Add basic routine visualization and update README

.flake8

@@ -25,4 +25,7 @@ ignore =
 per-file-ignores =
     tests/**/test_*.py:D103,D102,D101
     __init__.py:F401
-
+copyright-check = True
+copyright-regexp = Copyright\s+(©\s+)?\d{4}([-,]\d{4})*\s+%(author)s
+copyright-author = PsiQuantum Corp.
+copyright-min-file-size = 1

.github/workflows/quality_checks.yaml

@@ -13,6 +13,8 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
+      - name: Setup Graphviz
+        uses: ts-graphviz/setup-graphviz@v2
       - name: Install dependencies and the package
         run: |
           python -m pip install --upgrade pip poetry

.pre-commit-config.yaml

@@ -20,4 +20,4 @@ repos:
     rev: 6.0.0
     hooks:
       - id: flake8
-
+        additional_dependencies: [flake8-copyright]

README.md

@@ -1,2 +1,141 @@
-# hqar
-Hierarchical Quantum Algorithms Representation
+# HQAR
+Hierarchical Quantum Algorithms Representation is an open format for representing
+quantum algorithms, optimized for usage in quantum resource estimation (QRE).
+
+HQAR comprises:
+
+- Definition of data format, formalized as a JSON schema.
+- A Python library for validation of quantum programs written in HQAR format using [Pydantic](https://docs.pydantic.dev/).
+- Rudimentary visualization tool `hqar-render`.
+
+## Installation
+
+Using HQAR data format does not require installation - you can easily write quantum
+programs in YAML or JSON.
+
+To install HQAR Python package, clone this repository and install it as usual with `pip`:
+
+```bash
+# Clone HQAR repo (you can use HTTP link as well)
+git clone git@github.com:PsiQ/hqar.git
+cd hqar
+pip install .
+```
+
+## HQAR format
+
+HQAR format represents quantum programs as a hierarchical directed acyclic graphs (DAGs).
+That's a mouthful, so let us unpack what it means:
+
+- *hierarchical*: each node can contain subgraphs, i.e. routines can be nested inside
+  larger routines.
+- *directed*: information flow is unidirectional, and the direction is unambiguous.
+- *acyclic*: meaning there are no loops.
+
+Consider the following hierarchical DAG of a hypothetical quantum program:
+
+![program example](example_routine.svg)
+
+It can be succinctly written in HQAR format as:
+
+
+```yaml
+version: v1
+program:
+  name: my_algorithm
+  ports:
+  - direction: input
+    name: in_0
+    size: 2
+  - direction: input
+    name: in_1
+    size: 2
+  - direction: output
+    name: out_0
+    size: 4
+  children:
+  - name: subroutine_1
+    ports:
+    - direction: input
+      name: in_0
+      size: 2
+    - direction: output
+      name: out_0
+      size: 3
+  - name: subroutine_2
+    ports:
+    - direction: input
+      name: in_0
+      size: 2
+    - direction: output
+      name: out_0
+      size: 1
+    - direction: output
+      name: out_1
+      size: 1
+  - name: merge
+    ports:
+    - direction: input
+      name: in_0
+      size: 1
+    - direction: input
+      name: in_1
+      size: 1
+    - direction: input
+      name: in_2
+      size: 2
+    - direction: output
+      name: out_0
+      size: 4
+  connections:
+  - source: in_0
+    target: subroutine_1.in_0
+  - source: in_1
+    target: subroutine_2.in_0
+  - source: subroutine_1.out_0
+    target: merge.in_2
+  - source: subroutine_2.out_0
+    target: merge.in_0
+  - source: subroutine_2.out_1
+    target: merge.in_1
+  - source: merge.out_0
+    target: out_0
+```
+
+
+For full description of HQAR format, check our [docs](https://example.com).
+
+## Using HQAR package
+
+### Using JSON schema for validating data in HQAR format
+
+JSON schema for HQAR format can be obtained by calling `generate_program_schema` function.
+Such schema can be then used for validating user's input, e.g. using `jsonschema` package:
+
+```python
+from jsonschema import validate
+from hqar import generate_program_schema
+
+# Hypothetical function loading your data as native Python dictionary.
+data = load_some_program()  
+schema = generate_program_schema()
+
+# This will raise if there are some validation errors.
+validate(schema, data)
+```
+
+### Validation using Pydantic models
+
+If you are familiar with Pydantic, you might find it easier to work with HQAR Pydantic
+models instead of interacting with JSON schema directly. In the example below, we create
+an instance of `SchemaV1` model from validated data stored in HQAR format:
+
+```python
+from hqar import SchemaV1
+
+data = load_some_program()
+
+# This will raise if data is not valid
+program = SchemaV1.model_validate(data)
+```
+

example_routine.yaml

@@ -0,0 +1,60 @@
+version: v1
+program:
+  name: my_algorithm
+  ports:
+  - direction: input
+    name: in_0
+    size: 2
+  - direction: input
+    name: in_1
+    size: 2
+  - direction: output
+    name: out_0
+    size: 4
+  children:
+  - name: subroutine_1
+    ports:
+    - direction: input
+      name: in_0
+      size: 2
+    - direction: output
+      name: out_0
+      size: 3
+  - name: subroutine_2
+    ports:
+    - direction: input
+      name: in_0
+      size: 2
+    - direction: output
+      name: out_0
+      size: 1
+    - direction: output
+      name: out_1
+      size: 1
+  - name: merge
+    ports:
+    - direction: input
+      name: in_0
+      size: 1
+    - direction: input
+      name: in_1
+      size: 1
+    - direction: input
+      name: in_2
+      size: 2
+    - direction: output
+      name: out_0
+      size: 4
+  connections:
+  - source: in_0
+    target: subroutine_1.in_0
+  - source: in_1
+    target: subroutine_2.in_0
+  - source: subroutine_1.out_0
+    target: merge.in_2
+  - source: subroutine_2.out_0
+    target: merge.in_0
+  - source: subroutine_2.out_1
+    target: merge.in_1
+  - source: merge.out_0
+    target: out_0

pyproject.toml

@@ -9,6 +9,7 @@ readme = "README.md"
 [tool.poetry.dependencies]
 python = "^3.9"
 pydantic = "^2.0"
+graphviz = "^0.20.3"
 
 
 [tool.poetry.group.dev.dependencies]
@@ -19,6 +20,11 @@ black = "^24.2.0"
 pyyaml = "^6"
 jsonschema = "^4"
 
+
+[tool.poetry.scripts]
+hqar-render = "hqar.experimental.rendering:render_entry_point"
+
+
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
@@ -27,3 +33,8 @@ build-backend = "poetry.core.masonry.api"
 [tool.black]
 line-length = 100
 target-version = ['py39']
+
+
+[[tool.mypy.overrides]]
+module = "graphviz.*"
+ignore_missing_imports = true