From 99c8e034f83ad7e34fddbff6018bf0639533f2d9 Mon Sep 17 00:00:00 2001
From: Arun Isaac
Date: Sun, 27 Sep 2026 01:18:25 +0100
Subject: Support std::string_view in swig.

swig does not yet support std::string_view. We add support here for
our immediate use. We will contribute this upstream to the swig
project.
---
 .guix/guile-xapian-package.scm |  7 +++--
 Makefile.am                    |  4 +--
 configure.ac                   |  2 +-
 std_string_view.i              | 68 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 76 insertions(+), 5 deletions(-)
 create mode 100644 std_string_view.i

diff --git a/.guix/guile-xapian-package.scm b/.guix/guile-xapian-package.scm
index cc88be7..e8394b5 100644
--- a/.guix/guile-xapian-package.scm
+++ b/.guix/guile-xapian-package.scm
@@ -21,6 +21,7 @@
   #:use-module ((gnu packages autotools) #:select (autoconf autoconf-archive automake libtool))
   #:use-module ((gnu packages guile) #:select (guile-2.2))
   #:use-module ((gnu packages guile-xyz) #:prefix guix:)
+  #:use-module ((gnu packages swig) #:select (swig))
   #:use-module (guix gexp)
   #:use-module (guix git-download)
   #:use-module (guix packages)
@@ -36,7 +37,8 @@
                                       (const #t))))
     (native-inputs
      (modify-inputs (package-native-inputs guix:guile-xapian)
-       (prepend autoconf autoconf-archive automake libtool)))))
+       (prepend autoconf autoconf-archive automake libtool)
+       (replace "swig" swig)))))
 
 (define-public guile2.2-xapian
   (package
@@ -48,6 +50,7 @@
                                       (const #t))))
     (native-inputs
      (modify-inputs (package-native-inputs guix:guile2.2-xapian)
-       (prepend autoconf autoconf-archive automake libtool)))))
+       (prepend autoconf autoconf-archive automake libtool)
+       (replace "swig" swig)))))
 
 guile-xapian
diff --git a/Makefile.am b/Makefile.am
index 800cef5..9ba38b7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -47,7 +47,7 @@ CLEANFILES = xapian.i xapian_wrap.cc xapian/wrap.scm
 xapian.i: xapian.i.in Makefile
 	sed -e 's|@libdir[@]|$(libdir)|g' -e 's|@GUILE_EFFECTIVE_VERSION[@]|$(GUILE_EFFECTIVE_VERSION)|g' $< > $@
 
-xapian_wrap.cc xapian/wrap.scm &: xapian.i xapian-head.i xapian-headers.i except.i
+xapian_wrap.cc xapian/wrap.scm &: xapian.i xapian-head.i xapian-headers.i except.i std_string_view.i
 	$(MKDIR_P) xapian
 	$(SWIG_GEN)$(SWIG) $(SWIG_FLAGS) -I$(srcdir) -scmstub -o xapian_wrap.cc -guile -package xapian -c++ $<
 
@@ -83,4 +83,4 @@ check-local:
 
 EXTRA_DIST = $(test_files) $(SOURCES) \
              examples/100-objects.sexp examples/index.scm examples/search.scm \
-             except.i xapian.i.in xapian-head.i xapian-headers.i
+             except.i std_string_view.i xapian.i.in xapian-head.i xapian-headers.i
diff --git a/configure.ac b/configure.ac
index 93930da..7573248 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,7 +23,7 @@ AM_SILENT_RULES([yes])
 LT_INIT
 
 AC_PROG_CXX
-AX_PKG_SWIG
+AX_PKG_SWIG([4.2], [], [ AC_MSG_ERROR([swig >= 4.2 is required]) ])
 GUILE_PKG([3.0 2.2])
 PKG_CHECK_MODULES([GUILE], [guile-3.0],,[
     PKG_CHECK_MODULES([GUILE], [guile-2.2])
diff --git a/std_string_view.i b/std_string_view.i
new file mode 100644
index 0000000..585281f
--- /dev/null
+++ b/std_string_view.i
@@ -0,0 +1,68 @@
+/* -----------------------------------------------------------------------------
+ * std_string_view.i
+ *
+ * std::string_view typemaps for Guile
+ * ----------------------------------------------------------------------------- */
+
+%{
+#include <string>
+#include <string_view>
+%}
+
+namespace std {
+
+  %naturalvar string_view;
+
+  %typemap(in) string_view (std::string temp) {
+    char *ptr = scm_to_stringn($input, NULL, "utf8",
+                               SCM_FAILED_CONVERSION_ERROR);
+    temp.assign(ptr);
+    SWIG_free(ptr);
+    $1 = std::string_view(temp);
+  }
+
+  %typemap(out) string_view %{
+    $result = scm_from_stringn($1.data(), $1.size(), "utf8",
+                               SCM_FAILED_CONVERSION_ERROR);
+    %}
+
+  %typemap(in) const string_view& (std::string temp, $*1_ltype view) {
+    char *ptr = scm_to_stringn($input, NULL, "utf8",
+                               SCM_FAILED_CONVERSION_ERROR);
+    temp.assign(ptr);
+    SWIG_free(ptr);
+    view = std::string_view(temp);
+    $1 = &view;
+  }
+
+  %typemap(out) const string_view& %{
+    $result = scm_from_stringn($1->data(), $1->size(), "utf8",
+                               SCM_FAILED_CONVERSION_ERROR);
+    %}
+
+  %typemap(varout) string_view %{
+    $result = scm_from_stringn($1.data(), $1.size(), "utf8",
+                               SCM_FAILED_CONVERSION_ERROR);
+    %}
+
+  // for throwing of any kind of string_view, string_view ref's and
+  // string_view pointers we convert all to Guile strings
+  %typemap(throws) string_view, string_view&, const string_view& %{
+    scm_throw(scm_from_locale_symbol("swig-exception"),
+              scm_list_1(scm_from_stringn($1.data(), $1.size(), "utf8",
+                                          SCM_FAILED_CONVERSION_ERROR)));
+    %}
+
+  %typemap(throws) string_view*, const string_view* %{
+    scm_throw(scm_from_locale_symbol("swig-exception"),
+              scm_list_1(scm_from_stringn($1->data(), $1->size(), "utf8",
+                                          SCM_FAILED_CONVERSION_ERROR)));
+    %}
+
+  %typemap(typecheck,precedence=SWIG_TYPECHECK_STRINGVIEW) string_view, const string_view& {
+    $1 = scm_is_string($input);
+  }
+
+  class string_view;
+
+}
-- 
cgit 1.4.1