Tauris Expression Engine

Boolean evaluation and digital calculation expression engine for Java

Boolean Evaluation：

$country in ['cn', 'us', 'jp'] && $length > 100
$host == 'cs.qa.com' && 'Webkit' not in $ua

Digital calculation:

( 1 ^ 5) + (2 << 3)
4 | 3 + 3

Requirements

Java 1.8+

Maven

  <dependency>
    <groupId>io.tauris</groupId>
    <artifactId>expression</artifactId>
    <version>{ LATEST_VERSION }</version>
  </dependency>

Tutorials

First import class

import io.tauris.expression.TExpression;

Boolean Evaluation

String expr = "$status == '200' && $request_uri =~ /\\/.*/";
TExpression expression = TExpression.compile(expr);

MapContext ctx = new MapContext();
ctx.set("$status", "200");
ctx.set("$request_uri", "/hello/world");

if (expression.check(ctx)) {
	// print true
}

Digital calculation:

String expr = "1000 / $rnd";
TExpression expression = TExpression.compile(expr);

MapContext ctx = new MapContext();
ctx.set("$rnd", 200");

System.out.println(expression.calc(ctx).intValue()); //print 5

Definition

Arithmetic Operators

Operator	Description	Example
+	addition	1+1=2
-	subtraction	2-1=1
*	multiplication	2*2=4
/	division	2/2=1
%	modulus	5/2=1
^	pow	2^4=16

不支持位运算

Comparison Operators

Operator	Description	Example
==	equal	$A==$B
!=	not equal	$A!=$B
>	greater than	$A>$B
<	less than	$A<$B
>=	greater than or equal to	$A>=$B
<=	less than or equal to)	$A<=$B

notice the type of left value MUST same with right value

Logical Operators

Operator	Description	Example
&&	and	$A && $B
||	or	$A || $B
not	not	not（$A && $B)

Contain Operator

Operator	Description	Example
in	true, if the left value in the right value	$c in ['a', 'b', 'c', 'd']

Regular Expression Match

Operator	Description	Example
=~	true, the right expressio is matched to left value	'world' =~ /.+orl.+/

IS

Operator	Description	Example
is	left value IS the right type	$v is empty
is not	left vlaue IS NOT the right type	$v is not null

below is right types:

name	Description	Example
string		$v is string
integer		$v is integer
float		$v is float
boolean		$v is boolean && not $v
host	hostname	$v is host
ip4	ipv4 address	$v is ip4
empty	null、empty string or empty array	$v is not empty
null	null	$v is not null

Function

eval

Evaluated an expression

example:

// $exp = "$remote_addr is ip4"
"eval($exp)"