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)"