Enable support for multiple variable assignments.
This happens in for loops, list comprehensions and simple assigment.
e.g.
a, b = expr
[a for a, b in expr]
--
MOS_MIGRATED_REVID=89123977
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
index 2a1b495..1637525 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
@@ -351,6 +351,44 @@
"bar/quux.java", "bar/quux.cc").inOrder();
}
+ @Test
+ public void testListComprehensionsMultipleVariables() throws Exception {
+ assertThat(eval("[x + y for x, y in [(1, 2), (3, 4)]]").toString())
+ .isEqualTo("[3, 7]");
+ assertThat(eval("[x + y for (x, y) in [[1, 2], [3, 4]]]").toString())
+ .isEqualTo("[3, 7]");
+ }
+
+ @Test
+ public void testListComprehensionsMultipleVariablesFail() throws Exception {
+ checkEvalError("[x + y for x, y, z in [(1, 2), (3, 4)]]",
+ "lvalue has length 3, but rvalue has has length 2");
+
+ checkEvalError("[x + y for x, y in (1, 2)]",
+ "type 'int' is not a collection");
+ }
+
+ @Test
+ public void testTupleDestructuring() throws Exception {
+ exec(parseFile("a, b = 1, 2"), env);
+ assertThat(env.lookup("a")).isEqualTo(1);
+ assertThat(env.lookup("b")).isEqualTo(2);
+
+ exec(parseFile("c, d = {'key1':2, 'key2':3}"), env);
+ assertThat(env.lookup("c")).isEqualTo("key1");
+ assertThat(env.lookup("d")).isEqualTo("key2");
+ }
+
+ @Test
+ public void testRecursiveTupleDestructuring() throws Exception {
+ List<Statement> input = parseFile("((a, b), (c, d)) = [(1, 2), (3, 4)]");
+ exec(input, env);
+ assertThat(env.lookup("a")).isEqualTo(1);
+ assertThat(env.lookup("b")).isEqualTo(2);
+ assertThat(env.lookup("c")).isEqualTo(3);
+ assertThat(env.lookup("d")).isEqualTo(4);
+ }
+
// TODO(bazel-team): should this test work in Skylark?
@SuppressWarnings("unchecked")
@Test
@@ -371,6 +409,7 @@
eval("{'k_' + d : d for d in ['a', 'b']}"));
assertEquals(ImmutableMap.of("k_a", "v_a", "k_b", "v_b"),
eval("{'k_' + e : 'v_' + e for e in ['a', 'b']}"));
+ assertEquals(ImmutableMap.of(5, 6), eval("{x+y : x*y for x, y in [[2, 3]]}"));
}
@Test
@@ -410,7 +449,8 @@
@Test
public void testInvalidAssignment() throws Exception {
Environment env = singletonEnv("x", 1);
- checkEvalError(parseStmt("x + 1 = 2"), env, "can only assign to variables, not to 'x + 1'");
+ checkEvalError(parseStmt("x + 1 = 2"), env,
+ "can only assign to variables and tuples, not to 'x + 1'");
}
@Test
