Method rewritePresenceExpr

cel/inlining.go:154–188

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.

(ctx *OptimizerContext, prev, inlined ast.Expr, inlinedType *Type)

//
// 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) {
	// If the input inlined expression is not a select expression it won't work with the has()
	// macro. Attempt to rewrite the presence test in terms of the typed input, otherwise error.
	if inlined.Kind() == ast.SelectKind {
		presenceTest, hasMacro := ctx.NewHasMacro(prev.ID(), inlined)
		ctx.UpdateExpr(prev, presenceTest)
		ctx.SetMacroCall(prev.ID(), hasMacro)
		return
	}

	ctx.ClearMacroCall(prev.ID())
	if inlinedType.IsAssignableType(NullType) {
		ctx.UpdateExpr(prev,
			ctx.NewCall(operators.NotEquals,
				inlined,
				ctx.NewLiteral(types.NullValue),
			))
		return
	}
	if inlinedType.HasTrait(traits.SizerType) {
		ctx.UpdateExpr(prev,
			ctx.NewCall(operators.NotEquals,
				ctx.NewMemberCall(overloads.Size, inlined),
				ctx.NewLiteral(types.IntZero),
			))
		return
	}
	if zeroValExpr, ok := zeroValueExpr(ctx, inlinedType); ok {
		ctx.UpdateExpr(prev,
			ctx.NewCall(operators.NotEquals,
				inlined, zeroValExpr))
		return
	}
	ctx.ReportErrorAtID(prev.ID(), "unable to inline expression type %v into presence test", inlinedType)
}

// zeroValueExpr creates an expression representing the empty or zero value for the given type
// Note: bytes, lists, maps, and strings are supported via the `SizerType` trait.