A lightweight runtime math expressions solver/compiler for JVM.
- does not use any scripting engine
- uses java reflection
- writes JVM bytecode
- aimed to reuse compiled expressions
Future:
- integer expressions, bitwise operations
- double precision expressions
Download built jar library file from GitHub
RunExp requires one dependency since v1.1
version used: asm-all-5.2
ASM is used for runtime java-bytecode generation.
with x:
Expression expression = RunExp.compile("sin(x) * 0.5 + (x * 0.1)"); expression.eval(1.25f); // same as sin(1.25f) * 0.5f + (1.25f * 0.1f) // or RunExpSolver solver = new RunExpSolver(); Expression expression = solver.compile("sin(x) * 0.5 + (x * 0.1)"); expression.eval(1.25f);
float value = RunExp.eval("pi * 0.5");
if Expression wrapper needed (ConstantExpression used):
ConstantExpression expression = RunExp.compileConstant("pi ^ 2");
RunExp class uses RunExpSolver instance available as RunExp.solver, but it's preferred
to create new one.
RunExpSolver solver = new RunExpSolver(); solver.addConstant("g", 9.8f); ... float value = solver.eval(expressionString);
solver.allowJVM - allow compiling expressions directly into JVM bytecode (true by default)
Method:
RunExpSolver.addConstant(String name, float value);
Example:
solver.addConstant("g", 9.8f);
Methods:
RunExpSolver.addFunction(String name, Class<?> class, String methodName); RunExpSolver.addFunction(String name, Class<?> class, String methodName, Class<?>... args);
Example:
try { // adding Noise.noise2d(float, float) static method as function 'noise' solver.addFunction("noise", Noise.class, "noise2d"); // if Noise.noise is overloaded solver.addFunction("noise", Noise.class, "noise2d", class.float, class.float); } catch (NoSuchMethodException e){ ... } // see RunExpSolver.addFunction docs for more info
Built-in functions may be overriden.
Example:
// override built-in 'rand' with some MathUtils.random method solver.addFunction("rand", MathUtils.class, "random");
- unary operations: '-'
- binary operations: '+', '-', '*', '/' and '^' (exponentation)
- functions:
- abs
- sin, cos, tan
- sqrt, exp, pow (same as '^' operator)
- min(a, b), max(a, b)
- round, floor, ceil
- sign / signum
- rand - random number in range
[0.0, 1.0] - smoother (smoother step)
- constants:
- pi (Math.PI)
- pi2 (Math.PI * 2)
- e (Math.E)
- raddeg (180.0 / Math.PI) usage: degrees = radians * raddeg
- degrad (Math.PI / 180.0) usage: radians = degreen * degrad
- custom constants
- custom functions (directly calling static methods as functions)