Update documentation of `dict`, mention it's mutable.

RELNOTES: None.
PiperOrigin-RevId: 162505701

1 files changed, 3 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java
index 08318226b5..40c9c9ddb3 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkDict.java
@@ -31,13 +31,15 @@ import javax.annotation.Nullable;
       "A language built-in type representating a dictionary (associative mapping). "
           + "Dictionaries may be constructed with a special literal syntax:<br>"
           + "<pre class=\"language-python\">d = {\"a\": 2, \"b\": 5}</pre>"
+          + "See also the <a href=\"globals.html#dict\">dict()</a> constructor function. "
           + "When using the literal syntax, it is an error to have duplicated keys. "
           + "Use square brackets to access elements:<br>"
           + "<pre class=\"language-python\">e = d[\"a\"]   # e == 2</pre>"
           + "Like lists, they can also be constructed using a comprehension syntax:<br>"
           + "<pre class=\"language-python\">d = {i: 2*i for i in range(20)}\n"
           + "e = d[8]       # e == 16</pre>"
-          + "See also the <a href=\"globals.html#dict\">dict()</a> constructor function. "
+          + "Dictionaries are mutable. You can add new elements or mutate existing ones:"
+          + "<pre class=\"language-python\">d[\"key\"] = 5</pre>"
           + "<p>Iterating over a dict is equivalent to iterating over its keys. The "
           + "<code>in</code> operator tests for membership in the keyset of the dict.<br>"
           + "<pre class=\"language-python\">\"a\" in {\"a\" : 2, \"b\" : 5} "