lib: Add matching and argv support

Queries may be run against DFA's to find matching
cmd_element, and argument lists may be constructed.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

1 files changed, 48 insertions, 10 deletions

diff --git a/lib/command_match.h b/lib/command_match.h
index 695dda2827..24cd1287e6 100644
--- a/lib/command_match.h
+++ b/lib/command_match.h
@@ -1,22 +1,21 @@
 #ifndef COMMAND_MATCH_H
 #define COMMAND_MATCH_H
 
+#include "command.h"
 #include "command_graph.h"
 #include "linklist.h"
 
-/**
- * Filter types. These tell the parser whether to allow
- * partial matching on tokens.
- */
+
+/** These definitions exist in command.c in
+ * the current engine but will be relocated
+ * here in the new engine*/
 enum filter_type
 {
   FILTER_RELAXED,
   FILTER_STRICT
 };
 
-/**
- * Command matcher result value.
- */
+/* matcher result value. */
 enum matcher_rv
 {
   MATCHER_OK,
@@ -34,8 +33,8 @@ enum match_type
   partly_match,
   exact_match
 };
-/**
- * Defines which matcher_rv values constitute
+
+/* Defines which matcher_rv values constitute
  * an error. Should be used against matcher_rv
  * return values to do basic error checking.
  */
@@ -46,7 +45,46 @@ enum match_type
    || (matcher_rv) == MATCHER_EXCEED_ARGC_MAX \
   )
 
+/**
+ * Attempt to find an exact command match for a line of user input.
+ *
+ * @return cmd_element found, or NULL if there is no match.
+ */
+struct cmd_element *
+match_command (struct graph_node *, const char *, enum filter_type);
+
+/**
+ * Compiles next-hops for a given line of user input.
+ *
+ * Given a string of input and a start node for a matching DFA, runs the input
+ * against the DFA until the input is exhausted or a mismatch is encountered.
+ *
+ * This function returns all valid next hops away from the current node.
+ *  - If the input is a valid prefix to a longer command(s), the set of next
+ *    hops determines what tokens are valid to follow the prefix. In other words,
+ *    the returned list is a list of possible completions.
+ *  - If the input matched a full command, exactly one of the next hops will be
+ *    a node of type END_GN and its function pointer will be set.
+ *  - If the input did not match any valid token sequence, the returned list
+ *    will be empty (there are no transitions away from a nonexistent state).
+ *
+ * @param[in] start the start node of the DFA to match against
+ * @param[in] filter the filtering method
+ * @param[in] input the input string
+ * @return pointer to linked list with all possible next hops from the last
+ *         matched token. If this is empty, the input did not match any command.
+ */
+struct list *
+match_command_complete (struct graph_node *, const char *, enum filter_type);
+
+/**
+ * Builds an argument list given a cmd_element and a matching input line.
+ *
+ * @param[in] input line
+ * @param[in] cmd_element struct
+ * @return pointer to argument linked list
+ */
 struct list *
-match_command (struct graph_node *, enum filter_type, const char *);
+match_build_argv (const char *, struct cmd_element *);
 
 #endif