François
4ef110ab70
ImportBase opened the input with a default std::fstream (in|out), which had two consequences: a missing file silently produced an empty module (no error), and a present-but-read-only file failed to open and also loaded as empty. Open the stream read-only (std::ios::in) instead, and expose is_open(). System::Load now builds the importer first, checks is_open(), and throws "cannot open file: <path>" before creating the module — so a failed load surfaces as `load failed: …` and leaves no empty module behind. A read-only but present file now loads correctly. Flip the test that pinned the old silent-empty behaviour to assert the clean failure (error + no module created). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
essim — system digital twin
Interactive simulator for the inter-card connections inside a system. Built around a domain model of modules → parts → pins / signals → connections, with importers for Mentor Graphics, Altium and ODS pinout sheets, a TUI shell with scripting, snapshots and BFS net analysis.
Status: early work-in-progress.
Quick start
cmake -S . -B build
cmake --build build -j
./build/essim
The build is layered: essim_core is the frontend-agnostic business
library (domain + importers + operations); the essim binary comes from a
frontend under src/frontends/<name>/ that links it. Select one with
-DESSIM_FRONTEND=<name> (default tui); -DESSIM_FRONTEND=none builds the
core + tests only, with no GUI toolkit fetched. Architecture in
DESIGN.md.
Inside the shell, type help for the live command list — or read the
auto-generated reference at doc/user/commands.md.
A worked bring-up script is at test/system.essim;
load it with source test/system.essim.
To run a script without the TUI and print its output to stdout (CI-friendly):
./build/essim --batch --source bring-up.essim
Step-by-step walkthroughs for both the batch and TUI workflows are in
doc/user/tutorial.md.
Dependencies
- C++17 compiler and CMake 3.14+.
- System libraries libzip and pugixml — install the development
packages:
- Debian/Ubuntu —
sudo apt install libzip-dev libpugixml-dev - Arch —
sudo pacman -S libzip pugixml - Fedora —
sudo dnf install libzip-devel pugixml-devel
- Debian/Ubuntu —
- libbsdl — the standalone BSDL parser, a sibling repo expected at
../libbsdl, pulled in viaadd_subdirectoryand linked dynamically. Override its location with-DBSDL_DIR=/path/to/libbsdl. Powers theattach-bsdlcommand and the pin/JTAG checks. - Fetched automatically via
FetchContent(nothing to install): FTXUI v6.1.9 — only when building the tui frontend — and doctest v2.4.11 for the tests. - Optional, only for the
doctarget: doxygen and python3.
libzip, pugixml and libbsdl are the core dependencies; FTXUI belongs to the
tui frontend, so a -DESSIM_FRONTEND=none build needs none of it.
Tests
./build/essim_tests
# or
ctest --test-dir build
ctest runs essim_tests (core — links essim_core, no GUI toolkit) and
essim_tui_tests (the FTXUI frontend's tests, under tests/tui/).
Skip building tests entirely:
cmake -S . -B build -DBUILD_TESTING=OFF
Documentation
doc/user/— user guide, command reference, scripting.doc/api/— auto-generated C++ API reference.DESIGN.md— implementation notes (domain conventions, TUI internals, gotchas).doc/README.md— how the doc pipeline is wired.
Regenerate auto-generated parts after substantive code changes:
cmake --build build --target doc # needs doxygen + python3
Project layout
src/
core/ business logic, NO GUI toolkit (→ libessim_core)
domain/ model (Module/Part/Pin/Signal, Connection, Transform…) + analyses
imports/ Mentor / Altium / ODS netlist importers + ODS writer
app/ use-case operations (export → CSV/ODS, …)
frontends/ one dir per GUI/TUI engine, each links essim_core
tui/ FTXUI shell + main.cpp (→ libessim_tui + the `essim` binary)
tests/ core tests (link essim_core)
tui/ frontend tests (link essim_tui)
doc/ api/ + user/ Markdown, Doxyfile.in, gen_api_md.py
test/ sample netlists + system.essim bring-up script
Full layout & rationale in DESIGN.md.
Licence
Copyright (c) 2026 François Dausseur
Licensed under the European Union Public Licence (EUPL), Version 1.2 —
the "Licence". You may not use this work except in compliance with the
Licence. You may obtain a copy of the Licence in the LICENSE
file or at https://joinup.ec.europa.eu/software/page/eupl.
Unless required by applicable law or agreed to in writing, software distributed under the Licence is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the Licence for the specific language governing permissions and limitations under the Licence.
SPDX-License-Identifier: EUPL-1.2