Add prin, eprint, and eprin functions.

The print family of functions now writes output
to an optional buffer instead of a file bound to :out.
This means output can be more easily captured an redirected.

src/boot/boot.janet

@@ -1183,13 +1183,13 @@
   nil)
 
 (defn printf
-  "Print formatted strings to stdout, followed by
+  "Print formatted strings to stdout or (dyn :out), followed by
   a new line."
   [f & args]
-  (file/write stdout (buffer/format @"" f ;args)))
+  (prin (buffer/format @"" f ;args)))
 
 (defn pp
-  "Pretty print to stdout."
+  "Pretty print to stdout or (dyn :out)."
   [x]
   (print (buffer/format @"" (dyn :pretty-format "%q") x)))
 
@@ -1630,31 +1630,29 @@
   [p where]
   (def ec (dyn :err-color))
   (def [line col] (parser/where p))
-  (file/write stderr
-              (if ec "\e[31m" "")
-              "parse error in "
-              where
-              " around line "
-              (string line)
-              ", column "
-              (string col)
-              ": "
-              (parser/error p)
-              (if ec "\e[0m" "")
-              "\n"))
+  (eprint
+    (if ec "\e[31m" "")
+    "parse error in "
+    where
+    " around line "
+    (string line)
+    ", column "
+    (string col)
+    ": "
+    (parser/error p)
+    (if ec "\e[0m" "")))
 
 (defn bad-compile
   "Default handler for a compile error."
   [msg macrof where]
   (def ec (dyn :err-color))
-  (file/write stderr
-              (if ec "\e[31m" "")
-              "compile error: "
-              msg
-              " while compiling "
-              where
-              (if ec "\e[0m" "")
-              "\n")
+  (eprint
+    (if ec "\e[31m" "")
+    "compile error: "
+    msg
+    " while compiling "
+    where
+    (if ec "\e[0m" ""))
   (when macrof (debug/stacktrace macrof)))
 
 (defn run-context

src/core/capi.c

@@ -51,19 +51,6 @@ void janet_panicf(const char *format, ...) {
     janet_panics(ret);
 }
 
-void janet_printf(const char *format, ...) {
-    va_list args;
-    JanetBuffer buffer;
-    int32_t len = 0;
-    while (format[len]) len++;
-    janet_buffer_init(&buffer, len);
-    va_start(args, format);
-    janet_formatb(&buffer, format, args);
-    va_end(args);
-    fwrite(buffer.data, buffer.count, 1, janet_dynfile("out", stdout));
-    janet_buffer_deinit(&buffer);
-}
-
 void janet_panic(const char *message) {
     janet_panicv(janet_cstringv(message));
 }

src/core/debug.c

@@ -90,9 +90,6 @@ void janet_debug_find(
     if (best_def) {
         *def_out = best_def;
         *pc_out = besti;
-        if (best_def->name) {
-            janet_printf("name: %S\n", best_def->name);
-        }
     } else {
         janet_panic("could not find breakpoint");
     }
@@ -102,13 +99,12 @@ void janet_debug_find(
  * consitency with the top level code it is defined once. */
 void janet_stacktrace(JanetFiber *fiber, Janet err) {
     int32_t fi;
-    FILE *out = janet_dynfile("err", stderr);
     const char *errstr = (const char *)janet_to_string(err);
     JanetFiber **fibers = NULL;
     int wrote_error = 0;
 
     int print_color = janet_truthy(janet_dyn("err-color"));
-    if (print_color) fprintf(out, "\x1b[31m");
+    if (print_color) janet_eprintf("\x1b[31m");
 
     while (fiber) {
         janet_v_push(fibers, fiber);
@@ -127,47 +123,47 @@ void janet_stacktrace(JanetFiber *fiber, Janet err) {
             if (!wrote_error) {
                 JanetFiberStatus status = janet_fiber_status(fiber);
                 const char *prefix = status == JANET_STATUS_ERROR ? "" : "status ";
-                fprintf(out, "%s%s: %s\n",
-                        prefix,
-                        janet_status_names[status],
-                        errstr);
+                janet_eprintf("%s%s: %s\n",
+                              prefix,
+                              janet_status_names[status],
+                              errstr);
                 wrote_error = 1;
             }
 
-            fprintf(out, "  in");
+            janet_eprintf("  in");
 
             if (frame->func) {
                 def = frame->func->def;
-                fprintf(out, " %s", def->name ? (const char *)def->name : "<anonymous>");
+                janet_eprintf(" %s", def->name ? (const char *)def->name : "<anonymous>");
                 if (def->source) {
-                    fprintf(out, " [%s]", (const char *)def->source);
+                    janet_eprintf(" [%s]", (const char *)def->source);
                 }
             } else {
                 JanetCFunction cfun = (JanetCFunction)(frame->pc);
                 if (cfun) {
                     Janet name = janet_table_get(janet_vm_registry, janet_wrap_cfunction(cfun));
                     if (!janet_checktype(name, JANET_NIL))
-                        fprintf(out, " %s", (const char *)janet_to_string(name));
+                        janet_eprintf(" %s", (const char *)janet_to_string(name));
                     else
-                        fprintf(out, " <cfunction>");
+                        janet_eprintf(" <cfunction>");
                 }
             }
             if (frame->flags & JANET_STACKFRAME_TAILCALL)
-                fprintf(out, " (tailcall)");
+                janet_eprintf(" (tailcall)");
             if (frame->func && frame->pc) {
                 int32_t off = (int32_t)(frame->pc - def->bytecode);
                 if (def->sourcemap) {
                     JanetSourceMapping mapping = def->sourcemap[off];
-                    fprintf(out, " on line %d, column %d", mapping.line, mapping.column);
+                    janet_eprintf(" on line %d, column %d", mapping.line, mapping.column);
                 } else {
-                    fprintf(out, " pc=%d", off);
+                    janet_eprintf(" pc=%d", off);
                 }
             }
-            fprintf(out, "\n");
+            janet_eprintf("\n");
         }
     }
 
-    if (print_color) fprintf(out, "\x1b[0m");
+    if (print_color) janet_eprintf("\x1b[0m");
 
     janet_v_free(fibers);
 }

src/core/io.c

@@ -384,8 +384,35 @@ FILE *janet_dynfile(const char *name, FILE *def) {
     return iofile->file;
 }
 
-static Janet cfun_io_print(int32_t argc, Janet *argv) {
-    FILE *f = janet_dynfile("out", stdout);
+static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
+                                int newline, const char *name, FILE *dflt_file) {
+    FILE *f;
+    Janet x = janet_dyn(name);
+    switch (janet_type(x)) {
+        default:
+            goto err;
+        case JANET_BUFFER: {
+            /* Special case buffer */
+            JanetBuffer *buf = janet_unwrap_buffer(x);
+            for (int32_t i = 0; i < argc; ++i) {
+                const uint8_t *vstr = janet_to_string(argv[i]);
+                janet_buffer_push_string(buf, vstr);
+            }
+            if (newline)
+                janet_buffer_push_u8(buf, '\n');
+            return janet_wrap_nil();
+        }
+        case JANET_NIL:
+            f = dflt_file;
+            break;
+        case JANET_ABSTRACT: {
+            void *abstract = janet_unwrap_abstract(x);
+            if (janet_abstract_type(abstract) != &cfun_io_filetype) goto err;
+            IOFile *iofile = abstract;
+            f = iofile->file;
+            break;
+        }
+    }
     for (int32_t i = 0; i < argc; ++i) {
         int32_t j, len;
         const uint8_t *vstr = janet_to_string(argv[i]);
@@ -394,8 +421,60 @@ static Janet cfun_io_print(int32_t argc, Janet *argv) {
             putc(vstr[j], f);
         }
     }
-    putc('\n', f);
+    if (newline)
+        putc('\n', f);
     return janet_wrap_nil();
+err:
+    janet_panicf("expected (dyn :%s) to be a file, buffer, or nil; got %v", name, x);
+}
+
+static Janet cfun_io_print(int32_t argc, Janet *argv) {
+    return cfun_io_print_impl(argc, argv, 1, "out", stdout);
+}
+
+static Janet cfun_io_prin(int32_t argc, Janet *argv) {
+    return cfun_io_print_impl(argc, argv, 0, "out", stdout);
+}
+
+static Janet cfun_io_eprint(int32_t argc, Janet *argv) {
+    return cfun_io_print_impl(argc, argv, 1, "err", stderr);
+}
+
+static Janet cfun_io_eprin(int32_t argc, Janet *argv) {
+    return cfun_io_print_impl(argc, argv, 0, "err", stderr);
+}
+
+void janet_dynprintf(const char *name, FILE *dflt_file, const char *format, ...) {
+    va_list args;
+    va_start(args, format);
+    Janet x = janet_dyn(name);
+    JanetType xtype = janet_type(x);
+    switch (xtype) {
+        default:
+        case JANET_ABSTRACT: {
+            FILE *f = dflt_file;
+            JanetBuffer buffer;
+            int32_t len = 0;
+            while (format[len]) len++;
+            janet_buffer_init(&buffer, len);
+            janet_formatb(&buffer, format, args);
+            if (xtype == JANET_ABSTRACT) {
+                void *abstract = janet_unwrap_abstract(x);
+                if (janet_abstract_type(abstract) == &cfun_io_filetype) {
+                    IOFile *iofile = abstract;
+                    f = iofile->file;
+                }
+            }
+            fwrite(buffer.data, buffer.count, 1, f);
+            janet_buffer_deinit(&buffer);
+            break;
+        }
+        case JANET_BUFFER:
+            janet_formatb(janet_unwrap_buffer(x), format, args);
+            break;
+    }
+    va_end(args);
+    return;
 }
 
 static const JanetReg io_cfuns[] = {
@@ -404,7 +483,24 @@ static const JanetReg io_cfuns[] = {
         JDOC("(print & xs)\n\n"
              "Print values to the console (standard out). Value are converted "
              "to strings if they are not already. After printing all values, a "
-             "newline character is printed. Returns nil.")
+             "newline character is printed. Use the value of (dyn :out stdout) to determine "
+             "what to push characters to. Expects (dyn :out stdout) to be either a core/file or "
+             "a buffer. Returns nil.")
+    },
+    {
+        "prin", cfun_io_prin,
+        JDOC("(prin & xs)\n\n"
+             "Same as print, but does not add trailing newline.")
+    },
+    {
+        "eprin", cfun_io_eprin,
+        JDOC("(eprin & xs)\n\n"
+             "Same as prin, but uses (dyn :err stderr) instead of (dyn :out stdout).")
+    },
+    {
+        "eprint", cfun_io_eprint,
+        JDOC("(eprint & xs)\n\n"
+             "Same as print, but uses (dyn :err stderr) instead of (dyn :out stdout).")
     },
     {
         "file/open", cfun_io_fopen,

src/core/run.c

@@ -28,7 +28,6 @@
 /* Run a string */
 int janet_dobytes(JanetTable *env, const uint8_t *bytes, int32_t len, const char *sourcePath, Janet *out) {
     JanetParser parser;
-    FILE *errf = janet_dynfile("err", stderr);
     int errflags = 0, done = 0;
     int32_t index = 0;
     Janet ret = janet_wrap_nil();
@@ -56,8 +55,8 @@ int janet_dobytes(JanetTable *env, const uint8_t *bytes, int32_t len, const char
                     done = 1;
                 }
             } else {
-                fprintf(errf, "compile error in %s: %s\n", sourcePath,
-                        (const char *)cres.error);
+                janet_eprintf("compile error in %s: %s\n", sourcePath,
+                              (const char *)cres.error);
                 errflags |= 0x02;
                 done = 1;
             }
@@ -70,8 +69,8 @@ int janet_dobytes(JanetTable *env, const uint8_t *bytes, int32_t len, const char
                 break;
             case JANET_PARSE_ERROR:
                 errflags |= 0x04;
-                fprintf(errf, "parse error in %s: %s\n",
-                        sourcePath, janet_parser_error(&parser));
+                janet_eprintf("parse error in %s: %s\n",
+                              sourcePath, janet_parser_error(&parser));
                 done = 1;
                 break;
             case JANET_PARSE_PENDING:

src/include/janet.h

@@ -1326,7 +1326,9 @@ 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_panicf(const char *format, ...);
-JANET_API void janet_printf(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__)
+#define janet_eprintf(...) janet_dynprintf("err", stderr, __VA_ARGS__)
 JANET_NO_RETURN JANET_API void janet_panic_type(Janet x, int32_t n, int expected);
 JANET_NO_RETURN JANET_API void janet_panic_abstract(Janet x, int32_t n, const JanetAbstractType *at);
 JANET_API void janet_arity(int32_t arity, int32_t min, int32_t max);

test/suite7.janet

@@ -170,4 +170,16 @@
 (assert (idx= (take 10 (range 100)) (range 10)) "take 10")
 (assert (idx= (drop 10 (range 100)) (range 10 100)) "drop 10")
 
+# Printing to buffers
+(def out-buf @"")
+(def err-buf @"")
+(with-dyns [:out out-buf :err err-buf]
+  (print "Hello")
+  (prin "hi")
+  (eprint "Sup")
+  (eprin "not much."))
+
+(assert (= (string out-buf) "Hello\nhi") "print and prin to buffer 1")
+(assert (= (string err-buf) "Sup\nnot much.") "eprint and eprin to buffer 1")
+
 (end-suite)