From 7a2b987920afbc62a1b252a29ff7ce832a49396b Mon Sep 17 00:00:00 2001
From: Purdea Andrei <andrei@purdea.ro>
Date: Sun, 4 Aug 2024 01:40:03 +0300
Subject: [PATCH] docs/stdlib/data: view value-likes can't be used _anywhere_
values can
Clarify where View value-likes can/can't be used like plain values
---
docs/stdlib/data.rst | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/docs/stdlib/data.rst b/docs/stdlib/data.rst
index be8448e11..6fd9e205a 100644
--- a/docs/stdlib/data.rst
+++ b/docs/stdlib/data.rst
@@ -81,12 +81,24 @@ While this implementation works, it is repetitive, error-prone, hard to read, an
m.d.comb += o_gray.eq((i_color.red + i_color.green + i_color.blue) << 1)
-The :class:`View` is :ref:`value-like <lang-valuelike>` and can be used anywhere a plain value can be used. For example, it can be assigned to in the usual way:
+Signals with a layout based shape are automatically wrapped in the :class:`View` :ref:`value-like <lang-valuelike>` wrapper, and can be used in many places where a plain value can be used. For example, it can be assigned to in the usual way:
.. testcode::
m.d.comb += i_color.eq(0) # everything is black
+They can be compared for equality with other value-like objects of the same layout, however they cannot be compared with value-like objects of other shapes, and most operators are also not supported:
+
+.. testcode::
+
+ other_color = Signal(rgb565_layout)
+
+ i_color == other_color
+
+ # The following expressions would raise a TypeError:
+ # i_color == 0
+ # i_color | 1
+
Composing layouts
+++++++++++++++++