Emacs polymode for Markdown and Python - emacs

Question

I use the python3 pweave library (http://mpastell.com/pweave/usage.html) for literate programming.
pweave uses as text mode markdown, as code mode python3,
and it is possible to use noweb (https://en.wikipedia.org/wiki/Noweb) literate programming syntax.
For correct syntax highlighting in emacs I aimed to use the polymode library (https://polymode.github.io/ and https://github.com/polymode).
I use emacs version26.1.
And I was able to install polymode from melpa.
Unfortunate there is no pre-existing polymode for
host-mode: markdown, inner-mode: python3, syntax: noweb
so I tried, based on documentation and the existing code, to write my one
poly-pweave-mode, by putting the following lisp code into my .emacs file.
(require 'polymode-classes)
(defcustom pm-host/pweave-text
(pm-host-chunkmode :name "pweave-text"
:mode 'markdown-mode)
"markdown host chunkmode"
:group 'poly-hostmodes
:type 'object)
(defcustom pm-inner/pweave-code
(pm-inner-chunkmode :name "pweave-code"
:head-matcher "^[ \t]*<<\\(.*\\)>>="
:tail-matcher "^[ \t]*#.*$"
:mode 'python-mode)
"noweb static python3 inner chunkmode."
:group 'poly-innermodes
:type 'object)
(define-polymode poly-pweave-mode
:hostmode 'pm-host/pweave-text
:innermode 'pm-inner/pweave-code)
(add-to-list 'auto-mode-alist '("\\.pymd" . poly-pweave-mode))
But somehow emacs is not eating this.
When I open emacs I get the following error:
Warning (initialization): An error occurred while loading `/Users/abc/.emacs':
Symbol's function definition is void: pm-host-chunkmode
To ensure normal operation, you should investigate and remove the
cause of the error in your initialization file. Start Emacs with
the `--debug-init' option to view a complete error backtrace.
What do I wrong?
How I could get the desired polymode running?

Answer 1

This is the solution how to specify a markdown-python3-noweb polymode
;; define pwn polymode
(require 'poly-noweb)
(require 'poly-markdown)
(defcustom pm-inner/noweb-python
(clone pm-inner/noweb
:name "noweb-python"
:mode 'python-mode)
"Noweb for Python"
:group 'poly-innermodes
:type 'object)
(define-polymode poly-pweave-mode poly-markdown-mode
:innermodes '(pm-inner/noweb-python :inherit))
(add-to-list 'auto-mode-alist '("\\.pymd" . poly-pweave-mode))
My thank goes to Vitalie Spinu, the author of the polymode package, who helped me resolving this question!
For a detailed discussion have a look at polymode issue 180 at github.
Alternatively I found this post at emacs stack exchange: https://emacs.stackexchange.com/questions/20136/pythontex-and-auctex So, following this post, this is the solution to get to a markdown-python3-noweb mmm-mode
;; define pwn multi major modes mode
(require 'mmm-auto)
(mmm-add-classes
'((noweb-python
:submode python-mode
:face mmm-default-submode-face
:front "^<<.*>>=\n"
:back "^#$")))
(setq mmm-global-mode 'maybe)
(mmm-add-mode-ext-class 'markdown-mode nil 'noweb-python)
(add-to-list 'auto-mode-alist '("\\.pymd" . markdown-mode))
My thank belongs to Jean Pierre, whose detailed explanation in the post made it a piece of cake to get it running for my case!