dart - Reading text file using readAsString() and using the result -

the following example (1) reads file , prints contents without explicitly assigning file contents variable (ie. “.then(stdout.write)”). however, if want more print contents (2), need assign contents variable (i think).

is possible achieve (print contents , more), without assigning text of file variable?

in first example, implicit variable created? or, put way, example1 use less resources not creating explicit variable?

//example 1: import 'dart:io'; void main() {   new file(new options().script)     .readasstring(encoding: encoding.ascii)     .then(stdout.write)     .catcherror((oerror) => print(oerror));   print("reading file ...\n"); }  //example 2: import 'dart:io'; void main() {   new file(new options().script)     .readasstring(encoding: encoding.ascii)     .then((string stext) {       stdout.write(stext+"\n\n");       print ('completed');     })     .catcherror((oerror) => print(oerror));   print("reading file ...\n"); } 

in first example, this:

.then(stdout.write) 

is equivalent this:

.then((string stext) {   stdout.write(stext); }) 

technically there's 1 more function call, , have 1 more variable, should cost few bytes (i'm not sure on exact implementation). strings immutable; receiving reference string, not saving resources (other function call , few bytes of memory) using second version.

whatever want contents of string involve using resources, of course, shouldn't issue unless file huge.