/* -*-c-*-
*
- * $Id: scan.h,v 1.1 1999/07/01 08:56:23 mdw Exp $
+ * $Id: scan.h,v 1.2 1999/07/26 23:24:33 mdw Exp $
*
* Character scanners
*
- * (c) 1999 Mark Wooding
+ * (c) 1999 Straylight/Edgeware
*/
/*----- Licensing notice --------------------------------------------------*
/*----- Revision history --------------------------------------------------*
*
* $Log: scan.h,v $
- * Revision 1.1 1999/07/01 08:56:23 mdw
- * Initial revision
+ * Revision 1.2 1999/07/26 23:24:33 mdw
+ * Complete rewrite. Allow a list of character sources to enable changes
+ * during parsing of syntactic constructs.
+ *
+ * Revision 1.1.1.1 1999/07/01 08:56:23 mdw
+ * Initial revision.
*
*/
/*----- Data structures ---------------------------------------------------*/
-/* --- A configuration scanner --- */
+/* --- A low-level scanner source --- */
+
+typedef struct scansrc {
+ struct scansrc *next; /* Next one in the list */
+ struct scansrc_ops *ops; /* Pointer to operations table */
+ char *src; /* Name of this source */
+ int line; /* Current line number */
+ int pushback; /* Pushback character */
+ char *tok; /* Token pushback */
+ unsigned t; /* Token type pushback */
+} scansrc;
+
+/* --- Scanner source operations --- */
-typedef struct scan_ops {
- int (*scan)(void */*p*/); /* Character scan function */
- void (*unscan)(int /*ch*/, void */*p*/); /* Character pushback function */
-} scan_ops;
+typedef struct scansrc_ops {
+ int (*scan)(scansrc */*ss*/); /* Read another character */
+ void (*destroy)(scansrc */*ss*/); /* Destroy an unwanted source */
+} scansrc_ops;
+
+/* --- A character scanner --- */
typedef struct scanner {
- scan_ops *ops; /* Pointer to scanner operations */
- const char *src; /* Name of this source */
- int line; /* Current line number */
+ scansrc *head, **tail; /* Scanner list head and tail */
int t; /* Token type */
dstr d; /* Current token value */
} scanner;
-/*----- Scanners provided -------------------------------------------------*/
+/*----- Particular scanner types ------------------------------------------*/
+
+/* --- @scan_file@ --- *
+ *
+ * Arguments: @FILE *fp@ = pointer to file descriptor
+ * @char *name@ = pointer to source file name
+ * @unsigned f@ = flags
+ *
+ * Returns: A scanner source.
+ *
+ * Use: Creates a new scanner source for reading from a file.
+ */
+
+extern scansrc *scan_file(FILE */*fp*/, char */*name*/, unsigned /*f*/);
+
+#define SCF_NOCLOSE 1u
+#define SCF_FREENAME 2u
+
+/* --- @scan_argv@ --- *
+ *
+ * Arguments: @char **av@ = pointer to argument array (null terminated)
+ *
+ * Returns: A scanner source.
+ *
+ * Use: Creates a new scanner source for reading from an @argv@
+ * array.
+ */
+
+extern scansrc *scan_argv(char **/*av*/);
+
+/*----- General scanner handling ------------------------------------------*/
+
+/* --- @scan@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to main scanner context
+ *
+ * Returns: Character read, or end-of-file.
+ *
+ * Use: Scans a character from a source of characters.
+ */
+
+extern int scan(scanner */*sc*/);
-/* --- The @argv@ scanner --- */
+/* --- @unscan@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to main scanner context
+ * @int ch@ = character to unscan
+ *
+ * Returns: ---
+ *
+ * Use: Scans a character from a source of characters.
+ */
-typedef struct scan_argvctx {
- scanner sc; /* Scanner base structure */
- char *p; /* Pointer to next character */
- char **pp; /* Pointer to next string */
- int ch; /* Pushback character */
-} scan_argvctx;
+extern void unscan(scanner */*sc*/, int /*ch*/);
-extern void scan_argvinit(scan_argvctx */*c*/, char **/*pp*/);
+/* --- @scan_push@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to main scanner context
+ * @scansrc *ss@ = souorce to push
+ *
+ * Returns: ---
+ *
+ * Use: Pushes a scanner source onto the front of the queue.
+ */
-/* --- The file scanner --- */
+extern void scan_push(scanner */*sc*/, scansrc */*ss*/);
-typedef struct scan_filectx {
- scanner sc; /* Scanner base structure */
- FILE *fp; /* Stream pointer */
-} scan_filectx;
+/* --- @scan_add@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to main scanner context
+ * @scansrc *ss@ = souorce to push
+ *
+ * Returns: ---
+ *
+ * Use: Adds a scanner source onto the end of the queue.
+ */
+
+extern void scan_add(scanner */*sc*/, scansrc */*ss*/);
+
+/* --- @scan_create@ --- *
+ *
+ * Arguments: @scanner *sc@ = scanner context to initialize
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a scanner block ready for use.
+ */
+
+extern void scan_create(scanner */*sc*/);
+
+/* --- @scan_destroy@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to scanner context
+ *
+ * Returns: ---
+ *
+ * Use: Destroys a scanner and all the sources attached to it.
+ */
-extern void scan_fileinit(scan_filectx */*c*/,
- FILE */*fp*/, const char */*file*/);
+extern void scan_destroy(scanner */*sc*/);
/*----- That's all, folks -------------------------------------------------*/
~mdw / fwd / blobdiff