https://github.com/knordman/esstee

Structured Text (ST) Interpreter
https://github.com/knordman/esstee

Last synced: 2 months ago
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Structured Text (ST) Interpreter

• Host: GitHub
• URL: https://github.com/knordman/esstee
• Owner: knordman
• License: gpl-3.0
• Created: 2014-03-10T20:38:33.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2017-03-13T21:36:00.000Z (almost 8 years ago)
• Last Synced: 2024-04-24T15:35:07.502Z (9 months ago)
• Language: C
• Homepage:
• Size: 620 KB
• Stars: 9
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• AwesomeInterpreter - esstee

README

        
# esstee

[![Build Status](https://travis-ci.org/knordman/esstee.svg?branch=master)](https://travis-ci.org/knordman/esstee)

esstee is an interpreter written in C (GNU C99), currently under work,

for the Structured Text (ST) programming language. Structured Text is

one of the five languages defined in the IEC-61131-3 standard, and

used a lot in the automation industry.

The aim of esstee is to provide a, "free as in freedom", platform for

building better testing and debug tools for ST applications. 

esstee is licensed under GPLv3. Besides Bison and Flex, esstee has no

external dependencies besides the header libraries included in the

source. Compiling has so far only been tested under Debian, but should

work without problems in any Linux distro.

## Quick Start

The first milestone of esstee is to provide a library that allows ST

syntax to be parsed into a representation which can be

stepped/run. The public interface to the library is defined in

`src/esstee/esstee.h`.

Currently, the parsing step of the library is complete (Flex and Bison

grammar). In addition there is support for types (elementary, derived

and complex), all statements and expressions, however it is not yet

properly tested (automatic integration tests not ready), and should be

considered as **under work**.

A simple test program using the library interface (and building all

the current code) can be built by;

```

make build/program-tester

```

The program parses ST syntax from a file, then executes possible "pre"

queries on the runnable representation, runs N cycles and finally

executes possible "post" queries. A query is either a variable

reference or an assignment. The program takes the following options:

- **file** the file to parse

- **program** the `PROGRAM` in the file that is to be run (a file may contain multiple programs)

- **pre-run-queries** the queries to run right after parsing

- **run-cycles** number of cycles to run (default 1)

- **post-run-queries** the queries to run after the cycles have been run

An example:

```

build/program-tester --file="src/tests/programs/example.ST" --program="testprgm" --pre-run-queries="testprgm.a:=10*5+1" --post-run-queries="testprgm.a" 

```

## Development

A rudimentary ticket list exists in `utils/todos-5.1.2016`.