first commit

plugin/filter/ir.go

@@ -0,0 +1,159 @@
+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() {}