52533: add module to provide alternate readonly views of the content of .zle.hlgroups

4 files changed, 252 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 639f19369..6d064eaf6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2024-02-15  Oliver Kiddle  <opk@zsh.org>
+
+	* 52533: Src/Modules/hlgroup.c, Src/Modules/hlgroup.mdd,
+	Src/prompt.c: add module to provide alternate readonly views of
+	the content of .zle.hlgroups
+
 2024-02-09  Mikael Magnusson  <mikachu@gmail.com>
 
 	* 52526: Src/Modules/terminfo.c: metafy terminfo capabilities
diff --git a/Src/Modules/hlgroup.c b/Src/Modules/hlgroup.c
new file mode 100644
index 000000000..6382f3216
--- /dev/null
+++ b/Src/Modules/hlgroup.c
@@ -0,0 +1,211 @@
+/*
+ * hlgroup.c - Supporting parameters for highlight groups
+ *
+ * This file is part of zsh, the Z shell.
+ *
+ * Copyright (c) 2024 Oliver Kiddle
+ * All rights reserved.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and to distribute modified versions of this software for any
+ * purpose, provided that the above copyright notice and the following
+ * two paragraphs appear in all copies of this software.
+ *
+ * In no event shall Oliver Kiddle or the Zsh Development Group be liable
+ * to any party for direct, indirect, special, incidental, or consequential
+ * damages arising out of the use of this software and its documentation,
+ * even if Oliver Kiddle and the Zsh Development Group have been advised of
+ * the possibility of such damage.
+ *
+ * Oliver Kiddle and the Zsh Development Group specifically disclaim any
+ * warranties, including, but not limited to, the implied warranties of
+ * merchantability and fitness for a particular purpose.  The software
+ * provided hereunder is on an "as is" basis, and Oliver Kiddle and the
+ * Zsh Development Group have no obligation to provide maintenance,
+ * support, updates, enhancements, or modifications.
+ *
+ */
+
+#include "hlgroup.mdh"
+#include "hlgroup.pro"
+
+#define GROUPVAR ".zle.hlgroups"
+
+static const struct gsu_scalar pmesc_gsu =
+{ strgetfn, nullstrsetfn, nullunsetfn };
+
+/**/
+static char *
+convertattr(char *attrstr, int sgr)
+{
+    zattr atr;
+    char *r, *s;
+    int len;
+
+    match_highlight(attrstr, &atr, NULL);
+    s = zattrescape(atr, sgr ? NULL : &len);
+
+    if (sgr) {
+	char *c = s, *t = s - 1;
+
+	while (c[0] == '\033' && c[1] == '[') {
+	    c += 2;
+	    while (isdigit(*c) || *c == ';')
+		*++t = *c++;
+	    t++;
+	    if (*c != 'm')
+		break;
+	    *t = ';';
+	    c++;
+	}
+	*t = '\0';
+	len = t - s;
+    }
+
+    r = dupstring_wlen(s, len);
+    free(s);
+    return r;
+}
+
+/**/
+static HashNode
+getgroup(const char *name, int sgr)
+{
+    Param pm = NULL;
+    HashNode hn;
+    HashTable hlg;
+    Value v;
+    struct value vbuf;
+    char *var = GROUPVAR;
+
+    pm = (Param) hcalloc(sizeof(struct param));
+    pm->gsu.s = &pmesc_gsu;
+    pm->node.nam = dupstring(name);
+    pm->node.flags = PM_SCALAR|PM_SPECIAL;
+
+    if (!(v = getvalue(&vbuf, &var, 0)) ||
+	     PM_TYPE(v->pm->node.flags) != PM_HASHED ||
+	     !(hlg = v->pm->gsu.h->getfn(v->pm)) ||
+	     !(hn = gethashnode2(hlg, name)))
+    {
+	pm->u.str = dupstring("");
+	pm->node.flags |= PM_UNSET;
+    } else {
+	pm->u.str = convertattr(((Param) hn)->u.str, sgr);
+    }
+
+    return &pm->node;
+}
+
+/**/
+static void
+scangroup(ScanFunc func, int flags, int sgr)
+{
+    struct param pm;
+    int i;
+    HashNode hn;
+    HashTable hlg;
+    Value v;
+    struct value vbuf;
+    char *var = GROUPVAR;
+
+    if (!(v = getvalue(&vbuf, &var, 0)) ||
+	     PM_TYPE(v->pm->node.flags) != PM_HASHED)
+	return;
+    hlg = v->pm->gsu.h->getfn(v->pm);
+
+    memset((void *)&pm, 0, sizeof(struct param));
+    pm.node.flags = PM_SCALAR;
+    pm.gsu.s = &pmesc_gsu;
+
+    for (i = 0; i < hlg->hsize; i++)
+	for (hn = hlg->nodes[i]; hn; hn = hn->next) {
+	    pm.u.str = convertattr(((Param) hn)->u.str, sgr);
+	    pm.node.nam = hn->nam;
+	    func(&pm.node, flags);
+	}
+}
+/**/
+static HashNode
+getpmesc(UNUSED(HashTable ht), const char *name)
+{
+    return getgroup(name, 0);
+}
+
+/**/
+static void
+scanpmesc(UNUSED(HashTable ht), ScanFunc func, int flags)
+{
+    return scangroup(func, flags, 0);
+}
+
+/**/
+static HashNode
+getpmsgr(UNUSED(HashTable ht), const char *name)
+{
+    return getgroup(name, 1);
+}
+
+/**/
+static void
+scanpmsgr(UNUSED(HashTable ht), ScanFunc func, int flags)
+{
+    return scangroup(func, flags, 1);
+}
+
+static struct paramdef partab[] = {
+    SPECIALPMDEF(".zle.esc", PM_READONLY_SPECIAL, 0, getpmesc, scanpmesc),
+    SPECIALPMDEF(".zle.sgr", PM_READONLY_SPECIAL, 0, getpmsgr, scanpmsgr)
+};
+
+static struct features module_features = {
+    NULL, 0,
+    NULL, 0,
+    NULL, 0,
+    partab, sizeof(partab)/sizeof(*partab),
+    0
+};
+
+/**/
+int
+setup_(UNUSED(Module m))
+{
+    return 0;
+}
+
+/**/
+int
+features_(Module m, char ***features)
+{
+    *features = featuresarray(m, &module_features);
+    return 0;
+}
+
+/**/
+int
+enables_(Module m, int **enables)
+{
+    return handlefeatures(m, &module_features, enables);
+}
+
+/**/
+int
+boot_(UNUSED(Module m))
+{
+    return 0;
+}
+
+/**/
+int
+cleanup_(Module m)
+{
+    return setfeatureenables(m, &module_features, NULL);
+}
+
+/**/
+int
+finish_(UNUSED(Module m))
+{
+    return 0;
+}
diff --git a/Src/Modules/hlgroup.mdd b/Src/Modules/hlgroup.mdd
new file mode 100644
index 000000000..ee3ba7260
--- /dev/null
+++ b/Src/Modules/hlgroup.mdd
@@ -0,0 +1,7 @@
+name=zsh/hlgroup
+link=either
+load=yes
+
+autofeatures="p:.zle.esc p:.zle.sgr"
+
+objects="hlgroup.o"
diff --git a/Src/prompt.c b/Src/prompt.c
index 0d674ceab..7acbe0e47 100644
--- a/Src/prompt.c
+++ b/Src/prompt.c
@@ -241,6 +241,34 @@ promptexpand(char *s, int ns, char *rs, char *Rs)
     return new_vars.buf;
 }
 
+/* Get the escape sequence for a given attribute. */
+/**/
+mod_export char *
+zattrescape(zattr atr, int *len)
+{
+    struct buf_vars new_vars;
+    zattr savecurrent = txtcurrentattrs;
+    zattr saveunknown = txtunknownattrs;
+
+    memset(&new_vars, 0, sizeof(new_vars));
+    new_vars.last = bv;
+    bv = &new_vars;
+    new_vars.bufspc = 256;
+    new_vars.bp = new_vars.bufline = new_vars.buf = zshcalloc(new_vars.bufspc);
+    new_vars.dontcount = 1;
+
+    txtunknownattrs = 0;
+    treplaceattrs(atr);
+    applytextattributes(TSC_PROMPT);
+
+    bv = new_vars.last;
+
+    txtpendingattrs = txtcurrentattrs = savecurrent;
+    txtunknownattrs = saveunknown;
+
+    return unmetafy(new_vars.buf, len);
+}
+
 /* Parse the argument for %H */
 static char *
 parsehighlight(char *arg, char endchar, zattr *atr)