Add parsing for tuple types

test/mjsunit/harmony/typesystem/testgen.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var debug = false;
+
+function CheckValid(type) {
+  if (debug) { print("V:", type); }
+  assertDoesNotThrow("'use types'; var x: " + type + ";");
+}
+
+function CheckInvalid(type) {
+  if (debug) { print("I:", type); }
+  assertThrows("'use types'; var x: " + type + ";", SyntaxError);
+}
+
+// Parameters:
+//   multiplicity: positive integer
+//   generator: (size: positive integer, ...params: any[]) => Iterator<SomeType>
+//   transformations: [false | ((t: SomeType) => OtherType)]
+//   params: any[]
+//
+// A "test generator" object will have its "generator" generate tests,
+// will transform each generated test with all of its "transformations"
+// and will yield the results.  false transformations will be ignored.
+class TestGen {
+  constructor(multiplicity, generator, transformations, ...params) {
+    // Determines how often this generator will run, compared to other ones.
+    this.multiplicity = multiplicity;
+    // The generator function.  It will be called with (size, ...params),
+    // for an appropriate size provided externally to method initialize.
+    this.generator = generator;
+    // The list of transformation functions, excluding false ones.
+    this.transformations = transformations.filter(f => f !== false);
+    // The optional parameters to be passed to the generator function.
+    this.params = params;
+  }
+  // Returns how many tests this test generator is expected to yield
+  // in a row.
+  weight() {
+    return this.multiplicity * this.transformations.length;
+  }
+  // Initialize the generator function.
+  initialize(size) {
+    this.factory = this.generator(size, ...this.params);
+  }
+  // Is the test generator exhausted?
+  exhausted() {
+    return this.factory === null;
+  }
+  // Return a generator that will yield up to weight tests.
+  // It returns an Iterator<OtherType>.
+  * [Symbol.iterator]() {
+    for (let i = 0; i < this.multiplicity; i++) {
+      let element = this.factory.next();
+      if (element.done) {
+        this.factory = null;
+        return;
+      }
+      for (let f of this.transformations) yield f(element.value);
+    }
+  }
+}
+
+// Parameters:
+//   size:       positive integer
+//   generators: [false | string | TestGen]
+//
+// This generator function will yield up to size tests.  It will iterate
+// cyclically through the list of test generators.  A string in this list
+// behaves as a simple generator yielding just one test; a false value
+// behaves as a generator yielding nothing.  For every test generator in
+// the list, this function will generate as many tests as its weight
+// before proceeding to the next test generator.  Once a generator is
+// exhausted, it is ignored in subsequent iterations.
+function* Generate(size, generators) {
+  let fixed = 0, flexible = 0;
+  for (let gen of generators) {
+    if (gen === false) continue;
+    if (typeof gen === "string") fixed++;
+    else flexible += gen.weight();
+  }
+  if (fixed + flexible == 0) throw "Empty list of test generators";
+  let remaining = 0;
+  for (let gen of generators) {
+    if (gen === false) continue;
+    if (typeof gen !== "string") {
+      let weight = 1 + gen.weight();
+      gen.initialize(Math.ceil(size * weight / flexible));
+      remaining++;
+    }
+  }
+  for (let once = true; true; once = false) {
+    if (remaining == 0) return;
+    for (let gen of generators) {
+      if (gen === false) continue;
+      if (typeof gen === "string") {
+        if (once) {
+          if (size-- <= 0) return; else yield gen;
+        }
+        continue;
+      }
+      if (gen.exhausted()) continue;
+      for (let test of gen) {
+        if (size-- <= 0) return; else yield test;
+      }
+      if (gen.exhausted()) remaining--;
+    }
+  }
+}
+
+// Parameters:
+//   size:       positive integer
+//   generators: [string | TestGen]
+//
+// This function will generate all tests yielded by Generate and will
+// discard the results.  It will normally be called with test generators
+// whose transformation functions test for validity (e.g. CheckValid or
+// CheckInvalid) and do not return anything interesting.
+function Test(size, generators) {
+  for (let attempt of Generate(size, generators)) continue;
+}