text: /*
  Package pattern contains utilities for Goji Pattern authors.
  
  Goji users should not import this package. Instead, use the utilities provided
  by your Pattern package. If you are looking for an implementation of Pattern,
  try Goji's pat subpackage, which contains a simple domain specific language for
  specifying routes.
  
  For Pattern authors, use of this subpackage is entirely optional. Nevertheless,
  authors who wish to take advantage of Goji's PathPrefix optimization or who wish
  to standardize on a few common interfaces may find this package useful.
  */
  package pattern
  
  import (
  	"context"
  
  	"goji.io/internal"
  )
  
  /*
  Variable is a standard type for the names of Pattern-bound variables, e.g.
  variables extracted from the URL. Pass the name of a variable, cast to this
  type, to context.Context.Value to retrieve the value bound to that name.
  */
  type Variable string
  
  type allVariables struct{}
  
  /*
  AllVariables is a standard value which, when passed to context.Context.Value,
  returns all variable bindings present in the context, with bindings in newer
  contexts overriding values deeper in the stack. The concrete type
  
  	map[Variable]interface{}
  
  is used for this purpose. If no variables are bound, nil should be returned
  instead of an empty map.
  */
  var AllVariables = allVariables{}
  
  /*
  Path returns the path that the Goji router uses to perform the PathPrefix
  optimization. While this function does not distinguish between the absence of a
  path and an empty path, Goji will automatically extract a path from the request
  if none is present.
  
  By convention, paths are stored in their escaped form (i.e., the value returned
  by net/url.URL.EscapedPath, and not URL.Path) to ensure that Patterns have as
  much discretion as possible (e.g., to behave differently for '/' and '%2f').
  */
  func Path(ctx context.Context) string {
  	pi := ctx.Value(internal.Path)
  	if pi == nil {
  		return ""
  	}
  	return pi.(string)
  }
  
  /*
  SetPath returns a new context in which the given path is used by the Goji Router
  when performing the PathPrefix optimization. See Path for more information about
  the intended semantics of this path.
  */
  func SetPath(ctx context.Context, path string) context.Context {
  	return context.WithValue(ctx, internal.Path, path)
  }
  