Added fable docker

fable/docker/Dockerfile

@@ -0,0 +1,39 @@
+# syntax=docker/dockerfile:1.4
+# use latest debian
+FROM debian:sid-slim
+
+ENV RUNLEVEL 1
+ENV DEBIAN_FRONTEND noninteractive
+ENV LC_ALL C.UTF-8
+
+RUN <<EOF
+#!/usr/bin/env bash
+set -exo pipefail
+
+# update OS
+apt-get -y update
+apt-get -y upgrade
+
+# install cctbx
+declare -ar pkgs=(
+    # seems to be needed
+    #10 70.95 Setting up dbus-system-bus-common (1.16.0-1) ...
+    #10 70.96 Can't locate Encode.pm in @INC (you may need to install the Encode module)
+    'libencode-perl'
+    # this is huge, qt, hdf...
+    'python3-cctbx'
+    # fable wants to compile c++
+    'g++'
+)
+apt-get -y --no-install-recommends install "${pkgs[@]}"
+
+# run fable to check works
+fable.cout --example
+
+# docker cleanup
+apt-get -y autoremove --purge
+rm -rf /var/lib/apt/lists/*
+EOF
+
+# /usr/bin
+ENTRYPOINT ["fable.cout"]

fable/docker/README.md

@@ -0,0 +1,44 @@
+
+docker to run fable FORTRAN converter
+
+# remember name of docker to build
+```
+export DOCK_NAME='fable-dock'
+```
+
+# build fable docker
+```
+docker buildx build -t ${DOCK_NAME} .
+```
+
+# run bash in fable docker
+# overriding entrypoint
+```
+docker run -i --entrypoint /usr/bin/env -t ${DOCK_NAME} bash
+```
+
+# run fable, see help
+```
+docker run -it ${DOCK_NAME}
+```
+
+# run fable --example to current dir
+# fable.cout and fable_cout.cpp are created
+```
+docker run -i -w $(pwd) --volume=$(pwd):$(pwd):rw -t ${DOCK_NAME} --example
+```
+
+# run fable on local files
+# send cout to cpp file
+```
+declare -ar cmda=(
+    docker run -i -w $(pwd)
+    --volume=$(pwd):$(pwd):rw
+    -t ${DOCK_NAME}
+     <user fortran file>
+     <user fortran file>
+    --namespace <user namespace>
+)
+
+${cmda[@]} > <user cpp file>
+```