1 files changed, 29 insertions, 0 deletions
diff --git a/src/version.nim b/src/version.nim
new file mode 100644
index 00000000..407b974a
--- /dev/null
+++ b/src/version.nim
@@ -0,0 +1,29 @@
+{.used.}
+
+import macros
+
+template imp(x: untyped) = import x
+
+macro tryImport(x: untyped, name: static string) =
+  let vs = ident(name & "Version")
+  quote do:
+    when not compiles(imp `x`):
+      static:
+        error("Cannot find submodule " & `name` & ".\n" &
+          "Please run `make submodule` to fetch the required submodules.")
+    import `x` as `vs`
+
+macro checkVersion(xs: static string, major, minor, patch: int) =
+  let x = ident(xs & "Version")
+  quote do:
+    when `x`.Major < `major` or `x`.Minor < `minor` or `x`.Patch < `patch`:
+      var es = $`major` & "." & $`minor` & "." & $`patch`
+      var gs = $`x`.Major & "." & $`x`.Minor & "." & $`x`.Patch
+      error("Version of " & `xs` & " too low (expected " & es & ", got " &
+        gs & ").\n" &
+        "Please run `make submodule` to update.")
+
+tryImport chakasu/version, "chakasu"
+
+static:
+  checkVersion("chakasu", 0, 1, 2)