Add license types to the documentation

Fixes #642.

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MOS_MIGRATED_REVID=125351602

1 files changed, 48 insertions, 0 deletions

diff --git a/site/docs/skylark/bzl-style.md b/site/docs/skylark/bzl-style.md
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+
+# .bzl file style guide
+
+## Style
+
+* When in doubt, follow the
+  [Python style guide](https://www.python.org/dev/peps/pep-0008/).
+
+* Code should be documented using
+  [docstrings](https://www.python.org/dev/peps/pep-0257/). Use a docstring at
+  the top of the file, and a docstring for each public function.
+
+* Variables and function names use lowercase with words separated by underscores
+  (`[a-z][a-z0-9_]*`), e.g. `cc_library`. Top-level private values start with
+  one underscore. Bazel enforces that private values cannot be used from other
+  files.
+
+* As in BUILD files, there is no strict line length limit as labels can be long.
+  When possible, try to use at most 79 characters per line.
+
+* In keyword arguments, spaces around the equal sign are optional. In general,
+  we follow the BUILD file convention when calling macros and native rules, and
+  the Python convention for other functions, e.g.
+
+```python
+def fct(name, srcs):
+  filtered_srcs = my_filter(source=srcs)
+  native.cc_library(
+    name = name,
+    srcs = filtered_srcs,
+  )
+```
+
+## Macros
+
+A [macro](macros.md) is a function which instantiates one or many rules during
+the loading phase.
+
+* Macros must accept a name attribute and each invocation should specify a name.
+  The generated name attribute of rules should include the name attribute as a
+  prefix. For example, `my_macro(name = "foo")` can generate a rule `foo` and a
+  rule `foo_gen`. *Rationale*: Users should be able to find easily which macro
+  generated a rule. Also, automated refactoring tools need a way to identify a
+  specific rule to edit.
+
+* When calling a macro, use only keyword arguments. *Rationale*: This is for
+  consistency with rules, it greatly improves readability.
+