pseudocode-interpreter

CC BY-SA 2021 Alfred Taylor & Conqu3red

(AQA) Exam Compatible Psuedocode V1 ALPHA (A.E.C.P/E.C.P)

PLEASE EXPECT LIMITED FUNCTIONALITY.

Introduction:

This is an adaptation of the pseudocode used by the AQA GCSE testing body (found here) that has had its syntax tweaked for use in a compiler and had some additional functionality added. The language will be fully Turing complete. Pseudocode found in tests is compatible with AECP/ECP. It is procedurally based, and shares similarities with python (It is programmed on python, after all.) It is intended as a scripting language, that is separate from python, but has the same basic functionality, whilst maintaining some resemblance of simplicity. Considering it is entirely written in python, it is not for use in situations where speed is a priority.

Interpreters

Currently we only have a python based interpreter, altough we have a C++ based interpreter coming soon.

How it works

AECP/ECP code is analysed and then parsed into a python AST (Abstract Syntax Tree). This can then be executed by the python interpreter. This allows near seamless integration with python and almost identical speed and behaviour.

Usage

Command Line arguments

usage: python -m ecp [-h] [--debug] [--trace [TRACE [TRACE ...]]] [--tracecompact] [--pause] [--version] [inputfile]

ECP interpreter

positional arguments:
  inputfile

optional arguments:
  -h, --help            show this help message and exit
  --debug               show debug information like token list
  --trace [TRACE [TRACE ...]]
                        space seperated names of the variables to be traced
  --tracecompact        trace compactly
  --pause               pause on completion
  --version             show program's version number and exit

Installation

pip install py-ecp

Running

python -m ecp path/to/ecp/file.ecp

Embedding ecp code in python files

from ecp import ecp

ecp("""
SUBROUTINE TotalOut(a, b)
    c ← a + b
    WHILE a < c
        a ← a + 1
        b ← b - a
    ENDWHILE
    RETURN b
ENDSUBROUTINE
""", scope=globals())

print(TotalOut(3, 4))

Converting ECp to python source code

python -m ecp path/to/ecp/file.ecp --topython

or:

from ecp import to_py_source
text = """
SUBROUTINE DoSomething(a, b)
    RETURN a + b
ENDSUBROUTINE
"""

print(to_py_source(text))

MORE COMING SOON!