X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/aa14a4cddcb96b681d5c19a2ec8bad382f43b264..dfdcf6ca08c0c619900fd7d81893121f80f02d9b:/src/parser/scanner-proto.lisp

diff --git a/src/parser/scanner-proto.lisp b/src/parser/scanner-proto.lisp
index 966c77c..bd7e160 100644
--- a/src/parser/scanner-proto.lisp
+++ b/src/parser/scanner-proto.lisp
@@ -172,32 +172,11 @@
 ;;;--------------------------------------------------------------------------
 ;;; Token scanner protocol.
 
-;; A place marker.
-
-(export '(token-scanner-place token-scanner-place-p))
-(defstruct token-scanner-place
-  "A link in the chain of lookahead tokens; capturable as a place.
-
-   If the scanner's place is captured, it starts to maintain a list of
-   lookahead tokens.  The list contains internal links -- it works out
-   slightly easier that way.  This is basically a simpler version of the
-   charbuf scanner (q.v.); most significantly, the chain links here do double
-   duty as place markers.
-
-   The details of this structure are not a defined part of the token scanner
-   protocol."
-
-  (next nil :type (or token-scanner-place null))
-  (type nil :read-only t)
-  (value nil :read-only t)
-  (line 1 :type (or fixnum null) :read-only t)
-  (column 0 :type (or fixnum null) :read-only t))
-
 ;; The token scanner base class and parser context.
 
 (export '(token-scanner token-type token-value))
 (defclass token-scanner ()
-  ((type :reader token-type)
+  ((%type :reader token-type)
    (value :reader token-value)
    (captures :initform 0 :type fixnum)
    (tail :initform nil :type (or token-scanner-place null))
@@ -212,11 +191,11 @@
    scanner protocol, which explains the model.
 
    Subclasses must provide the detailed scanning behaviour -- most notably
-   the `scanner-token' generic function.  This function should also update
-   the `line' and `column' slots to track the position in the underlying
-   source, if appropriate, and also implement a method on `file-location' to
-   return the location.  This class will handle the remaining details, such
-   as dealing correctly with rewinding."))
+   the `scanner-token' generic function -- and also implement a method on
+   `file-location' to return the location.  The `scanner-token' method should
+   also update the `line' and `column' slots to track the position in the
+   underlying source, if appropriate.  This class will handle the remaining
+   details, such as dealing correctly with rewinding."))
 
 (export 'token-scanner-context)
 (defclass token-scanner-context (scanner-context token-parser-context)
@@ -224,6 +203,33 @@
   (:documentation
    "A parser context for a richer token-based scanners."))
 
+;; A place marker.
+
+(export '(token-scanner-place token-scanner-place-p))
+(defstruct (token-scanner-place
+	     (:constructor make-token-scanner-place
+			   (&key scanner next type value line column
+			    &aux (%type type))))
+  "A link in the chain of lookahead tokens; capturable as a place.
+
+   If the scanner's place is captured, it starts to maintain a list of
+   lookahead tokens.  The list contains internal links -- it works out
+   slightly easier that way.  This is basically a simpler version of the
+   charbuf scanner (q.v.); most significantly, the chain links here do double
+   duty as place markers.
+
+   The details of this structure are not a defined part of the token scanner
+   protocol."
+
+  (scanner nil :type token-scanner :read-only t)
+  (next nil :type (or token-scanner-place null))
+  (%type nil :read-only t)
+  (value nil :read-only t)
+  (line 1 :type (or fixnum null) :read-only t)
+  (column 0 :type (or fixnum null) :read-only t))
+(define-access-wrapper token-scanner-place-type token-scanner-place-%type
+		       :read-only t)
+
 ;; Protocol.
 
 (export 'scanner-token)