the beginning of a new interpreter

version3.0/lib/io.nas

@@ -0,0 +1,74 @@
+# nasal lib io.nas
+# 2020/2/8
+# this file is used to avoid name confliction
+# and is used to avoid name undefined
+# before running this file will be translated to abstract syntax tree
+# and this ast will be linked before main ast as main-ast's beginning
+
+var io=
+{
+    # Opens the file with the specified mode (as per ANSI fopen()) and returns a ghost object representing the filehandle.
+    # Failures are thrown as runtime errors as per die(). 
+    open:func(filename,mode="r")
+    {
+        return nasal_call_builtin_c_fopen(filename,mode);
+    },
+    # Closes the specified file as per ANSI fclose(). 
+    close:func(filehandle)
+    {
+        nasal_call_builtin_c_fclose(filehandle);
+        return;
+    },
+    # Attempts to read length bytes from the filehandle into the beginning of the mutable string buf.
+    # Failures (including overruns when length > size(buf)) are thrown as runtime errors as per die().
+    # Returns the number of bytes successfully read. 
+    read:func(filehandle,buf,length)
+    {
+        return nasal_call_builtin_c_read(filehandle,buf,length);
+    },
+    # Attempts to write the entirety of the specified string to the filehandle.
+    # Failures are thrown as runtime errors as per die().
+    # Returns the number of bytes successfully written. 
+    write:func(filehandle,str)
+    {
+        return nasal_call_builtin_c_write(filehandle,str);
+    },
+    # As ANSI fseek().
+    # Attempts to seek to the specified position based on the whence value
+    # (which must be one of io.SEEK_SET,io.SEEK_END, or io.SEEK_CUR)
+    SEEK_SET:1,
+    SEEK_CUR:2,
+    SEEK_END:3,
+    seek:func(filehandle,position,whence)
+    {
+        nasal_call_builtin_c_seek(filehandle,position,whence);
+        return;
+    },
+    # Returns the current seek position of the filehandle. 
+    tell:func(filehandle)
+    {
+        return nasal_call_builtin_c_tell(filehandle);
+    },
+    # Reads and returns a single text line from the filehandle.
+    # Interprets both "\n" and "\r\n" as end of line markers,
+    # and does not include the "\r" or "\n" bytes in the returned string.
+    # End offile or error is signaled by returning nil. 
+    readln:func(filehandle)
+    {
+        return nasal_call_builtin_builtin_c_getline(filehandle);
+    },
+    # Calls unix or win32 stat() on the specified file name and
+    # returns a seven element array whose contents are,
+    # in order: dev, ino, mode,nlink, uid, gid, rdef, size, atime, mtime, ctime.
+    # Errors are signaled as exceptions as per die().
+    stat:func(filename)
+    {
+        return nasal_call_builtin_builtin_stat(filename);
+    },
+};
+
+var print=func(dyn...)
+{
+    nasal_call_builtin_c_std_puts(dyn);
+    return nil;
+};