convert to go buildpack

1 files changed, 38 insertions, 0 deletions

diff --git a/vendor/github.com/Xe/ln/context.go b/vendor/github.com/Xe/ln/context.go
new file mode 100644
index 0000000..0ea3229
--- /dev/null
+++ b/vendor/github.com/Xe/ln/context.go
@@ -0,0 +1,38 @@
+package ln
+
+import (
+	"context"
+)
+
+type ctxKey int
+
+const (
+	fKey = iota
+)
+
+// WithF stores or appends a given F instance into a context.
+func WithF(ctx context.Context, f F) context.Context {
+	pf, ok := FFromContext(ctx)
+	if !ok {
+		return context.WithValue(ctx, fKey, f)
+	}
+
+	pf.Extend(f)
+
+	return context.WithValue(ctx, fKey, pf)
+}
+
+// FFromContext fetches the `F` out of the context if it exists.
+func FFromContext(ctx context.Context) (F, bool) {
+	fvp := ctx.Value(fKey)
+	if fvp == nil {
+		return nil, false
+	}
+
+	f, ok := fvp.(F)
+	if !ok {
+		return nil, false
+	}
+
+	return f, true
+}