memos/plugin/filter/ir.go
Johnny cbf46a2988 feat(filter): add CEL list comprehension support for tag filtering
Add support for CEL exists() comprehension with startsWith, endsWith, and
contains predicates to enable powerful tag filtering patterns.

Features:
- tags.exists(t, t.startsWith("prefix")) - Match tags by prefix
- tags.exists(t, t.endsWith("suffix")) - Match tags by suffix
- tags.exists(t, t.contains("substring")) - Match tags by substring
- Negation: !tags.exists(...) to exclude matching tags
- Works with all operators (AND, OR, NOT) and other filters

Implementation:
- Added ListComprehensionCondition IR type for comprehension expressions
- Parser detects exists() macro and extracts predicates
- Renderer generates optimized SQL for SQLite, MySQL, PostgreSQL
- Proper NULL/empty array handling across all database dialects
- Helper functions reduce code duplication

Design decisions:
- Only exists() supported (all() rejected at parse time with clear error)
- Only simple predicates (matches() excluded to avoid regex complexity)
- Fail-fast validation with helpful error messages

Tests:
- Comprehensive test suite covering all predicates and edge cases
- Tests for NULL/empty arrays, combined filters, negation
- Real-world use case test for Issue #5480 (archive workflow)
- All tests pass on SQLite, MySQL, PostgreSQL

Closes #5480
2026-01-17 12:36:39 +08:00

159 lines
3.7 KiB
Go

package filter
// Condition represents a boolean expression derived from the CEL filter.
type Condition interface {
isCondition()
}
// LogicalOperator enumerates the supported logical operators.
type LogicalOperator string
const (
LogicalAnd LogicalOperator = "AND"
LogicalOr LogicalOperator = "OR"
)
// LogicalCondition composes two conditions with a logical operator.
type LogicalCondition struct {
Operator LogicalOperator
Left Condition
Right Condition
}
func (*LogicalCondition) isCondition() {}
// NotCondition negates a child condition.
type NotCondition struct {
Expr Condition
}
func (*NotCondition) isCondition() {}
// FieldPredicateCondition asserts that a field evaluates to true.
type FieldPredicateCondition struct {
Field string
}
func (*FieldPredicateCondition) isCondition() {}
// ComparisonOperator lists supported comparison operators.
type ComparisonOperator string
const (
CompareEq ComparisonOperator = "="
CompareNeq ComparisonOperator = "!="
CompareLt ComparisonOperator = "<"
CompareLte ComparisonOperator = "<="
CompareGt ComparisonOperator = ">"
CompareGte ComparisonOperator = ">="
)
// ComparisonCondition represents a binary comparison.
type ComparisonCondition struct {
Left ValueExpr
Operator ComparisonOperator
Right ValueExpr
}
func (*ComparisonCondition) isCondition() {}
// InCondition represents an IN predicate with literal list values.
type InCondition struct {
Left ValueExpr
Values []ValueExpr
}
func (*InCondition) isCondition() {}
// ElementInCondition represents the CEL syntax `"value" in field`.
type ElementInCondition struct {
Element ValueExpr
Field string
}
func (*ElementInCondition) isCondition() {}
// ContainsCondition models the <field>.contains(<value>) call.
type ContainsCondition struct {
Field string
Value string
}
func (*ContainsCondition) isCondition() {}
// ConstantCondition captures a literal boolean outcome.
type ConstantCondition struct {
Value bool
}
func (*ConstantCondition) isCondition() {}
// ValueExpr models arithmetic or scalar expressions whose result feeds a comparison.
type ValueExpr interface {
isValueExpr()
}
// FieldRef references a named schema field.
type FieldRef struct {
Name string
}
func (*FieldRef) isValueExpr() {}
// LiteralValue holds a literal scalar.
type LiteralValue struct {
Value interface{}
}
func (*LiteralValue) isValueExpr() {}
// FunctionValue captures simple function calls like size(tags).
type FunctionValue struct {
Name string
Args []ValueExpr
}
func (*FunctionValue) isValueExpr() {}
// ListComprehensionCondition represents CEL macros like exists(), all(), filter().
type ListComprehensionCondition struct {
Kind ComprehensionKind
Field string // The list field to iterate over (e.g., "tags")
IterVar string // The iteration variable name (e.g., "t")
Predicate PredicateExpr // The predicate to evaluate for each element
}
func (*ListComprehensionCondition) isCondition() {}
// ComprehensionKind enumerates the types of list comprehensions.
type ComprehensionKind string
const (
ComprehensionExists ComprehensionKind = "exists"
)
// PredicateExpr represents predicates used in comprehensions.
type PredicateExpr interface {
isPredicateExpr()
}
// StartsWithPredicate represents t.startsWith("prefix").
type StartsWithPredicate struct {
Prefix string
}
func (*StartsWithPredicate) isPredicateExpr() {}
// EndsWithPredicate represents t.endsWith("suffix").
type EndsWithPredicate struct {
Suffix string
}
func (*EndsWithPredicate) isPredicateExpr() {}
// ContainsPredicate represents t.contains("substring").
type ContainsPredicate struct {
Substring string
}
func (*ContainsPredicate) isPredicateExpr() {}