lib/command_match.h

   1 #ifndef COMMAND_MATCH_H
   2 #define COMMAND_MATCH_H
   3
   4 #include "command.h"
   5 #include "command_graph.h"
   6 #include "linklist.h"
   7
   8
   9 /** These definitions exist in command.c in
  10  * the current engine but will be relocated
  11  * here in the new engine*/
  12 enum filter_type
  13 {
  14   FILTER_RELAXED,
  15   FILTER_STRICT
  16 };
  17
  18 /* matcher result value. */
  19 enum matcher_rv
  20 {
  21   MATCHER_OK,
  22   MATCHER_COMPLETE,
  23   MATCHER_INCOMPLETE,
  24   MATCHER_NO_MATCH,
  25   MATCHER_AMBIGUOUS,
  26   MATCHER_EXCEED_ARGC_MAX
  27 };
  28
  29 /* Completion match types. */
  30 enum match_type
  31 {
  32   no_match,
  33   partly_match,
  34   exact_match
  35 };
  36
  37 /* Defines which matcher_rv values constitute
  38  * an error. Should be used against matcher_rv
  39  * return values to do basic error checking.
  40  */
  41 #define MATCHER_ERROR(matcher_rv) \
  42   (   (matcher_rv) == MATCHER_INCOMPLETE \
  43    || (matcher_rv) == MATCHER_NO_MATCH \
  44    || (matcher_rv) == MATCHER_AMBIGUOUS \
  45    || (matcher_rv) == MATCHER_EXCEED_ARGC_MAX \
  46   )
  47
  48 /**
  49  * Attempt to find an exact command match for a line of user input.
  50  *
  51  * @return cmd_element found, or NULL if there is no match.
  52  */
  53 struct cmd_element *
  54 match_command (struct graph_node *, const char *, enum filter_type);
  55
  56 /**
  57  * Compiles next-hops for a given line of user input.
  58  *
  59  * Given a string of input and a start node for a matching DFA, runs the input
  60  * against the DFA until the input is exhausted or a mismatch is encountered.
  61  *
  62  * This function returns all valid next hops away from the current node.
  63  *  - If the input is a valid prefix to a longer command(s), the set of next
  64  *    hops determines what tokens are valid to follow the prefix. In other words,
  65  *    the returned list is a list of possible completions.
  66  *  - If the input matched a full command, exactly one of the next hops will be
  67  *    a node of type END_GN and its function pointer will be set.
  68  *  - If the input did not match any valid token sequence, the returned list
  69  *    will be empty (there are no transitions away from a nonexistent state).
  70  *
  71  * @param[in] start the start node of the DFA to match against
  72  * @param[in] filter the filtering method
  73  * @param[in] input the input string
  74  * @return pointer to linked list with all possible next hops from the last
  75  *         matched token. If this is empty, the input did not match any command.
  76  */
  77 struct list *
  78 match_command_complete (struct graph_node *, const char *, enum filter_type);
  79
  80 /**
  81  * Builds an argument list given a cmd_element and a matching input line.
  82  *
  83  * @param[in] input line
  84  * @param[in] cmd_element struct
  85  * @return pointer to argument linked list
  86  */
  87 struct list *
  88 match_build_argv (const char *, struct cmd_element *);
  89
  90 #endif