shithub: mc

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Handle wildcards in patterns correctly.

    If we have a wildcard, prefer it over any equal node. This means
    that something like:

        match x
        | (x, false):
        | (false, x):
        | (false, false)
        ;;

    will correctly be detected as having a redundant match.

--- a/mi/match.c

+++ b/mi/match.c

@@ -34,6 +34,7 @@

 };

 static Dtree *addpat(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap);

+void dtdump(Dtree *dt, FILE *f);

 /* We treat all integer types, boolean types, etc, as having 2^n constructors.

  *

@@ -110,6 +111,8 @@

     Dtree *sub;

     size_t i;

+    if (t->any)

+        return t->any;

     /* if we have the value already... */

     sub = NULL;

     for (i = 0; i < t->nval; i++) {

@@ -131,6 +134,8 @@

     Dtree *sub;

     size_t i;

+    if (t->any)

+        return t->any;

     for (i = 0; i < t->nval; i++) {

         if (liteq(t->val[i]->expr.args[0], pat->expr.args[0]))

             return addpat(t->sub[i], pat->expr.args[1], NULL, cap, ncap);

@@ -147,6 +152,8 @@

 {

     size_t i;

+    if (t->any)

+        return t->any;

     for (i = 0; i < pat->expr.nargs; i++)

         t = addpat(t, pat->expr.args[i], NULL, cap, ncap);

     return t;

@@ -156,6 +163,8 @@

 {

     size_t i;

+    if (t->any)

+        return t->any;

     for (i = 0; i < pat->expr.nargs; i++)

         t = addpat(t, pat->expr.args[i], NULL, cap, ncap);

     return t;

@@ -166,6 +175,8 @@

     Node *elt;

     size_t i, j;

+    if (t->any)

+        return t->any;

     for (i = 0; i < pat->expr.nargs; i++) {

         elt = pat->expr.args[i];

         for (j = 0; j < t->nval; j++) {