kubernetes/vendor/github.com/google/cel-go/cel/inlining.go

type InlineVariable …

// Name returns the qualified variable or field selection to replace.
func (v *InlineVariable) Name() string { … }

// Alias returns the alias to use when performing cel.bind() calls during inlining.
func (v *InlineVariable) Alias() string { … }

// Expr returns the inlined expression value.
func (v *InlineVariable) Expr() ast.Expr { … }

// Type indicates the inlined expression type.
func (v *InlineVariable) Type() *Type { … }

// NewInlineVariable declares a variable name to be replaced by a checked expression.
func NewInlineVariable(name string, definition *Ast) *InlineVariable { … }

// NewInlineVariableWithAlias declares a variable name to be replaced by a checked expression.
// If the variable occurs more than once, the provided alias will be used to replace the expressions
// where the variable name occurs.
func NewInlineVariableWithAlias(name, alias string, definition *Ast) *InlineVariable { … }

// NewInliningOptimizer creates and optimizer which replaces variables with expression definitions.
//
// If a variable occurs one time, the variable is replaced by the inline definition. If the
// variable occurs more than once, the variable occurences are replaced by a cel.bind() call.
func NewInliningOptimizer(inlineVars ...*InlineVariable) ASTOptimizer { … }

type inliningOptimizer …

func (opt *inliningOptimizer) Optimize(ctx *OptimizerContext, a *ast.AST) *ast.AST { … }

// inlineExpr replaces the current expression with the inlined one, unless the location of the inlining
// happens within a presence test, e.g. has(a.b.c) -> inline alpha for a.b.c in which case an attempt is
// made to determine whether the inlined value can be presence or existence tested.
func (opt *inliningOptimizer) inlineExpr(ctx *OptimizerContext, prev ast.NavigableExpr, inlined ast.Expr, inlinedType *Type) { … }

// rewritePresenceExpr converts the inlined expression, when it occurs within a has() macro, to type-safe
// expression appropriate for the inlined type, if possible.
//
// If the rewrite is not possible an error is reported at the inline expression site.
func (opt *inliningOptimizer) rewritePresenceExpr(ctx *OptimizerContext, prev, inlined ast.Expr, inlinedType *Type) { … }

// isBindable indicates whether the inlined type can be used within a cel.bind() if the expression
// being replaced occurs within a presence test. Value types with a size() method or field selection
// support can be bound.
//
// In future iterations, support may also be added for indexer types which can be rewritten as an `in`
// expression; however, this would imply a rewrite of the inlined expression that may not be necessary
// in most cases.
func isBindable(matches []ast.NavigableExpr, inlined ast.Expr, inlinedType *Type) bool { … }

// matchVariable matches simple identifiers, select expressions, and presence test expressions
// which match the (potentially) qualified variable name provided as input.
//
// Note, this function does not support inlining against select expressions which includes optional
// field selection. This may be a future refinement.
func (opt *inliningOptimizer) matchVariable(varName string) ast.ExprMatcher { … }