feat: graalvm artifact mappings

- feat: add struct which defines maven coordinates for well-known
  graalvm maven dependencies

- feat: user-facing API to easily access these coordinates and
  declare them with `rules_jvm_external`

Signed-off-by: Sam Gammon <sam@elide.ventures>

docs/api/BUILD.bazel

@@ -16,6 +16,15 @@ bzl_library(
     ],
 )
 
+stardoc(
+    name = "artifacts",
+    out = "artifacts.md",
+    input = "//graalvm/artifacts:maven.bzl",
+    deps = [
+        ":repo_tools",
+    ],
+)
+
 stardoc(
     name = "defs",
     out = "defs.md",

docs/api/artifacts.md

@@ -0,0 +1,116 @@
+<!-- Generated with Stardoc: http://skydoc.bazel.build -->
+
+Defines Maven helpers and coordinates for GraalVM artifacts.
+
+<a id="graalvm.artifact"></a>
+
+## graalvm.artifact
+
+<pre>
+graalvm.artifact(<a href="#graalvm.artifact-maven">maven</a>, <a href="#graalvm.artifact-artifact">artifact</a>, <a href="#graalvm.artifact-version">version</a>)
+</pre>
+
+Helper which declares a Maven artifact using `rules_jvm_external` macros for the provided inputs.
+
+Any struct can be provided as `artifact` which has the `artifact` and `group` properties. For
+convenience, well-known GraalVM artifact coordinates are available at `graalvm.catalog`.
+
+Example of use from `WORKSPACE.bazel`:
+
+    ```starlark
+    load("@rules_jvm_external//:specs.bzl", "maven")
+    load("@rules_graalvm//artifacts:maven.bzl", "graalvm")
+
+    # ...
+    graalvm.artifact(
+        maven,
+        artifact = graalvm.catalog.SDK,
+        version = "23.0.1",
+    )
+    ```
+
+Example of use from Bzlmod:
+
+    ```starlark
+    maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
+    graalvm = use_extension("@rules_graalvm//:extensions.bzl", "graalvm")
+
+    # ...
+    graalvm.artifact(
+        maven,
+        artifact = graalvm.catalog.SDK,
+        version = "23.0.1",
+    )
+    ```
+
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="graalvm.artifact-maven"></a>maven |  Maven artifact spawn struct provided by `rules_jvm_external`.   |  none |
+| <a id="graalvm.artifact-artifact"></a>artifact |  Artifact to use from `MavenArtifacts`, or a `struct` with `artifact` and `group`.   |  none |
+| <a id="graalvm.artifact-version"></a>version |  Version of the artifact to declare.   |  none |
+
+**RETURNS**
+
+Maven artifact specification.
+
+
+<a id="graalvm_maven_artifact"></a>
+
+## graalvm_maven_artifact
+
+<pre>
+graalvm_maven_artifact(<a href="#graalvm_maven_artifact-maven">maven</a>, <a href="#graalvm_maven_artifact-artifact">artifact</a>, <a href="#graalvm_maven_artifact-version">version</a>)
+</pre>
+
+Helper which declares a Maven artifact using `rules_jvm_external` macros for the provided inputs.
+
+Any struct can be provided as `artifact` which has the `artifact` and `group` properties. For
+convenience, well-known GraalVM artifact coordinates are available at `graalvm.catalog`.
+
+Example of use from `WORKSPACE.bazel`:
+
+    ```starlark
+    load("@rules_jvm_external//:specs.bzl", "maven")
+    load("@rules_graalvm//artifacts:maven.bzl", "graalvm")
+
+    # ...
+    graalvm.artifact(
+        maven,
+        artifact = graalvm.catalog.SDK,
+        version = "23.0.1",
+    )
+    ```
+
+Example of use from Bzlmod:
+
+    ```starlark
+    maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
+    graalvm = use_extension("@rules_graalvm//:extensions.bzl", "graalvm")
+
+    # ...
+    graalvm.artifact(
+        maven,
+        artifact = graalvm.catalog.SDK,
+        version = "23.0.1",
+    )
+    ```
+
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="graalvm_maven_artifact-maven"></a>maven |  Maven artifact spawn struct provided by `rules_jvm_external`.   |  none |
+| <a id="graalvm_maven_artifact-artifact"></a>artifact |  Artifact to use from `MavenArtifacts`, or a `struct` with `artifact` and `group`.   |  none |
+| <a id="graalvm_maven_artifact-version"></a>version |  Version of the artifact to declare.   |  none |
+
+**RETURNS**
+
+Maven artifact specification.
+
+

graalvm/artifacts/BUILD.bazel

@@ -1 +1,5 @@
-# Nothing at this time.
+package(default_visibility = ["//visibility:public"])
+
+exports_files([
+    "maven.bzl",
+])

graalvm/artifacts/maven.bzl

@@ -0,0 +1,84 @@
+"Defines Maven helpers and coordinates for GraalVM artifacts."
+
+# buildifier: disable=name-conventions
+_MavenArtifacts = struct(
+    SDK = struct(
+        artifact = "graal-sdk",
+        group = "org.graalvm.sdk",
+    ),
+    TRUFFLE = struct(
+        artifact = "truffle-api",
+        group = "org.graalvm.truffle",
+
+        NFI = struct(
+            artifact = "truffle-api",
+            group = "org.graalvm.truffle",
+        ),
+    ),
+)
+
+def _graalvm_maven_artifact(maven, artifact, version):
+    """Helper which declares a Maven artifact using `rules_jvm_external` macros for the provided inputs.
+
+    Any struct can be provided as `artifact` which has the `artifact` and `group` properties. For
+    convenience, well-known GraalVM artifact coordinates are available at `graalvm.catalog`.
+
+    Example of use from `WORKSPACE.bazel`:
+
+        ```starlark
+        load("@rules_jvm_external//:specs.bzl", "maven")
+        load("@rules_graalvm//artifacts:maven.bzl", "graalvm")
+
+        # ...
+        graalvm.artifact(
+            maven,
+            artifact = graalvm.catalog.SDK,
+            version = "23.0.1",
+        )
+        ```
+
+    Example of use from Bzlmod:
+
+        ```starlark
+        maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
+        graalvm = use_extension("@rules_graalvm//:extensions.bzl", "graalvm")
+
+        # ...
+        graalvm.artifact(
+            maven,
+            artifact = graalvm.catalog.SDK,
+            version = "23.0.1",
+        )
+        ```
+
+    Args:
+        maven: Maven artifact spawn struct provided by `rules_jvm_external`.
+        artifact: Artifact to use from `MavenArtifacts`, or a `struct` with `artifact` and `group`.
+        version: Version of the artifact to declare.
+
+    Returns:
+        Maven artifact specification.
+    """
+
+    return maven.artifact(
+        artifact = artifact.artifact,
+        group = artifact.group,
+        version = version,
+    )
+
+
+# buildifier: disable=name-conventions
+_MavenTools = struct(
+    catalog = _MavenArtifacts,
+    artifact = _graalvm_maven_artifact,
+)
+
+# Exports.
+
+# buildifier: disable=name-conventions
+graalvm = _MavenTools
+
+# buildifier: disable=name-conventions
+MavenArtifacts = _MavenArtifacts
+
+graalvm_maven_artifact = _graalvm_maven_artifact