diff --git a/src/glyphs.c b/src/glyphs.c
index 226a7f208..8e12da56d 100644
--- a/src/glyphs.c
+++ b/src/glyphs.c
@@ -373,8 +373,10 @@ compose_glyph_name(int glyph, char *buf, size_t bufsz)
             };
 
             j = glyph - GLYPH_SWALLOW_OFF;
-            cmap = glyph_to_swallow(glyph);
             mnum = j / ((S_sw_br - S_sw_tl) + 1);
+            if (!attacktype(&mons[mnum], AT_ENGL))
+                return 0;
+            cmap = glyph_to_swallow(glyph);
             Snprintf(tmpbuf[3], sizeof tmpbuf[3], "swallow %s %s",
                      monsdump[mnum].nm, swallow_texts[cmap]);
             buf3 = tmpbuf[3];
diff --git a/src/symbols.c b/src/symbols.c
index 1512ed7c5..b1f459341 100644
--- a/src/symbols.c
+++ b/src/symbols.c
@@ -7,6 +7,9 @@
 
 staticfn void savedsym_add(const char *, const char *, int);
 staticfn struct _savedsym *savedsym_find(const char *, int);
+staticfn const struct symparse *search_loadsyms(const char *buf, size_t len);
+staticfn int symparse_compare(const void *s1_, const void *s2_);
+staticfn int symparse_find(const void *bstr_, const void *rec_);
 
 extern const uchar def_r_oc_syms[MAXOCLASSES];      /* drawing.c */
 
@@ -29,6 +32,11 @@ void (*utf8graphics_mode_callback)(void) = 0; /* set in term_start_screen and
                                                * found in unixtty,windtty,&c */
 #endif
 
+struct bounded_string {
+    const char *str;
+    size_t len;
+};
+
 /*
  * Explanations of the functions found below:
  *
@@ -864,42 +872,113 @@ match_sym(char *buf)
         { "S_explode8", "S_expl_bc" }, { "S_explode9", "S_expl_br" },
     };
     int i;
-    size_t len = strlen(buf);
-    const char *p = strchr(buf, ':'), *q = strchr(buf, '=');
-    const struct symparse *sp = loadsyms;
+    size_t len;
+    const struct symparse *sp;
 
     /* G_ lines will never match here */
     if ((buf[0] == 'G' || buf[0] == 'g') && buf[1] == '_')
         return (struct symparse *) 0;
 
-    if (!p || (q && q < p))
-        p = q;
-    if (p) {
-        /* note: there will be at most one space before the '='
-           because caller has condensed buf[] with mungspaces() */
-        if (p > buf && p[-1] == ' ')
-            p--;
-        len = (int) (p - buf);
-    }
-    while (sp->range) {
-        if ((len >= strlen(sp->name)) && !strncmpi(buf, sp->name, len))
-            return sp;
-        sp++;
-    }
+    len = strcspn(buf, "=:");
+    /* note: there will be at most one space before the '='
+       because caller has condensed buf[] with mungspaces() */
+    if (len != 0 && buf[len-1] == ' ')
+        len--;
+    sp = search_loadsyms(buf, len);
+    if (sp != NULL)
+        return sp;
     for (i = 0; i < SIZE(alternates); ++i) {
         if ((len >= strlen(alternates[i].altnm))
             && !strncmpi(buf, alternates[i].altnm, len)) {
-            sp = loadsyms;
-            while (sp->range) {
-                if (!strcmp(alternates[i].nm, sp->name))
-                    return sp;
-                sp++;
-            }
+            sp = search_loadsyms(alternates[i].nm, strlen(alternates[i].nm));
+            if (sp != NULL)
+                return sp;
         }
     }
     return (struct symparse *) 0;
 }
 
+staticfn const struct symparse *
+search_loadsyms(const char *buf, size_t len)
+{
+    struct bounded_string bstr;
+
+    /* Sorted index to loadsyms */
+    static boolean first_time = TRUE;
+    static const struct symparse *loadsyms_sorted[SIZE(loadsyms) - 1];
+    if (first_time) {
+        const struct symparse *sp = loadsyms;
+        size_t i = 0;
+        while (sp->range) {
+            loadsyms_sorted[i] = sp;
+            ++sp;
+            ++i;
+        }
+        qsort(loadsyms_sorted, SIZE(loadsyms_sorted), sizeof(loadsyms_sorted[0]),
+                symparse_compare);
+        first_time = FALSE;
+    }
+
+    bstr.str = buf;
+    bstr.len = len;
+    const struct symparse **sp = bsearch(&bstr, loadsyms_sorted,
+            SIZE(loadsyms_sorted), sizeof(loadsyms_sorted[0]),
+            symparse_find);
+    return sp ? *sp : NULL;
+}
+
+staticfn int
+symparse_compare(const void *s1_, const void *s2_)
+{
+    const struct symparse **s1 = (const struct symparse **)s1_;
+    const struct symparse **s2 = (const struct symparse **)s2_;
+    const char *n1 = (*s1)->name;
+    const char *n2 = (*s2)->name;
+    size_t i;
+
+    /* Can we count on strcmpi to say less than or greater than consistently? */
+    for (i = 0; n1[i] != 0 && n2[i] != 0; ++i) {
+        char c1 = n1[i];
+        char c2 = n2[i];
+        if ('A' <= c1 && c1 <= 'Z') {
+            c1 += 'a' - 'A';
+        }
+        if ('A' <= c2 && c2 <= 'Z') {
+            c2 += 'a' - 'A';
+        }
+        if (c1 != c2) {
+            return c1 - c2;
+        }
+    }
+
+    return n1[i] - n2[i];
+}
+
+staticfn int
+symparse_find(const void *bstr_, const void *rec_)
+{
+    const struct bounded_string *bstr = (const struct bounded_string *)bstr_;
+    const struct symparse **rec = (const struct symparse **)rec_;
+    size_t i;
+
+    /* Can we count on strcmpi to say less than or greater than consistently? */
+    for (i = 0; i < bstr->len; ++i) {
+        char c1 = bstr->str[i];
+        char c2 = (*rec)->name[i];
+        if ('A' <= c1 && c1 <= 'Z') {
+            c1 += 'a' - 'A';
+        }
+        if ('A' <= c2 && c2 <= 'Z') {
+            c2 += 'a' - 'A';
+        }
+        if (c1 != c2) {
+            return c1 - c2;
+        }
+    }
+
+    return 0;
+}
+
 DISABLE_WARNING_FORMAT_NONLITERAL
 
 /*