feat: Add hugr-to-json encoding, and validate it (#83)

guppy/hugr/hugr.py

@@ -777,3 +777,7 @@ def to_raw(self) -> raw.RawHugr:
     def serialize(self) -> bytes:
         """Serialize this Hugr in binary format."""
         return self.to_raw().packb()
+
+    def serialize_json(self) -> str:
+        """Serialize this Hugr in JSON format."""
+        return self.to_raw().to_json()

guppy/hugr/raw.py

@@ -1,4 +1,4 @@
-from typing import Literal
+from typing import Any, Literal
 
 import ormsgpack
 from pydantic import BaseModel
@@ -17,6 +17,16 @@ class RawHugr(BaseModel):
     def packb(self) -> bytes:
         return ormsgpack.packb(self.model_dump(), option=ormsgpack.OPT_NON_STR_KEYS)
 
+    def to_json(self) -> str:
+        """Return a JSON representation of the Hugr."""
+        return self.model_dump_json()
+
     @classmethod
     def unpackb(cls, b: bytes) -> "RawHugr":
+        """Decode a msgpack-encoded Hugr."""
         return cls(**ormsgpack.unpackb(b, option=ormsgpack.OPT_NON_STR_KEYS))
+
+    @classmethod
+    def load_json(cls, json: dict[Any, Any]) -> "RawHugr":
+        """Decode a JSON-encoded Hugr."""
+        return cls(**json)

tests/integration/conftest.py

@@ -14,8 +14,14 @@ def export_test_cases_dir(request):
 @pytest.fixture()
 def validate(request, export_test_cases_dir):
     def validate_impl(hugr, name=None):
+        # Validate via the msgpack encoding
         bs = hugr.serialize()
         util.validate_bytes(bs)
+
+        # Validate via the json encoding
+        js = hugr.serialize_json()
+        util.validate_json(js)
+
         if export_test_cases_dir:
             file_name = f"{request.node.name}{f'_{name}' if name else ''}.msgpack"
             export_file = export_test_cases_dir / file_name

tests/integration/util.py

@@ -4,7 +4,11 @@
 
 
 def validate_bytes(hugr: bytes):
-    validator.validate(hugr)
+    validator.validate_bytes(hugr)
+
+
+def validate_json(hugr: str):
+    validator.validate_json(hugr)
 
 
 class Decorator:

validator/Cargo.toml

@@ -13,3 +13,4 @@ pyo3 = "0.19.0"
 quantinuum-hugr = { git = "https://github.com/CQCL/hugr.git", rev = "d07406c13b03a93014ae08a70bb789b25e0b31eb" }
 rmp-serde = "1.1.1"
 lazy_static = "1.4.0"
+serde_json = "1.0.111"

validator/src/lib.rs

@@ -16,15 +16,25 @@ lazy_static! {
     .unwrap();
 }
 
+/// Validate a msgpack-encoded Hugr
 #[pyfunction]
-fn validate(hugr: Vec<u8>) -> PyResult<()> {
+fn validate_bytes(hugr: Vec<u8>) -> PyResult<()> {
     let hg: hugr::Hugr = rmp_serde::from_slice(&hugr).unwrap();
     hg.validate(&REGISTRY).unwrap();
     Ok(())
 }
 
+/// Validate a json-encoded Hugr
+#[pyfunction]
+fn validate_json(hugr: String) -> PyResult<()> {
+    let hg: hugr::Hugr = serde_json::from_str(&hugr).unwrap();
+    hg.validate(&REGISTRY).unwrap();
+    Ok(())
+}
+
 #[pymodule]
 fn validator(_py: Python, m: &PyModule) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(validate, m)?)?;
+    m.add_function(wrap_pyfunction!(validate_bytes, m)?)?;
+    m.add_function(wrap_pyfunction!(validate_json, m)?)?;
     Ok(())
 }