Initial implementation of gendo: an LLM-based programming language

[thejhh]

This PR and branch is obsolete. Current work is done in the gnd repository: https://github.com/hyperifyio/gnd/pulls

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This pull request introduces the first working version of Gendo, a simple, node-based programming language designed to orchestrate LLM behavior through declarative flows. Gendo allows you to define how inputs are parsed, processed, and returned—entirely through structured prompt logic and tool integration.

✅ Included Example: examples/calculator.gendo

This example demonstrates a minimal but fully functional program that turns natural language into a math result using an OpenAI-compatible LLM backend:

# Calculator example using math tool

# Error handler
2: Explain what went wrong with the calculation in simple terms.

# If any following operation fails, it goes to node 2 for error explanation
2!

# Input formatter (from stdin)
0: Extract the mathematical operation from the text. Return only the mathematical expression, removing any natural language. For example: "What is 1 plus 1?" -> "1 + 1", "Calculate 5 times 3" -> "5 * 3", "Divide 10 by 2" -> "10 / 2"

# Result formatter (to stdout)
1: Format the calculation result in a natural language response. For example: If input is "2", respond with "The result is 2."

# Define a math tool for calculations
3: tool math

# Formatted input lines go to math tool
3 < 0

# Math result goes to the output formatter
1 < 3

🧪 How to Run

This example runs with any OpenAI-compatible LLM backend. For local testing, we use Microsoft's BitNet:

export GENDO_API_BASE=http://localhost:18080/v1
export GENDO_API_KEY=
export GENDO_MODEL=bitnet
make
echo 'What is 1+1?' | ./gendo examples/calculator.gendo

Expected output:

The result is 2.

🧠 Behind the Scenes

This Gendo program consists of:

• A natural language input formatter (node 0)
• A math tool (node 3) that performs the actual computation
• A result formatter (node 1) that constructs the output
• An error handler (node 2) that explains failures in user-friendly terms
• Node routing: 3 < 0 and 1 < 3, with fallback to 2! for all nodes

🚀 BitNet Setup

You can run the BitNet LLM server locally like this:

./build/bin/llama-server --alias bitnet \
  -m models/BitNet-b1.58-2B-4T/ggml-model-i2_s.gguf \
  --host 0.0.0.0 --port 18080 -t 3 -np 2 --prio 3

No GPU is required. BitNet runs in approximately 2 GB of RAM.

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Feedback is especially welcome on:

• Node syntax and chaining (< and !)
• Prompt conventions and formatting
• Error routing behavior
• Tool integration patterns

This release lays the foundation for building composable LLM-based applications with declarative logic.

[Copilot]

Pull Request Overview

This PR provides the initial implementation for the Gendo programming language with integration to a local BitNet server running an OpenAI‐compatible API.

• Implements a logging package with different verbosity levels.
• Integrates the OpenAI LLM interface and registers it within the runtime.
• Establishes the core engine to parse and process Gendo scripts and nodes.

Reviewed Changes

Copilot reviewed 18 out of 29 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
pkg/log/log.go	New logging functions for debug, info, and error reporting.
pkg/llm/openai/openai.go	OpenAI LLM integration including API key management and request handling.
pkg/llm/llm.go	Defines the LLM interface and registry.
internal/gendo/gendo_test.go	Unit tests for node processing ensuring expected prompt and input handling.
internal/gendo/gendo.go	Implements the script execution engine and processing chain for nodes.
examples/README.md	Documentation on script examples and configuration details.
cmd/gendo/main.go	Command-line entry point for running Gendo scripts.
README.md	Updated language specification for Gendo.
LICENSE	Updated license information.

Files not reviewed (11)

• .cursor/rules/development-workflow.mdc: Language not supported
• .cursor/rules/llm-integration.mdc: Language not supported
• .cursor/rules/math-tool.mdc: Language not supported
• .cursor/rules/project-structure.mdc: Language not supported
• .cursor/rules/testing-requirements.mdc: Language not supported
• Makefile: Language not supported
• examples/calculator.gendo: Language not supported
• examples/file_processor.gendo: Language not supported
• examples/hello.gendo: Language not supported
• examples/random_story.gendo: Language not supported
• go.mod: Language not supported

[Copilot]

Pull Request Overview

This pull request introduces the initial implementation of Gendo, an LLM-based programming language for orchestrating language model behavior through node-based pipelines. Key changes include a core LLM interface and registry (pkg/llm/llm.go), the main Gendo engine for processing nodes and script I/O (internal/gendo/gendo.go), and comprehensive tests and documentation updates that demonstrate tool integration and node chaining.

Reviewed Changes

Copilot reviewed 26 out of 38 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
pkg/llm/llm.go	Defines the LLM interface and registry for language model implementations.
internal/gendo/gendo_test.go	Introduces unit tests for node processing and prompt handling.
internal/gendo/gendo.go	Implements core processing logic for nodes, I/O, error handling, and routing.
examples/README.md	Provides example scripts and configuration guidelines for Gendo.
cmd/gendo/main.go	Adds the command-line interface to run Gendo scripts.
README.md	Updates the language specification and documentation for Gendo.
LICENSE	Updates the copyright information.
.github/copilot-instructions.md	Contains internal Copilot instructions for code review.

Files not reviewed (12)

• .cursor/rules/development-workflow.mdc: Language not supported
• .cursor/rules/git-commit-practices.mdc: Language not supported
• .cursor/rules/llm-integration.mdc: Language not supported
• .cursor/rules/math-tool.mdc: Language not supported
• .cursor/rules/project-structure.mdc: Language not supported
• .cursor/rules/testing-requirements.mdc: Language not supported
• Makefile: Language not supported
• examples/calculator.gendo: Language not supported
• examples/file_processor.gendo: Language not supported
• examples/hello.gendo: Language not supported
• examples/random_story.gendo: Language not supported
• go.mod: Language not supported

[Copilot]

[nitpick] Consider refactoring the hard-coded node ID loop into a more flexible mechanism (e.g., iterating based on dynamic node chaining order) to enhance scalability and maintainability.