Fixes/upgrades

protocol/mizan-codegen/python/pydantic_to_rust/templates/default.rs.j2

@@ -0,0 +1,29 @@
+{#- A default's body: one Rust expression, no trailing semicolon. -#}
+{%- macro default_body(node) -%}
+{%- if node.kind == "none" -%}::std::option::Option::None
+{%- elif node.kind == "unit" -%}::std::default::Default::default()
+{%- elif node.kind == "bool" -%}{{ "true" if node.value else "false" }}
+{%- elif node.kind == "int" -%}{{ node.value }}
+{%- elif node.kind == "float" -%}{{ node.value | rust_f64 }}
+{%- elif node.kind == "string" -%}String::from({{ node.value | rust_string }})
+{%- elif node.kind == "empty_vec" -%}::std::vec::Vec::new()
+{%- elif node.kind == "empty_map" -%}::std::collections::BTreeMap::new()
+{%- elif node.kind == "array" -%}[{% for element in node.elements %}{{ rust_value(element) }}{{ ", " if not loop.last }}{% endfor %}]
+{%- elif node.kind == "enum_variant" -%}{{ node.type }}::{{ node.variant }}
+{%- elif node.kind == "delegate" -%}<{{ node.type }} as ::std::default::Default>::default()
+{%- endif -%}
+{%- endmacro -%}
+
+{#- A JSON-shaped value whose typed shape is not carried alongside. -#}
+{%- macro rust_value(node) -%}
+{%- if node.kind == "unit" -%}::std::default::Default::default()
+{%- elif node.kind == "bool" -%}{{ "true" if node.value else "false" }}
+{%- elif node.kind == "int" -%}{{ node.value }}_i64
+{%- elif node.kind == "float" -%}{{ node.value | rust_f64 }}
+{%- elif node.kind == "string" -%}String::from({{ node.value | rust_string }})
+{%- elif node.kind == "empty_vec" -%}::std::vec::Vec::new()
+{%- elif node.kind == "empty_map" -%}::std::collections::BTreeMap::new()
+{%- elif node.kind == "vec" -%}vec![{% for element in node.elements %}{{ rust_value(element) }}{{ ", " if not loop.last }}{% endfor %}]
+{%- elif node.kind == "map" -%}[{% for pair in node.pairs %}(String::from({{ pair.key | rust_string }}), {{ rust_value(pair.value) }}){{ ", " if not loop.last }}{% endfor %}].into_iter().collect()
+{%- endif -%}
+{%- endmacro -%}

protocol/mizan-codegen/python/pydantic_to_rust/templates/struct.rs.j2

@@ -0,0 +1,38 @@
+{%- import "type.rs.j2" as types -%}
+{%- import "default.rs.j2" as defaults -%}
+{%- for line in doc_lines -%}
+/// {{ line }}
+{% endfor -%}
+#[derive({{ derives | join(", ") }})]
+{% for attr in extra_attrs -%}
+{{ attr }}
+{% endfor -%}
+pub struct {{ name }} {
+{%- for field in fields %}
+{%- if field.default_fn %}
+    #[serde(default = "{{ field.default_fn }}")]
+{%- endif %}
+    pub {{ field.ident }}: {{ types.rust_type(field.type) }},
+{%- endfor %}
+}
+
+{% for fn in default_fns -%}
+fn {{ fn.name }}() -> {{ types.rust_type(fn.type) }} { {{ defaults.default_body(fn.body) }} }
+{% endfor -%}
+{% if default_fns %}
+{% endif -%}
+{% if fields -%}
+impl Default for {{ name }} {
+    fn default() -> Self {
+        Self {
+{%- for field in fields %}
+{%- if field.default_fn %}
+            {{ field.ident }}: {{ field.default_fn }}(),
+{%- else %}
+            {{ field.ident }}: ::std::default::Default::default(),
+{%- endif %}
+{%- endfor %}
+        }
+    }
+}
+{% endif -%}

protocol/mizan-codegen/python/pydantic_to_rust/templates/type.rs.j2

@@ -0,0 +1,16 @@
+{#- Rust type spelling. `node` is the classified shape emit.py produces. -#}
+{%- macro rust_type(node) -%}
+{%- if node.kind == "primitive" -%}
+{%- if node.primitive == "integer" -%}i64
+{%- elif node.primitive == "number" -%}f64
+{%- elif node.primitive == "boolean" -%}bool
+{%- else -%}String
+{%- endif -%}
+{%- elif node.kind == "ref" -%}{{ node.name }}
+{%- elif node.kind == "array" -%}[{{ rust_type(node.element) }}; {{ node.length }}]
+{%- elif node.kind == "vec" -%}Vec<{{ rust_type(node.inner) }}>
+{%- elif node.kind == "option" -%}Option<{{ rust_type(node.inner) }}>
+{%- elif node.kind == "opaque" -%}::serde_json::Value
+{%- elif node.kind == "map" -%}::std::collections::BTreeMap<{{ rust_type(node.key) }}, {{ rust_type(node.value) }}>
+{%- endif -%}
+{%- endmacro -%}