Update examples

examples/error.sp

@@ -1,5 +1,5 @@
-import core/flow;
+const { exit } from @'core/os';
 
-@main {
-    flow.exit(1);
+let @main in {
+    exit(1);
 }

examples/file.sp

@@ -1,10 +1,10 @@
-import core/io;
-import core/fs;
+const io from @'core/io';
+const { open } from @'core/fs';
 
-@main {
-    io.out('What\'s your name? ');
-    str name = io.in();
-    fs.File nameFile = fs.open('name.txt');
-    nameFile.write(name);
-    nameFile.close();
+let @main in {
+    io.out("What is your name? ");
+    let name = io.in();
+    let file = open("name.txt");
+    file.write(name);
+    file.close();
 }

examples/float128.sp

@@ -1,8 +1,9 @@
-import core/io;
-import core/string;
+const io from @'core/io';
+const { concat } from @'core/string';
+const { toString } from @'core/float_utils';
 
-@main {
-    f128 float1 = 234.6;
-    f128 float2 = 2934748348291930404.5;
-    io.outln(string.concat('Result is: ',(str)(float1 + float2)));
+let @main in {
+    let float1 : f128 = 234.6;
+    f128 float2 : f128 = 2934748348291930404.5;
+    io.outln(concat('Result is: ',toString(float1 + float2)));
 }

examples/hello-world.sp

@@ -1,5 +1,5 @@
-import core/io;
+const io from @'core/io';
 
-@main {
+let @main in {
     io.outln('Hello world!');
 }

examples/input.sp

@@ -1,8 +1,8 @@
-import core/io;
+const io from @'core/io';
 
-@main {
+let @main in {
     io.out('What\'s your name? ');
-    str name = io.in();
+    let name = io.in();
     io.out('Hello, ');
     io.out(name);
     io.out('!!');

examples/new-syntax.sp

@@ -1,12 +1,10 @@
-let { io } in @'core/io';
+const { io } from @'core/io';
 
-let good_food : String = 'watermelon';
+const good_food : String = 'watermelon';
 
-let @main : i32 in {
+let @main in {
 
     io.outln('Hello world!');
 
     io.outf('My favorite food is %s\n',good_food);
-
-    return 0;
 }

examples/variables.sp

@@ -1,7 +1,7 @@
-import core/io;
+const io from @'core/io';
 
 @main {
-    i32 age = 64;
+    let age : i32 = 64;
     io.out('I am ');
     io.out(age);
     io.outln(' years old.');