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WorldEditExpression syntax
The WorldEdit expression parser is supposed to work like Java and related languages, with a few subtle differences:
 Final semicolons can be omitted in most cases.
 The last value in a sequence is always returned, even without a return statement.
 The binary infix ^ operator is a power operator instead of an xor operator and has an according priority as well.
 There is a postfix factorial operator (!).
 There is a binary infix near operator (~=).
 No objects :)
Contents 
Operators
The expression parser uses Java's precedence rules, with the following exceptions and additions:
 The binary power operator (
^
) is between priority 2 and 3  The postfix factorial operator (
!
) has a priority of 2  The near operator (
~=
) has a priority of 7
Binary infix
These operators are put between their two operands.
Arithmetic
+ Addition  Subtraction * Multiplication / Division % Modulo ^ Power
Bitwise
These operators interpret their operands as 32 bit integers and operate on their bits.
<< Leftshift >> Rightshift
Logical
These operators interpret everything greater than zero as true and everything else as false.
They return 1 for true and 0 for false.
&& Logical and  Logical or
Comparison
These operators compare their operands and return 1 for true and 0 for false.
< less than > greater than <= less or equal >= greater or equal == equal != not equal ~= near
Assignment
These operators require a variable on the left side.
Using the simple assignment operator (=) to assign to a nonexistant variable creates a temporary variable.
= simple assignment += addition+assignment = subtraction+assignment *= multiplication+assignment /= division+assignment %= modulo+assignment ^= power+assignment
Prefix
These operators precede the expression they apply to.
x (negation) ~x Bitwise complement (see bitwise binary operators) !x Logical complement (see logical binary operators) ++x Preincrement x Predecrement
Postfix
These operators succeed the expression they apply to.
x! Factorial x++ Postincrement x Postdecrement
Ternary infix
The ternary operator is used to represent a conditional expression in a compact way.
<condition> ? <truebranch> : <falsebranch>
It works exactly like the if/else statement, except that the branches can only be single expressions.
Functions
The expression parser provides the following functions from the Java Math library:

abs
 Returns the absolute value of a number. 
acos
 Returns the arc cosine of a value; the returned angle is in the range 0.0 through pi. 
asin
 Returns the arc sine of a value; the returned angle is in the range pi/2 through pi/2. 
atan2
 Returns the angle theta from the conversion of rectangular coordinates (x, y) to polar coordinates (r, theta). 
atan
 Returns the arc tangent of a value; the returned angle is in the range pi/2 through pi/2. 
cbrt
 Returns the cube root of a value. 
ceil
 Returns the smallest (closest to negative infinity) value that is greater than or equal to the argument and is equal to a mathematical integer. 
cos
 Returns the trigonometric cosine of an angle. 
cosh
 Returns the hyperbolic cosine of a value. 
exp
 Returns Euler's number e raised to the power of a value. 
floor
 Returns the largest (closest to positive infinity) value that is less than or equal to the argument and is equal to a mathematical integer. 
ln
 Returns the natural logarithm (base e) of a value. 
log
 Returns the natural logarithm (base e) of a value. 
log10
 Returns the base 10 logarithm (base e) of a value. 
max
 Returns the greatest of the values. (supports 2 and 3 arguments) 
min
 Returns the smallest of the values. (supports 2 and 3 arguments) 
rint
 Returns the number that is closest in value to the argument and is equal to a mathematical integer. 
round
 Returns the closest number to the argument 
sin
 Returns the trigonometric sine of an angle. 
sinh
 Returns the hyperbolic sine of a value. 
sqrt
 Returns the correctly rounded positive square root of a value. 
tan
 Returns the trigonometric tangent of an angle. 
tanh
 Returns the hyperbolic tangent of a value.
Additionally, it provides the following functions:

rotate(x, y, angle)
 Rotates the given coordinate pair by the given angle. 
swap(x, y)
 Swaps the contents of the 2 given variables. 
random()
 Returns a random positive number less than 1.0. 
randint(max)
 Returns a random positive integer less thanmax
.
Block query functions:

query(x, y, z, type, data)
 Returnstrue
, if the block at the given coordinates has the given type and data value. If possible, the type and data of the block will be assigned totype
anddata
. 
queryRel(dx, dy, dz, type, data)
 Likequery
, except with relative world coordinates 
queryAbs(xp, yp, zp, type, data)
 Likequery
, except with absolute world coordinates
Constants
 e = 2.7182818284590452354  The base of the natural logarithm
 pi = 3.14159265358979323846  The ratio between circumference and diameter of a circle
 true = 1  for boolean operations
 false = 0  for boolean operations
Block statements
Block statements are groups of statements enclosed in braces.
Example:
{ x=5; y=6; }
They are mostly used in conjunction with control structures.
if/else
if (<condition>) <truebranch> if (<condition>) <truebranch> else <falsebranch>

<condition>
is evaluated to decide which branch to execute.
Everything greater than zero is interpreted as true and everything else as false. 
<truecode>
and<falsecode>
can either be single statements delimited with a semicolon or block statements.
Note:
An else
keyword is always associated with the last if
.
This allows elseif constructs like these:
if (<condition 1>) <truecode 1> else if (<condition 2>) <truecode 2> else <falsecode>
Loops
Loops can at most loop 256 times.
While
while (<condition>) <body> do <body> while (<condition>);

<condition>
is evaluated to decide whether to continue looping. 
<body>
can either be a single statement delimited with a semicolon or a block statement.  dowhile checks the condition after executing the body.
Java/Cstyle for
for (<init>; <condition>; <increment>) <body>

<init>
,<condition>
and<increment>
are single expressions.

<body>
can either be a single statement delimited with a semicolon or a block statement.
Execution steps
First, <init>
is evaluated once, then, each iteration follows these steps:
 If
<condition>
evaluates as less than or equal to zero (i.e. false), the loop is aborted. 
<body>
is executed. 
<increment>
is executed.
Simple for
for (<counter> = <first>, <last>) <body>

<counter>
is a variable used to count the iterations.

<first>
and<last>
are single expressions.

<body>
can either be a single statement delimited with a semicolon or a block statement.
Execution steps
First, an internal counter is set to <first>
. Then, each iteration follows these steps:
 If the internal counter exceeds
<last>
, the loop is aborted. 
<counter>
is set to the internal counter. 
<body>
is executed. 
<counter>
is incremented by 1.0.
<first>
and <last>
are only evaluated once.