get-csv: rewrite in C.

* autload.c (csv_set_entries, csv_instantiate): Functions
removed.
(autoload_init): Autoload registration for stdlib/csv
removed.

* stdlib/csv.tl: File removed.

* stream.c (get_csv): New function.
(stream_init): Register get-csv intrinsic.

* stream.h (get_csv): Declared.

4 files changed, 79 insertions, 91 deletions

diff --git a/autoload.c b/autoload.c
index 251707aa..dd1ef410 100644
--- a/autoload.c
+++ b/autoload.c
@@ -1020,22 +1020,6 @@ static val enum_instantiate(void)
   return nil;
 }
 
-static val csv_set_entries(val fun)
-{
-  val name[] = {
-    lit("get-csv"),
-    nil
-  };
-  autoload_set(al_fun, name, fun);
-  return nil;
-}
-
-static val csv_instantiate(void)
-{
-  load(scat2(stdlib_path, lit("csv")));
-  return nil;
-}
-
 val autoload_reg(val (*instantiate)(void),
                  val (*set_entries)(val))
 {
@@ -1108,7 +1092,6 @@ void autoload_init(void)
   autoload_reg(csort_instantiate, csort_set_entries);
   autoload_reg(glob_instantiate, glob_set_entries);
   autoload_reg(enum_instantiate, enum_set_entries);
-  autoload_reg(csv_instantiate, csv_set_entries);
 
   reg_fun(intern(lit("autoload-try-fun"), system_package), func_n1(autoload_try_fun));
 }
diff --git a/stdlib/csv.tl b/stdlib/csv.tl
deleted file mode 100644
index f3b4f190..00000000
--- a/stdlib/csv.tl
+++ /dev/null
@@ -1,74 +0,0 @@
-;; Copyright 2025
-;; Kaz Kylheku <kaz@kylheku.com>
-;; Vancouver, Canada
-;; All rights reserved.
-;;
-;; Redistribution and use in source and binary forms, with or without
-;; modification, are permitted provided that the following conditions are met:
-;;
-;; 1. Redistributions of source code must retain the above copyright notice,
-;;    this list of conditions and the following disclaimer.
-;;
-;; 2. Redistributions in binary form must reproduce the above copyright notice,
-;;    this list of conditions and the following disclaimer in the documentation
-;;    and/or other materials provided with the distribution.
-;;
-;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-;; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-;; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-;; ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-;; LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-;; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-;; SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-;; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-;; CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-;; ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-;; POSSIBILITY OF SUCH DAMAGE.
-
-(defun get-csv (: (stream *stdin*))
-  (if (stringp stream)
-    (upd stream make-string-input-stream))
-  (let ((record (vec))
-        (field (str 0))
-        (state :rfield)
-        (done nil))
-    (while (not done)
-      (let ((ch (get-char stream)))
-        (when (eq ch #\return)
-          (let ((ch2 (get-char stream)))
-            (if (eq ch2 #\newline)
-              (set ch ch2)
-              (if ch2
-                (unget-char ch2 stream)))))
-        (caseq state
-          (:rfield (caseql* ch
-                     (#\newline (vec-push record field)
-                                (set done t))
-                     (#\,       (vec-push record field)
-                                (set field (str 0)))
-                     (#\"       (cond
-                                  ((empty field)
-                                   (set state :qfield))
-                                  (t
-                                    (string-extend field ch))))
-                     (nil       (vec-push record field)
-                                (set done t))
-                     (t         (string-extend field ch))))
-          (:qfield (caseql* ch
-                     (#\"       (set state :quot))
-                     (nil       (vec-push record field)
-                                (set done t))
-                     (t         (string-extend field ch))))
-          (:quot   (caseql* ch
-                     (#\,       (vec-push record field)
-                                (set field (str 0)
-                                     state :rfield))
-                     (#\"       (string-extend field ch)
-                                (set state :qfield))
-                     (#\newline (vec-push record field)
-                                (set done t))
-                     (nil       (vec-push record field)
-                                (set done t))
-                     (t         (string-extend field ch)
-                                (set state :rfield)))))))
-    record))
diff --git a/stream.c b/stream.c
index 51b8c4d9..8b9b2f60 100644
--- a/stream.c
+++ b/stream.c
@@ -5422,6 +5422,83 @@ val make_byte_input_stream(val obj)
   }
 }
 
+val get_csv(val source_opt)
+{
+  val source = if3(missingp(source_opt),
+                   std_input,
+                   if3(stringp(source_opt),
+                       make_string_input_stream(source_opt),
+                       source_opt));
+  val record = vector(zero, nil);
+  val field = mkstring(zero, chr(' '));
+  enum { rfield, qfield, quot } state = rfield;
+  int done = 0;
+
+  while (!done) {
+    val ch = get_char(source);
+
+    if (ch == chr('\r')) {
+      val ch2 = get_char(source);
+      if (ch2 == chr('\n'))
+        ch = ch2;
+      else if (ch2)
+        unget_char(ch2, source);
+    }
+
+    switch (state) {
+    case rfield:
+      if (ch == chr('\n')) {
+        vec_push(record, field);
+        done = 1;
+      } else if (ch == chr(',')) {
+        vec_push(record, field);
+        field = mkstring(zero, chr(' '));
+      } else if (ch == chr('"')) {
+        if (empty(field))
+          state = qfield;
+        else
+          string_extend(field, ch, nil);
+      } else if (ch == nil) {
+        vec_push(record, field);
+        done = 1;
+      } else {
+        string_extend(field, ch, nil);
+      }
+      break;
+    case qfield:
+      if (ch == chr('"')) {
+        state = quot;
+      } else if (ch == nil) {
+        vec_push(record, field);
+        done = 1;
+      } else {
+        string_extend(field, ch, nil);
+      }
+      break;
+    case quot:
+      if (ch == chr(',')) {
+        vec_push(record, field);
+        field = mkstring(zero, chr(' '));
+        state = rfield;
+      } else if (ch == chr('"')) {
+        string_extend(field, ch, nil);
+        state = qfield;
+      } else if (ch == chr('\n')) {
+        vec_push(record, field);
+        done = 1;
+      } else if (ch == nil) {
+        vec_push(record, field);
+        done = 1;
+      } else {
+        string_extend(field, ch, nil);
+        state = rfield;
+      }
+    }
+  }
+
+  return record;
+}
+
 val tmpfile_wrap(void)
 {
   val self = lit("tmpfile");
@@ -5697,6 +5774,7 @@ void stream_init(void)
   reg_varl(intern(lit("indent-data"), user_package), num_fast(indent_data));
   reg_varl(intern(lit("indent-code"), user_package), num_fast(indent_code));
   reg_varl(intern(lit("indent-foff"), user_package), num_fast(indent_foff));
+  reg_fun(intern(lit("get-csv"), user_package), func_n1o(get_csv, 0));
   reg_fun(intern(lit("tmpfile"), user_package), func_n0(tmpfile_wrap));
 #if HAVE_MKDTEMP
   reg_fun(intern(lit("mkdtemp"), user_package), func_n1(mkdtemp_wrap));
diff --git a/stream.h b/stream.h
index a0042933..23ca546d 100644
--- a/stream.h
+++ b/stream.h
@@ -285,6 +285,7 @@ val trim_path_seps(val name);
 val path_cat(val dir_name, val base_name);
 val add_suffix(val name, val suffix);
 val make_byte_input_stream(val obj);
+val get_csv(val source_opt);
 val iobuf_get(void);
 void iobuf_put(val buf);
 void iobuf_list_empty(void);