anhtuduong / mexpeditor Goto Github PK

Simple example of Xtext project.

The project implements a simple editor for mathematical expressions. The editor allows defining:

• constants
• variables
• expressions

Constants are introduced by the keyword Const, followed by an identifier that allows using constant in expressions and a numerical value. Examples of constants are:

• Const c1 : 10;
• Const c2 : 3;

The definition of a variable has the same syntax of the definition of constants, but it is prefixed by keyword Var. Examples of variables are:

• Var x : 7;
• Var y : 12;

Expressions allow combining constants, variables, and numerical values with mathematical operators + and -. The definition of and expression follows the same syntax used for constants and variables, but it is prefixed by keyword Exp. Examples of expressions are:

• Exp e1 : x + c1;
• Exp e2 : 7 - c2 + y;

Expression definition also support the use of parentheses

• Exp e3 : (x + c1 ) - (7 - c2 + y);

The editor implements some basic syntactic checkers:

• Constant and variable identifiers cannot be duplicated. For instance, the following is not permitted

Const c1 : 10;

Var c1 : 7;

• Constant and variable identifiers used in a expression must be defined. For instance, the following is not permitted

Var x : 7;

Exp e : x + y ;

The project has been developed with Eclipse version 2022-06 (4.24.0) and Xtext version 2.27.0.