(no commit message)

[libreriscv.git] / HDL_workflow.mdwn

diff --git a/HDL_workflow.mdwn b/HDL_workflow.mdwn
index d56c31520fd98276892139fee3862152910e65e2..90ee9c614db82b7618e9b6ee9e9f6ee22cfda4f5 100644 (file)
--- a/HDL_workflow.mdwn
+++ b/HDL_workflow.mdwn
@@ -389,7 +389,7 @@ flows.
 prior to installing any further python-based Libre-SOC HDL repositories.
 If "pip3 list" shows that nmigen has been auto-installed please remove it**
 
-[nmigen](https://nmigen.info/) may be installed as follows:
+[nmigen](https://m-labs.hk/gateware/nmigen/) may be installed as follows:
 
 * mkdir ~/src
 * cd !$
@@ -898,6 +898,55 @@ easy-to-find message, it cannot even be located, and once found, if the
 commit confuses several unrelated changes, not only the diff is larger
 than it should be, the reversion process becomes extremely painful.
 
+### PHP-style python format-strings
+
+As the name suggests, "PHP-style" is not given as a compliment.
+Format-strings - `f"{variable} {pythoncodefragment}" are a nightmare
+to read.  The lesson from PHP, Zope and Plone: when code is embedded,
+the purpose of the formatting - the separation of the format from
+the data to be placed in it - is merged, and consequently become
+unreadable.
+
+By contrast, let us imagine a situation where 12 variables need to
+be inserted into a string, four of which are the same variablename:
+
+     x = "%s %s %s %s %s %s %s %s %s %s %s %s" % (var1, var2, var3,
+                                                  var3, var4, var2,
+                                                  var1, var9, var1,
+                                                  var3, var4, var1)
+
+This is just as unreadable, but for different reasons.  Here it *is*
+useful to do this as:
+
+     x = f"{var1} {var2} {var3}" \
+         ...
+         f"{var3} {var4} {var1}"
+
+As a general rule, though, format-specifiers should be strongly
+avoided, given that they mix even variable-names directly inside
+a string.
+
+This additionally gives text editors (and online web syntax
+highlighters) the opportunity to colour syntax-highlight the
+ASCII string (the format) from the variables to be inserted *into*
+that format.  gitweb for example (used by this project) cannot
+highlight string-formatted code.
+
+It turns out that colour is processed by the **opposite** hemisphere
+of the brain from written language.  Thus, colour-syntax-highlighting
+is not just a "nice-to-have", it's **vital** for easier and faster
+identification of context and an aid to rapid understanding.
+
+Anything that interferes with that - such as python format-strings -
+has to take a back seat, regardless of its perceived benefits.
+
+**If you absolutely must** use python-format-strings, **only** do
+so by restricting to variables.  Create temporary variables if you
+have to.
+
+    y = '/'.join(a_list)
+    x = f"{y}"
+
 ### PEP8 format
 
 * all code needs to conform to pep8.  use either pep8checker or better
@@ -1124,8 +1173,10 @@ with further details as to why the unit test should not be run.
 5. Assign the budget to the task in `"USER=SUM"` form, where "USER"
   corresponds to your username and "SUM" corresponds to the actual
   budget in EUR. There may be multiple users.
-6. When the task is completed, you can begin writing an RFP. **do not**
-   submit it without authorisation.
+6. When the task is completed, you can begin writing an RFP.
+   **DO NOT submit it without explicit authorisation and review**.
+   Leave out your bank and personal address details if you prefer
+   when sending to the Team Manager for review.
 7. Once the RFP is written, notify the Team Manager and obtain their
    explicit approval to send it.
 8. Once approval is received and the RFP sent, update the `"USER=SUM"`
@@ -1141,6 +1192,8 @@ Throughout all of this you should be using budget-sync to check the
 database consistency
 <https://git.libre-soc.org/?p=utils.git;a=blob;f=README.txt;hb=HEAD>
 
+[[!img bugzilla_RFP_fields.jpg size=640x ]]
+
 # TODO Tutorials
 
 Find appropriate tutorials for nmigen and yosys, as well as symbiyosys.