Function getFactsFromTypeofSwitch

test/fixtures/snapshot/typescript.js:77974–78009

* Collect the TypeFacts learned from a typeof switch with * total clauses `witnesses`, and the active clause ranging * from `start` to `end`. Parameter `hasDefault` denotes * whether the active clause contains a default clause.

(start, end, witnesses, hasDefault)

         * whether the active clause contains a default clause.
         */
        function getFactsFromTypeofSwitch(start, end, witnesses, hasDefault) {
            var facts = 0 /* TypeFacts.None */;
            // When in the default we only collect inequality facts
            // because default is 'in theory' a set of infinite
            // equalities.
            if (hasDefault) {
                // Value is not equal to any types after the active clause.
                for (var i = end; i < witnesses.length; i++) {
                    facts |= typeofNEFacts.get(witnesses[i]) || 32768 /* TypeFacts.TypeofNEHostObject */;
                }
                // Remove inequalities for types that appear in the
                // active clause because they appear before other
                // types collected so far.
                for (var i = start; i < end; i++) {
                    facts &= ~(typeofNEFacts.get(witnesses[i]) || 0);
                }
                // Add inequalities for types before the active clause unconditionally.
                for (var i = 0; i < start; i++) {
                    facts |= typeofNEFacts.get(witnesses[i]) || 32768 /* TypeFacts.TypeofNEHostObject */;
                }
            }
            // When in an active clause without default the set of
            // equalities is finite.
            else {
                // Add equalities for all types in the active clause.
                for (var i = start; i < end; i++) {
                    facts |= typeofEQFacts.get(witnesses[i]) || 128 /* TypeFacts.TypeofEQHostObject */;
                }
                // Remove equalities for types that appear before the
                // active clause.
                for (var i = 0; i < start; i++) {
                    facts &= ~(typeofEQFacts.get(witnesses[i]) || 0);
                }
            }
            return facts;
        }
        function isExhaustiveSwitchStatement(node) {
            var links = getNodeLinks(node);
            return links.isExhaustive !== undefined ? links.isExhaustive : (links.isExhaustive = computeExhaustiveSwitchStatement(node));