Update OPy README with the shell commands I use.

A lot of the commands there had "rotted".

opy/README.md

@@ -1,29 +1,67 @@
OPy Compiler
============
OPy Compiler and Byterun
========================

Getting started / smoke test:
The OPy compiler is a Python bytecode compiler written in Python.  See
[Building Oil with the OPy Bytecode Compiler][oil-with-opy].  It's currently
used to translate Python source code in Oil to `.pyc` files.

    ./build.sh grammar
    ./run.sh parse-test
    ./run.sh compile-hello2  # prints hello world
    ./run.sh compile-hello3  # no __future__ print_function
The `byterun/` directory is a fork of [byterun][].  It's an experiment for
learning what it will take to write a minimal interpreter for Oil.  It can
curretly run all the Oil unit tests, but isn't otherwise used.

Compiling Oil:
[oil-with-opy]: http://www.oilshell.org/blog/2018/03/04.html

    ./build.sh oil-repo  # makes _tmp/osh-opy and _tmp/osh-ccompile
[byterun]: http://aosabook.org/en/500L/a-python-interpreter-written-in-python.html

Testing:
Getting started
---------------

    ./test.sh unit  # Run Oil unit tests
Start with https://github.com/oilshell/oil/wiki/Contributing .  This is
necessary to build the `py27.grammar` file and so forth.

Test the binary:
Then:

    ./test.sh osh-help 
    ./test.sh osh-version 
    ./test.sh spec smoke
    ./test.sh spec all  # Failures due to $0
    $ ./smoke.sh opy-hello2  # basic test of compiler and runtime

OPy Divergences from CPython
Compile Oil with the OPy compiler:

    $ ./build.sh oil-repo  # makes _tmp/osh-opy and _tmp/osh-ccompile

Run Oil unit tests, compiled with OPy, under CPython:

    $ ./test.sh oil-unit

Run Oil unit tests, compiled with OPy, under byterun (OPyPy):

    $ ./test.sh oil-unit-byterun   # Run Oil unit tests, compiled with OPy, under CPython


Another way I test it like this:

    $ testdata/regex_compile.py  # run with CPython
    $ ../bin/opyc run testdata/regex_compile.py

(TODO: these should be gold tests)


Demo: speed difference between OSH under CPython and OSH under byterun/OPyPy:

    ./demo.sh opypy-speed

TODO:

- Spec tests
  - ./test.sh spec all  # Some failures due to $0

OPy Compiler Regtest
--------------------

This uses golden data in `_regtest/`.

    ./regtest.sh compile  # note: different files than 'build.sh oil-repo'
    ./regtest.sh verify-golden

OPy Compiler Divergences from CPython
----------------------------

### Lexer
@@ -48,8 +86,3 @@ OPy Divergences from CPython
  histogram using `opy/misc/inspect_pyc`.
- The OPy bytecode is bigger than the CPython bytecode!  Why is that?

### Other

OSH tests don't run under byterun.  I probably don't care.

    ./test.sh unit '' byterun

scripts/opy.sh → opy/demo.sh

@@ -7,12 +7,18 @@ set -o nounset
set -o pipefail
set -o errexit

readonly THIS_DIR=$(cd $(dirname $0) && pwd)

# Show the difference between OSH running under CPython and OSH running under
# byterun.
opypy-demo() {
opypy-speed() {
  pushd $THIS_DIR/..

  local prog='for i in $(seq 10); do echo $i; done'
  time bin/osh -c "$prog"
  time bin/opypy-osh -c "$prog"

  popd
}

"$@"

opy/test.sh

@@ -12,32 +12,10 @@ readonly OPYC=$THIS_DIR/../bin/opyc

source $THIS_DIR/common.sh

osh-opy() {
  _tmp/oil-opy/bin/osh "$@"
}

oil-opy() {
  _tmp/oil-opy/bin/oil "$@"
}

osh-help() {
  osh-opy --help
}

# TODO: Add compiled with "OPy".
# How will it know?  You can have a special function bin/oil.py:
# def __GetCompilerName__():
#   return "CPython"
#
# If the function name is opy stub, then Opy ret
#
# Or __COMPILER_NAME__ = "CPython"
# The OPy compiler can rewrite this to "OPy".

osh-version() {
  osh-opy --version
}

# TODO:
# - Run with oil.ovm{,-dbg}