Espresso

Espresso is a mathematical expression evaluator in .NET based on ANTLR4.

Quick Start

using Espresso;

Expression expression = new ("3E2+3*2^(1+1)");
double result = (double) expression.Evaluate();
Debug.Assert(result == 312);

Table Of Content

• Quick Start
• Summary
  • Operators
• Values
• Basic Arithmetic Operations

Summary

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Operators

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Listed from higher priority to lower priority

Operator	Description	Usage
Standard Operators
^	exponentiation (power)	exp ^ exp
E	exponential notation	exp E exp
%	modulo or percentage	exp % exp or exp%
!	factorial	exp!
* or ×	multiplication	exp * exp
/ or ÷	division	exp / exp
+	positive sign or addition	+exp or exp + exp
- or −	negative sign or subtraction	-exp or exp - exp
* exp; expression

Values

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Espresso suppports exponential notation and floats, both are handled as double.

.2  is equivalent to  0.2  
>> 0.2

2E3  
>> 2000  
2E3E2  
>> 2E+300

Note that exponential notation is right-associative i.e, evaluates from right to left.

 

Basic Arithmetic Operations

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Espresso follows standard order of evaluation and supports overriding order with parentheses.
Espresso can and will ignore whitespaces, including \n, \r\n, \t, and \u000C.

5 + 1 - 2 * 3 / 4 % 5  is equivalent to  5 + (1 - (2 * (3 / (4 % 5))))

2^3^2  is equivalent to  2^(3^2)  
>> 512

Note that exponentiation operator (^) is right-associative i.e, evaluates from right to left.