More file system checking functions:

- Stat#isFile
- Stat#isDirectory
- Directory.exists()
- File.exists()

doc/site/modules/io/directory.markdown

@@ -4,6 +4,11 @@ A directory on the file system.
 
 ## Static Methods
 
+### Directory.**exists**(path)
+
+Whether a directory exists at `path`. This returns `false` for files or other
+special file system entities.
+
 ### Directory.**list**(path)
 
 Lists the contents of the directory at `path`. Returns a sorted list of path

doc/site/modules/io/file.markdown

@@ -25,6 +25,11 @@ automatically closed.
 
 Deletes the file at `path`.
 
+### File.**exists**(path)
+
+Whether a regular file exists at `path`. This returns `false` for directories
+or other special file system entities.
+
 ### File.**open**(path, fn)
 
 Opens the file at `path` for reading and passes it to `fn`. After the function

doc/site/modules/io/stat.markdown

@@ -10,45 +10,54 @@ A data structure describing the low-level details of a file system entry.
 
 ## Methods
 
+### **blockCount**
+
+The number of system blocks allocated on disk for the file.
+
+### **blockSize**
+
+The preferred block size in bytes for interacting with the file. It may vary
+from file to file.
+
 ### **device**
 
 The ID of the device containing the entry.
 
+### **group**
+
+Numeric group ID of the file's owner.
+
 ### **inode**
 
 The [inode][] number of the entry.
 
 [inode]: https://en.wikipedia.org/wiki/Inode
 
-### **mode**
+### **isDirectory**
 
-A bit field describing the entry's type and protection flags.
+Whether the file system entity is a directory.
+
+### **isFile**
+
+Whether the file system entity is a regular file, as opposed to a directory or
+other special entity.
 
 ### **linkCount**
 
 The number of hard links to the entry.
 
-### **user**
+### **mode**
 
-Numeric user ID of the file's owner.
+A bit field describing the entry's type and protection flags.
-
-### **group**
-
-Numeric group ID of the file's owner.
-
-### **specialDevice**
-
-The device ID for the entry, if it's a special file.
 
 ### **size**
 
 The size of the entry in bytes.
 
-### **blockSize**
+### **specialDevice**
 
-The preferred block size in bytes for interacting with the file. It may vary
+The device ID for the entry, if it's a special file.
-from file to file.
 
-### **blockCount**
+### **user**
 
-The number of system blocks allocated on disk for the file.
+Numeric user ID of the file's owner.

src/cli/modules.c

@@ -32,6 +32,8 @@ extern void statMode(WrenVM* vm);
 extern void statSize(WrenVM* vm);
 extern void statSpecialDevice(WrenVM* vm);
 extern void statUser(WrenVM* vm);
+extern void statIsDirectory(WrenVM* vm);
+extern void statIsFile(WrenVM* vm);
 extern void stdinReadStart(WrenVM* vm);
 extern void stdinReadStop(WrenVM* vm);
 extern void schedulerCaptureMethods(WrenVM* vm);
@@ -45,7 +47,7 @@ extern void timerStartTimer(WrenVM* vm);
 // If you add a new method to the longest class below, make sure to bump this.
 // Note that it also includes an extra slot for the sentinel value indicating
 // the end of the list.
-#define MAX_METHODS_PER_CLASS 12
+#define MAX_METHODS_PER_CLASS 14
 
 // The maximum number of foreign classes a single built-in module defines.
 //
@@ -133,6 +135,8 @@ static ModuleRegistry modules[] =
       METHOD("size", statSize)
       METHOD("specialDevice", statSpecialDevice)
       METHOD("user", statUser)
+      METHOD("isDirectory", statIsDirectory)
+      METHOD("isFile", statIsFile)
     END_CLASS
     CLASS(Stdin)
       STATIC_METHOD("readStart_()", stdinReadStart)

src/module/io.c

@@ -442,6 +442,18 @@ void statUser(WrenVM* vm)
   wrenSetSlotDouble(vm, 0, (double)stat->st_uid);
 }
 
+void statIsDirectory(WrenVM* vm)
+{
+  uv_stat_t* stat = (uv_stat_t*)wrenGetSlotForeign(vm, 0);
+  wrenSetSlotBool(vm, 0, S_ISDIR(stat->st_mode));
+}
+
+void statIsFile(WrenVM* vm)
+{
+  uv_stat_t* stat = (uv_stat_t*)wrenGetSlotForeign(vm, 0);
+  wrenSetSlotBool(vm, 0, S_ISREG(stat->st_mode));
+}
+
 static void allocCallback(uv_handle_t* handle, size_t suggestedSize,
                           uv_buf_t* buf)
 {

src/module/io.wren

@@ -6,6 +6,18 @@ class Directory {
     if (!(path is String)) Fiber.abort("Path must be a string.")
   }
 
+  static exists(path) {
+    ensurePath_(path)
+    var stat
+    Fiber.new {
+      stat = Stat.path(path)
+    }.try()
+
+    // If we can't stat it, there's nothing there.
+    if (stat == null) return false
+    return stat.isDirectory
+  }
+
   static list(path) {
     ensurePath_(path)
     list_(path, Fiber.current)
@@ -31,11 +43,23 @@ foreign class File {
   }
 
   static delete(path) {
-    File.ensurePath_(path)
+    ensurePath_(path)
     delete_(path, Fiber.current)
     return Scheduler.runNextScheduled_()
   }
 
+  static exists(path) {
+    ensurePath_(path)
+    var stat
+    Fiber.new {
+      stat = Stat.path(path)
+    }.try()
+
+    // If we can't stat it, there's nothing there.
+    if (stat == null) return false
+    return stat.isFile
+  }
+
   static open(path) { openWithFlags(path, FileFlags.readOnly) }
 
   static open(path, fn) { openWithFlags(path, FileFlags.readOnly, fn) }
@@ -43,8 +67,8 @@ foreign class File {
   // TODO: Add named parameters and then call this "open(_,flags:_)"?
   // TODO: Test.
   static openWithFlags(path, flags) {
-    File.ensurePath_(path)
+    ensurePath_(path)
-    File.ensureInt_(flags, "Flags")
+    ensureInt_(flags, "Flags")
     open_(path, flags, Fiber.current)
     var fd = Scheduler.runNextScheduled_()
     return new_(fd)
@@ -68,7 +92,7 @@ foreign class File {
   }
 
   static size(path) {
-    File.ensurePath_(path)
+    ensurePath_(path)
     sizePath_(path, Fiber.current)
     return Scheduler.runNextScheduled_()
   }
@@ -175,6 +199,10 @@ foreign class Stat {
   foreign size
   foreign specialDevice
   foreign user
+
+  foreign isFile
+  foreign isDirectory
+  // TODO: Other mode checks.
 }
 
 class Stdin {

src/module/io.wren.inc

@@ -8,6 +8,18 @@ static const char* ioModuleSource =
 "    if (!(path is String)) Fiber.abort(\"Path must be a string.\")\n"
 "  }\n"
 "\n"
+"  static exists(path) {\n"
+"    ensurePath_(path)\n"
+"    var stat\n"
+"    Fiber.new {\n"
+"      stat = Stat.path(path)\n"
+"    }.try()\n"
+"\n"
+"    // If we can't stat it, there's nothing there.\n"
+"    if (stat == null) return false\n"
+"    return stat.isDirectory\n"
+"  }\n"
+"\n"
 "  static list(path) {\n"
 "    ensurePath_(path)\n"
 "    list_(path, Fiber.current)\n"
@@ -33,11 +45,23 @@ static const char* ioModuleSource =
 "  }\n"
 "\n"
 "  static delete(path) {\n"
-"    File.ensurePath_(path)\n"
+"    ensurePath_(path)\n"
 "    delete_(path, Fiber.current)\n"
 "    return Scheduler.runNextScheduled_()\n"
 "  }\n"
 "\n"
+"  static exists(path) {\n"
+"    ensurePath_(path)\n"
+"    var stat\n"
+"    Fiber.new {\n"
+"      stat = Stat.path(path)\n"
+"    }.try()\n"
+"\n"
+"    // If we can't stat it, there's nothing there.\n"
+"    if (stat == null) return false\n"
+"    return stat.isFile\n"
+"  }\n"
+"\n"
 "  static open(path) { openWithFlags(path, FileFlags.readOnly) }\n"
 "\n"
 "  static open(path, fn) { openWithFlags(path, FileFlags.readOnly, fn) }\n"
@@ -45,8 +69,8 @@ static const char* ioModuleSource =
 "  // TODO: Add named parameters and then call this \"open(_,flags:_)\"?\n"
 "  // TODO: Test.\n"
 "  static openWithFlags(path, flags) {\n"
-"    File.ensurePath_(path)\n"
+"    ensurePath_(path)\n"
-"    File.ensureInt_(flags, \"Flags\")\n"
+"    ensureInt_(flags, \"Flags\")\n"
 "    open_(path, flags, Fiber.current)\n"
 "    var fd = Scheduler.runNextScheduled_()\n"
 "    return new_(fd)\n"
@@ -70,7 +94,7 @@ static const char* ioModuleSource =
 "  }\n"
 "\n"
 "  static size(path) {\n"
-"    File.ensurePath_(path)\n"
+"    ensurePath_(path)\n"
 "    sizePath_(path, Fiber.current)\n"
 "    return Scheduler.runNextScheduled_()\n"
 "  }\n"
@@ -177,6 +201,10 @@ static const char* ioModuleSource =
 "  foreign size\n"
 "  foreign specialDevice\n"
 "  foreign user\n"
+"\n"
+"  foreign isFile\n"
+"  foreign isDirectory\n"
+"  // TODO: Other mode checks.\n"
 "}\n"
 "\n"
 "class Stdin {\n"

test/io/directory/exists.wren

@@ -0,0 +1,9 @@
+import "io" for Directory
+
+System.print(Directory.exists("test/io/file")) // expect: true
+System.print(Directory.exists("nonexistent")) // expect: false
+
+// Files are not directories.
+System.print(Directory.exists("test/io/file/file.txt")) // expect: false
+
+// TODO: Symlinks.

test/io/directory/exists_path_not_string.wren

@@ -0,0 +1,3 @@
+import "io" for Directory
+
+Directory.exists(123) // expect runtime error: Path must be a string.

test/io/file/exists.wren

@@ -0,0 +1,9 @@
+import "io" for File
+
+System.print(File.exists("test/io/file/file.txt")) // expect: true
+System.print(File.exists("nonexistent")) // expect: false
+
+// Directories are not files.
+System.print(File.exists("test/io/file")) // expect: false
+
+// TODO: Symlinks.

test/io/file/exists_path_not_string.wren

@@ -0,0 +1,3 @@
+import "io" for File
+
+File.exists(123) // expect runtime error: Path must be a string.

test/io/stat/is_directory.wren

@@ -0,0 +1,4 @@
+import "io" for Stat
+
+System.print(Stat.path("test/io/file/file.txt").isDirectory) // expect: false
+System.print(Stat.path("test").isDirectory) // expect: true

test/io/stat/is_file.wren

@@ -0,0 +1,4 @@
+import "io" for Stat
+
+System.print(Stat.path("test/io/file/file.txt").isFile) // expect: true
+System.print(Stat.path("test").isFile) // expect: false

test/io/stat/path.wren

@@ -1,5 +1,4 @@
 import "io" for Stat
-import "scheduler" for Scheduler
 
 var stat = Stat.path("test/io/file/file.txt")
 

test/io/stat/path_directory.wren

@@ -1,5 +1,4 @@
 import "io" for Stat
-import "scheduler" for Scheduler
 
 var stat = Stat.path("test/io/directory/dir")