Getting Started

Install, configure and run NETS parser.

Download and Installation

To download and install use npm.

npm -install nets-parser

The 'node_modules/nets-parser' folder contains the executables and libraries required to run NETS on all supported platforms including:

macos-x86-64
linux-x86-64
wasm-wasi-32
wasm-node-32
wasm-web-32

Configuration

Update the paths in nets-parser.js when using the wasm-node-32 build. If required add the node_modules/nets-parser folder to the PATH.

Executables and scripts are contained in the node_modules/nets-parser root folder. Tests are contained in the tests subfolder.

Dependencies

Native executables depend on system libraries. Use lld nets-parser to determine these on Linux or otool -L nets-parser on MacOS. Platform version dependencies are undocumented at present.

The wasm-wasi-32 build depends on a Web Assembly (WASM) and Web Aassembly System Interface (WASI) runtime such as Wasmtime. The wasm-node-32 build depends on node > v12.x. The wasm-web-32 build depends on a WASM capable web browser.

Running

NETS is started from the command line by invoking the 'nets-parser' executable.


            > nets-parser-macos-x86-64-v1.0 [arguments]

nets-parser-macos-x86-64-v1.0d is the executable file name on MacOS for the x86 64 bit architrecture, in debug mode.

To see more detailed logging information set -loglevel=3


            > nets-parser-macos-x86-64-v1.0 -loglevel=3

NETS3 Command Line Interface MacOS-x64-v1.0. (C) Copyright 2020 NETS3 Ltd 16/10/15 18:12:45 INF 6908:3 Working directory c:\netscli 16/10/15 18:12:45 INF 6908:3 Opening grammar library nets-parser-iconv 16/10/15 18:12:45 INF 6908:3 Opening grammar library nets-parser-library 16/10/15 18:12:45 ERR 6908:3 Opening default.g file 16/10/15 18:12:45 ERR 6908:3 Cannot start parser. Parser needs to be initialised.

The Node and Wasmtime executables run in a very similar way and details are given documentation in the Command Line Interface documentation.

Version

v1.0.2462 31-01-2021 (latest)

Initial support for linux-x86-64

v1.0.2443 26-01-2021

Initial support for macos-x86-64, wasm-wasi-32, wasm-node-32 and wasm-web-32 architectures
Initial feature set including ISO 14977, EBNF, PEG, Grammar XML, pipelines, input/output semantics, abstract syntax trees, logging, breakpoints, single byte characters, wide characters, echo, production terminals, predicates
Internal libraries ctype, utility, compress, encrypt, command
External libraries encrypt and iconv

Hello World

The parser needs an to be configured with a grammar, an input and an output.


            >nets-parser -loglevel=3 -grammar="mem:start={wchar.};" -input="mem:Hello World" -output=stdout -grammar_encoding="WCHAR_T" -encoding="WCHAR_T/ASCII"

NETS3 Command Line Interface v1.0. (C) Copyright 2016 NETS3 Ltd 16/10/15 18:45:58 INF 8040:3 Working directory c:\netscli 16/10/15 18:45:58 INF 8040:3 Opening grammar library nets-parser-iconv 16/10/15 18:45:58 INF 8040:3 Opening grammar library nets-parser-library 16/10/15 18:45:58 INF 8040:3 Parser started 16/10/15 18:45:58 INF 8040:3 Parser ended Hello World16/10/15 18:45:58 INF 8040:3 Closing error file

Notice that in addition to the -input, -output and -grammar parameters the -grammar_encoding and -encoding parameters are required to read the grammar and input from memory.

A Simple Grammar

Now create two files default.g and default.in with the following code snippets.


            start={char.};

The grammar is constructed using a rule ('start'), an iteration (using '{}'), a rule reference ('char'), the echo paramater ('.') and the end of rule symbol (';'). This grammar repeatedely reads a character from the input and echos it to the output until no more characters can be found.


            Hello World

Run nets-parser with default.g as the grammar, default.in as the input and default.out as the output.


            >nets-parser -loglevel=3 -grammar=default.g -input=default.in -output=default.out

NETS3 Command Line Interface v1.0. (C) Copyright 2016 NETS3 Ltd 16/10/15 19:02:13 INF 6820:3 Working directory c:\netscli 16/10/15 19:02:13 INF 6820:3 Opening grammar library nets-parser-iconv 16/10/15 19:02:13 INF 6820:3 Opening grammar library nets-parser-library 16/10/15 19:02:13 INF 6820:3 Opening default.g file 16/10/15 19:02:13 INF 6820:32 Parse finished before end of input by 2 bytes 16/10/15 19:02:13 INF 6820:3 Closing file default.g 16/10/15 19:02:13 INF 6820:3 Parser started 16/10/15 19:02:13 INF 6820:3 Opening default.in file 16/10/15 19:02:13 INF 6820:3 Opening default.out file 16/10/15 19:02:13 INF 6820:3 Parser ended 16/10/15 19:02:13 INF 6820:3 Closing file default.in 16/10/15 19:02:13 INF 6820:3 Closing file default.out 16/10/15 19:02:13 INF 6820:3 Closing error file

The result will be the following.


            Hello World