diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6d4743bb..5d6ff822 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ All notable changes to this project will be documented in this file.
 - `jpm` will use `CC` and `AR` environment variables when compiling programs.
 - Add `comptime` macro for compile time evaluation.
 - Run `main` functions in scripts if they exist, just like jpm standalone binaries.
+- Add `protect` macro.
 - Change marshalling protocol with regard to abstract types.
 - Numerous small bug fixes and usability improvements.
 
diff --git a/appveyor.yml b/appveyor.yml
index 1fab060a..60b7f5ce 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -30,7 +30,7 @@ install:
     - call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" %platform%
     - build_win test-install
     - set janet_outname=%appveyor_repo_tag_name%
-    - if "%janet_outname%"=="" set janet_outname=v1.5.1
+    - if "%janet_outname%"=="" set janet_outname=v1.6.0
 build: off
 
 artifacts:
diff --git a/auxbin/jpm b/auxbin/jpm
index acb740d3..6661fadf 100755
--- a/auxbin/jpm
+++ b/auxbin/jpm
@@ -221,12 +221,15 @@
 (defn rm
   "Remove a directory and all sub directories."
   [path]
-  (if (= (os/stat path :mode) :directory)
-    (do
-      (each subpath (os/dir path)
-        (rm (string path sep subpath)))
-      (os/rmdir path))
-    (os/rm path)))
+  (try
+    (if (= (os/stat path :mode) :directory)
+      (do
+        (each subpath (os/dir path)
+          (rm (string path sep subpath)))
+        (os/rmdir path))
+      (os/rm path))
+    ([err f] (unless (string/has-prefix? "No such file or directory" err)
+               (propagate err f)))))
 
 (defn copy
   "Copy a file or directory recursively from one location to another."
@@ -238,6 +241,17 @@
         (shell "xcopy" src (if isdir (string dest "\\" end) dest) "/y" "/s" "/e" "/i"))
     (shell "cp" "-rf" src dest)))
 
+(defn mkdir
+  "Create a directory if it doesn't exist. If it does exist, do nothing.
+  If we can't create it, give a friendly error. Return true if created, false if
+  existing. Throw an error if we can't create it."
+  [dir]
+  (if (os/mkdir dir)
+    true
+    (if (os/stat dir :mode)
+      false
+      (error (string "Could not create " dir " - this could be a permission issue.")))))
+
 #
 # C Compilation
 #
@@ -562,9 +576,7 @@ int main(int argc, const char **argv) {
     (def path ((string/split "\n" line) 0))
     (def path ((string/split "\r" path) 0))
     (print "removing " path)
-    (try (rm path) ([err]
-                    (unless (= err "No such file or directory")
-                      (error err)))))
+    (rm path))
   (:close f)
   (print "removing " manifest)
   (rm manifest)
@@ -585,17 +597,17 @@ int main(int argc, const char **argv) {
 
 (defn install-git
   "Install a bundle from git. If the bundle is already installed, the bundle
-                                             is reinistalled (but not rebuilt if artifacts are cached)."
+   is reinistalled (but not rebuilt if artifacts are cached)."
   [repotab &opt recurse]
   (def repo (if (string? repotab) repotab (repotab :repo)))
   (def tag (unless (string? repotab) (repotab :tag)))
-  # prevent infinite recursion (very unlikely, but consider 
+  # prevent infinite recursion (very unlikely, but consider
   # 'my-package "my-package" in the package listing)
   (when (> (or recurse 0) 100)
     (error "too many references resolving package url"))
   # Handle short names
   (unless (string/find ":" repo)
-    (def pkgs 
+    (def pkgs
       (try (require "pkgs")
                    ([err f]
                     (install-git (dyn :pkglist default-pkglist))
@@ -607,13 +619,14 @@ int main(int argc, const char **argv) {
       (error (string "expected string or table for repository, got " next-repo)))
     (break (install-git next-repo (if recurse (inc recurse) 0))))
   (def cache (find-cache))
-  (os/mkdir cache)
+  (mkdir cache)
   (def id (filepath-replace repo))
   (def module-dir (string cache sep id))
   (var fresh false)
-  (when (os/mkdir module-dir)
-    (set fresh true)
-    (os/execute ["git" "clone" repo module-dir] :p))
+  (when (mkdir module-dir)
+      (set fresh true)
+      (print "cloning repository " repo " to " module-dir)
+      (os/execute ["git" "clone" repo module-dir] :p))
   (def olddir (os/cwd))
   (try
     (with-dyns [:rules @{}
@@ -642,7 +655,7 @@ int main(int argc, const char **argv) {
   (def path (string destdir sep name))
   (array/push (dyn :installed-files) path)
   (add-body "install"
-            (os/mkdir destdir)
+            (mkdir destdir)
             (copy src destdir)))
 
 #
@@ -783,12 +796,12 @@ int main(int argc, const char **argv) {
   (setdyn :manifest-dir manifests)
   (setdyn :installed-files installed-files)
 
-  (rule "./build" [] (os/mkdir "build"))
+  (rule "./build" [] (mkdir "build"))
   (phony "build" ["./build"])
 
   (phony "manifest" []
          (print "generating " manifest "...")
-         (os/mkdir manifests)
+         (mkdir manifests)
          (spit manifest (string (string/join installed-files "\n") "\n")))
   (phony "install" ["uninstall" "build" "manifest"]
          (when (dyn :test)
diff --git a/janet-installer.nsi b/janet-installer.nsi
index 45279727..ab8a1bd5 100644
--- a/janet-installer.nsi
+++ b/janet-installer.nsi
@@ -1,5 +1,5 @@
 # Version
-!define VERSION "1.5.1"
+!define VERSION "1.6.0"
 !define PRODUCT_VERSION "${VERSION}.0"
 VIProductVersion "${PRODUCT_VERSION}"
 VIFileVersion "${PRODUCT_VERSION}"
diff --git a/meson.build b/meson.build
index c072e0b4..0be899ae 100644
--- a/meson.build
+++ b/meson.build
@@ -20,7 +20,7 @@
 
 project('janet', 'c',
   default_options : ['c_std=c99', 'b_lundef=false', 'default_library=both'],
-  version : '1.5.1')
+  version : '1.6.0-dev')
 
 # Global settings
 janet_path = join_paths(get_option('prefix'), get_option('libdir'), 'janet')
diff --git a/src/boot/boot.janet b/src/boot/boot.janet
index c0777dc5..15c7e1b8 100644
--- a/src/boot/boot.janet
+++ b/src/boot/boot.janet
@@ -218,11 +218,21 @@
         f (gensym)
         r (gensym)]
     ~(let [,f (,fiber/new (fn [] ,body) :ie)
-           ,r (resume ,f)]
+           ,r (,resume ,f)]
        (if (= (,fiber/status ,f) :error)
          (do (def ,err ,r) ,(if fib ~(def ,fib ,f)) ,;(tuple/slice catch 1))
          ,r))))
 
+(defmacro protect
+  "Evaluate expressions, while capturing any errors. Evaluates to a tuple
+  of two elements. The first element is true if successful, false if an
+  error, and the second is the return value or error."
+  [& body]
+  (let [f (gensym) r (gensym)]
+    ~(let [,f (,fiber/new (fn [] ,;body) :ie)
+          ,r (,resume ,f)]
+      [(,not= :error (,fiber/status ,f)) ,r])))
+
 (defmacro and
   "Evaluates to the last argument if all preceding elements are true, otherwise
   evaluates to false."
diff --git a/src/conf/janetconf.h b/src/conf/janetconf.h
index a5908ece..243513b6 100644
--- a/src/conf/janetconf.h
+++ b/src/conf/janetconf.h
@@ -27,10 +27,10 @@
 #define JANETCONF_H
 
 #define JANET_VERSION_MAJOR 1
-#define JANET_VERSION_MINOR 5
-#define JANET_VERSION_PATCH 1
-#define JANET_VERSION_EXTRA ""
-#define JANET_VERSION "1.5.1"
+#define JANET_VERSION_MINOR 6
+#define JANET_VERSION_PATCH 0
+#define JANET_VERSION_EXTRA "-dev"
+#define JANET_VERSION "1.6.0-dev"
 
 /* #define JANET_BUILD "local" */
 
diff --git a/src/core/capi.c b/src/core/capi.c
index f26a81d3..dd9119aa 100644
--- a/src/core/capi.c
+++ b/src/core/capi.c
@@ -103,13 +103,15 @@ type janet_opt##name(const Janet *argv, int32_t argc, int32_t n, int32_t dflt_le
     return janet_get##name(argv, n); \
 }
 
-Janet janet_getmethod(const uint8_t *method, const JanetMethod *methods) {
+int janet_getmethod(const uint8_t *method, const JanetMethod *methods, Janet *out) {
     while (methods->name) {
-        if (!janet_cstrcmp(method, methods->name))
-            return janet_wrap_cfunction(methods->cfun);
+        if (!janet_cstrcmp(method, methods->name)) {
+            *out = janet_wrap_cfunction(methods->cfun);
+            return 1;
+        }
         methods++;
     }
-    return janet_wrap_nil();
+    return 0;
 }
 
 DEFINE_GETTER(number, NUMBER, double)
diff --git a/src/core/inttypes.c b/src/core/inttypes.c
index ac00854e..38387a7f 100644
--- a/src/core/inttypes.c
+++ b/src/core/inttypes.c
@@ -36,8 +36,8 @@
 
 #define MAX_INT_IN_DBL 9007199254740992ULL /* 2^53 */
 
-static Janet it_s64_get(void *p, Janet key);
-static Janet it_u64_get(void *p, Janet key);
+static int it_s64_get(void *p, Janet key, Janet *out);
+static int it_u64_get(void *p, Janet key, Janet *out);
 
 static void int64_marshal(void *p, JanetMarshalContext *ctx) {
     janet_marshal_abstract(ctx, p);
@@ -351,18 +351,18 @@ static JanetMethod it_u64_methods[] = {
     {NULL, NULL}
 };
 
-static Janet it_s64_get(void *p, Janet key) {
+static int it_s64_get(void *p, Janet key, Janet *out) {
     (void) p;
     if (!janet_checktype(key, JANET_KEYWORD))
-        janet_panicf("expected keyword, got %v", key);
-    return janet_getmethod(janet_unwrap_keyword(key), it_s64_methods);
+        return 0;
+    return janet_getmethod(janet_unwrap_keyword(key), it_s64_methods, out);
 }
 
-static Janet it_u64_get(void *p, Janet key) {
+static int it_u64_get(void *p, Janet key, Janet *out) {
     (void) p;
     if (!janet_checktype(key, JANET_KEYWORD))
-        janet_panicf("expected keyword, got %v", key);
-    return janet_getmethod(janet_unwrap_keyword(key), it_u64_methods);
+        return 0;
+    return janet_getmethod(janet_unwrap_keyword(key), it_u64_methods, out);
 }
 
 static const JanetReg it_cfuns[] = {
diff --git a/src/core/io.c b/src/core/io.c
index 004125c1..a89265bd 100644
--- a/src/core/io.c
+++ b/src/core/io.c
@@ -53,7 +53,7 @@ struct IOFile {
 };
 
 static int cfun_io_gc(void *p, size_t len);
-static Janet io_file_get(void *p, Janet);
+static int io_file_get(void *p, Janet key, Janet *out);
 
 JanetAbstractType cfun_io_filetype = {
     "core/file",
@@ -353,11 +353,11 @@ static JanetMethod io_file_methods[] = {
     {NULL, NULL}
 };
 
-static Janet io_file_get(void *p, Janet key) {
+static int io_file_get(void *p, Janet key, Janet *out) {
     (void) p;
     if (!janet_checktype(key, JANET_KEYWORD))
-        janet_panicf("expected keyword, got %v", key);
-    return janet_getmethod(janet_unwrap_keyword(key), io_file_methods);
+        return 0;
+    return janet_getmethod(janet_unwrap_keyword(key), io_file_methods, out);
 }
 
 FILE *janet_dynfile(const char *name, FILE *def) {
diff --git a/src/core/math.c b/src/core/math.c
index 62bcb8ed..8b936275 100644
--- a/src/core/math.c
+++ b/src/core/math.c
@@ -29,7 +29,7 @@
 
 static JANET_THREAD_LOCAL JanetRNG janet_vm_rng = {0, 0, 0, 0, 0};
 
-static Janet janet_rng_get(void *p, Janet key);
+static int janet_rng_get(void *p, Janet key, Janet *out);
 
 static void janet_rng_marshal(void *p, JanetMarshalContext *ctx) {
     JanetRNG *rng = (JanetRNG *)p;
@@ -196,10 +196,10 @@ static const JanetMethod rng_methods[] = {
     {NULL, NULL}
 };
 
-static Janet janet_rng_get(void *p, Janet key) {
+static int janet_rng_get(void *p, Janet key, Janet *out) {
     (void) p;
-    if (!janet_checktype(key, JANET_KEYWORD)) janet_panicf("expected keyword method");
-    return janet_getmethod(janet_unwrap_keyword(key), rng_methods);
+    if (!janet_checktype(key, JANET_KEYWORD)) return 0;
+    return janet_getmethod(janet_unwrap_keyword(key), rng_methods, out);
 }
 
 /* Get a random number */
diff --git a/src/core/os.c b/src/core/os.c
index 1387ed3a..e7f9379f 100644
--- a/src/core/os.c
+++ b/src/core/os.c
@@ -613,7 +613,7 @@ static Janet os_link(int32_t argc, Janet *argv) {
     const char *oldpath = janet_getcstring(argv, 0);
     const char *newpath = janet_getcstring(argv, 1);
     int res = ((argc == 3 && janet_getboolean(argv, 2)) ? symlink : link)(oldpath, newpath);
-    if (res == -1) janet_panic(strerror(errno));
+    if (-1 == res) janet_panicf("%s: %s -> %s", strerror(errno), oldpath, newpath);
     return janet_wrap_integer(res);
 #endif
 }
@@ -637,7 +637,7 @@ static Janet os_rmdir(int32_t argc, Janet *argv) {
 #else
     int res = rmdir(path);
 #endif
-    if (res == -1) janet_panic(strerror(errno));
+    if (-1 == res) janet_panicf("%s: %s", strerror(errno), path);
     return janet_wrap_nil();
 }
 
@@ -649,7 +649,7 @@ static Janet os_cd(int32_t argc, Janet *argv) {
 #else
     int res = chdir(path);
 #endif
-    if (res == -1) janet_panic(strerror(errno));
+    if (-1 == res) janet_panicf("%s: %s", strerror(errno), path);
     return janet_wrap_nil();
 }
 
@@ -677,7 +677,7 @@ static Janet os_remove(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 1);
     const char *path = janet_getcstring(argv, 0);
     int status = remove(path);
-    if (-1 == status) janet_panic(strerror(errno));
+    if (-1 == status) janet_panicf("%s: %s", strerror(errno), path);
     return janet_wrap_nil();
 }
 
diff --git a/src/core/parse.c b/src/core/parse.c
index 92486500..ad1293b3 100644
--- a/src/core/parse.c
+++ b/src/core/parse.c
@@ -730,7 +730,7 @@ static int parsergc(void *p, size_t size) {
     return 0;
 }
 
-static Janet parserget(void *p, Janet key);
+static int parserget(void *p, Janet key, Janet *out);
 
 static JanetAbstractType janet_parse_parsertype = {
     "core/parser",
@@ -1055,10 +1055,10 @@ static const JanetMethod parser_methods[] = {
     {NULL, NULL}
 };
 
-static Janet parserget(void *p, Janet key) {
+static int parserget(void *p, Janet key, Janet *out) {
     (void) p;
-    if (!janet_checktype(key, JANET_KEYWORD)) janet_panicf("expected keyword method");
-    return janet_getmethod(janet_unwrap_keyword(key), parser_methods);
+    if (!janet_checktype(key, JANET_KEYWORD)) return 0;
+    return janet_getmethod(janet_unwrap_keyword(key), parser_methods, out);
 }
 
 static const JanetReg parse_cfuns[] = {
diff --git a/src/core/typedarray.c b/src/core/typedarray.c
index e34fc69b..f92e6f96 100644
--- a/src/core/typedarray.c
+++ b/src/core/typedarray.c
@@ -166,50 +166,50 @@ static void *ta_view_unmarshal(JanetMarshalContext *ctx) {
 
 static JanetMethod tarray_view_methods[6];
 
-static Janet ta_getter(void *p, Janet key) {
-    Janet value;
+static int ta_getter(void *p, Janet key, Janet *out) {
     size_t index, i;
     JanetTArrayView *array = p;
-    if (janet_checktype(key, JANET_KEYWORD))
-        return janet_getmethod(janet_unwrap_keyword(key), tarray_view_methods);
+    if (janet_checktype(key, JANET_KEYWORD)) {
+        return janet_getmethod(janet_unwrap_keyword(key), tarray_view_methods, out);
+    }
     if (!janet_checksize(key)) janet_panic("expected size as key");
     index = (size_t) janet_unwrap_number(key);
     i = index * array->stride;
     if (index >= array->size) {
-        value = janet_wrap_nil();
+        return 0;
     } else {
         switch (array->type) {
             case JANET_TARRAY_TYPE_U8:
-                value = janet_wrap_number(array->as.u8[i]);
+                *out = janet_wrap_number(array->as.u8[i]);
                 break;
             case JANET_TARRAY_TYPE_S8:
-                value = janet_wrap_number(array->as.s8[i]);
+                *out = janet_wrap_number(array->as.s8[i]);
                 break;
             case JANET_TARRAY_TYPE_U16:
-                value = janet_wrap_number(array->as.u16[i]);
+                *out = janet_wrap_number(array->as.u16[i]);
                 break;
             case JANET_TARRAY_TYPE_S16:
-                value = janet_wrap_number(array->as.s16[i]);
+                *out = janet_wrap_number(array->as.s16[i]);
                 break;
             case JANET_TARRAY_TYPE_U32:
-                value = janet_wrap_number(array->as.u32[i]);
+                *out = janet_wrap_number(array->as.u32[i]);
                 break;
             case JANET_TARRAY_TYPE_S32:
-                value = janet_wrap_number(array->as.s32[i]);
+                *out = janet_wrap_number(array->as.s32[i]);
                 break;
 #ifdef JANET_INT_TYPES
             case JANET_TARRAY_TYPE_U64:
-                value = janet_wrap_u64(array->as.u64[i]);
+                *out = janet_wrap_u64(array->as.u64[i]);
                 break;
             case JANET_TARRAY_TYPE_S64:
-                value = janet_wrap_s64(array->as.s64[i]);
+                *out = janet_wrap_s64(array->as.s64[i]);
                 break;
 #endif
             case JANET_TARRAY_TYPE_F32:
-                value = janet_wrap_number_safe(array->as.f32[i]);
+                *out = janet_wrap_number_safe(array->as.f32[i]);
                 break;
             case JANET_TARRAY_TYPE_F64:
-                value = janet_wrap_number_safe(array->as.f64[i]);
+                *out = janet_wrap_number_safe(array->as.f64[i]);
                 break;
             default:
                 janet_panicf("cannot get from typed array of type %s",
@@ -217,7 +217,7 @@ static Janet ta_getter(void *p, Janet key) {
                 break;
         }
     }
-    return value;
+    return 1;
 }
 
 static void ta_setter(void *p, Janet key, Janet value) {
@@ -450,7 +450,8 @@ static Janet cfun_typed_array_slice(int32_t argc, Janet *argv) {
     JanetArray *array = janet_array(range.end - range.start);
     if (array->data) {
         for (int32_t i = range.start; i < range.end; i++) {
-            array->data[i - range.start] = ta_getter(src, janet_wrap_number(i));
+            if (!ta_getter(src, janet_wrap_number(i), &array->data[i - range.start]))
+                array->data[i - range.start] = janet_wrap_nil();
         }
     }
     array->count = range.end - range.start;
diff --git a/src/core/value.c b/src/core/value.c
index 1189e3fb..7f436773 100644
--- a/src/core/value.c
+++ b/src/core/value.c
@@ -197,7 +197,8 @@ Janet janet_in(Janet ds, Janet key) {
         case JANET_ABSTRACT: {
             JanetAbstractType *type = (JanetAbstractType *)janet_abstract_type(janet_unwrap_abstract(ds));
             if (type->get) {
-                value = (type->get)(janet_unwrap_abstract(ds), key);
+                if (!(type->get)(janet_unwrap_abstract(ds), key, &value))
+                    janet_panicf("key %v not found in %v ", key, ds);
             } else {
                 janet_panicf("no getter for %v ", ds);
             }
@@ -223,10 +224,13 @@ Janet janet_get(Janet ds, Janet key) {
             return janet_wrap_integer(str[index]);
         }
         case JANET_ABSTRACT: {
+            Janet value;
             void *abst = janet_unwrap_abstract(ds);
             JanetAbstractType *type = (JanetAbstractType *)janet_abstract_type(abst);
             if (!type->get) return janet_wrap_nil();
-            return (type->get)(abst, key);
+            if ((type->get)(abst, key, &value))
+                return value;
+            return janet_wrap_nil();
         }
         case JANET_ARRAY:
         case JANET_TUPLE:
@@ -304,7 +308,8 @@ Janet janet_getindex(Janet ds, int32_t index) {
         case JANET_ABSTRACT: {
             JanetAbstractType *type = (JanetAbstractType *)janet_abstract_type(janet_unwrap_abstract(ds));
             if (type->get) {
-                value = (type->get)(janet_unwrap_abstract(ds), janet_wrap_integer(index));
+                if (!(type->get)(janet_unwrap_abstract(ds), janet_wrap_integer(index), &value))
+                    value = janet_wrap_nil();
             } else {
                 janet_panicf("no getter for %v ", ds);
             }
diff --git a/src/core/vm.c b/src/core/vm.c
index 6064143f..4fd94a55 100644
--- a/src/core/vm.c
+++ b/src/core/vm.c
@@ -1201,9 +1201,8 @@ Janet janet_mcall(const char *name, int32_t argc, Janet *argv) {
     if (janet_checktype(argv[0], JANET_ABSTRACT)) {
         void *abst = janet_unwrap_abstract(argv[0]);
         JanetAbstractType *type = (JanetAbstractType *)janet_abstract_type(abst);
-        if (!type->get)
+        if (!type->get || !(type->get)(abst, janet_ckeywordv(name), &method))
             janet_panicf("abstract value %v does not implement :%s", argv[0], name);
-        method = (type->get)(abst, janet_ckeywordv(name));
     } else if (janet_checktype(argv[0], JANET_TABLE)) {
         JanetTable *table = janet_unwrap_table(argv[0]);
         method = janet_table_get(table, janet_ckeywordv(name));
diff --git a/src/include/janet.h b/src/include/janet.h
index 842e3e8c..7b3501ce 100644
--- a/src/include/janet.h
+++ b/src/include/janet.h
@@ -328,6 +328,14 @@ typedef struct JanetRange JanetRange;
 typedef struct JanetRNG JanetRNG;
 typedef Janet(*JanetCFunction)(int32_t argc, Janet *argv);
 
+/* String and other aliased pointer types */
+typedef const uint8_t *JanetString;
+typedef const uint8_t *JanetSymbol;
+typedef const uint8_t *JanetKeyword;
+typedef const Janet *JanetTuple;
+typedef const JanetKV *JanetStruct;
+typedef void *JanetAbstract;
+
 /* Basic types for all Janet Values */
 typedef enum JanetType {
     JANET_NUMBER,
@@ -822,8 +830,8 @@ struct JanetFuncDef {
 
     /* Various debug information */
     JanetSourceMapping *sourcemap;
-    const uint8_t *source;
-    const uint8_t *name;
+    JanetString source;
+    JanetString name;
 
     int32_t flags;
     int32_t slotcount; /* The amount of stack space required for the function */
@@ -899,7 +907,7 @@ struct JanetAbstractType {
     const char *name;
     int (*gc)(void *data, size_t len);
     int (*gcmark)(void *data, size_t len);
-    Janet(*get)(void *data, Janet key);
+    int (*get)(void *data, Janet key, Janet *out);
     void (*put)(void *data, Janet key, Janet value);
     void (*marshal)(void *p, JanetMarshalContext *ctx);
     void *(*unmarshal)(JanetMarshalContext *ctx);
@@ -1090,7 +1098,7 @@ enum JanetAssembleStatus {
 };
 struct JanetAssembleResult {
     JanetFuncDef *funcdef;
-    const uint8_t *error;
+    JanetString error;
     enum JanetAssembleStatus status;
 };
 JANET_API JanetAssembleResult janet_asm(Janet source, int flags);
@@ -1106,12 +1114,12 @@ enum JanetCompileStatus {
 };
 struct JanetCompileResult {
     JanetFuncDef *funcdef;
-    const uint8_t *error;
+    JanetString error;
     JanetFiber *macrofiber;
     JanetSourceMapping error_mapping;
     enum JanetCompileStatus status;
 };
-JANET_API JanetCompileResult janet_compile(Janet source, JanetTable *env, const uint8_t *where);
+JANET_API JanetCompileResult janet_compile(Janet source, JanetTable *env, JanetString where);
 
 /* Get the default environment for janet */
 JANET_API JanetTable *janet_core_env(JanetTable *replacements);
@@ -1129,7 +1137,7 @@ JANET_API void janet_debug_break(JanetFuncDef *def, int32_t pc);
 JANET_API void janet_debug_unbreak(JanetFuncDef *def, int32_t pc);
 JANET_API void janet_debug_find(
     JanetFuncDef **def_out, int32_t *pc_out,
-    const uint8_t *source, int32_t line, int32_t column);
+    JanetString source, int32_t line, int32_t column);
 
 /* RNG */
 JANET_API JanetRNG *janet_default_rng(void);
@@ -1154,7 +1162,7 @@ JANET_API void janet_buffer_ensure(JanetBuffer *buffer, int32_t capacity, int32_
 JANET_API void janet_buffer_setcount(JanetBuffer *buffer, int32_t count);
 JANET_API void janet_buffer_extra(JanetBuffer *buffer, int32_t n);
 JANET_API void janet_buffer_push_bytes(JanetBuffer *buffer, const uint8_t *string, int32_t len);
-JANET_API void janet_buffer_push_string(JanetBuffer *buffer, const uint8_t *string);
+JANET_API void janet_buffer_push_string(JanetBuffer *buffer, JanetString string);
 JANET_API void janet_buffer_push_cstring(JanetBuffer *buffer, const char *cstring);
 JANET_API void janet_buffer_push_u8(JanetBuffer *buffer, uint8_t x);
 JANET_API void janet_buffer_push_u16(JanetBuffer *buffer, uint16_t x);
@@ -1172,35 +1180,35 @@ JANET_API void janet_buffer_push_u64(JanetBuffer *buffer, uint64_t x);
 #define janet_tuple_sm_column(t) (janet_tuple_head(t)->sm_column)
 #define janet_tuple_flag(t) (janet_tuple_head(t)->gc.flags)
 JANET_API Janet *janet_tuple_begin(int32_t length);
-JANET_API const Janet *janet_tuple_end(Janet *tuple);
-JANET_API const Janet *janet_tuple_n(const Janet *values, int32_t n);
-JANET_API int janet_tuple_equal(const Janet *lhs, const Janet *rhs);
-JANET_API int janet_tuple_compare(const Janet *lhs, const Janet *rhs);
+JANET_API JanetTuple janet_tuple_end(Janet *tuple);
+JANET_API JanetTuple janet_tuple_n(const Janet *values, int32_t n);
+JANET_API int janet_tuple_equal(JanetTuple lhs, JanetTuple rhs);
+JANET_API int janet_tuple_compare(JanetTuple lhs, JanetTuple rhs);
 
 /* String/Symbol functions */
 #define janet_string_head(s) ((JanetStringHead *)((char *)s - offsetof(JanetStringHead, data)))
 #define janet_string_length(s) (janet_string_head(s)->length)
 #define janet_string_hash(s) (janet_string_head(s)->hash)
 JANET_API uint8_t *janet_string_begin(int32_t length);
-JANET_API const uint8_t *janet_string_end(uint8_t *str);
-JANET_API const uint8_t *janet_string(const uint8_t *buf, int32_t len);
-JANET_API const uint8_t *janet_cstring(const char *cstring);
-JANET_API int janet_string_compare(const uint8_t *lhs, const uint8_t *rhs);
-JANET_API int janet_string_equal(const uint8_t *lhs, const uint8_t *rhs);
-JANET_API int janet_string_equalconst(const uint8_t *lhs, const uint8_t *rhs, int32_t rlen, int32_t rhash);
-JANET_API const uint8_t *janet_description(Janet x);
-JANET_API const uint8_t *janet_to_string(Janet x);
+JANET_API JanetString janet_string_end(uint8_t *str);
+JANET_API JanetString janet_string(const uint8_t *buf, int32_t len);
+JANET_API JanetString janet_cstring(const char *cstring);
+JANET_API int janet_string_compare(JanetString lhs, JanetString rhs);
+JANET_API int janet_string_equal(JanetString lhs, JanetString rhs);
+JANET_API int janet_string_equalconst(JanetString lhs, const uint8_t *rhs, int32_t rlen, int32_t rhash);
+JANET_API JanetString janet_description(Janet x);
+JANET_API JanetString janet_to_string(Janet x);
 JANET_API void janet_to_string_b(JanetBuffer *buffer, Janet x);
 JANET_API void janet_description_b(JanetBuffer *buffer, Janet x);
 #define janet_cstringv(cstr) janet_wrap_string(janet_cstring(cstr))
 #define janet_stringv(str, len) janet_wrap_string(janet_string((str), (len)))
-JANET_API const uint8_t *janet_formatc(const char *format, ...);
+JANET_API JanetString janet_formatc(const char *format, ...);
 JANET_API void janet_formatb(JanetBuffer *bufp, const char *format, va_list args);
 
 /* Symbol functions */
-JANET_API const uint8_t *janet_symbol(const uint8_t *str, int32_t len);
-JANET_API const uint8_t *janet_csymbol(const char *str);
-JANET_API const uint8_t *janet_symbol_gen(void);
+JANET_API JanetSymbol janet_symbol(const uint8_t *str, int32_t len);
+JANET_API JanetSymbol janet_csymbol(const char *str);
+JANET_API JanetSymbol janet_symbol_gen(void);
 #define janet_symbolv(str, len) janet_wrap_symbol(janet_symbol((str), (len)))
 #define janet_csymbolv(cstr) janet_wrap_symbol(janet_csymbol(cstr))
 
@@ -1217,12 +1225,12 @@ JANET_API const uint8_t *janet_symbol_gen(void);
 #define janet_struct_hash(t) (janet_struct_head(t)->hash)
 JANET_API JanetKV *janet_struct_begin(int32_t count);
 JANET_API void janet_struct_put(JanetKV *st, Janet key, Janet value);
-JANET_API const JanetKV *janet_struct_end(JanetKV *st);
-JANET_API Janet janet_struct_get(const JanetKV *st, Janet key);
-JANET_API JanetTable *janet_struct_to_table(const JanetKV *st);
-JANET_API int janet_struct_equal(const JanetKV *lhs, const JanetKV *rhs);
-JANET_API int janet_struct_compare(const JanetKV *lhs, const JanetKV *rhs);
-JANET_API const JanetKV *janet_struct_find(const JanetKV *st, Janet key);
+JANET_API JanetStruct janet_struct_end(JanetKV *st);
+JANET_API Janet janet_struct_get(JanetStruct st, Janet key);
+JANET_API JanetTable *janet_struct_to_table(JanetStruct st);
+JANET_API int janet_struct_equal(JanetStruct lhs, JanetStruct rhs);
+JANET_API int janet_struct_compare(JanetStruct lhs, JanetStruct rhs);
+JANET_API const JanetKV *janet_struct_find(JanetStruct st, Janet key);
 
 /* Table functions */
 JANET_API JanetTable *janet_table(int32_t capacity);
@@ -1233,9 +1241,9 @@ JANET_API Janet janet_table_get_ex(JanetTable *t, Janet key, JanetTable **which)
 JANET_API Janet janet_table_rawget(JanetTable *t, Janet key);
 JANET_API Janet janet_table_remove(JanetTable *t, Janet key);
 JANET_API void janet_table_put(JanetTable *t, Janet key, Janet value);
-JANET_API const JanetKV *janet_table_to_struct(JanetTable *t);
+JANET_API JanetStruct janet_table_to_struct(JanetTable *t);
 JANET_API void janet_table_merge_table(JanetTable *table, JanetTable *other);
-JANET_API void janet_table_merge_struct(JanetTable *table, const JanetKV *other);
+JANET_API void janet_table_merge_struct(JanetTable *table, JanetStruct other);
 JANET_API JanetKV *janet_table_find(JanetTable *t, Janet key);
 JANET_API JanetTable *janet_table_clone(JanetTable *table);
 
@@ -1257,13 +1265,13 @@ JANET_API const JanetKV *janet_dictionary_next(const JanetKV *kvs, int32_t cap,
 #define janet_abstract_type(u) (janet_abstract_head(u)->type)
 #define janet_abstract_size(u) (janet_abstract_head(u)->size)
 JANET_API void *janet_abstract_begin(const JanetAbstractType *type, size_t size);
-JANET_API void *janet_abstract_end(void *);
-JANET_API void *janet_abstract(const JanetAbstractType *type, size_t size); /* begin and end in one call */
+JANET_API JanetAbstract janet_abstract_end(void *abstractTemplate);
+JANET_API JanetAbstract janet_abstract(const JanetAbstractType *type, size_t size); /* begin and end in one call */
 
 /* Native */
 typedef void (*JanetModule)(JanetTable *);
 typedef JanetBuildConfig(*JanetModconf)(void);
-JANET_API JanetModule janet_native(const char *name, const uint8_t **error);
+JANET_API JanetModule janet_native(const char *name, JanetString *error);
 
 /* Marshaling */
 JANET_API void janet_marshal(
@@ -1305,7 +1313,7 @@ JANET_API JanetBuffer *janet_pretty(JanetBuffer *buffer, int depth, int flags, J
 JANET_API int janet_equals(Janet x, Janet y);
 JANET_API int32_t janet_hash(Janet x);
 JANET_API int janet_compare(Janet x, Janet y);
-JANET_API int janet_cstrcmp(const uint8_t *str, const char *other);
+JANET_API int janet_cstrcmp(JanetString str, const char *other);
 JANET_API Janet janet_in(Janet ds, Janet key);
 JANET_API Janet janet_get(Janet ds, Janet key);
 JANET_API Janet janet_getindex(Janet ds, int32_t index);
@@ -1343,7 +1351,7 @@ typedef enum {
 JANET_API void janet_def(JanetTable *env, const char *name, Janet val, const char *documentation);
 JANET_API void janet_var(JanetTable *env, const char *name, Janet val, const char *documentation);
 JANET_API void janet_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cfuns);
-JANET_API JanetBindingType janet_resolve(JanetTable *env, const uint8_t *sym, Janet *out);
+JANET_API JanetBindingType janet_resolve(JanetTable *env, JanetSymbol sym, Janet *out);
 JANET_API void janet_register(const char *name, JanetCFunction cfun);
 
 /* Get values from the core environment. */
@@ -1364,7 +1372,7 @@ JANET_API Janet janet_resolve_core(const char *name);
 
 JANET_NO_RETURN JANET_API void janet_panicv(Janet message);
 JANET_NO_RETURN JANET_API void janet_panic(const char *message);
-JANET_NO_RETURN JANET_API void janet_panics(const uint8_t *message);
+JANET_NO_RETURN JANET_API void janet_panics(JanetString message);
 JANET_NO_RETURN JANET_API void janet_panicf(const char *format, ...);
 JANET_API void janet_dynprintf(const char *name, FILE *dflt_file, const char *format, ...);
 #define janet_printf(...) janet_dynprintf("out", stdout, __VA_ARGS__)
@@ -1374,17 +1382,17 @@ JANET_NO_RETURN JANET_API void janet_panic_abstract(Janet x, int32_t n, const Ja
 JANET_API void janet_arity(int32_t arity, int32_t min, int32_t max);
 JANET_API void janet_fixarity(int32_t arity, int32_t fix);
 
-JANET_API Janet janet_getmethod(const uint8_t *method, const JanetMethod *methods);
+JANET_API int janet_getmethod(JanetKeyword method, const JanetMethod *methods, Janet *out);
 
 JANET_API double janet_getnumber(const Janet *argv, int32_t n);
 JANET_API JanetArray *janet_getarray(const Janet *argv, int32_t n);
-JANET_API const Janet *janet_gettuple(const Janet *argv, int32_t n);
+JANET_API JanetTuple janet_gettuple(const Janet *argv, int32_t n);
 JANET_API JanetTable *janet_gettable(const Janet *argv, int32_t n);
-JANET_API const JanetKV *janet_getstruct(const Janet *argv, int32_t n);
-JANET_API const uint8_t *janet_getstring(const Janet *argv, int32_t n);
+JANET_API JanetStruct janet_getstruct(const Janet *argv, int32_t n);
+JANET_API JanetString janet_getstring(const Janet *argv, int32_t n);
 JANET_API const char *janet_getcstring(const Janet *argv, int32_t n);
-JANET_API const uint8_t *janet_getsymbol(const Janet *argv, int32_t n);
-JANET_API const uint8_t *janet_getkeyword(const Janet *argv, int32_t n);
+JANET_API JanetSymbol janet_getsymbol(const Janet *argv, int32_t n);
+JANET_API JanetKeyword janet_getkeyword(const Janet *argv, int32_t n);
 JANET_API JanetBuffer *janet_getbuffer(const Janet *argv, int32_t n);
 JANET_API JanetFiber *janet_getfiber(const Janet *argv, int32_t n);
 JANET_API JanetFunction *janet_getfunction(const Janet *argv, int32_t n);
@@ -1407,12 +1415,12 @@ JANET_API uint64_t janet_getflags(const Janet *argv, int32_t n, const char *flag
 
 /* Optionals */
 JANET_API double janet_optnumber(const Janet *argv, int32_t argc, int32_t n, double dflt);
-JANET_API const Janet *janet_opttuple(const Janet *argv, int32_t argc, int32_t n, const Janet *dflt);
-JANET_API const JanetKV *janet_optstruct(const Janet *argv, int32_t argc, int32_t n, const JanetKV *dflt);
-JANET_API const uint8_t *janet_optstring(const Janet *argv, int32_t argc, int32_t n, const uint8_t *dflt);
+JANET_API JanetTuple janet_opttuple(const Janet *argv, int32_t argc, int32_t n, JanetTuple dflt);
+JANET_API JanetStruct janet_optstruct(const Janet *argv, int32_t argc, int32_t n, JanetStruct dflt);
+JANET_API JanetString janet_optstring(const Janet *argv, int32_t argc, int32_t n, JanetString dflt);
 JANET_API const char *janet_optcstring(const Janet *argv, int32_t argc, int32_t n, const char *dflt);
-JANET_API const uint8_t *janet_optsymbol(const Janet *argv, int32_t argc, int32_t n, const uint8_t *dflt);
-JANET_API const uint8_t *janet_optkeyword(const Janet *argv, int32_t argc, int32_t n, const uint8_t *dflt);
+JANET_API JanetSymbol janet_optsymbol(const Janet *argv, int32_t argc, int32_t n, JanetString dflt);
+JANET_API JanetKeyword janet_optkeyword(const Janet *argv, int32_t argc, int32_t n, JanetString dflt);
 JANET_API JanetFiber *janet_optfiber(const Janet *argv, int32_t argc, int32_t n, JanetFiber *dflt);
 JANET_API JanetFunction *janet_optfunction(const Janet *argv, int32_t argc, int32_t n, JanetFunction *dflt);
 JANET_API JanetCFunction janet_optcfunction(const Janet *argv, int32_t argc, int32_t n, JanetCFunction dflt);
@@ -1422,7 +1430,7 @@ JANET_API int32_t janet_optnat(const Janet *argv, int32_t argc, int32_t n, int32
 JANET_API int32_t janet_optinteger(const Janet *argv, int32_t argc, int32_t n, int32_t dflt);
 JANET_API int64_t janet_optinteger64(const Janet *argv, int32_t argc, int32_t n, int64_t dflt);
 JANET_API size_t janet_optsize(const Janet *argv, int32_t argc, int32_t n, size_t dflt);
-JANET_API void *janet_optabstract(const Janet *argv, int32_t argc, int32_t n, const JanetAbstractType *at, void *dflt);
+JANET_API JanetAbstract janet_optabstract(const Janet *argv, int32_t argc, int32_t n, const JanetAbstractType *at, JanetAbstract dflt);
 
 /* Mutable optional types specify a size default, and construct a new value if none is provided */
 JANET_API JanetBuffer *janet_optbuffer(const Janet *argv, int32_t argc, int32_t n, int32_t dflt_len);
@@ -1442,7 +1450,7 @@ JANET_API void janet_marshal_int64(JanetMarshalContext *ctx, int64_t value);
 JANET_API void janet_marshal_byte(JanetMarshalContext *ctx, uint8_t value);
 JANET_API void janet_marshal_bytes(JanetMarshalContext *ctx, const uint8_t *bytes, size_t len);
 JANET_API void janet_marshal_janet(JanetMarshalContext *ctx, Janet x);
-JANET_API void janet_marshal_abstract(JanetMarshalContext *ctx, void *abstract);
+JANET_API void janet_marshal_abstract(JanetMarshalContext *ctx, JanetAbstract abstract);
 
 JANET_API void janet_unmarshal_ensure(JanetMarshalContext *ctx, size_t size);
 JANET_API size_t janet_unmarshal_size(JanetMarshalContext *ctx);
@@ -1451,7 +1459,7 @@ JANET_API int64_t janet_unmarshal_int64(JanetMarshalContext *ctx);
 JANET_API uint8_t janet_unmarshal_byte(JanetMarshalContext *ctx);
 JANET_API void janet_unmarshal_bytes(JanetMarshalContext *ctx, uint8_t *dest, size_t len);
 JANET_API Janet janet_unmarshal_janet(JanetMarshalContext *ctx);
-JANET_API void *janet_unmarshal_abstract(JanetMarshalContext *ctx, size_t size);
+JANET_API JanetAbstract janet_unmarshal_abstract(JanetMarshalContext *ctx, size_t size);
 
 JANET_API void janet_register_abstract_type(const JanetAbstractType *at);
 JANET_API const JanetAbstractType *janet_get_abstract_type(Janet key);