use futures::FutureExt;
18use paste::paste;
19use risingwave_common::array::ListValue;
20use risingwave_common::types::{DataType, Datum, JsonbVal, MapType, Scalar, ScalarImpl};
21use risingwave_expr::aggregate::PbAggKind;
22use risingwave_expr::expr::build_from_prost;
23use risingwave_pb::expr::expr_node::RexNode;
24use risingwave_pb::expr::{ExprNode, ProjectSetSelectItem};
25use user_defined_function::UserDefinedFunctionDisplay;
26
27use crate::error::{ErrorCode, Result as RwResult};
28
29mod agg_call;
30mod correlated_input_ref;
31mod function_call;
32mod function_call_with_lambda;
33mod input_ref;
34mod literal;
35mod now;
36mod parameter;
37mod pure;
38mod subquery;
39mod table_function;
40mod user_defined_function;
41mod window_function;
42
43mod order_by_expr;
44pub use order_by_expr::{OrderBy, OrderByExpr};
45
46mod expr_mutator;
47mod expr_rewriter;
48mod expr_visitor;
49pub mod function_impl;
50mod session_timezone;
51mod type_inference;
52mod utils;
53
54pub use agg_call::AggCall;
55pub use correlated_input_ref::{CorrelatedId, CorrelatedInputRef, Depth};
56pub use expr_mutator::ExprMutator;
57pub use expr_rewriter::{ExprRewriter, default_rewrite_expr};
58pub use expr_visitor::{ExprVisitor, default_visit_expr};
59pub use function_call::{FunctionCall, FunctionCallDisplay, is_row_function};
60pub use function_call_with_lambda::FunctionCallWithLambda;
61pub use input_ref::{InputRef, InputRefDisplay, input_ref_to_column_indices};
62pub use literal::Literal;
63pub use now::{InlineNowProcTime, Now, NowProcTimeFinder};
64pub use parameter::Parameter;
65pub use pure::*;
66pub use risingwave_pb::expr::expr_node::Type as ExprType;
67pub use session_timezone::{SessionTimezone, TimestamptzExprFinder};
68pub use subquery::{Subquery, SubqueryKind};
69pub use table_function::{TableFunction, TableFunctionType};
70pub use type_inference::*;
71pub use user_defined_function::UserDefinedFunction;
72pub use utils::*;
73pub use window_function::WindowFunction;
74
75const EXPR_DEPTH_THRESHOLD: usize = 30;
76const EXPR_TOO_DEEP_NOTICE: &str = "Some expression is too complicated. \
77Consider simplifying or splitting the query if you encounter any issues.";
78
79/// the trait of bound expressions
80pub trait Expr: Into<ExprImpl> {
81    /// Get the return type of the expr
82    fn return_type(&self) -> DataType;
83
84    /// Serialize the expression
85    fn to_expr_proto(&self) -> ExprNode;
86}
87
88macro_rules! impl_expr_impl {
89    ($($t:ident,)*) => {
90        #[derive(Clone, Eq, PartialEq, Hash, EnumAsInner)]
91        pub enum ExprImpl {
92            $($t(Box<$t>),)*
93        }
94
95        impl ExprImpl {
96            pub fn variant_name(&self) -> &'static str {
97                match self {
98                    $(ExprImpl::$t(_) => stringify!($t),)*
99                }
100            }
101        }
102
103        $(
104        impl From<$t> for ExprImpl {
105            fn from(o: $t) -> ExprImpl {
106                ExprImpl::$t(Box::new(o))
107            }
108        })*
109
110        impl Expr for ExprImpl {
111            fn return_type(&self) -> DataType {
112                match self {
113                    $(ExprImpl::$t(expr) => expr.return_type(),)*
114                }
115            }
116
117            fn to_expr_proto(&self) -> ExprNode {
118                match self {
119                    $(ExprImpl::$t(expr) => expr.to_expr_proto(),)*
120                }
121            }
122        }
123    };
124}
125
126impl_expr_impl!(
127    // BoundColumnRef, might be used in binder.
128    CorrelatedInputRef,
129    InputRef,
130    Literal,
131    FunctionCall,
132    FunctionCallWithLambda,
133    AggCall,
134    Subquery,
135    TableFunction,
136    WindowFunction,
137    UserDefinedFunction,
138    Parameter,
139    Now,
140);
141
142impl ExprImpl {
143    /// A literal int value.
144    #[inline(always)]
145    pub fn literal_int(v: i32) -> Self {
146        Literal::new(Some(v.to_scalar_value()), DataType::Int32).into()
147    }
148
149    /// A literal bigint value
150    #[inline(always)]
151    pub fn literal_bigint(v: i64) -> Self {
152        Literal::new(Some(v.to_scalar_value()), DataType::Int64).into()
153    }
154
155    /// A literal float64 value.
156    #[inline(always)]
157    pub fn literal_f64(v: f64) -> Self {
158        Literal::new(Some(v.into()), DataType::Float64).into()
159    }
160
161    /// A literal boolean value.
162    #[inline(always)]
163    pub fn literal_bool(v: bool) -> Self {
164        Literal::new(Some(v.to_scalar_value()), DataType::Boolean).into()
165    }
166
167    /// A literal varchar value.
168    #[inline(always)]
169    pub fn literal_varchar(v: String) -> Self {
170        Literal::new(Some(v.into()), DataType::Varchar).into()
171    }
172
173    /// A literal null value.
174    #[inline(always)]
175    pub fn literal_null(element_type: DataType) -> Self {
176        Literal::new(None, element_type).into()
177    }
178
179    /// A literal jsonb value.
180    #[inline(always)]
181    pub fn literal_jsonb(v: JsonbVal) -> Self {
182        Literal::new(Some(v.into()), DataType::Jsonb).into()
183    }
184
185    /// A literal list value.
186    #[inline(always)]
187    pub fn literal_list(v: ListValue, element_type: DataType) -> Self {
188        Literal::new(
189            Some(v.to_scalar_value()),
190            DataType::List(Box::new(element_type)),
191        )
192        .into()
193    }
194
195    /// Takes the expression, leaving a literal null of the same type in its place.
196    pub fn take(&mut self) -> Self {
197        std::mem::replace(self, Self::literal_null(self.return_type()))
198    }
199
200    /// A `count(*)` aggregate function.
201    #[inline(always)]
202    pub fn count_star() -> Self {
203        AggCall::new(
204            PbAggKind::Count.into(),
205            vec![],
206            false,
207            OrderBy::any(),
208            Condition::true_cond(),
209            vec![],
210        )
211        .unwrap()
212        .into()
213    }
214
215    /// Create a new expression by merging the given expressions by `And`.
216    ///
217    /// If `exprs` is empty, return a literal `true`.
218    pub fn and(exprs: impl IntoIterator<Item = ExprImpl>) -> Self {
219        merge_expr_by_logical(exprs, ExprType::And, ExprImpl::literal_bool(true))
220    }
221
222    /// Create a new expression by merging the given expressions by `Or`.
223    ///
224    /// If `exprs` is empty, return a literal `false`.
225    pub fn or(exprs: impl IntoIterator<Item = ExprImpl>) -> Self {
226        merge_expr_by_logical(exprs, ExprType::Or, ExprImpl::literal_bool(false))
227    }
228
229    /// Collect all `InputRef`s' indexes in the expression.
230    ///
231    /// # Panics
232    /// Panics if `input_ref >= input_col_num`.
233    pub fn collect_input_refs(&self, input_col_num: usize) -> FixedBitSet {
234        collect_input_refs(input_col_num, [self])
235    }
236
237    /// Check if the expression has no side effects and output is deterministic
238    pub fn is_pure(&self) -> bool {
239        is_pure(self)
240    }
241
242    pub fn is_impure(&self) -> bool {
243        is_impure(self)
244    }
245
246    /// Count `Now`s in the expression.
247    pub fn count_nows(&self) -> usize {
248        let mut visitor = CountNow::default();
249        visitor.visit_expr(self);
250        visitor.count()
251    }
252
253    /// Check whether self is literal NULL.
254    pub fn is_null(&self) -> bool {
255        matches!(self, ExprImpl::Literal(literal) if literal.get_data().is_none())
256    }
257
258    /// Check whether self is a literal NULL or literal string.
259    pub fn is_untyped(&self) -> bool {
260        matches!(self, ExprImpl::Literal(literal) if literal.is_untyped())
261            || matches!(self, ExprImpl::Parameter(parameter) if !parameter.has_infer())
262    }
263
264    /// Shorthand to create cast expr to `target` type in implicit context.
265    pub fn cast_implicit(mut self, target: DataType) -> Result<ExprImpl, CastError> {
266        FunctionCall::cast_mut(&mut self, target, CastContext::Implicit)?;
267        Ok(self)
268    }
269
270    /// Shorthand to create cast expr to `target` type in assign context.
271    pub fn cast_assign(mut self, target: DataType) -> Result<ExprImpl, CastError> {
272        FunctionCall::cast_mut(&mut self, target, CastContext::Assign)?;
273        Ok(self)
274    }
275
276    /// Shorthand to create cast expr to `target` type in explicit context.
277    pub fn cast_explicit(mut self, target: DataType) -> Result<ExprImpl, CastError> {
278        FunctionCall::cast_mut(&mut self, target, CastContext::Explicit)?;
279        Ok(self)
280    }
281
282    /// Shorthand to inplace cast expr to `target` type in implicit context.
283    pub fn cast_implicit_mut(&mut self, target: DataType) -> Result<(), CastError> {
284        FunctionCall::cast_mut(self, target, CastContext::Implicit)
285    }
286
287    /// Shorthand to inplace cast expr to `target` type in explicit context.
288    pub fn cast_explicit_mut(&mut self, target: DataType) -> Result<(), CastError> {
289        FunctionCall::cast_mut(self, target, CastContext::Explicit)
290    }
291
292    /// Casting to Regclass type means getting the oid of expr.
293    /// See <https://www.postgresql.org/docs/current/datatype-oid.html>
294    pub fn cast_to_regclass(self) -> Result<ExprImpl, CastError> {
295        match self.return_type() {
296            DataType::Varchar => Ok(ExprImpl::FunctionCall(Box::new(
297                FunctionCall::new_unchecked(ExprType::CastRegclass, vec![self], DataType::Int32),
298            ))),
299            DataType::Int32 => Ok(self),
300            dt if dt.is_int() => Ok(self.cast_explicit(DataType::Int32)?),
301            _ => bail_cast_error!("unsupported input type"),
302        }
303    }
304
305    /// Shorthand to inplace cast expr to `regclass` type.
306    pub fn cast_to_regclass_mut(&mut self) -> Result<(), CastError> {
307        let owned = std::mem::replace(self, ExprImpl::literal_bool(false));
308        *self = owned.cast_to_regclass()?;
309        Ok(())
310    }
311
312    /// Ensure the return type of this expression is an array of some type.
313    pub fn ensure_array_type(&self) -> Result<(), ErrorCode> {
314        if self.is_untyped() {
315            return Err(ErrorCode::BindError(
316                "could not determine polymorphic type because input has type unknown".into(),
317            ));
318        }
319        match self.return_type() {
320            DataType::List(_) => Ok(()),
321            t => Err(ErrorCode::BindError(format!("expects array but got {t}"))),
322        }
323    }
324
325    /// Ensure the return type of this expression is a map of some type.
326    pub fn try_into_map_type(&self) -> Result<MapType, ErrorCode> {
327        if self.is_untyped() {
328            return Err(ErrorCode::BindError(
329                "could not determine polymorphic type because input has type unknown".into(),
330            ));
331        }
332        match self.return_type() {
333            DataType::Map(m) => Ok(m),
334            t => Err(ErrorCode::BindError(format!("expects map but got {t}"))),
335        }
336    }
337
338    /// Shorthand to enforce implicit cast to boolean
339    pub fn enforce_bool_clause(self, clause: &str) -> RwResult<ExprImpl> {
340        if self.is_untyped() {
341            let inner = self.cast_implicit(DataType::Boolean)?;
342            return Ok(inner);
343        }
344        let return_type = self.return_type();
345        if return_type != DataType::Boolean {
346            bail!(
347                "argument of {} must be boolean, not type {:?}",
348                clause,
349                return_type
350            )
351        }
352        Ok(self)
353    }
354
355    /// Create "cast" expr to string (`varchar`) type. This is different from a real cast, as
356    /// boolean is converted to a single char rather than full word.
357    ///
358    /// Choose between `cast_output` and `cast_{assign,explicit}(Varchar)` based on `PostgreSQL`'s
359    /// behavior on bools. For example, `concat(':', true)` is `:t` but `':' || true` is `:true`.
360    /// All other types have the same behavior when formatting to output and casting to string.
361    ///
362    /// References in `PostgreSQL`:
363    /// * [cast](https://github.com/postgres/postgres/blob/a3ff08e0b08dbfeb777ccfa8f13ebaa95d064c04/src/include/catalog/pg_cast.dat#L437-L444)
364    /// * [impl](https://github.com/postgres/postgres/blob/27b77ecf9f4d5be211900eda54d8155ada50d696/src/backend/utils/adt/bool.c#L204-L209)
365    pub fn cast_output(self) -> RwResult<ExprImpl> {
366        if self.return_type() == DataType::Boolean {
367            return Ok(FunctionCall::new(ExprType::BoolOut, vec![self])?.into());
368        }
369        // Use normal cast for other types. Both `assign` and `explicit` can pass the castability
370        // check and there is no difference.
371        self.cast_assign(DataType::Varchar)
372            .map_err(|err| err.into())
373    }
374
375    /// Evaluate the expression on the given input.
376    ///
377    /// TODO: This is a naive implementation. We should avoid proto ser/de.
378    /// Tracking issue: <https://github.com/risingwavelabs/risingwave/issues/3479>
379    pub async fn eval_row(&self, input: &OwnedRow) -> RwResult<Datum> {
380        let backend_expr = build_from_prost(&self.to_expr_proto())?;
381        Ok(backend_expr.eval_row(input).await?)
382    }
383
384    /// Try to evaluate an expression if it's a constant expression by `ExprImpl::is_const`.
385    ///
386    /// Returns...
387    /// - `None` if it's not a constant expression,
388    /// - `Some(Ok(_))` if constant evaluation succeeds,
389    /// - `Some(Err(_))` if there's an error while evaluating a constant expression.
390    pub fn try_fold_const(&self) -> Option<RwResult<Datum>> {
391        if self.is_const() {
392            self.eval_row(&OwnedRow::empty())
393                .now_or_never()
394                .expect("constant expression should not be async")
395                .into()
396        } else {
397            None
398        }
399    }
400
401    /// Similar to `ExprImpl::try_fold_const`, but panics if the expression is not constant.
402    pub fn fold_const(&self) -> RwResult<Datum> {
403        self.try_fold_const().expect("expression is not constant")
404    }
405}
406
407/// Implement helper functions which recursively checks whether an variant is included in the
408/// expression. e.g., `has_subquery(&self) -> bool`
409///
410/// It will not traverse inside subqueries.
411macro_rules! impl_has_variant {
412    ( $($variant:ty),* ) => {
413        paste! {
414            impl ExprImpl {
415                $(
416                    pub fn [<has_ $variant:snake>](&self) -> bool {
417                        struct Has { has: bool }
418
419                        impl ExprVisitor for Has {
420                            fn [<visit_ $variant:snake>](&mut self, _: &$variant) {
421                                self.has = true;
422                            }
423                        }
424
425                        let mut visitor = Has { has: false };
426                        visitor.visit_expr(self);
427                        visitor.has
428                    }
429                )*
430            }
431        }
432    };
433}
434
435impl_has_variant! {InputRef, Literal, FunctionCall, FunctionCallWithLambda, AggCall, Subquery, TableFunction, WindowFunction, UserDefinedFunction, Now}
436
437#[derive(Debug, Clone, PartialEq, Eq, Hash)]
438pub struct InequalityInputPair {
439    /// Input index of greater side of inequality.
440    pub(crate) key_required_larger: usize,
441    /// Input index of less side of inequality.
442    pub(crate) key_required_smaller: usize,
443    /// greater >= less + `delta_expression`
444    pub(crate) delta_expression: Option<(ExprType, ExprImpl)>,
445}
446
447impl InequalityInputPair {
448    fn new(
449        key_required_larger: usize,
450        key_required_smaller: usize,
451        delta_expression: Option<(ExprType, ExprImpl)>,
452    ) -> Self {
453        Self {
454            key_required_larger,
455            key_required_smaller,
456            delta_expression,
457        }
458    }
459}
460
461impl ExprImpl {
462    /// This function is not meant to be called. In most cases you would want
463    /// [`ExprImpl::has_correlated_input_ref_by_depth`].
464    ///
465    /// When an expr contains a [`CorrelatedInputRef`] with lower depth, the whole expr is still
466    /// considered to be uncorrelated, and can be checked with [`ExprImpl::has_subquery`] as well.
467    /// See examples on [`crate::binder::BoundQuery::is_correlated`] for details.
468    ///
469    /// This is a placeholder to trigger a compiler error when a trivial implementation checking for
470    /// enum variant is generated by accident. It cannot be called either because you cannot pass
471    /// `Infallible` to it.
472    pub fn has_correlated_input_ref(&self, _: std::convert::Infallible) -> bool {
473        unreachable!()
474    }
475
476    /// Used to check whether the expression has [`CorrelatedInputRef`].
477    ///
478    /// This is the core logic that supports [`crate::binder::BoundQuery::is_correlated`]. Check the
479    /// doc of it for examples of `depth` being equal, less or greater.
480    // We need to traverse inside subqueries.
481    pub fn has_correlated_input_ref_by_depth(&self, depth: Depth) -> bool {
482        struct Has {
483            depth: usize,
484            has: bool,
485        }
486
487        impl ExprVisitor for Has {
488            fn visit_correlated_input_ref(&mut self, correlated_input_ref: &CorrelatedInputRef) {
489                if correlated_input_ref.depth() == self.depth {
490                    self.has = true;
491                }
492            }
493
494            fn visit_subquery(&mut self, subquery: &Subquery) {
495                self.depth += 1;
496                self.visit_bound_set_expr(&subquery.query.body);
497                self.depth -= 1;
498            }
499        }
500
501        impl Has {
502            fn visit_bound_set_expr(&mut self, set_expr: &BoundSetExpr) {
503                match set_expr {
504                    BoundSetExpr::Select(select) => {
505                        select.exprs().for_each(|expr| self.visit_expr(expr));
506                        match select.from.as_ref() {
507                            Some(from) => from.is_correlated(self.depth),
508                            None => false,
509                        };
510                    }
511                    BoundSetExpr::Values(values) => {
512                        values.exprs().for_each(|expr| self.visit_expr(expr))
513                    }
514                    BoundSetExpr::Query(query) => {
515                        self.depth += 1;
516                        self.visit_bound_set_expr(&query.body);
517                        self.depth -= 1;
518                    }
519                    BoundSetExpr::SetOperation { left, right, .. } => {
520                        self.visit_bound_set_expr(left);
521                        self.visit_bound_set_expr(right);
522                    }
523                };
524            }
525        }
526
527        let mut visitor = Has { depth, has: false };
528        visitor.visit_expr(self);
529        visitor.has
530    }
531
532    pub fn has_correlated_input_ref_by_correlated_id(&self, correlated_id: CorrelatedId) -> bool {
533        struct Has {
534            correlated_id: CorrelatedId,
535            has: bool,
536        }
537
538        impl ExprVisitor for Has {
539            fn visit_correlated_input_ref(&mut self, correlated_input_ref: &CorrelatedInputRef) {
540                if correlated_input_ref.correlated_id() == self.correlated_id {
541                    self.has = true;
542                }
543            }
544
545            fn visit_subquery(&mut self, subquery: &Subquery) {
546                self.visit_bound_set_expr(&subquery.query.body);
547            }
548        }
549
550        impl Has {
551            fn visit_bound_set_expr(&mut self, set_expr: &BoundSetExpr) {
552                match set_expr {
553                    BoundSetExpr::Select(select) => {
554                        select.exprs().for_each(|expr| self.visit_expr(expr))
555                    }
556                    BoundSetExpr::Values(values) => {
557                        values.exprs().for_each(|expr| self.visit_expr(expr));
558                    }
559                    BoundSetExpr::Query(query) => self.visit_bound_set_expr(&query.body),
560                    BoundSetExpr::SetOperation { left, right, .. } => {
561                        self.visit_bound_set_expr(left);
562                        self.visit_bound_set_expr(right);
563                    }
564                }
565            }
566        }
567
568        let mut visitor = Has {
569            correlated_id,
570            has: false,
571        };
572        visitor.visit_expr(self);
573        visitor.has
574    }
575
576    /// Collect `CorrelatedInputRef`s in `ExprImpl` by relative `depth`, return their indices, and
577    /// assign absolute `correlated_id` for them.
578    pub fn collect_correlated_indices_by_depth_and_assign_id(
579        &mut self,
580        depth: Depth,
581        correlated_id: CorrelatedId,
582    ) -> Vec<usize> {
583        struct Collector {
584            depth: Depth,
585            correlated_indices: Vec<usize>,
586            correlated_id: CorrelatedId,
587        }
588
589        impl ExprMutator for Collector {
590            fn visit_correlated_input_ref(
591                &mut self,
592                correlated_input_ref: &mut CorrelatedInputRef,
593            ) {
594                if correlated_input_ref.depth() == self.depth {
595                    self.correlated_indices.push(correlated_input_ref.index());
596                    correlated_input_ref.set_correlated_id(self.correlated_id);
597                }
598            }
599
600            fn visit_subquery(&mut self, subquery: &mut Subquery) {
601                self.depth += 1;
602                self.visit_bound_set_expr(&mut subquery.query.body);
603                self.depth -= 1;
604            }
605        }
606
607        impl Collector {
608            fn visit_bound_set_expr(&mut self, set_expr: &mut BoundSetExpr) {
609                match set_expr {
610                    BoundSetExpr::Select(select) => {
611                        select.exprs_mut().for_each(|expr| self.visit_expr(expr));
612                        if let Some(from) = select.from.as_mut() {
613                            self.correlated_indices.extend(
614                                from.collect_correlated_indices_by_depth_and_assign_id(
615                                    self.depth,
616                                    self.correlated_id,
617                                ),
618                            );
619                        };
620                    }
621                    BoundSetExpr::Values(values) => {
622                        values.exprs_mut().for_each(|expr| self.visit_expr(expr))
623                    }
624                    BoundSetExpr::Query(query) => {
625                        self.depth += 1;
626                        self.visit_bound_set_expr(&mut query.body);
627                        self.depth -= 1;
628                    }
629                    BoundSetExpr::SetOperation { left, right, .. } => {
630                        self.visit_bound_set_expr(&mut *left);
631                        self.visit_bound_set_expr(&mut *right);
632                    }
633                }
634            }
635        }
636
637        let mut collector = Collector {
638            depth,
639            correlated_indices: vec![],
640            correlated_id,
641        };
642        collector.visit_expr(self);
643        collector.correlated_indices
644    }
645
646    /// Checks whether this is a constant expr that can be evaluated over a dummy chunk.
647    ///
648    /// The expression tree should only consist of literals and **pure** function calls.
649    pub fn is_const(&self) -> bool {
650        let only_literal_and_func = {
651            struct HasOthers {
652                has_others: bool,
653            }
654
655            impl ExprVisitor for HasOthers {
656                fn visit_expr(&mut self, expr: &ExprImpl) {
657                    match expr {
658                        ExprImpl::CorrelatedInputRef(_)
659                        | ExprImpl::InputRef(_)
660                        | ExprImpl::AggCall(_)
661                        | ExprImpl::Subquery(_)
662                        | ExprImpl::TableFunction(_)
663                        | ExprImpl::WindowFunction(_)
664                        | ExprImpl::UserDefinedFunction(_)
665                        | ExprImpl::Parameter(_)
666                        | ExprImpl::Now(_) => self.has_others = true,
667                        ExprImpl::Literal(_inner) => {}
668                        ExprImpl::FunctionCall(inner) => {
669                            if !self.is_short_circuit(inner) {
670                                // only if the current `func_call` is *not* a short-circuit
671                                // expression, e.g., true or (...) | false and (...),
672                                // shall we proceed to visit it.
673                                self.visit_function_call(inner)
674                            }
675                        }
676                        ExprImpl::FunctionCallWithLambda(inner) => {
677                            self.visit_function_call_with_lambda(inner)
678                        }
679                    }
680                }
681            }
682
683            impl HasOthers {
684                fn is_short_circuit(&self, func_call: &FunctionCall) -> bool {
685                    /// evaluate the first parameter of `Or` or `And` function call
686                    fn eval_first(e: &ExprImpl, expect: bool) -> bool {
687                        if let ExprImpl::Literal(l) = e {
688                            *l.get_data() == Some(ScalarImpl::Bool(expect))
689                        } else {
690                            false
691                        }
692                    }
693
694                    match func_call.func_type {
695                        ExprType::Or => eval_first(&func_call.inputs()[0], true),
696                        ExprType::And => eval_first(&func_call.inputs()[0], false),
697                        _ => false,
698                    }
699                }
700            }
701
702            let mut visitor = HasOthers { has_others: false };
703            visitor.visit_expr(self);
704            !visitor.has_others
705        };
706
707        let is_pure = self.is_pure();
708
709        only_literal_and_func && is_pure
710    }
711
712    /// Returns the `InputRefs` of an Equality predicate if it matches
713    /// ordered by the canonical ordering (lower, higher), else returns None
714    pub fn as_eq_cond(&self) -> Option<(InputRef, InputRef)> {
715        if let ExprImpl::FunctionCall(function_call) = self
716            && function_call.func_type() == ExprType::Equal
717            && let (_, ExprImpl::InputRef(x), ExprImpl::InputRef(y)) =
718                function_call.clone().decompose_as_binary()
719        {
720            if x.index() < y.index() {
721                Some((*x, *y))
722            } else {
723                Some((*y, *x))
724            }
725        } else {
726            None
727        }
728    }
729
730    pub fn as_is_not_distinct_from_cond(&self) -> Option<(InputRef, InputRef)> {
731        if let ExprImpl::FunctionCall(function_call) = self
732            && function_call.func_type() == ExprType::IsNotDistinctFrom
733            && let (_, ExprImpl::InputRef(x), ExprImpl::InputRef(y)) =
734                function_call.clone().decompose_as_binary()
735        {
736            if x.index() < y.index() {
737                Some((*x, *y))
738            } else {
739                Some((*y, *x))
740            }
741        } else {
742            None
743        }
744    }
745
746    pub fn reverse_comparison(comparison: ExprType) -> ExprType {
747        match comparison {
748            ExprType::LessThan => ExprType::GreaterThan,
749            ExprType::LessThanOrEqual => ExprType::GreaterThanOrEqual,
750            ExprType::GreaterThan => ExprType::LessThan,
751            ExprType::GreaterThanOrEqual => ExprType::LessThanOrEqual,
752            ExprType::Equal | ExprType::IsNotDistinctFrom => comparison,
753            _ => unreachable!(),
754        }
755    }
756
757    pub fn as_comparison_cond(&self) -> Option<(InputRef, ExprType, InputRef)> {
758        if let ExprImpl::FunctionCall(function_call) = self {
759            match function_call.func_type() {
760                ty @ (ExprType::LessThan
761                | ExprType::LessThanOrEqual
762                | ExprType::GreaterThan
763                | ExprType::GreaterThanOrEqual) => {
764                    let (_, op1, op2) = function_call.clone().decompose_as_binary();
765                    if let (ExprImpl::InputRef(x), ExprImpl::InputRef(y)) = (op1, op2) {
766                        if x.index < y.index {
767                            Some((*x, ty, *y))
768                        } else {
769                            Some((*y, Self::reverse_comparison(ty), *x))
770                        }
771                    } else {
772                        None
773                    }
774                }
775                _ => None,
776            }
777        } else {
778            None
779        }
780    }
781
782    /// Accepts expressions of the form `input_expr cmp now_expr` or `now_expr cmp input_expr`,
783    /// where `input_expr` contains an `InputRef` and contains no `now()`, and `now_expr`
784    /// contains a `now()` but no `InputRef`.
785    ///
786    /// Canonicalizes to the first ordering and returns `(input_expr, cmp, now_expr)`
787    pub fn as_now_comparison_cond(&self) -> Option<(ExprImpl, ExprType, ExprImpl)> {
788        if let ExprImpl::FunctionCall(function_call) = self {
789            match function_call.func_type() {
790                ty @ (ExprType::Equal
791                | ExprType::LessThan
792                | ExprType::LessThanOrEqual
793                | ExprType::GreaterThan
794                | ExprType::GreaterThanOrEqual) => {
795                    let (_, op1, op2) = function_call.clone().decompose_as_binary();
796                    if !op1.has_now()
797                        && op1.has_input_ref()
798                        && op2.has_now()
799                        && !op2.has_input_ref()
800                    {
801                        Some((op1, ty, op2))
802                    } else if op1.has_now()
803                        && !op1.has_input_ref()
804                        && !op2.has_now()
805                        && op2.has_input_ref()
806                    {
807                        Some((op2, Self::reverse_comparison(ty), op1))
808                    } else {
809                        None
810                    }
811                }
812                _ => None,
813            }
814        } else {
815            None
816        }
817    }
818
819    /// Accepts expressions of the form `InputRef cmp InputRef [+- const_expr]` or
820    /// `InputRef [+- const_expr] cmp InputRef`.
821    pub(crate) fn as_input_comparison_cond(&self) -> Option<InequalityInputPair> {
822        if let ExprImpl::FunctionCall(function_call) = self {
823            match function_call.func_type() {
824                ty @ (ExprType::LessThan
825                | ExprType::LessThanOrEqual
826                | ExprType::GreaterThan
827                | ExprType::GreaterThanOrEqual) => {
828                    let (_, mut op1, mut op2) = function_call.clone().decompose_as_binary();
829                    if matches!(ty, ExprType::LessThan | ExprType::LessThanOrEqual) {
830                        std::mem::swap(&mut op1, &mut op2);
831                    }
832                    if let (Some((lft_input, lft_offset)), Some((rht_input, rht_offset))) =
833                        (op1.as_input_offset(), op2.as_input_offset())
834                    {
835                        match (lft_offset, rht_offset) {
836                            (Some(_), Some(_)) => None,
837                            (None, rht_offset @ Some(_)) => {
838                                Some(InequalityInputPair::new(lft_input, rht_input, rht_offset))
839                            }
840                            (Some((operator, operand)), None) => Some(InequalityInputPair::new(
841                                lft_input,
842                                rht_input,
843                                Some((
844                                    if operator == ExprType::Add {
845                                        ExprType::Subtract
846                                    } else {
847                                        ExprType::Add
848                                    },
849                                    operand,
850                                )),
851                            )),
852                            (None, None) => {
853                                Some(InequalityInputPair::new(lft_input, rht_input, None))
854                            }
855                        }
856                    } else {
857                        None
858                    }
859                }
860                _ => None,
861            }
862        } else {
863            None
864        }
865    }
866
867    /// Returns the `InputRef` and offset of a predicate if it matches
868    /// the form `InputRef [+- const_expr]`, else returns None.
869    fn as_input_offset(&self) -> Option<(usize, Option<(ExprType, ExprImpl)>)> {
870        match self {
871            ExprImpl::InputRef(input_ref) => Some((input_ref.index(), None)),
872            ExprImpl::FunctionCall(function_call) => {
873                let expr_type = function_call.func_type();
874                match expr_type {
875                    ExprType::Add | ExprType::Subtract => {
876                        let (_, lhs, rhs) = function_call.clone().decompose_as_binary();
877                        if let ExprImpl::InputRef(input_ref) = &lhs
878                            && rhs.is_const()
879                        {
880                            // Currently we will return `None` for non-literal because the result of the expression might be '1 day'. However, there will definitely exist false positives such as '1 second + 1 second'.
881                            // We will treat the expression as an input offset when rhs is `null`.
882                            if rhs.return_type() == DataType::Interval
883                                && rhs.as_literal().is_none_or(|literal| {
884                                    literal.get_data().as_ref().is_some_and(|scalar| {
885                                        let interval = scalar.as_interval();
886                                        interval.months() != 0 || interval.days() != 0
887                                    })
888                                })
889                            {
890                                None
891                            } else {
892                                Some((input_ref.index(), Some((expr_type, rhs))))
893                            }
894                        } else {
895                            None
896                        }
897                    }
898                    _ => None,
899                }
900            }
901            _ => None,
902        }
903    }
904
905    pub fn as_eq_const(&self) -> Option<(InputRef, ExprImpl)> {
906        if let ExprImpl::FunctionCall(function_call) = self
907            && function_call.func_type() == ExprType::Equal
908        {
909            match function_call.clone().decompose_as_binary() {
910                (_, ExprImpl::InputRef(x), y) if y.is_const() => Some((*x, y)),
911                (_, x, ExprImpl::InputRef(y)) if x.is_const() => Some((*y, x)),
912                _ => None,
913            }
914        } else {
915            None
916        }
917    }
918
919    pub fn as_eq_correlated_input_ref(&self) -> Option<(InputRef, CorrelatedInputRef)> {
920        if let ExprImpl::FunctionCall(function_call) = self
921            && function_call.func_type() == ExprType::Equal
922        {
923            match function_call.clone().decompose_as_binary() {
924                (_, ExprImpl::InputRef(x), ExprImpl::CorrelatedInputRef(y)) => Some((*x, *y)),
925                (_, ExprImpl::CorrelatedInputRef(x), ExprImpl::InputRef(y)) => Some((*y, *x)),
926                _ => None,
927            }
928        } else {
929            None
930        }
931    }
932
933    pub fn as_is_null(&self) -> Option<InputRef> {
934        if let ExprImpl::FunctionCall(function_call) = self
935            && function_call.func_type() == ExprType::IsNull
936        {
937            match function_call.clone().decompose_as_unary() {
938                (_, ExprImpl::InputRef(x)) => Some(*x),
939                _ => None,
940            }
941        } else {
942            None
943        }
944    }
945
946    pub fn as_comparison_const(&self) -> Option<(InputRef, ExprType, ExprImpl)> {
947        fn reverse_comparison(comparison: ExprType) -> ExprType {
948            match comparison {
949                ExprType::LessThan => ExprType::GreaterThan,
950                ExprType::LessThanOrEqual => ExprType::GreaterThanOrEqual,
951                ExprType::GreaterThan => ExprType::LessThan,
952                ExprType::GreaterThanOrEqual => ExprType::LessThanOrEqual,
953                _ => unreachable!(),
954            }
955        }
956
957        if let ExprImpl::FunctionCall(function_call) = self {
958            match function_call.func_type() {
959                ty @ (ExprType::LessThan
960                | ExprType::LessThanOrEqual
961                | ExprType::GreaterThan
962                | ExprType::GreaterThanOrEqual) => {
963                    let (_, op1, op2) = function_call.clone().decompose_as_binary();
964                    match (op1, op2) {
965                        (ExprImpl::InputRef(x), y) if y.is_const() => Some((*x, ty, y)),
966                        (x, ExprImpl::InputRef(y)) if x.is_const() => {
967                            Some((*y, reverse_comparison(ty), x))
968                        }
969                        _ => None,
970                    }
971                }
972                _ => None,
973            }
974        } else {
975            None
976        }
977    }
978
979    pub fn as_in_const_list(&self) -> Option<(InputRef, Vec<ExprImpl>)> {
980        if let ExprImpl::FunctionCall(function_call) = self
981            && function_call.func_type() == ExprType::In
982        {
983            let mut inputs = function_call.inputs().iter().cloned();
984            let input_ref = match inputs.next().unwrap() {
985                ExprImpl::InputRef(i) => *i,
986                _ => return None,
987            };
988            let list: Vec<_> = inputs
989                .inspect(|expr| {
990                    // Non constant IN will be bound to OR
991                    assert!(expr.is_const());
992                })
993                .collect();
994
995            Some((input_ref, list))
996        } else {
997            None
998        }
999    }
1000
1001    pub fn as_or_disjunctions(&self) -> Option<Vec<ExprImpl>> {
1002        if let ExprImpl::FunctionCall(function_call) = self
1003            && function_call.func_type() == ExprType::Or
1004        {
1005            Some(to_disjunctions(self.clone()))
1006        } else {
1007            None
1008        }
1009    }
1010
1011    pub fn to_project_set_select_item_proto(&self) -> ProjectSetSelectItem {
1012        use risingwave_pb::expr::project_set_select_item::SelectItem::*;
1013
1014        ProjectSetSelectItem {
1015            select_item: Some(match self {
1016                ExprImpl::TableFunction(tf) => TableFunction(tf.to_protobuf()),
1017                expr => Expr(expr.to_expr_proto()),
1018            }),
1019        }
1020    }
1021
1022    pub fn from_expr_proto(proto: &ExprNode) -> RwResult<Self> {
1023        let rex_node = proto.get_rex_node()?;
1024        let ret_type = proto.get_return_type()?.into();
1025
1026        Ok(match rex_node {
1027            RexNode::InputRef(column_index) => Self::InputRef(Box::new(InputRef::from_expr_proto(
1028                *column_index as _,
1029                ret_type,
1030            )?)),
1031            RexNode::Constant(_) => Self::Literal(Box::new(Literal::from_expr_proto(proto)?)),
1032            RexNode::Udf(udf) => Self::UserDefinedFunction(Box::new(
1033                UserDefinedFunction::from_expr_proto(udf, ret_type)?,
1034            )),
1035            RexNode::FuncCall(function_call) => {
1036                Self::FunctionCall(Box::new(FunctionCall::from_expr_proto(
1037                    function_call,
1038                    proto.get_function_type()?, // only interpret if it's a function call
1039                    ret_type,
1040                )?))
1041            }
1042            RexNode::Now(_) => Self::Now(Box::new(Now {})),
1043        })
1044    }
1045}
1046
1047impl From<Condition> for ExprImpl {
1048    fn from(c: Condition) -> Self {
1049        ExprImpl::and(c.conjunctions)
1050    }
1051}
1052
1053/// A custom Debug implementation that is more concise and suitable to use with
1054/// [`std::fmt::Formatter::debug_list`] in plan nodes. If the verbose output is preferred, it is
1055/// still available via `{:#?}`.
1056impl std::fmt::Debug for ExprImpl {
1057    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1058        if f.alternate() {
1059            return match self {
1060                Self::InputRef(arg0) => f.debug_tuple("InputRef").field(arg0).finish(),
1061                Self::Literal(arg0) => f.debug_tuple("Literal").field(arg0).finish(),
1062                Self::FunctionCall(arg0) => f.debug_tuple("FunctionCall").field(arg0).finish(),
1063                Self::FunctionCallWithLambda(arg0) => {
1064                    f.debug_tuple("FunctionCallWithLambda").field(arg0).finish()
1065                }
1066                Self::AggCall(arg0) => f.debug_tuple("AggCall").field(arg0).finish(),
1067                Self::Subquery(arg0) => f.debug_tuple("Subquery").field(arg0).finish(),
1068                Self::CorrelatedInputRef(arg0) => {
1069                    f.debug_tuple("CorrelatedInputRef").field(arg0).finish()
1070                }
1071                Self::TableFunction(arg0) => f.debug_tuple("TableFunction").field(arg0).finish(),
1072                Self::WindowFunction(arg0) => f.debug_tuple("WindowFunction").field(arg0).finish(),
1073                Self::UserDefinedFunction(arg0) => {
1074                    f.debug_tuple("UserDefinedFunction").field(arg0).finish()
1075                }
1076                Self::Parameter(arg0) => f.debug_tuple("Parameter").field(arg0).finish(),
1077                Self::Now(_) => f.debug_tuple("Now").finish(),
1078            };
1079        }
1080        match self {
1081            Self::InputRef(x) => write!(f, "{:?}", x),
1082            Self::Literal(x) => write!(f, "{:?}", x),
1083            Self::FunctionCall(x) => write!(f, "{:?}", x),
1084            Self::FunctionCallWithLambda(x) => write!(f, "{:?}", x),
1085            Self::AggCall(x) => write!(f, "{:?}", x),
1086            Self::Subquery(x) => write!(f, "{:?}", x),
1087            Self::CorrelatedInputRef(x) => write!(f, "{:?}", x),
1088            Self::TableFunction(x) => write!(f, "{:?}", x),
1089            Self::WindowFunction(x) => write!(f, "{:?}", x),
1090            Self::UserDefinedFunction(x) => write!(f, "{:?}", x),
1091            Self::Parameter(x) => write!(f, "{:?}", x),
1092            Self::Now(x) => write!(f, "{:?}", x),
1093        }
1094    }
1095}
1096
1097pub struct ExprDisplay<'a> {
1098    pub expr: &'a ExprImpl,
1099    pub input_schema: &'a Schema,
1100}
1101
1102impl std::fmt::Debug for ExprDisplay<'_> {
1103    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1104        let that = self.expr;
1105        match that {
1106            ExprImpl::InputRef(x) => write!(
1107                f,
1108                "{:?}",
1109                InputRefDisplay {
1110                    input_ref: x,
1111                    input_schema: self.input_schema
1112                }
1113            ),
1114            ExprImpl::Literal(x) => write!(f, "{:?}", x),
1115            ExprImpl::FunctionCall(x) => write!(
1116                f,
1117                "{:?}",
1118                FunctionCallDisplay {
1119                    function_call: x,
1120                    input_schema: self.input_schema
1121                }
1122            ),
1123            ExprImpl::FunctionCallWithLambda(x) => write!(
1124                f,
1125                "{:?}",
1126                FunctionCallDisplay {
1127                    function_call: &x.to_full_function_call(),
1128                    input_schema: self.input_schema
1129                }
1130            ),
1131            ExprImpl::AggCall(x) => write!(f, "{:?}", x),
1132            ExprImpl::Subquery(x) => write!(f, "{:?}", x),
1133            ExprImpl::CorrelatedInputRef(x) => write!(f, "{:?}", x),
1134            ExprImpl::TableFunction(x) => {
1135                // TODO: TableFunctionCallVerboseDisplay
1136                write!(f, "{:?}", x)
1137            }
1138            ExprImpl::WindowFunction(x) => {
1139                // TODO: WindowFunctionCallVerboseDisplay
1140                write!(f, "{:?}", x)
1141            }
1142            ExprImpl::UserDefinedFunction(x) => {
1143                write!(
1144                    f,
1145                    "{:?}",
1146                    UserDefinedFunctionDisplay {
1147                        func_call: x,
1148                        input_schema: self.input_schema
1149                    }
1150                )
1151            }
1152            ExprImpl::Parameter(x) => write!(f, "{:?}", x),
1153            ExprImpl::Now(x) => write!(f, "{:?}", x),
1154        }
1155    }
1156}
1157
1158impl std::fmt::Display for ExprDisplay<'_> {
1159    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1160        (self as &dyn std::fmt::Debug).fmt(f)
1161    }
1162}
1163
1164#[cfg(test)]
1165/// Asserts that the expression is an [`InputRef`] with the given index.
1166macro_rules! assert_eq_input_ref {
1167    ($e:expr, $index:expr) => {
1168        match $e {
1169            ExprImpl::InputRef(i) => assert_eq!(i.index(), $index),
1170            _ => assert!(false, "Expected input ref, found {:?}", $e),
1171        }
1172    };
1173}
1174
1175#[cfg(test)]
1176pub(crate) use assert_eq_input_ref;
1177use risingwave_common::bail;
1178use risingwave_common::catalog::Schema;
1179use risingwave_common::row::OwnedRow;
1180
1181use crate::binder::BoundSetExpr;
1182use crate::utils::Condition;
1183
1184#[cfg(test)]
1185mod tests {
1186    use super::*;
1187
1188    #[test]
1189    fn test_expr_debug_alternate() {
1190        let mut e = InputRef::new(1, DataType::Boolean).into();
1191        e = FunctionCall::new(ExprType::Not, vec![e]).unwrap().into();
1192        let s = format!("{:#?}", e);
1193        assert!(s.contains("return_type: Boolean"))
1194    }
1195}
risingwave_frontend/expr/mod.rs

risingwave_frontend/expr/
mod.rs
