Function createTypeChecker

test/fixtures/snapshot/typescript.js:48232–89260

(host)

    }
    ts.isInstantiatedModule = isInstantiatedModule;
    function createTypeChecker(host) {
        var getPackagesMap = ts.memoize(function () {
            // A package name maps to true when we detect it has .d.ts files.
            // This is useful as an approximation of whether a package bundles its own types.
            // Note: we only look at files already found by module resolution,
            // so there may be files we did not consider.
            var map = new ts.Map();
            host.getSourceFiles().forEach(function (sf) {
                if (!sf.resolvedModules)
                    return;
                sf.resolvedModules.forEach(function (r) {
                    if (r && r.packageId)
                        map.set(r.packageId.name, r.extension === ".d.ts" /* Extension.Dts */ || !!map.get(r.packageId.name));
                });
            });
            return map;
        });
        var deferredDiagnosticsCallbacks = [];
        var addLazyDiagnostic = function (arg) {
            deferredDiagnosticsCallbacks.push(arg);
        };
        // Cancellation that controls whether or not we can cancel in the middle of type checking.
        // In general cancelling is *not* safe for the type checker.  We might be in the middle of
        // computing something, and we will leave our internals in an inconsistent state.  Callers
        // who set the cancellation token should catch if a cancellation exception occurs, and
        // should throw away and create a new TypeChecker.
        //
        // Currently we only support setting the cancellation token when getting diagnostics.  This
        // is because diagnostics can be quite expensive, and we want to allow hosts to bail out if
        // they no longer need the information (for example, if the user started editing again).
        var cancellationToken;
        var requestedExternalEmitHelpers;
        var externalHelpersModule;
        var Symbol = ts.objectAllocator.getSymbolConstructor();
        var Type = ts.objectAllocator.getTypeConstructor();
        var Signature = ts.objectAllocator.getSignatureConstructor();
        var typeCount = 0;
        var symbolCount = 0;
        var enumCount = 0;
        var totalInstantiationCount = 0;
        var instantiationCount = 0;
        var instantiationDepth = 0;
        var inlineLevel = 0;
        var currentNode;
        var varianceTypeParameter;
        var emptySymbols = ts.createSymbolTable();
        var arrayVariances = [1 /* VarianceFlags.Covariant */];
        var compilerOptions = host.getCompilerOptions();
        var languageVersion = ts.getEmitScriptTarget(compilerOptions);
        var moduleKind = ts.getEmitModuleKind(compilerOptions);
        var useDefineForClassFields = ts.getUseDefineForClassFields(compilerOptions);
        var allowSyntheticDefaultImports = ts.getAllowSyntheticDefaultImports(compilerOptions);
        var strictNullChecks = ts.getStrictOptionValue(compilerOptions, "strictNullChecks");
        var strictFunctionTypes = ts.getStrictOptionValue(compilerOptions, "strictFunctionTypes");
        var strictBindCallApply = ts.getStrictOptionValue(compilerOptions, "strictBindCallApply");
        var strictPropertyInitialization = ts.getStrictOptionValue(compilerOptions, "strictPropertyInitialization");
        var noImplicitAny = ts.getStrictOptionValue(compilerOptions, "noImplicitAny");
        var noImplicitThis = ts.getStrictOptionValue(compilerOptions, "noImplicitThis");