Initial golang implementation

The initial implementation of the golang binding generation. This
implementation is currently incomplete, as it is missing a few key
features, namely:
 * Linking support

And probably more, as well as many architectural problems

However, this is implementation is sufficient to start getting feedback
on the general structure of the bindings

src/shacl2code/lang/__init__.py

@@ -10,3 +10,4 @@
 from .jinja import JinjaRender  # noqa: F401
 from .jsonschema import JsonSchemaRender  # noqa: F401
 from .python import PythonRender  # noqa: F401
+from .golang import GoLangRender  # noqa: F401

src/shacl2code/lang/golang.py

@@ -0,0 +1,238 @@
+#
+# Copyright (c) 2024 Joshua Watt
+#
+# SPDX-License-Identifier: MIT
+
+from .common import BasicJinjaRender
+from .lang import language, TEMPLATE_DIR
+
+import re
+import keyword
+
+GO_KEYWORDS = (
+    "break",
+    "default",
+    "func",
+    "interface",
+    "select",
+    "case",
+    "defer",
+    "go",
+    "map",
+    "struct",
+    "chan",
+    "else",
+    "goto",
+    "package",
+    "switch",
+    "const",
+    "fallthrough",
+    "if",
+    "range",
+    "type",
+    "continue",
+    "for",
+    "import",
+    "return",
+    "var",
+)
+
+
+def varname(*name, public=True):
+    new_name = []
+    for n in name:
+        for s in re.split(r"[^a-zA-Z0-9]+", n):
+            if not s:
+                continue
+            new_name.append(s)
+    if public:
+        new_name = [s[0].upper() + s[1:] for s in new_name]
+    else:
+        new_name = [new_name[0][0].lower() + new_name[0][1:]] + [
+            s[0].upper() + s[1:] for s in new_name[1:]
+        ]
+    new_name = "".join(new_name)
+    if new_name in GO_KEYWORDS:
+        new_name = new_name + "_"
+    return new_name
+
+
+def struct_name(cls):
+    return varname(*cls.clsname) + "Object"
+
+
+def interface_name(cls):
+    return varname(*cls.clsname)
+
+
+def class_type_var(cls):
+    return varname(*cls.clsname, public=False) + "Type"
+
+
+def prop_name(prop):
+    return varname(prop.varname, public=False)
+
+
+def prop_is_list(prop):
+    return prop.max_count is None or prop.max_count != 1
+
+
+def prop_go_type(prop, classes):
+    if prop.enum_values:
+        return "string"
+
+    if prop.class_id:
+        intf = interface_name(classes.get(prop.class_id))
+        return f"Ref[{intf}]"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#string":
+        return "string"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#anyURI":
+        return "string"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#integer":
+        return "int"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#positiveInteger":
+        return "int"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#nonNegativeInteger":
+        return "int"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#boolean":
+        return "bool"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#decimal":
+        return "float64"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#dateTime":
+        return "time.Time"
+
+    if prop.datatype == "http://www.w3.org/2001/XMLSchema#dateTimeStamp":
+        return "time.Time"
+
+    raise Exception("Unknown data type " + prop.datatype)  # pragma: no cover
+
+
+def prop_ctx_name(cls, prop):
+    return varname(*cls.clsname, public=False) + varname(prop.varname) + "Context"
+
+
+def prop_decode_func(cls, prop, classes):
+    if prop.enum_values:
+        func = "DecodeIRI"
+
+    elif prop.class_id:
+        func = "Decode" + interface_name(classes.get(prop.class_id))
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#string":
+        func = "DecodeString"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#anyURI":
+        func = "DecodeString"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#integer":
+        func = "DecodeInteger"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#positiveInteger":
+        func = "DecodeInteger"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#nonNegativeInteger":
+        func = "DecodeInteger"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#boolean":
+        func = "DecodeBoolean"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#decimal":
+        func = "DecodeFloat"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#dateTime":
+        func = "DecodeDateTime"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#dateTimeStamp":
+        func = "DecodeDateTimeStamp"
+
+    else:
+        raise Exception("Unknown data type " + prop.datatype)  # pragma: no cover
+
+    if prop_is_list(prop):
+        return f"DecodeList[{prop_go_type(prop, classes)}](value, path, {prop_ctx_name(cls, prop)}, {func})"
+
+    return f"{func}(value, path, {prop_ctx_name(cls, prop)})"
+
+
+def prop_encode_func(cls, prop, classes):
+    if prop.enum_values:
+        func = "EncodeIRI"
+
+    elif prop.class_id:
+        func = "EncodeRef[" + interface_name(classes.get(prop.class_id)) + "]"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#string":
+        func = "EncodeString"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#anyURI":
+        func = "EncodeString"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#integer":
+        func = "EncodeInteger"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#positiveInteger":
+        func = "EncodeInteger"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#nonNegativeInteger":
+        func = "EncodeInteger"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#boolean":
+        func = "EncodeBoolean"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#decimal":
+        func = "EncodeFloat"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#dateTime":
+        func = "EncodeDateTime"
+
+    elif prop.datatype == "http://www.w3.org/2001/XMLSchema#dateTimeStamp":
+        func = "EncodeDateTime"
+
+    else:
+        raise Exception("Unknown data type " + prop.datatype)  # pragma: no cover
+
+    if prop_is_list(prop):
+        return f'EncodeList[{prop_go_type(prop, classes)}](self.{prop_name(prop)}.Get(), path.PushPath("{prop_name(prop)}"), {prop_ctx_name(cls, prop)}, state, {func})'
+
+    return f'{func}(self.{prop_name(prop)}.Get(), path.PushPath("{prop_name(prop)}"), {prop_ctx_name(cls, prop)}, state)'
+
+
+@language("golang")
+class GoLangRender(BasicJinjaRender):
+    HELP = "Go Schema"
+
+    def __init__(self, args):
+        super().__init__(args, TEMPLATE_DIR / "golang.j2")
+        self.__render_args = {
+            "package": args.package,
+        }
+
+    @classmethod
+    def get_arguments(cls, parser):
+        super().get_arguments(parser)
+        parser.add_argument("-p", "--package", help="Go Package Name", default="model")
+
+    def get_extra_env(self):
+        return {
+            "varname": varname,
+            "struct_name": struct_name,
+            "interface_name": interface_name,
+            "class_type_var": class_type_var,
+            "prop_name": prop_name,
+            "prop_is_list": prop_is_list,
+            "prop_go_type": prop_go_type,
+            "prop_ctx_name": prop_ctx_name,
+            "prop_decode_func": prop_decode_func,
+            "prop_encode_func": prop_encode_func,
+        }
+
+    def get_additional_render_args(self):
+        return self.__render_args