Following the similar style wtd implemented, (actually ripped off, but all credit to wtd
) of intro tutorials for the Turing programmer:
BeanShell (the beginning steps to Java) for the Turing Programmer
Input-Output
Printing to the standard output.
Turing
| code: |
put "Hello" .. |
BeanShell
| code: |
print("Hello"); |
As for not skipping the new line:
Turing
| code: |
put "Hello" |
BeanShell
| code: |
print("Hello\n"); |
Printing an integer.
Turing
| code: |
put 42 |
BeanShell
| code: |
print(42); |
Printing a floating point number.
Turing
| code: |
put 42.3 |
BeanShell
| code: |
println(42.3); |
Getting a line from the keyboard.
Turing
| code: |
var line : string
get line : * |
BeanShell
| code: |
import *;
in = new BufferedReader( new InputStreamReader(System.in) ); var string = in.readLine(); |
Getting a single character from the keyboard.
Turing
| code: |
var ch : string
get ch : 1 |
BeanShell
| code: |
var ch = (char) System.in.read(); |
Getting an integer from the keyboard.
Turing
| code: |
var i : int
get i |
BeanShell
| code: |
import *;
in = new DataInputStream( new BufferedInputSream(System.in) ); var i = in.readInt(); |
Getting a float from the keyboard.
Turing
| code: |
var f : real
get f |
BeanShell
| code: |
import *;
var in = new DataInputStream( new BufferedInputSream(System.in) ); var f = in.readFloat(); |
Math
| code: |
Turing | BeanShell | Result
----------+-------------+--------- 4 + 3 | 4 + 3 | 7 4 - 2 | 4 - 2 | 2 2 * 3 | 2 * 3 | 6 2 / 5 | 2 / 5 | 0.4 6 div 4 | | 1 6 rem 4 | 6 % 4 | 2 3 ** 2 |Math.pow(3,2)| 9.0 sin | Math.sin() | cos | Math.cos() | | Math.tan() | | Math.asin() | | Math.acos() | | Math.atan() | |
Comparisons
| code: |
Turing | BeanShell
--------+------------ = | == not= | != <, <= | <, <= >, >= | >, >= not | ! and | && or | || | & | | |
Conditional Statements/Expressions
| code: |
Turing | BeanShell
----------------------------+------------------------------ if condition then | if (condition) { statement1 | expression1; statement2 | expression2; elsif otherCondition then | } else if (otherCondition) statement3 | expression2; else | else defaultExpression; defaultStatement | end if | ----------------------------+------------------------------ case value of | switch (value) { label 1: statement1 | case 1: expression1; break; label 2: statement2 | case 2: expression2; break; label: default | default: default_expression; end case | } |
Function Definition
| code: |
Turing | BeanShell | Java
------------------------------------+-------------------------------------------------------- function fooBar : string | fooBar() { | String fooBar() { result "foo, bar" | return "foo, bar"; | return "foo, bar"; end fooBar | } | } ------------------------------------+-------------------------------------------------------- function square (n : int) : float | square(n) { | float square(int n) { result n ** 2 | return Math.pow(n,2); | return Math.pow(n,2); end square | } | } ------------------------------------+-------------------------------------------------------- procedure greet (name : string) | greet(name) { | String greet(String name) { put "Hello, " + name | return "Hello, "+name;| return "Hello, " + name; end greet | } | } ------------------------------------+------------------------------------------------------- function fact (n : int) : int | fact(n) { | int fact(int n) { if n = 0 then | if (n == 0) | if (n == 0) result 1 | return 1; | return 1; else | else | else result n * fact (n - 1) | return n*fact(n-1);| return n*fact(n-1); end if | } | } end fact | |
Types of Variables in BeanShell
| code: |
int x; // a type(d) variable, can only hold specified type (int) of data
var x; // a var variable can hold any kind of data x = value; // gloabal variable, behaves like a var variable, but has global scope |
Comments
| code: |
Turing | BeanShell
------------+------------- % | // /* ... */ | /* ... */ | /** ... */ |
More to come.
