Allow IO redirection on windows.

This should help cover a number of common cases for
use of subprocesses. This should also eventually work well
with the ev branch via

.builds/meson2.yml

@@ -0,0 +1,15 @@
+image: openbsd/latest
+sources:
+- https://git.sr.ht/~bakpakin/janet
+packages:
+- meson
+tasks:
+- build: |
+    cd janet
+    meson setup build --buildtype=release
+    cd build
+    meson configure -Dprf=true
+    ninja
+    ninja test
+    doas ninja install
+    doas jpm --verbose install circlet

.builds/meson_min.yml

@@ -19,5 +19,4 @@ tasks:
     meson configure -Dint_types=false
     meson configure -Dtyped_array=false
     meson configure -Dreduced_os=true
-    meson configure -Dprf=false
     ninja # will not pass tests but should build

CHANGELOG.md

@@ -1,9 +1,34 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
-## 1.11.2 - 2020-08-03
+## Unreleased - ???
+- Add `os/proc-wait` and `os/proc-kill` for interacting with processes.
+- Add `janet_getjfile` to C API.
+- Allow redirection of stdin, stdout, and stderr by passing keywords in the env table.
+- Add `:a` flag to `os/execute` to get a core/process back instead of an exit code.
+  When called like this, `os/execute` returns immediately.
+- Add `:x` flag to os/execute to raise error when exit code is non-zero.
+- Don't run `main` when flychecking.
+- Add `:n` flag to `file/open` to raise an error if file cannot be opened.
+- Fix import macro to not try and coerce everything to a string.
+- Allow passing a second argument to `disasm`.
+- Add `cancel`. Resumes a fiber but makes it immediately error at the yield point.
+- Allow multi-line paste into built in repl.
+- Add `(curenv)`.
+- Change `net/read`, `net/chunk`, and `net/write` to raise errors in the case of failures.
+- Add `janet_continue_signal` to C API. This indirectly enables C functions that yield to the event loop
+  to raise errors or other signals.
+- Update meson build script to fix bug on Debian's version of meson
+- Add `xprint`, `xprin`, `xprintf`, and `xprinf`.
+- `net/write` now raises an error message if write fails.
+- Fix issue with SIGPIPE on macOS and BSDs.
+
+## 1.11.3 - 2020-08-03
+- Add `JANET_HASHSEED` environment variable when `JANET_PRF` is enabled.
+- Expose `janet_cryptorand` in C API.
+- Properly initialize PRF in default janet program
 - Add `index-of` to core library.
-- Add `-fPIC` back to core CFLAGS (non-optional when compiling default client  with Makefile)
+- Add `-fPIC` back to core CFLAGS (non-optional when compiling default client with Makefile)
 - Fix defaults on Windows for ARM
 - Fix defaults on NetBSD.
 

README.md

@@ -2,10 +2,10 @@
  
 [![Appveyor Status](https://ci.appveyor.com/api/projects/status/bjraxrxexmt3sxyv/branch/master?svg=true)](https://ci.appveyor.com/project/bakpakin/janet/branch/master)
 [![Build Status](https://travis-ci.org/janet-lang/janet.svg?branch=master)](https://travis-ci.org/janet-lang/janet)
-[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/freebsd.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/freebsd.yml?)
-[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/openbsd.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/openbsd.yml?)
-[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/meson.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/meson.yml?)
-[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/meson_min.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/meson_min.yml?)
+[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/commits/freebsd.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/freebsd.yml?)
+[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/commits/openbsd.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/openbsd.yml?)
+[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/commits/meson.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/meson.yml?)
+[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/commits/meson_min.yml.svg)](https://builds.sr.ht/~bakpakin/janet/commits/meson_min.yml?)
 
 <img src="https://raw.githubusercontent.com/janet-lang/janet/master/assets/janet-w200.png" alt="Janet logo" width=200 align="left">
 

janet.1

@@ -213,5 +213,13 @@ find native and source code modules. If no JANET_PATH is set, Janet will look in
 the default location set at compile time.
 .RE
 
+.B JANET_HASHSEED
+.RS
+To disable randomization of Janet's PRF on start up, one can set this variable. This can have the
+effect of making programs deterministic that otherwise would depend on the random seed chosen at program start.
+This variable does nothing in the default configuration of Janet, as PRF is disabled by default. Also, JANET_REDUCED_OS
+cannot be defined for this variable to have an effect.
+.RE
+
 .SH AUTHOR
 Written by Calvin Rose <calsrose@gmail.com>

jpm

@@ -535,6 +535,23 @@
     ```
 
 int main(int argc, const char **argv) {
+
+#if defined(JANET_PRF)
+    uint8_t hash_key[JANET_HASH_KEY_SIZE + 1];
+#ifdef JANET_REDUCED_OS
+    char *envvar = NULL;
+#else
+    char *envvar = getenv("JANET_HASHSEED");
+#endif
+    if (NULL != envvar) {
+        strncpy((char *) hash_key, envvar, sizeof(hash_key) - 1);
+    } else if (janet_cryptorand(hash_key, JANET_HASH_KEY_SIZE) != 0) {
+        fputs("unable to initialize janet PRF hash function.\n", stderr);
+        return 1;
+    }
+    janet_init_hash_key(hash_key);
+#endif
+
     janet_init();
 
     /* Get core env */

meson.build

@@ -20,7 +20,7 @@
 
 project('janet', 'c',
   default_options : ['c_std=c99', 'b_lundef=false', 'default_library=both'],
-  version : '1.11.2')
+  version : '1.11.4')
 
 # Global settings
 janet_path = join_paths(get_option('prefix'), get_option('libdir'), 'janet')
@@ -178,30 +178,28 @@ libjanet = library('janet', janetc,
 
 # Extra c flags - adding -fvisibility=hidden matches the Makefile and
 # shaves off about 10k on linux x64, likely similar on other platforms.
-native_cc = meson.get_compiler('c', native: true)
-cross_cc = meson.get_compiler('c', native: false)
-if native_cc.has_argument('-fvisibility=hidden')
-  extra_native_cflags = ['-fvisibility=hidden']
+if cc.has_argument('-fvisibility=hidden')
+  extra_cflags = ['-fvisibility=hidden']
 else
-  extra_native_cflags = []
+  extra_cflags = []
 endif
-if cross_cc.has_argument('-fvisibility=hidden')
-  extra_cross_cflags = ['-fvisibility=hidden']
-else
-  extra_cross_cflags = []
-endif
-
 janet_mainclient = executable('janet', janetc, mainclient_src,
   include_directories : incdir,
   dependencies : [m_dep, dl_dep, thread_dep],
-  c_args : extra_native_cflags,
+  c_args : extra_cflags,
   install : true)
 
 if meson.is_cross_build()
+  native_cc = meson.get_compiler('c', native: true)
+  if native_cc.has_argument('-fvisibility=hidden')
+    extra_native_cflags = ['-fvisibility=hidden']
+  else
+    extra_native_cflags = []
+  endif
   janet_nativeclient = executable('janet-native', janetc, mainclient_src,
     include_directories : incdir,
     dependencies : [m_dep, dl_dep, thread_dep],
-    c_args : extra_cross_cflags,
+    c_args : extra_native_cflags,
     native : true)
 else
   janet_nativeclient = janet_mainclient
@@ -216,16 +214,17 @@ docs = custom_target('docs',
 
 # Tests
 test_files = [
-  'test/suite0.janet',
-  'test/suite1.janet',
-  'test/suite2.janet',
-  'test/suite3.janet',
-  'test/suite4.janet',
-  'test/suite5.janet',
-  'test/suite6.janet',
-  'test/suite7.janet',
-  'test/suite8.janet',
-  'test/suite9.janet'
+  'test/suite0000.janet',
+  'test/suite0001.janet',
+  'test/suite0002.janet',
+  'test/suite0003.janet',
+  'test/suite0004.janet',
+  'test/suite0005.janet',
+  'test/suite0006.janet',
+  'test/suite0007.janet',
+  'test/suite0008.janet',
+  'test/suite0009.janet',
+  'test/suite0010.janet'
 ]
 foreach t : test_files
   test(t, janet_nativeclient, args : files([t]), workdir : meson.current_source_dir())

src/boot/boot.janet

@@ -1804,14 +1804,16 @@
   (defn expandqq [t]
     (defn qq [x]
       (case (type x)
-        :tuple (do
-                 (def x0 (in x 0))
-                 (if (or (= 'unquote x0) (= 'unquote-splicing x0))
-                   (tuple x0 (recur (in x 1)))
-                   (tuple/slice (map qq x))))
+        :tuple (if (= :brackets (tuple/type x))
+                 ~[,;(map qq x)]
+                 (do
+                   (def x0 (get x 0))
+                   (if (= 'unquote x0)
+                     (tuple x0 (recur (get x 1)))
+                     (tuple/slice (map qq x)))))
         :array (map qq x)
-        :table (table (map qq (kvs x)))
-        :struct (struct (map qq (kvs x)))
+        :table (table ;(map qq (kvs x)))
+        :struct (struct ;(map qq (kvs x)))
         x))
     (tuple (in t 0) (qq (in t 1))))
 
@@ -2067,6 +2069,14 @@
       (if ec "\e[0m" "")))
   (eflush))
 
+(defn curenv
+  "Get the current environment table. Same as (fiber/getenv (fiber/current)). If n
+  is provided, gets the nth prototype of the environment table."
+  [&opt n]
+  (var e (fiber/getenv (fiber/current)))
+  (if n (repeat n (if (= nil e) (break)) (set e (table/getproto e))))
+  e)
+
 (defn run-context
   "Run a context. This evaluates expressions in an environment,
   and is encapsulates the parsing, compilation, and evaluation.
@@ -2465,7 +2475,8 @@
   to be called. Dynamic bindings will NOT be imported. Use :fresh to bypass the
   module cache."
   [path & args]
-  (def argm (map |(if (keyword? $) $ (string $)) args))
+  (def ps (partition 2 args))
+  (def argm (mapcat (fn [[k v]] [k (if (= k :as) (string v) v)]) ps))
   (tuple import* (string path) ;argm))
 
 (defmacro use
@@ -2848,9 +2859,10 @@
         (def subargs (array/slice args i))
         (put env :args subargs)
         (dofile arg :prefix "" :exit *exit-on-error* :evaluator evaluator :env env)
-        (if-let [main (get (in env 'main) :value)]
-          (let [thunk (compile [main ;(tuple/slice args i)] env arg)]
-            (if (function? thunk) (thunk) (error (thunk :error)))))
+        (unless *compile-only*
+          (if-let [main (get (in env 'main) :value)]
+            (let [thunk (compile [main ;(tuple/slice args i)] env arg)]
+              (if (function? thunk) (thunk) (error (thunk :error))))))
         (set i lenargs))))
 
   (when (and (not *compile-only*) (or *should-repl* *no-file*))

src/conf/janetconf.h

@@ -28,9 +28,9 @@
 
 #define JANET_VERSION_MAJOR 1
 #define JANET_VERSION_MINOR 11
-#define JANET_VERSION_PATCH 2
-#define JANET_VERSION_EXTRA ""
-#define JANET_VERSION "1.11.2"
+#define JANET_VERSION_PATCH 4
+#define JANET_VERSION_EXTRA "-dev"
+#define JANET_VERSION "1.11.4-dev"
 
 /* #define JANET_BUILD "local" */
 
@@ -57,6 +57,7 @@
 /* #define JANET_NO_UMASK */
 
 /* Other settings */
+/* #define JANET_DEBUG */
 /* #define JANET_PRF */
 /* #define JANET_NO_UTC_MKTIME */
 /* #define JANET_OUT_OF_MEMORY do { printf("janet out of memory\n"); exit(1); } while (0) */

src/core/asm.c

@@ -73,6 +73,7 @@ static const JanetInstructionDef janet_ops[] = {
     {"call", JOP_CALL},
     {"clo", JOP_CLOSURE},
     {"cmp", JOP_COMPARE},
+    {"cncl", JOP_CANCEL},
     {"div", JOP_DIVIDE},
     {"divim", JOP_DIVIDE_IMMEDIATE},
     {"eq", JOP_EQUALS},
@@ -840,85 +841,110 @@ Janet janet_asm_decode_instruction(uint32_t instr) {
     return janet_wrap_nil();
 }
 
-Janet janet_disasm(JanetFuncDef *def) {
-    int32_t i;
+/*
+ * Disasm sections
+ */
+
+static Janet janet_disasm_arity(JanetFuncDef *def) {
+    return janet_wrap_integer(def->arity);
+}
+
+static Janet janet_disasm_min_arity(JanetFuncDef *def) {
+    return janet_wrap_integer(def->min_arity);
+}
+
+static Janet janet_disasm_max_arity(JanetFuncDef *def) {
+    return janet_wrap_integer(def->max_arity);
+}
+
+static Janet janet_disasm_slotcount(JanetFuncDef *def) {
+    return janet_wrap_integer(def->slotcount);
+}
+
+static Janet janet_disasm_bytecode(JanetFuncDef *def) {
     JanetArray *bcode = janet_array(def->bytecode_length);
-    JanetArray *constants;
-    JanetTable *ret = janet_table(10);
-    janet_table_put(ret, janet_ckeywordv("arity"), janet_wrap_integer(def->arity));
-    janet_table_put(ret, janet_ckeywordv("min-arity"), janet_wrap_integer(def->min_arity));
-    janet_table_put(ret, janet_ckeywordv("max-arity"), janet_wrap_integer(def->max_arity));
-    janet_table_put(ret, janet_ckeywordv("bytecode"), janet_wrap_array(bcode));
-    if (NULL != def->source) {
-        janet_table_put(ret, janet_ckeywordv("source"), janet_wrap_string(def->source));
-    }
-    if (def->flags & JANET_FUNCDEF_FLAG_VARARG) {
-        janet_table_put(ret, janet_ckeywordv("vararg"), janet_wrap_true());
-    }
-    if (NULL != def->name) {
-        janet_table_put(ret, janet_ckeywordv("name"), janet_wrap_string(def->name));
-    }
-
-    /* Add constants */
-    if (def->constants_length > 0) {
-        constants = janet_array(def->constants_length);
-        janet_table_put(ret, janet_ckeywordv("constants"), janet_wrap_array(constants));
-        for (i = 0; i < def->constants_length; i++) {
-            constants->data[i] = def->constants[i];
-        }
-        constants->count = def->constants_length;
-    }
-
-    /* Add bytecode */
-    for (i = 0; i < def->bytecode_length; i++) {
+    for (int32_t i = 0; i < def->bytecode_length; i++) {
         bcode->data[i] = janet_asm_decode_instruction(def->bytecode[i]);
     }
     bcode->count = def->bytecode_length;
+    return janet_wrap_array(bcode);
+}
 
-    /* Add source map */
-    if (NULL != def->sourcemap) {
-        JanetArray *sourcemap = janet_array(def->bytecode_length);
-        for (i = 0; i < def->bytecode_length; i++) {
-            Janet *t = janet_tuple_begin(2);
-            JanetSourceMapping mapping = def->sourcemap[i];
-            t[0] = janet_wrap_integer(mapping.line);
-            t[1] = janet_wrap_integer(mapping.column);
-            sourcemap->data[i] = janet_wrap_tuple(janet_tuple_end(t));
-        }
-        sourcemap->count = def->bytecode_length;
-        janet_table_put(ret, janet_ckeywordv("sourcemap"), janet_wrap_array(sourcemap));
+static Janet janet_disasm_source(JanetFuncDef *def) {
+    if (def->source != NULL) return janet_wrap_string(def->source);
+    return janet_wrap_nil();
+}
+
+static Janet janet_disasm_name(JanetFuncDef *def) {
+    if (def->name != NULL) return janet_wrap_string(def->name);
+    return janet_wrap_nil();
+}
+
+static Janet janet_disasm_vararg(JanetFuncDef *def) {
+    return janet_wrap_boolean(def->flags & JANET_FUNCDEF_FLAG_VARARG);
+}
+
+static Janet janet_disasm_constants(JanetFuncDef *def) {
+    JanetArray *constants = janet_array(def->constants_length);
+    for (int32_t i = 0; i < def->constants_length; i++) {
+        constants->data[i] = def->constants[i];
     }
+    constants->count = def->constants_length;
+    return janet_wrap_array(constants);
+}
 
-    /* Add environments */
-    if (NULL != def->environments) {
-        JanetArray *envs = janet_array(def->environments_length);
-        for (i = 0; i < def->environments_length; i++) {
-            envs->data[i] = janet_wrap_integer(def->environments[i]);
-        }
-        envs->count = def->environments_length;
-        janet_table_put(ret, janet_ckeywordv("environments"), janet_wrap_array(envs));
+static Janet janet_disasm_sourcemap(JanetFuncDef *def) {
+    if (NULL == def->sourcemap) return janet_wrap_nil();
+    JanetArray *sourcemap = janet_array(def->bytecode_length);
+    for (int32_t i = 0; i < def->bytecode_length; i++) {
+        Janet *t = janet_tuple_begin(2);
+        JanetSourceMapping mapping = def->sourcemap[i];
+        t[0] = janet_wrap_integer(mapping.line);
+        t[1] = janet_wrap_integer(mapping.column);
+        sourcemap->data[i] = janet_wrap_tuple(janet_tuple_end(t));
     }
+    sourcemap->count = def->bytecode_length;
+    return janet_wrap_array(sourcemap);
+}
 
-    /* Add closures */
-    /* Funcdefs cannot be recursive */
-    if (NULL != def->defs) {
-        JanetArray *defs = janet_array(def->defs_length);
-        for (i = 0; i < def->defs_length; i++) {
-            defs->data[i] = janet_disasm(def->defs[i]);
-        }
-        defs->count = def->defs_length;
-        janet_table_put(ret, janet_ckeywordv("defs"), janet_wrap_array(defs));
+static Janet janet_disasm_environments(JanetFuncDef *def) {
+    JanetArray *envs = janet_array(def->environments_length);
+    for (int32_t i = 0; i < def->environments_length; i++) {
+        envs->data[i] = janet_wrap_integer(def->environments[i]);
     }
+    envs->count = def->environments_length;
+    return janet_wrap_array(envs);
+}
 
-    /* Add slotcount */
-    janet_table_put(ret, janet_ckeywordv("slotcount"), janet_wrap_integer(def->slotcount));
+static Janet janet_disasm_defs(JanetFuncDef *def) {
+    JanetArray *defs = janet_array(def->defs_length);
+    for (int32_t i = 0; i < def->defs_length; i++) {
+        defs->data[i] = janet_disasm(def->defs[i]);
+    }
+    defs->count = def->defs_length;
+    return janet_wrap_array(defs);
+}
 
+Janet janet_disasm(JanetFuncDef *def) {
+    JanetTable *ret = janet_table(10);
+    janet_table_put(ret, janet_ckeywordv("arity"), janet_disasm_arity(def));
+    janet_table_put(ret, janet_ckeywordv("min-arity"), janet_disasm_min_arity(def));
+    janet_table_put(ret, janet_ckeywordv("max-arity"), janet_disasm_max_arity(def));
+    janet_table_put(ret, janet_ckeywordv("bytecode"), janet_disasm_bytecode(def));
+    janet_table_put(ret, janet_ckeywordv("source"), janet_disasm_source(def));
+    janet_table_put(ret, janet_ckeywordv("vararg"), janet_disasm_vararg(def));
+    janet_table_put(ret, janet_ckeywordv("name"), janet_disasm_name(def));
+    janet_table_put(ret, janet_ckeywordv("slotcount"), janet_disasm_slotcount(def));
+    janet_table_put(ret, janet_ckeywordv("constants"), janet_disasm_constants(def));
+    janet_table_put(ret, janet_ckeywordv("sourcemap"), janet_disasm_sourcemap(def));
+    janet_table_put(ret, janet_ckeywordv("environments"), janet_disasm_environments(def));
+    janet_table_put(ret, janet_ckeywordv("defs"), janet_disasm_defs(def));
     return janet_wrap_struct(janet_table_to_struct(ret));
 }
 
 /* C Function for assembly */
 static Janet cfun_asm(int32_t argc, Janet *argv) {
-    janet_arity(argc, 1, 1);
+    janet_fixarity(argc, 1);
     JanetAssembleResult res;
     res = janet_asm(argv[0], 0);
     if (res.status != JANET_ASSEMBLE_OK) {
@@ -928,9 +954,26 @@ static Janet cfun_asm(int32_t argc, Janet *argv) {
 }
 
 static Janet cfun_disasm(int32_t argc, Janet *argv) {
-    janet_arity(argc, 1, 1);
+    janet_arity(argc, 1, 2);
     JanetFunction *f = janet_getfunction(argv, 0);
-    return janet_disasm(f->def);
+    if (argc == 2) {
+        JanetKeyword kw = janet_getkeyword(argv, 1);
+        if (!janet_cstrcmp(kw, "arity")) return janet_disasm_arity(f->def);
+        if (!janet_cstrcmp(kw, "min-arity")) return janet_disasm_min_arity(f->def);
+        if (!janet_cstrcmp(kw, "max-arity")) return janet_disasm_max_arity(f->def);
+        if (!janet_cstrcmp(kw, "bytecode")) return janet_disasm_bytecode(f->def);
+        if (!janet_cstrcmp(kw, "source")) return janet_disasm_source(f->def);
+        if (!janet_cstrcmp(kw, "name")) return janet_disasm_name(f->def);
+        if (!janet_cstrcmp(kw, "vararg")) return janet_disasm_vararg(f->def);
+        if (!janet_cstrcmp(kw, "slotcount")) return janet_disasm_slotcount(f->def);
+        if (!janet_cstrcmp(kw, "constants")) return janet_disasm_constants(f->def);
+        if (!janet_cstrcmp(kw, "sourcemap")) return janet_disasm_sourcemap(f->def);
+        if (!janet_cstrcmp(kw, "environments")) return janet_disasm_environments(f->def);
+        if (!janet_cstrcmp(kw, "defs")) return janet_disasm_defs(f->def);
+        janet_panicf("unknown disasm key %v", argv[1]);
+    } else {
+        return janet_disasm(f->def);
+    }
 }
 
 static const JanetReg asm_cfuns[] = {
@@ -938,15 +981,29 @@ static const JanetReg asm_cfuns[] = {
         "asm", cfun_asm,
         JDOC("(asm assembly)\n\n"
              "Returns a new function that is the compiled result of the assembly.\n"
-             "The syntax for the assembly can be found on the Janet website. Will throw an\n"
+             "The syntax for the assembly can be found on the Janet website, and should correspond\n"
+             "to the return value of disasm. Will throw an\n"
              "error on invalid assembly.")
     },
     {
         "disasm", cfun_disasm,
-        JDOC("(disasm func)\n\n"
+        JDOC("(disasm func &opt field)\n\n"
              "Returns assembly that could be used be compile the given function.\n"
              "func must be a function, not a c function. Will throw on error on a badly\n"
-             "typed argument.")
+             "typed argument. If given a field name, will only return that part of the function assembly.\n"
+             "Possible fields are:\n\n"
+             "\t:arity - number of required and optional arguments.\n"
+             "\t:min-arity - minimum number of arguments function can be called with.\n"
+             "\t:max-arity - maximum number of arguments function can be called with.\n"
+             "\t:vararg - true if function can take a variable number of arguments.\n"
+             "\t:bytecode - array of parsed bytecode instructions. Each instruction is a tuple.\n"
+             "\t:source - name of source file that this function was compiled from.\n"
+             "\t:name - name of function.\n"
+             "\t:slotcount - how many virtual registers, or slots, this function uses. Corresponds to stack space used by function.\n"
+             "\t:constants - an array of constants referenced by this function.\n"
+             "\t:sourcemap - a mapping of each bytecode instruction to a line and column in the source file.\n"
+             "\t:environments - an internal mapping of which enclosing functions are referenced for bindings.\n"
+             "\t:defs - other function definitions that this function may instantiate.\n")
     },
     {NULL, NULL, NULL}
 };

src/core/bytecode.c

@@ -103,6 +103,7 @@ enum JanetInstructionType janet_instructions[JOP_INSTRUCTION_COUNT] = {
     JINT_SSS, /* JOP_NEXT */
     JINT_SSS, /* JOP_NOT_EQUALS, */
     JINT_SSI, /* JOP_NOT_EQUALS_IMMEDIATE, */
+    JINT_SSS /* JOP_CANCEL, */
 };
 
 /* Verify some bytecode */

src/core/cfuns.c

@@ -231,6 +231,9 @@ static JanetSlot do_yield(JanetFopts opts, JanetSlot *args) {
 static JanetSlot do_resume(JanetFopts opts, JanetSlot *args) {
     return opfunction(opts, args, JOP_RESUME, janet_wrap_nil());
 }
+static JanetSlot do_cancel(JanetFopts opts, JanetSlot *args) {
+    return opfunction(opts, args, JOP_CANCEL, janet_wrap_nil());
+}
 static JanetSlot do_apply(JanetFopts opts, JanetSlot *args) {
     /* Push phase */
     JanetCompiler *c = opts.compiler;
@@ -383,6 +386,7 @@ static const JanetFunOptimizer optimizers[] = {
     {fixarity2, do_modulo},
     {fixarity2, do_remainder},
     {fixarity2, do_cmp},
+    {fixarity2, do_cancel},
 };
 
 const JanetFunOptimizer *janetc_funopt(uint32_t flags) {

src/core/compile.h

@@ -61,6 +61,7 @@
 #define JANET_FUN_MODULO 29
 #define JANET_FUN_REMAINDER 30
 #define JANET_FUN_CMP 31
+#define JANET_FUN_CANCEL 32
 
 /* Compiler typedefs */
 typedef struct JanetCompiler JanetCompiler;

src/core/corelib.c

@@ -946,6 +946,10 @@ static const uint32_t resume_asm[] = {
     JOP_RESUME | (1 << 24),
     JOP_RETURN
 };
+static const uint32_t cancel_asm[] = {
+    JOP_CANCEL | (1 << 24),
+    JOP_RETURN
+};
 static const uint32_t in_asm[] = {
     JOP_IN | (1 << 24),
     JOP_LOAD_NIL | (3 << 8),
@@ -1083,6 +1087,11 @@ JanetTable *janet_core_env(JanetTable *replacements) {
                          "Yield a value to a parent fiber. When a fiber yields, its execution is paused until "
                          "another thread resumes it. The fiber will then resume, and the last yield call will "
                          "return the value that was passed to resume."));
+    janet_quick_asm(env, JANET_FUN_CANCEL,
+                    "cancel", 2, 2, 2, 2, cancel_asm, sizeof(cancel_asm),
+                    JDOC("(cancel fiber err)\n\n"
+                         "Resume a fiber but have it immediately raise an error. This lets a programmer unwind a pending fiber. "
+                         "Returns the same result as resume."));
     janet_quick_asm(env, JANET_FUN_RESUME,
                     "resume", 2, 1, 2, 2, resume_asm, sizeof(resume_asm),
                     JDOC("(resume fiber &opt x)\n\n"

src/core/features.h

@@ -25,8 +25,15 @@
 #ifndef JANET_FEATURES_H_defined
 #define JANET_FEATURES_H_defined
 
-#ifndef _POSIX_C_SOURCE
-#define _POSIX_C_SOURCE 200809L
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(__OpenBSD__) \
+    || defined(__bsdi__) || defined(__DragonFly__)
+/* Use BSD soucre on any BSD systems, include OSX */
+# define _BSD_SOURCE
+#else
+/* Use POSIX feature flags */
+# ifndef _POSIX_C_SOURCE
+# define _POSIX_C_SOURCE 200809L
+# endif
 #endif
 
 #if defined(WIN32) || defined(_WIN32)

src/core/fiber.c

@@ -85,6 +85,22 @@ JanetFiber *janet_fiber(JanetFunction *callee, int32_t capacity, int32_t argc, c
     return janet_fiber_reset(fiber_alloc(capacity), callee, argc, argv);
 }
 
+#ifdef JANET_DEBUG
+/* Test for memory issues by reallocating fiber every time we push a stack frame */
+static void janet_fiber_refresh_memory(JanetFiber *fiber) {
+    int32_t n = fiber->capacity;
+    if (n) {
+        Janet *newData = malloc(sizeof(Janet) * n);
+        if (NULL == newData) {
+            JANET_OUT_OF_MEMORY;
+        }
+        memcpy(newData, fiber->data, fiber->capacity * sizeof(Janet));
+        free(fiber->data);
+        fiber->data = newData;
+    }
+}
+#endif
+
 /* Ensure that the fiber has enough extra capacity */
 void janet_fiber_setcapacity(JanetFiber *fiber, int32_t n) {
     Janet *newData = realloc(fiber->data, sizeof(Janet) * n);
@@ -173,6 +189,10 @@ int janet_fiber_funcframe(JanetFiber *fiber, JanetFunction *func) {
 
     if (fiber->capacity < nextstacktop) {
         janet_fiber_setcapacity(fiber, 2 * nextstacktop);
+#ifdef JANET_DEBUG
+    } else {
+        janet_fiber_refresh_memory(fiber);
+#endif
     }
 
     /* Nil unset stack arguments (Needed for gc correctness) */
@@ -305,6 +325,10 @@ int janet_fiber_funcframe_tail(JanetFiber *fiber, JanetFunction *func) {
 
     if (fiber->capacity < nextstacktop) {
         janet_fiber_setcapacity(fiber, 2 * nextstacktop);
+#ifdef JANET_DEBUG
+    } else {
+        janet_fiber_refresh_memory(fiber);
+#endif
     }
 
     Janet *stack = fiber->data + fiber->frame;
@@ -367,6 +391,10 @@ void janet_fiber_cframe(JanetFiber *fiber, JanetCFunction cfun) {
 
     if (fiber->capacity < nextstacktop) {
         janet_fiber_setcapacity(fiber, 2 * nextstacktop);
+#ifdef JANET_DEBUG
+    } else {
+        janet_fiber_refresh_memory(fiber);
+#endif
     }
 
     /* Set the next frame */

src/core/fiber.h

@@ -46,7 +46,8 @@
 #define JANET_FIBER_MASK_USERN(N) (16 << (N))
 #define JANET_FIBER_MASK_USER 0x3FF0
 
-#define JANET_FIBER_STATUS_MASK 0xFF0000
+#define JANET_FIBER_RESUME_SIGNAL 0x800000
+#define JANET_FIBER_STATUS_MASK 0x7F0000
 #define JANET_FIBER_STATUS_OFFSET 16
 
 #define JANET_FIBER_BREAKPOINT       0x1000000

src/core/io.c

@@ -56,8 +56,8 @@ static int32_t checkflags(const uint8_t *str) {
     int32_t flags = 0;
     int32_t i;
     int32_t len = janet_string_length(str);
-    if (!len || len > 3)
-        janet_panic("file mode must have a length between 1 and 3");
+    if (!len || len > 10)
+        janet_panic("file mode must have a length between 1 and 10");
     switch (*str) {
         default:
             janet_panicf("invalid flag %c, expected w, a, or r", *str);
@@ -75,7 +75,7 @@ static int32_t checkflags(const uint8_t *str) {
     for (i = 1; i < len; i++) {
         switch (str[i]) {
             default:
-                janet_panicf("invalid flag %c, expected + or b", str[i]);
+                janet_panicf("invalid flag %c, expected +, b, or n", str[i]);
                 break;
             case '+':
                 if (flags & JANET_FILE_UPDATE) return -1;
@@ -85,6 +85,10 @@ static int32_t checkflags(const uint8_t *str) {
                 if (flags & JANET_FILE_BINARY) return -1;
                 flags |= JANET_FILE_BINARY;
                 break;
+            case 'n':
+                if (flags & JANET_FILE_NONIL) return -1;
+                flags |= JANET_FILE_NONIL;
+                break;
         }
     }
     return flags;
@@ -112,11 +116,11 @@ static Janet cfun_io_popen(int32_t argc, Janet *argv) {
     int32_t flags;
     if (argc == 2) {
         fmode = janet_getkeyword(argv, 1);
-        if (janet_string_length(fmode) != 1 ||
-                !(fmode[0] == 'r' || fmode[0] == 'w')) {
-            janet_panicf("invalid file mode :%S, expected :r or :w", fmode);
+        flags = JANET_FILE_PIPED | checkflags(fmode);
+        if (flags & (JANET_FILE_UPDATE | JANET_FILE_BINARY | JANET_FILE_APPEND)) {
+            janet_panicf("invalid popen file mode :%S, expected :r or :w", fmode);
         }
-        flags = JANET_FILE_PIPED | (fmode[0] == 'r' ? JANET_FILE_READ : JANET_FILE_WRITE);
+        fmode = (const uint8_t *)((fmode[0] == 'r') ? "r" : "w");
     } else {
         fmode = (const uint8_t *)"r";
         flags = JANET_FILE_PIPED | JANET_FILE_READ;
@@ -126,6 +130,8 @@ static Janet cfun_io_popen(int32_t argc, Janet *argv) {
 #endif
     FILE *f = popen((const char *)fname, (const char *)fmode);
     if (!f) {
+        if (flags & JANET_FILE_NONIL)
+            janet_panicf("failed to popen %s: %s", fname, strerror(errno));
         return janet_wrap_nil();
     }
     return janet_makefile(f, flags);
@@ -155,7 +161,9 @@ static Janet cfun_io_fopen(int32_t argc, Janet *argv) {
         flags = JANET_FILE_READ;
     }
     FILE *f = fopen((const char *)fname, (const char *)fmode);
-    return f ? janet_makefile(f, flags) : janet_wrap_nil();
+    return f ? janet_makefile(f, flags)
+           : (flags & JANET_FILE_NONIL) ? (janet_panicf("failed to open file %s: %s", fname, strerror(errno)), janet_wrap_nil())
+           : janet_wrap_nil();
 }
 
 /* Read up to n bytes into buffer. */
@@ -282,6 +290,8 @@ static Janet cfun_io_fclose(int32_t argc, Janet *argv) {
         iof->flags |= JANET_FILE_CLOSED;
         if (status == -1) janet_panic("could not close file");
         return janet_wrap_integer(WEXITSTATUS(status));
+#else
+        return janet_wrap_nil();
 #endif
     } else {
         if (fclose(iof->file)) {
@@ -389,18 +399,16 @@ FILE *janet_dynfile(const char *name, FILE *def) {
     return iofile->file;
 }
 
-static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
-                                int newline, const char *name, FILE *dflt_file) {
+static Janet cfun_io_print_impl_x(int32_t argc, Janet *argv, int newline,
+                                  FILE *dflt_file, int32_t offset, Janet x) {
     FILE *f;
-    Janet x = janet_dyn(name);
     switch (janet_type(x)) {
         default:
-            /* Other values simply do nothing */
-            return janet_wrap_nil();
+            janet_panicf("cannot print to %v", x);
         case JANET_BUFFER: {
             /* Special case buffer */
             JanetBuffer *buf = janet_unwrap_buffer(x);
-            for (int32_t i = 0; i < argc; ++i) {
+            for (int32_t i = offset; i < argc; ++i) {
                 janet_to_string_b(buf, argv[i]);
             }
             if (newline)
@@ -409,6 +417,7 @@ static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
         }
         case JANET_NIL:
             f = dflt_file;
+            if (f == NULL) janet_panic("cannot print to nil");
             break;
         case JANET_ABSTRACT: {
             void *abstract = janet_unwrap_abstract(x);
@@ -419,7 +428,7 @@ static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
             break;
         }
     }
-    for (int32_t i = 0; i < argc; ++i) {
+    for (int32_t i = offset; i < argc; ++i) {
         int32_t len;
         const uint8_t *vstr;
         if (janet_checktype(argv[i], JANET_BUFFER)) {
@@ -432,7 +441,11 @@ static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
         }
         if (len) {
             if (1 != fwrite(vstr, len, 1, f)) {
-                janet_panicf("could not print %d bytes to (dyn :%s)", len, name);
+                if (f == dflt_file) {
+                    janet_panicf("cannot print %d bytes", len);
+                } else {
+                    janet_panicf("cannot print %d bytes to %v", len, x);
+                }
             }
         }
     }
@@ -441,6 +454,13 @@ static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
     return janet_wrap_nil();
 }
 
+
+static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
+                                int newline, const char *name, FILE *dflt_file) {
+    Janet x = janet_dyn(name);
+    return cfun_io_print_impl_x(argc, argv, newline, dflt_file, 0, x);
+}
+
 static Janet cfun_io_print(int32_t argc, Janet *argv) {
     return cfun_io_print_impl(argc, argv, 1, "out", stdout);
 }
@@ -457,25 +477,33 @@ static Janet cfun_io_eprin(int32_t argc, Janet *argv) {
     return cfun_io_print_impl(argc, argv, 0, "err", stderr);
 }
 
-static Janet cfun_io_printf_impl(int32_t argc, Janet *argv, int newline,
-                                 const char *name, FILE *dflt_file) {
-    FILE *f;
+static Janet cfun_io_xprint(int32_t argc, Janet *argv) {
     janet_arity(argc, 1, -1);
-    const char *fmt = janet_getcstring(argv, 0);
-    Janet x = janet_dyn(name);
+    return cfun_io_print_impl_x(argc, argv, 1, NULL, 1, argv[0]);
+}
+
+static Janet cfun_io_xprin(int32_t argc, Janet *argv) {
+    janet_arity(argc, 1, -1);
+    return cfun_io_print_impl_x(argc, argv, 0, NULL, 1, argv[0]);
+}
+
+static Janet cfun_io_printf_impl_x(int32_t argc, Janet *argv, int newline,
+                                   FILE *dflt_file, int32_t offset, Janet x) {
+    FILE *f;
+    const char *fmt = janet_getcstring(argv, offset);
     switch (janet_type(x)) {
         default:
-            /* Other values simply do nothing */
-            return janet_wrap_nil();
+            janet_panicf("cannot print to %v", x);
         case JANET_BUFFER: {
             /* Special case buffer */
             JanetBuffer *buf = janet_unwrap_buffer(x);
-            janet_buffer_format(buf, fmt, 0, argc, argv);
+            janet_buffer_format(buf, fmt, offset, argc, argv);
             if (newline) janet_buffer_push_u8(buf, '\n');
             return janet_wrap_nil();
         }
         case JANET_NIL:
             f = dflt_file;
+            if (f == NULL) janet_panic("cannot print to nil");
             break;
         case JANET_ABSTRACT: {
             void *abstract = janet_unwrap_abstract(x);
@@ -487,11 +515,11 @@ static Janet cfun_io_printf_impl(int32_t argc, Janet *argv, int newline,
         }
     }
     JanetBuffer *buf = janet_buffer(10);
-    janet_buffer_format(buf, fmt, 0, argc, argv);
+    janet_buffer_format(buf, fmt, offset, argc, argv);
     if (newline) janet_buffer_push_u8(buf, '\n');
     if (buf->count) {
         if (1 != fwrite(buf->data, buf->count, 1, f)) {
-            janet_panicf("could not print %d bytes to file", buf->count, name);
+            janet_panicf("could not print %d bytes to file", buf->count);
         }
     }
     /* Clear buffer to make things easier for GC */
@@ -502,6 +530,14 @@ static Janet cfun_io_printf_impl(int32_t argc, Janet *argv, int newline,
     return janet_wrap_nil();
 }
 
+static Janet cfun_io_printf_impl(int32_t argc, Janet *argv, int newline,
+                                 const char *name, FILE *dflt_file) {
+    janet_arity(argc, 1, -1);
+    Janet x = janet_dyn(name);
+    return cfun_io_printf_impl_x(argc, argv, newline, dflt_file, 0, x);
+
+}
+
 static Janet cfun_io_printf(int32_t argc, Janet *argv) {
     return cfun_io_printf_impl(argc, argv, 1, "out", stdout);
 }
@@ -518,6 +554,16 @@ static Janet cfun_io_eprinf(int32_t argc, Janet *argv) {
     return cfun_io_printf_impl(argc, argv, 0, "err", stderr);
 }
 
+static Janet cfun_io_xprintf(int32_t argc, Janet *argv) {
+    janet_arity(argc, 2, -1);
+    return cfun_io_printf_impl_x(argc, argv, 1, NULL, 1, argv[0]);
+}
+
+static Janet cfun_io_xprinf(int32_t argc, Janet *argv) {
+    janet_arity(argc, 2, -1);
+    return cfun_io_printf_impl_x(argc, argv, 0, NULL, 1, argv[0]);
+}
+
 static void janet_flusher(const char *name, FILE *dflt_file) {
     Janet x = janet_dyn(name);
     switch (janet_type(x)) {
@@ -631,6 +677,29 @@ static const JanetReg io_cfuns[] = {
         JDOC("(eprinf fmt & xs)\n\n"
              "Like eprintf but with no trailing newline.")
     },
+    {
+        "xprint", cfun_io_xprint,
+        JDOC("(xprint to & xs)\n\n"
+             "Print to a file or other value explicitly (no dynamic bindings) with a trailing "
+             "newline character. The value to print "
+             "to is the first argument, and is otherwise the same as print. Returns nil.")
+    },
+    {
+        "xprin", cfun_io_xprin,
+        JDOC("(xprin to & xs)\n\n"
+             "Print to a file or other value explicitly (no dynamic bindings). The value to print "
+             "to is the first argument, and is otherwise the same as prin. Returns nil.")
+    },
+    {
+        "xprintf", cfun_io_xprintf,
+        JDOC("(xprint to fmt & xs)\n\n"
+             "Like printf but prints to an explicit file or value to. Returns nil.")
+    },
+    {
+        "xprinf", cfun_io_xprinf,
+        JDOC("(xprin to fmt & xs)\n\n"
+             "Like prinf but prints to an explicit file or value to. Returns nil.")
+    },
     {
         "flush", cfun_io_flush,
         JDOC("(flush)\n\n"
@@ -659,7 +728,8 @@ static const JanetReg io_cfuns[] = {
              "\tw - allow writing to the file\n"
              "\ta - append to the file\n"
              "\tb - open the file in binary mode (rather than text mode)\n"
-             "\t+ - append to the file instead of overwriting it")
+             "\t+ - append to the file instead of overwriting it\n"
+             "\tn - error if the file cannot be opened instead of returning nil")
     },
     {
         "file/close", cfun_io_fclose,
@@ -719,6 +789,10 @@ static const JanetReg io_cfuns[] = {
 
 /* C API */
 
+JanetFile *janet_getjfile(const Janet *argv, int32_t n) {
+    return janet_getabstract(argv, n, &janet_file_type);
+}
+
 FILE *janet_getfile(const Janet *argv, int32_t n, int *flags) {
     JanetFile *iof = janet_getabstract(argv, n, &janet_file_type);
     if (NULL != flags) *flags = iof->flags;
@@ -743,17 +817,18 @@ FILE *janet_unwrapfile(Janet j, int *flags) {
 void janet_lib_io(JanetTable *env) {
     janet_core_cfuns(env, NULL, io_cfuns);
     janet_register_abstract_type(&janet_file_type);
+    int default_flags = JANET_FILE_NOT_CLOSEABLE | JANET_FILE_SERIALIZABLE;
     /* stdout */
     janet_core_def(env, "stdout",
-                   janet_makefile(stdout, JANET_FILE_APPEND | JANET_FILE_NOT_CLOSEABLE | JANET_FILE_SERIALIZABLE),
+                   janet_makefile(stdout, JANET_FILE_APPEND | default_flags),
                    JDOC("The standard output file."));
     /* stderr */
     janet_core_def(env, "stderr",
-                   janet_makefile(stderr, JANET_FILE_APPEND | JANET_FILE_NOT_CLOSEABLE | JANET_FILE_SERIALIZABLE),
+                   janet_makefile(stderr, JANET_FILE_APPEND | default_flags),
                    JDOC("The standard error file."));
     /* stdin */
     janet_core_def(env, "stdin",
-                   janet_makefile(stdin, JANET_FILE_READ | JANET_FILE_NOT_CLOSEABLE | JANET_FILE_SERIALIZABLE),
+                   janet_makefile(stdin, JANET_FILE_READ | default_flags),
                    JDOC("The standard input file."));
 
 }

src/core/net.c

@@ -139,6 +139,19 @@ static int janet_stream_close(void *p, size_t s) {
     return 0;
 }
 
+
+static void nosigpipe(JSock s) {
+#ifdef SO_NOSIGPIPE
+    int enable = 1;
+    if (setsockopt(s, SOL_SOCKET, SO_NOSIGPIPE, &enable, sizeof(int)) < 0) {
+        JSOCKCLOSE(s);
+        janet_panic("setsockopt(SO_NOSIGPIPE) failed");
+    }
+#else
+    (void) s;
+#endif
+}
+
 /*
  * Event loop
  */
@@ -262,8 +275,11 @@ static size_t janet_loop_event(size_t index) {
     int ret = 1;
     int should_resume = 0;
     Janet resumeval = janet_wrap_nil();
+    JanetSignal resumesignal = JANET_SIGNAL_OK;
     if (stream->flags & JANET_STREAM_CLOSED) {
         should_resume = 1;
+        resumeval = janet_cstringv("stream is closed");
+        resumesignal = JANET_SIGNAL_ERROR;
         ret = 0;
     } else {
         switch (jlfd->event_type) {
@@ -275,6 +291,8 @@ static size_t janet_loop_event(size_t index) {
                 if (!(stream->flags & JANET_STREAM_READABLE)) {
                     should_resume = 1;
                     ret = 0;
+                    resumesignal = JANET_SIGNAL_ERROR;
+                    resumeval = janet_cstringv("stream not readable");
                     break;
                 }
                 JReadInt nread;
@@ -296,6 +314,13 @@ static size_t janet_loop_event(size_t index) {
                     should_resume = 1;
                     if (nread > 0) {
                         resumeval = janet_wrap_buffer(buffer);
+                    } else {
+                        if (nread == 0) {
+                            resumeval = janet_cstringv("could not read from stream");
+                        } else {
+                            resumeval = janet_cstringv(strerror(JLASTERR));
+                        }
+                        resumesignal = JANET_SIGNAL_ERROR;
                     }
                     ret = 0;
                 } else {
@@ -308,6 +333,7 @@ static size_t janet_loop_event(size_t index) {
                 JSock connfd = accept(fd, NULL, NULL);
                 if (JSOCKVALID(connfd)) {
                     /* Made a new connection socket */
+                    nosigpipe(connfd);
                     JanetStream *stream = make_stream(connfd, JANET_STREAM_READABLE | JANET_STREAM_WRITABLE);
                     Janet streamv = janet_wrap_abstract(stream);
                     JanetFunction *handler = jlfd->data.read_accept.handler;
@@ -328,6 +354,8 @@ static size_t janet_loop_event(size_t index) {
                 const uint8_t *bytes;
                 if (!(stream->flags & JANET_STREAM_WRITABLE)) {
                     should_resume = 1;
+                    resumesignal = JANET_SIGNAL_ERROR;
+                    resumeval = janet_cstringv("stream not writeable");
                     ret = 0;
                     break;
                 }
@@ -350,6 +378,12 @@ static size_t janet_loop_event(size_t index) {
                     if (nwrote > 0) {
                         start += nwrote;
                     } else {
+                        resumesignal = JANET_SIGNAL_ERROR;
+                        if (nwrote == -1) {
+                            resumeval = janet_cstringv(strerror(JLASTERR));
+                        } else {
+                            resumeval = janet_cstringv("could not write");
+                        }
                         start = len;
                     }
                 }
@@ -376,7 +410,7 @@ static size_t janet_loop_event(size_t index) {
     if (NULL != jlfd->fiber && should_resume) {
         /* Resume the fiber */
         Janet out;
-        JanetSignal sig = janet_continue(jlfd->fiber, resumeval, &out);
+        JanetSignal sig = janet_continue_signal(jlfd->fiber, resumeval, &out, resumesignal);
         if (sig != JANET_SIGNAL_OK && sig != JANET_SIGNAL_EVENT) {
             janet_stacktrace(jlfd->fiber, out);
         }
@@ -511,6 +545,8 @@ static Janet cfun_net_connect(int32_t argc, Janet *argv) {
         janet_panic("could not connect to socket");
     }
 
+    nosigpipe(sock);
+
     /* Wrap socket in abstract type JanetStream */
     JanetStream *stream = make_stream(sock, JANET_STREAM_READABLE | JANET_STREAM_WRITABLE);
     return janet_wrap_abstract(stream);
@@ -536,12 +572,7 @@ static Janet cfun_net_server(int32_t argc, Janet *argv) {
             JSOCKCLOSE(sfd);
             janet_panic("setsockopt(SO_REUSEADDR) failed");
         }
-#ifdef SO_NOSIGPIPE
-        if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, &enable, sizeof(int)) < 0) {
-            JSOCKCLOSE(sfd);
-            janet_panic("setsockopt(SO_NOSIGPIPE) failed");
-        }
-#endif
+        nosigpipe(sfd);
 #ifdef SO_REUSEPORT
         if (setsockopt(sfd, SOL_SOCKET, SO_REUSEPORT, &enable, sizeof(int)) < 0) {
             JSOCKCLOSE(sfd);
@@ -637,7 +668,7 @@ static const JanetReg net_cfuns[] = {
         JDOC("(net/read stream nbytes &opt buf)\n\n"
              "Read up to n bytes from a stream, suspending the current fiber until the bytes are available. "
              "If less than n bytes are available (and more than 0), will push those bytes and return early. "
-             "Returns a buffer with up to n more bytes in it.")
+             "Returns a buffer with up to n more bytes in it, or raises an error if the read failed.")
     },
     {
         "net/chunk", cfun_stream_chunk,
@@ -648,7 +679,7 @@ static const JanetReg net_cfuns[] = {
         "net/write", cfun_stream_write,
         JDOC("(net/write stream data)\n\n"
              "Write data to a stream, suspending the current fiber until the write "
-             "completes. Returns stream.")
+             "completes. Returns nil, or raises an error if the write failed.")
     },
     {
         "net/close", cfun_stream_close,

src/core/os.c

@@ -24,6 +24,7 @@
 #include "features.h"
 #include <janet.h>
 #include "util.h"
+#include "gc.h"
 #endif
 
 #ifndef JANET_REDUCED_OS
@@ -36,8 +37,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
-
-#define RETRY_EINTR(RC, CALL) do { (RC) = CALL; } while((RC) < 0 && errno == EINTR)
+#include <signal.h>
 
 #ifdef JANET_APPLE
 #include <AvailabilityMacros.h>
@@ -68,12 +68,6 @@ extern char **environ;
 #include <mach/mach.h>
 #endif
 
-/* Setting C99 standard makes this not available, but it should
- * work/link properly if we detect a BSD */
-#if defined(JANET_BSD) || defined(MAC_OS_X_VERSION_10_7)
-void arc4random_buf(void *buf, size_t nbytes);
-#endif
-
 /* Not POSIX, but all Unixes but Solaris have this function. */
 #if defined(JANET_POSIX) && !defined(__sun)
 time_t timegm(struct tm *tm);
@@ -320,13 +314,127 @@ static JanetBuffer *os_exec_escape(JanetView args) {
 }
 #endif
 
+/* Process type for when running a subprocess and not immediately waiting */
+static const JanetAbstractType ProcAT;
+#define JANET_PROC_CLOSED 1
+#define JANET_PROC_WAITED 2
+typedef struct {
+    int flags;
+#ifdef JANET_WINDOWS
+    HANDLE pHandle;
+	HANDLE tHandle;
+#else
+    int pid;
+#endif
+    int return_code;
+    JanetFile *in;
+    JanetFile *out;
+    JanetFile *err;
+} JanetProc;
+
+static int janet_proc_mark(void *p, size_t s) {
+    (void) s;
+    JanetProc *proc = (JanetProc *)p;
+    if (NULL != proc->in) janet_mark(janet_wrap_abstract(proc->in));
+    if (NULL != proc->out) janet_mark(janet_wrap_abstract(proc->out));
+    if (NULL != proc->err) janet_mark(janet_wrap_abstract(proc->err));
+    return 0;
+}
+
+static Janet os_proc_wait_impl(JanetProc *proc) {
+    if (proc->flags & JANET_PROC_WAITED) {
+        janet_panicf("cannot wait on process that has already finished");
+    }
+    proc->flags |= JANET_PROC_WAITED;
+    int status = 0;
+#ifdef JANET_WINDOWS
+    WaitForSingleObject(proc->pHandle, INFINITE);
+    GetExitCodeProcess(proc->pHandle, &status);
+	if (!(proc->flags & JANET_PROC_CLOSED)) {
+		proc->flags |= JANET_PROC_CLOSED;
+		CloseHandle(proc->pHandle);
+		CloseHandle(proc->tHandle);
+    }
+#else
+    waitpid(proc->pid, &status, 0);
+#endif
+    proc->return_code = (int32_t) status;
+    return janet_wrap_integer(proc->return_code);
+}
+
+static Janet os_proc_wait(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+    JanetProc *proc = janet_getabstract(argv, 0, &ProcAT);
+    return os_proc_wait_impl(proc);
+}
+
+static Janet os_proc_kill(int32_t argc, Janet *argv) {
+    janet_arity(argc, 1, 2);
+    JanetProc *proc = janet_getabstract(argv, 0, &ProcAT);
+#ifdef JANET_WINDOWS
+    if (proc->flags & JANET_PROC_CLOSED) {
+        janet_panicf("cannot close process handle that is already closed");
+    }
+    proc->flags |= JANET_PROC_CLOSED;
+	CloseHandle(proc->pHandle);
+	CloseHandle(proc->tHandle);
+#else
+    int status = kill(proc->pid, SIGKILL);
+    if (status) {
+        janet_panic(strerror(errno));
+    }
+#endif
+    /* After killing process we wait on it. */
+    if (argc > 1 && janet_truthy(argv[1])) {
+        return os_proc_wait_impl(proc);
+    } else {
+        return argv[0];
+    }
+}
+
+static const JanetMethod proc_methods[] = {
+    {"wait", os_proc_wait},
+    {"kill", os_proc_kill},
+    {NULL, NULL}
+};
+
+static int janet_proc_get(void *p, Janet key, Janet *out) {
+    JanetProc *proc = (JanetProc *)p;
+    if (janet_keyeq(key, "in")) {
+        *out = (NULL == proc->in) ? janet_wrap_nil() : janet_wrap_abstract(proc->in);
+        return 1;
+    }
+    if (janet_keyeq(key, "out")) {
+        *out = (NULL == proc->out) ? janet_wrap_nil() : janet_wrap_abstract(proc->out);
+        return 1;
+    }
+    if (janet_keyeq(key, "err")) {
+        *out = (NULL == proc->out) ? janet_wrap_nil() : janet_wrap_abstract(proc->err);
+        return 1;
+    }
+    if ((-1 != proc->return_code) && janet_keyeq(key, "return-code")) {
+        *out = janet_wrap_integer(proc->return_code);
+        return 1;
+    }
+    if (!janet_checktype(key, JANET_KEYWORD)) return 0;
+    return janet_getmethod(janet_unwrap_keyword(key), proc_methods, out);
+}
+
+static const JanetAbstractType ProcAT = {
+    "core/process",
+    NULL,
+    janet_proc_mark,
+    janet_proc_get,
+    JANET_ATEND_GET
+};
+
 static Janet os_execute(int32_t argc, Janet *argv) {
     janet_arity(argc, 1, 3);
 
     /* Get flags */
     uint64_t flags = 0;
     if (argc > 1) {
-        flags = janet_getflags(argv, 1, "ep");
+        flags = janet_getflags(argv, 1, "epxa");
     }
 
     /* Get environment */
@@ -338,43 +446,77 @@ static Janet os_execute(int32_t argc, Janet *argv) {
         janet_panic("expected at least 1 command line argument");
     }
 
+    /* Optional stdio redirections */
+    JanetFile *new_in = NULL, *new_out = NULL, *new_err = NULL;
+
+    /* Get optional redirections */
+    if (argc > 2) {
+        JanetDictView tab = janet_getdictionary(argv, 2);
+        Janet maybe_stdin = janet_dictionary_get(tab.kvs, tab.cap, janet_ckeywordv("in"));
+        Janet maybe_stdout = janet_dictionary_get(tab.kvs, tab.cap, janet_ckeywordv("out"));
+        Janet maybe_stderr = janet_dictionary_get(tab.kvs, tab.cap, janet_ckeywordv("err"));
+        if (!janet_checktype(maybe_stdin, JANET_NIL)) new_in = janet_getjfile(&maybe_stdin, 0);
+        if (!janet_checktype(maybe_stdout, JANET_NIL)) new_out = janet_getjfile(&maybe_stdout, 0);
+        if (!janet_checktype(maybe_stderr, JANET_NIL)) new_err = janet_getjfile(&maybe_stderr, 0);
+    }
+
     /* Result */
     int status = 0;
+    int is_async = janet_flag_at(flags, 3);
 
 #ifdef JANET_WINDOWS
 
+    HANDLE pHandle, tHandle;
+	PROCESS_INFORMATION processInfo;
+	STARTUPINFO startupInfo;
+	memset(&processInfo, 0, sizeof(processInfo));
+	memset(&startupInfo, 0, sizeof(startupInfo));
+	startupInfo.cb = sizeof(startupInfo);
+	startupInfo.dwFlags |= STARTF_USESTDHANDLES;
+
     JanetBuffer *buf = os_exec_escape(exargs);
     if (buf->count > 8191) {
         janet_panic("command line string too long (max 8191 characters)");
     }
     const char *path = (const char *) janet_unwrap_string(exargs.items[0]);
-    char *cargv[2] = {(char *) buf->data, NULL};
+
+	/* Do IO redirection */
+	startupInfo.hStdInput = (HANDLE) _get_osfhandle((new_in == NULL) ? 0 : _fileno(new_in->file));
+	startupInfo.hStdOutput = (HANDLE) _get_osfhandle((new_out == NULL) ? 1 : _fileno(new_out->file));
+	startupInfo.hStdError = (HANDLE) _get_osfhandle((new_err == NULL) ? 2 : _fileno(new_err->file));
 
     /* Use _spawn family of functions. */
     /* Windows docs say do this before any spawns. */
     _flushall();
 
-    /* Use an empty env instead when envp is NULL to be consistent with other implementation. */
-    char *empty_env[1] = {NULL};
-    char **envp1 = (NULL == envp) ? empty_env : envp;
-
-    if (janet_flag_at(flags, 1) && janet_flag_at(flags, 0)) {
-        status = (int) _spawnvpe(_P_WAIT, path, cargv, envp1);
-    } else if (janet_flag_at(flags, 1)) {
-        status = (int) _spawnvp(_P_WAIT, path, cargv);
-    } else if (janet_flag_at(flags, 0)) {
-        status = (int) _spawnve(_P_WAIT, path, cargv, envp1);
-    } else {
-        status = (int) _spawnv(_P_WAIT, path, cargv);
+	/* TODO - redirection, :p flag */
+	if(!CreateProcess(janet_flag_at(flags, 1) ? NULL : path, /* NULL? */
+		(char *) buf->data, /* Single CLI argument */
+        NULL, /* no proc inheritance */
+        NULL, /* no thread inheritance */
+        TRUE, /* handle inheritance */
+        0, /* flags */
+        envp, /* pass in environment */
+        NULL, /* use parents starting directory */
+        &startupInfo,
+        &processInfo))  {
+        janet_panic("failed to create process");
     }
+	
+	pHandle = processInfo.hProcess;
+	tHandle = processInfo.hThread;
+
     os_execute_cleanup(envp, NULL);
 
-    /* Check error */
-    if (-1 == status) {
-        janet_panicf("%p: %s", argv[0], strerror(errno));
+	/* Wait and cleanup immedaitely */
+    if (!is_async) {
+		DWORD code;
+		WaitForSingleObject(pHandle, INFINITE);
+		GetExitCodeProcess(pHandle, &code);
+        status = (int) code;
+		CloseHandle(pHandle);
+		CloseHandle(tHandle);
     }
-
-    return janet_wrap_integer(status);
 #else
 
     const char **child_argv = janet_smalloc(sizeof(char *) * ((size_t) exargs.len + 1));
@@ -393,17 +535,32 @@ static Janet os_execute(int32_t argc, Janet *argv) {
         janet_lock_environ();
     }
 
+    /* Posix spawn setup */
+    posix_spawn_file_actions_t actions;
+    posix_spawn_file_actions_init(&actions);
+    if (new_in != NULL) {
+        posix_spawn_file_actions_adddup2(&actions, fileno(new_in->file), 0);
+    }
+    if (new_out != NULL) {
+        posix_spawn_file_actions_adddup2(&actions, fileno(new_out->file), 1);
+    }
+    if (new_err != NULL) {
+        posix_spawn_file_actions_adddup2(&actions, fileno(new_err->file), 2);
+    }
+
     pid_t pid;
     if (janet_flag_at(flags, 1)) {
         status = posix_spawnp(&pid,
-                              child_argv[0], NULL, NULL, cargv,
+                              child_argv[0], &actions, NULL, cargv,
                               use_environ ? environ : envp);
     } else {
         status = posix_spawn(&pid,
-                             child_argv[0], NULL, NULL, cargv,
+                             child_argv[0], &actions, NULL, cargv,
                              use_environ ? environ : envp);
     }
 
+    posix_spawn_file_actions_destroy(&actions);
+
     if (use_environ) {
         janet_unlock_environ();
     }
@@ -412,22 +569,43 @@ static Janet os_execute(int32_t argc, Janet *argv) {
     if (status) {
         os_execute_cleanup(envp, child_argv);
         janet_panicf("%p: %s", argv[0], strerror(errno));
+    } else if (janet_flag_at(flags, 3)) {
+        /* Get process handle */
+        os_execute_cleanup(envp, child_argv);
     } else {
+        /* Wait to complete */
         waitpid(pid, &status, 0);
+        os_execute_cleanup(envp, child_argv);
+        /* Use POSIX shell semantics for interpreting signals */
+        if (WIFEXITED(status)) {
+            status = WEXITSTATUS(status);
+        } else if (WIFSTOPPED(status)) {
+            status = WSTOPSIG(status) + 128;
+        } else {
+            status = WTERMSIG(status) + 128;
+        }
     }
 
-    os_execute_cleanup(envp, child_argv);
-    /* Use POSIX shell semantics for interpreting signals */
-    int ret;
-    if (WIFEXITED(status)) {
-        ret = WEXITSTATUS(status);
-    } else if (WIFSTOPPED(status)) {
-        ret = WSTOPSIG(status) + 128;
-    } else {
-        ret = WTERMSIG(status) + 128;
-    }
-    return janet_wrap_integer(ret);
 #endif
+    if (is_async) {
+        JanetProc *proc = janet_abstract(&ProcAT, sizeof(JanetProc));
+        proc->return_code = -1;
+#ifdef JANET_WINDOWS
+		proc->pHandle = pHandle;
+		proc->tHandle = tHandle;
+#else
+	    proc->pid = pid;
+#endif
+        proc->in = new_in;
+        proc->out = new_out;
+        proc->err = new_err;
+        proc->flags = 0;
+        return janet_wrap_abstract(proc);
+    } else if (janet_flag_at(flags, 2) && status) {
+        janet_panicf("command failed with non-zero exit code %d", status);
+    } else {
+        return janet_wrap_integer(status);
+    }
 }
 
 static Janet os_shell(int32_t argc, Janet *argv) {
@@ -557,7 +735,6 @@ static Janet os_cwd(int32_t argc, Janet *argv) {
 
 static Janet os_cryptorand(int32_t argc, Janet *argv) {
     JanetBuffer *buffer;
-    const char *genericerr = "unable to get sufficient random data";
     janet_arity(argc, 1, 2);
     int32_t offset;
     int32_t n = janet_getinteger(argv, 0);
@@ -572,44 +749,9 @@ static Janet os_cryptorand(int32_t argc, Janet *argv) {
     /* We could optimize here by adding setcount_uninit */
     janet_buffer_setcount(buffer, offset + n);
 
-#ifdef JANET_WINDOWS
-    for (int32_t i = offset; i < buffer->count; i += sizeof(unsigned int)) {
-        unsigned int v;
-        if (rand_s(&v))
-            janet_panic(genericerr);
-        for (int32_t j = 0; (j < sizeof(unsigned int)) && (i + j < buffer->count); j++) {
-            buffer->data[i + j] = v & 0xff;
-            v = v >> 8;
-        }
-    }
-#elif defined(JANET_LINUX) || ( defined(JANET_APPLE) && !defined(MAC_OS_X_VERSION_10_7) )
-    /* We should be able to call getrandom on linux, but it doesn't seem
-       to be uniformly supported on linux distros.
-       On Mac, arc4random_buf wasn't available on until 10.7.
-       In these cases, use this fallback path for now... */
-    int rc;
-    int randfd;
-    RETRY_EINTR(randfd, open("/dev/urandom", O_RDONLY | O_CLOEXEC));
-    if (randfd < 0)
-        janet_panic(genericerr);
-    while (n > 0) {
-        ssize_t nread;
-        RETRY_EINTR(nread, read(randfd, buffer->data + offset, n));
-        if (nread <= 0) {
-            RETRY_EINTR(rc, close(randfd));
-            janet_panic(genericerr);
-        }
-        offset += nread;
-        n -= nread;
-    }
-    RETRY_EINTR(rc, close(randfd));
-#elif defined(JANET_BSD) || defined(MAC_OS_X_VERSION_10_7)
-    (void) genericerr;
-    arc4random_buf(buffer->data + offset, n);
-#else
-    (void) genericerr;
-    janet_panic("cryptorand currently unsupported on this platform");
-#endif
+    if (janet_cryptorand(buffer->data + offset, n) != 0)
+        janet_panic("unable to get sufficient random data");
+
     return janet_wrap_buffer(buffer);
 }
 
@@ -1378,9 +1520,13 @@ static const JanetReg os_cfuns[] = {
              "\t:e - enables passing an environment to the program. Without :e, the "
              "current environment is inherited.\n"
              "\t:p - allows searching the current PATH for the binary to execute. "
-             "Without this flag, binaries must use absolute paths.\n\n"
-             "env is a table or struct mapping environment variables to values. "
-             "Returns the exit status of the program.")
+             "Without this flag, binaries must use absolute paths.\n"
+             "\t:x - raise error if exit code is non-zero.\n"
+             "\t:a - Runs the process asynchronously and returns a core/process.\n\n"
+             "env is a table or struct mapping environment variables to values. It can also "
+             "contain the keys :in, :out, and :err, which allow redirecting stdio in the subprocess. "
+             "These arguments should be core/file values. "
+             "Returns the exit status of the program, or a core/process object if the :a flag is given.")
     },
     {
         "os/shell", os_shell,
@@ -1472,6 +1618,18 @@ static const JanetReg os_cfuns[] = {
         JDOC("(os/perm-int bytes)\n\n"
              "Parse a 9 character permission string and return an integer that can be used by chmod.")
     },
+    {
+        "os/proc-wait", os_proc_wait,
+        JDOC("(os/proc-wait proc)\n\n"
+             "Block until the subprocess completes. Returns the subprocess return code.")
+    },
+    {
+        "os/proc-kill", os_proc_kill,
+        JDOC("(os/proc-kill proc &opt wait)\n\n"
+             "Kill a subprocess by sending SIGKILL to it on posix systems, or by closing the process "
+             "handle on windows. If wait is truthy, will wait for the process to finsih and "
+             "returns the exit code. Otherwise, returns proc.")
+    },
 #endif
     {NULL, NULL, NULL}
 };

src/core/util.c

@@ -28,6 +28,11 @@
 #include "gc.h"
 #ifdef JANET_WINDOWS
 #include <windows.h>
+#else
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 #endif
 #endif
 
@@ -630,3 +635,51 @@ int janet_gettime(struct timespec *spec) {
 }
 #endif
 #endif
+
+/* Setting C99 standard makes this not available, but it should
+ * work/link properly if we detect a BSD */
+#if defined(JANET_BSD) || defined(MAC_OS_X_VERSION_10_7)
+void arc4random_buf(void *buf, size_t nbytes);
+#endif
+
+int janet_cryptorand(uint8_t *out, size_t n) {
+#ifdef JANET_WINDOWS
+    for (size_t i = 0; i < n; i += sizeof(unsigned int)) {
+        unsigned int v;
+        if (rand_s(&v))
+            return -1;
+        for (int32_t j = 0; (j < sizeof(unsigned int)) && (i + j < n); j++) {
+            out[i + j] = v & 0xff;
+            v = v >> 8;
+        }
+    }
+    return 0;
+#elif defined(JANET_LINUX) || ( defined(JANET_APPLE) && !defined(MAC_OS_X_VERSION_10_7) )
+    /* We should be able to call getrandom on linux, but it doesn't seem
+       to be uniformly supported on linux distros.
+       On Mac, arc4random_buf wasn't available on until 10.7.
+       In these cases, use this fallback path for now... */
+    int rc;
+    int randfd;
+    RETRY_EINTR(randfd, open("/dev/urandom", O_RDONLY | O_CLOEXEC));
+    if (randfd < 0)
+        return -1;
+    while (n > 0) {
+        ssize_t nread;
+        RETRY_EINTR(nread, read(randfd, out, n));
+        if (nread <= 0) {
+            RETRY_EINTR(rc, close(randfd));
+            return -1;
+        }
+        out += nread;
+        n -= nread;
+    }
+    RETRY_EINTR(rc, close(randfd));
+    return 0;
+#elif defined(JANET_BSD) || defined(MAC_OS_X_VERSION_10_7)
+    arc4random_buf(out, n);
+    return 0;
+#else
+    return -1;
+#endif
+}

src/core/util.h

@@ -76,7 +76,6 @@ int32_t janet_tablen(int32_t n);
 void safe_memcpy(void *dest, const void *src, size_t len);
 void janet_buffer_push_types(JanetBuffer *buffer, int types);
 const JanetKV *janet_dict_find(const JanetKV *buckets, int32_t cap, Janet key);
-Janet janet_dict_get(const JanetKV *buckets, int32_t cap, Janet key);
 void janet_memempty(JanetKV *mem, int32_t count);
 void *janet_memalloc_empty(int32_t count);
 JanetTable *janet_get_core_table(const char *name);
@@ -108,6 +107,8 @@ void janet_core_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cf
 int janet_gettime(struct timespec *spec);
 #endif
 
+#define RETRY_EINTR(RC, CALL) do { (RC) = CALL; } while((RC) < 0 && errno == EINTR)
+
 /* Initialize builtin libraries */
 void janet_lib_io(JanetTable *env);
 void janet_lib_math(JanetTable *env);

src/core/vm.c

@@ -95,6 +95,10 @@ JANET_THREAD_LOCAL jmp_buf *janet_vm_jmp_buf = NULL;
     vm_commit(); \
     return (sig); \
 } while (0)
+#define vm_return_no_restore(sig, val) do { \
+    janet_vm_return_reg[0] = (val); \
+    return (sig); \
+} while (0)
 
 /* Next instruction variations */
 #define maybe_collect() do {\
@@ -376,7 +380,7 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
         &&label_JOP_NEXT,
         &&label_JOP_NOT_EQUALS,
         &&label_JOP_NOT_EQUALS_IMMEDIATE,
-        &&label_unknown_op,
+        &&label_JOP_CANCEL,
         &&label_unknown_op,
         &&label_unknown_op,
         &&label_unknown_op,
@@ -564,6 +568,15 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
     register Janet *stack;
     register uint32_t *pc;
     register JanetFunction *func;
+
+    if (fiber->flags & JANET_FIBER_RESUME_SIGNAL) {
+        JanetSignal sig = (fiber->gc.flags & JANET_FIBER_STATUS_MASK) >> JANET_FIBER_STATUS_OFFSET;
+        fiber->gc.flags &= ~JANET_FIBER_STATUS_MASK;
+        fiber->flags &= ~(JANET_FIBER_RESUME_SIGNAL | JANET_FIBER_FLAG_MASK);
+        janet_vm_return_reg[0] = in;
+        return sig;
+    }
+
     vm_restore();
 
     if (fiber->flags & JANET_FIBER_DID_LONGJUMP) {
@@ -614,7 +627,7 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
         Janet retval = stack[D];
         int entrance_frame = janet_stack_frame(stack)->flags & JANET_STACKFRAME_ENTRANCE;
         janet_fiber_popframe(fiber);
-        if (entrance_frame) vm_return(JANET_SIGNAL_OK, retval);
+        if (entrance_frame) vm_return_no_restore(JANET_SIGNAL_OK, retval);
         vm_restore();
         stack[A] = retval;
         vm_checkgc_pcnext();
@@ -624,7 +637,7 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
         Janet retval = janet_wrap_nil();
         int entrance_frame = janet_stack_frame(stack)->flags & JANET_STACKFRAME_ENTRANCE;
         janet_fiber_popframe(fiber);
-        if (entrance_frame) vm_return(JANET_SIGNAL_OK, retval);
+        if (entrance_frame) vm_return_no_restore(JANET_SIGNAL_OK, retval);
         vm_restore();
         stack[A] = retval;
         vm_checkgc_pcnext();
@@ -801,6 +814,7 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
     vm_pcnext();
 
     VM_OP(JOP_NEXT)
+    vm_commit();
     stack[A] = janet_next(stack[B], stack[C]);
     vm_pcnext();
 
@@ -1001,8 +1015,9 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
                 retreg = call_nonfn(fiber, callee);
             }
             janet_fiber_popframe(fiber);
-            if (entrance_frame)
-                vm_return(JANET_SIGNAL_OK, retreg);
+            if (entrance_frame) {
+                vm_return_no_restore(JANET_SIGNAL_OK, retreg);
+            }
             vm_restore();
             stack[A] = retreg;
             vm_checkgc_pcnext();
@@ -1049,6 +1064,25 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
         vm_return((int) sub_status, stack[B]);
     }
 
+    VM_OP(JOP_CANCEL) {
+        Janet retreg;
+        vm_assert_type(stack[B], JANET_FIBER);
+        JanetFiber *child = janet_unwrap_fiber(stack[B]);
+        if (janet_check_can_resume(child, &retreg)) {
+            vm_commit();
+            janet_panicv(retreg);
+        }
+        fiber->child = child;
+        JanetSignal sig = janet_continue_signal(child, stack[C], &retreg, JANET_SIGNAL_ERROR);
+        if (sig != JANET_SIGNAL_OK && !(child->flags & (1 << sig))) {
+            vm_return(sig, retreg);
+        }
+        fiber->child = NULL;
+        stack = fiber->data + fiber->frame;
+        stack[A] = retreg;
+        vm_checkgc_pcnext();
+    }
+
     VM_OP(JOP_PUT)
     vm_commit();
     fiber->flags |= JANET_FIBER_RESUME_NO_USEVAL;
@@ -1366,6 +1400,20 @@ JanetSignal janet_continue(JanetFiber *fiber, Janet in, Janet *out) {
     return janet_continue_no_check(fiber, in, out);
 }
 
+/* Enter the main vm loop but immediately raise a signal */
+JanetSignal janet_continue_signal(JanetFiber *fiber, Janet in, Janet *out, JanetSignal sig) {
+    JanetSignal tmp_signal = janet_check_can_resume(fiber, out);
+    if (tmp_signal) return tmp_signal;
+    if (sig != JANET_SIGNAL_OK) {
+        JanetFiber *child = fiber;
+        while (child->child) child = child->child;
+        child->gc.flags &= ~JANET_FIBER_STATUS_MASK;
+        child->gc.flags |= sig << JANET_FIBER_STATUS_OFFSET;
+        child->flags |= JANET_FIBER_RESUME_SIGNAL;
+    }
+    return janet_continue_no_check(fiber, in, out);
+}
+
 JanetSignal janet_pcall(
     JanetFunction *fun,
     int32_t argc,

src/include/janet.h

@@ -1131,6 +1131,7 @@ enum JanetOpCode {
     JOP_NEXT,
     JOP_NOT_EQUALS,
     JOP_NOT_EQUALS_IMMEDIATE,
+    JOP_CANCEL,
     JOP_INSTRUCTION_COUNT
 };
 
@@ -1412,6 +1413,7 @@ JANET_API int janet_symeq(Janet x, const char *cstring);
 JANET_API int janet_init(void);
 JANET_API void janet_deinit(void);
 JANET_API JanetSignal janet_continue(JanetFiber *fiber, Janet in, Janet *out);
+JANET_API JanetSignal janet_continue_signal(JanetFiber *fiber, Janet in, Janet *out, JanetSignal sig);
 JANET_API JanetSignal janet_pcall(JanetFunction *fun, int32_t argn, const Janet *argv, Janet *out, JanetFiber **f);
 JANET_API JanetSignal janet_step(JanetFiber *fiber, Janet in, Janet *out);
 JANET_API Janet janet_call(JanetFunction *fun, int32_t argc, const Janet *argv);
@@ -1538,13 +1540,17 @@ extern JANET_API const JanetAbstractType janet_file_type;
 #define JANET_FILE_BINARY 64
 #define JANET_FILE_SERIALIZABLE 128
 #define JANET_FILE_PIPED 256
+#define JANET_FILE_NONIL 512
 
 JANET_API Janet janet_makefile(FILE *f, int32_t flags);
 JANET_API FILE *janet_getfile(const Janet *argv, int32_t n, int32_t *flags);
 JANET_API FILE *janet_dynfile(const char *name, FILE *def);
+JANET_API JanetFile *janet_getjfile(const Janet *argv, int32_t n);
 JANET_API JanetAbstract janet_checkfile(Janet j);
 JANET_API FILE *janet_unwrapfile(Janet j, int32_t *flags);
 
+JANET_API int janet_cryptorand(uint8_t *out, size_t n);
+
 /* Marshal API */
 JANET_API void janet_marshal_size(JanetMarshalContext *ctx, size_t value);
 JANET_API void janet_marshal_int(JanetMarshalContext *ctx, int32_t value);

src/mainclient/shell.c

@@ -180,7 +180,7 @@ static int rawmode(void) {
     t.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
     t.c_cc[VMIN] = 1;
     t.c_cc[VTIME] = 0;
-    if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t) < 0) goto fatal;
+    if (tcsetattr(STDIN_FILENO, TCSADRAIN, &t) < 0) goto fatal;
     gbl_israwmode = 1;
     return 0;
 fatal:
@@ -193,7 +193,7 @@ fatal:
 
 /* Disable raw mode */
 static void norawmode(void) {
-    if (gbl_israwmode && tcsetattr(STDIN_FILENO, TCSAFLUSH, &gbl_termios_start) != -1)
+    if (gbl_israwmode && tcsetattr(STDIN_FILENO, TCSADRAIN, &gbl_termios_start) != -1)
         gbl_israwmode = 0;
 #ifndef JANET_SINGLE_THREADED
     pthread_mutex_unlock(&gbl_lock);
@@ -1017,6 +1017,23 @@ int main(int argc, char **argv) {
     atexit(norawmode);
 #endif
 
+#if defined(JANET_PRF)
+    uint8_t hash_key[JANET_HASH_KEY_SIZE + 1];
+#ifdef JANET_REDUCED_OS
+    char *envvar = NULL;
+#else
+    char *envvar = getenv("JANET_HASHSEED");
+#endif
+    if (NULL != envvar) {
+        strncpy((char *) hash_key, envvar, sizeof(hash_key) - 1);
+    } else if (janet_cryptorand(hash_key, JANET_HASH_KEY_SIZE) != 0) {
+        fputs("unable to initialize janet PRF hash function.\n", stderr);
+        return 1;
+    }
+    janet_init_hash_key(hash_key);
+#endif
+
+
     /* Set up VM */
     janet_init();
 

test/suite0010.janet

@@ -0,0 +1,64 @@
+# Copyright (c) 2020 Calvin Rose & contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+(import ./helper :prefix "" :exit true)
+(start-suite 10)
+
+# index-of
+(assert (= nil (index-of 10 [])) "index-of 1")
+(assert (= nil (index-of 10 [1 2 3])) "index-of 2")
+(assert (= 1 (index-of 2 [1 2 3])) "index-of 3")
+(assert (= 0 (index-of :a [:a :b :c])) "index-of 4")
+(assert (= nil (index-of :a {})) "index-of 5")
+(assert (= :a (index-of :A {:a :A :b :B})) "index-of 6")
+(assert (= :a (index-of :A @{:a :A :b :B})) "index-of 7")
+(assert (= 0 (index-of (chr "a") "abc")) "index-of 8")
+(assert (= nil (index-of (chr "a") "")) "index-of 9")
+(assert (= nil (index-of 10 @[])) "index-of 10")
+(assert (= nil (index-of 10 @[1 2 3])) "index-of 11")
+
+# Regression
+(assert (= {:x 10} (|(let [x $] ~{:x ,x}) 10)) "issue 463")
+
+# macex testing
+(assert (deep= (macex1 '~{1 2 3 4}) '~{1 2 3 4}) "macex1 qq struct")
+(assert (deep= (macex1 '~@{1 2 3 4}) '~@{1 2 3 4}) "macex1 qq table")
+(assert (deep= (macex1 '~(1 2 3 4)) '~[1 2 3 4]) "macex1 qq tuple")
+(assert (= :brackets (tuple/type (1 (macex1 '~[1 2 3 4])))) "macex1 qq bracket tuple")
+(assert (deep= (macex1 '~@[1 2 3 4 ,blah]) '~@[1 2 3 4 ,blah]) "macex1 qq array")
+
+# Cancel test
+(def f (fiber/new (fn [&] (yield 1) (yield 2) (yield 3) 4) :yti))
+(assert (= 1 (resume f)) "cancel resume 1")
+(assert (= 2 (resume f)) "cancel resume 2")
+(assert (= :hi (cancel f :hi)) "cancel resume 3")
+(assert (= :error (fiber/status f)) "cancel resume 4")
+
+# Curenv
+(assert (= (curenv) (curenv 0)) "curenv 1")
+(assert (= (table/getproto (curenv)) (curenv 1)) "curenv 2")
+(assert (= nil (curenv 1000000)) "curenv 3")
+(assert (= root-env (curenv 1)) "curenv 4")
+
+# Import macro test
+(assert-no-error "import macro 1" (macex '(import a :as b :fresh maybe)))
+(assert (deep= ~(,import* "a" :as "b" :fresh maybe) (macex '(import a :as b :fresh maybe))) "import macro 2")
+
+(end-suite)