Move various multi-dispatch data structures into a header file, plus …

…way that we'll be able to get at the dispatcher list, dispatcher info stash and so forth.

src/binder/multidispatch.h

@@ -0,0 +1,45 @@
+/* This is how a Code looks on the inside. Once again, C struct that should
+ * match what P6opaque computes for the Code class. */
+typedef struct {
+    PMC    *st;                 /* S-table, though we don't care about that here. */
+    PMC    *sc;                 /* Serialization context, though we don't care about that here. */
+    PMC    *spill;              /* Attribute spill storage. */
+    PMC    *_do;                /* Lower-level code object. */
+    PMC    *signature;          /* Signature object. */
+    PMC    *dispatchees;        /* List of dispatchees, if any. */
+    PMC    *dispatcher_info;    /* Holder for any extra dispatcher info. */
+} Rakudo_Code;
+
+/* Represents a candidate. We extract various bits of information about it when
+ * we are building the sorted candidate list and store them in here for fast
+ * access during a dispatch. */
+typedef struct {
+    PMC   *sub;         /* The sub that is the candidate. */
+    PMC   *signature;   /* The signature of the sub. */
+    PMC  **types;       /* Class or role type constraints for each parameter. */
+    PMC  **constraints; /* Refinement type constraints for each parameter. */
+    INTVAL num_types;   /* Number of entries in the above two arrays. */
+    INTVAL min_arity;   /* Number of required positional arguments. */
+    INTVAL max_arity;   /* Number of required and optional positional arguments. */
+    INTVAL bind_check;  /* A true value if any parameters have constraints and/or are named. */
+    STRING *req_named;  /* Name of one required named argument, if any. This is to allow us
+                         * to quickly rule out candidates disambiguated by a required named
+                         * argument, as is the common case for traits. */
+} Rakudo_md_candidate_info;
+
+/* Overall multi-dispatcher info, which we will hang off the dispatcher
+ * info slot in a dispatcher sub. */
+typedef struct {
+    Rakudo_md_candidate_info **candidates;
+    /* XXX TODO: Cache goes here also. */
+} Rakudo_md_info;
+
+/* Represents the produced information about a candidate as well as the graph
+ * edges originating from it. The edges array contains pointers to the edges
+ * in the graph that we have arrows to. */
+typedef struct candidate_graph_node {
+    Rakudo_md_candidate_info     *info;
+    struct candidate_graph_node **edges;
+    INTVAL                        edges_in;
+    INTVAL                        edges_out;
+} Rakudo_md_candidate_graph_node;