`N` does not respect precision values below 17

[alldaygooning]

Description.
When not-evaluated number (e.g. Pi or 1/7) is passed toN(numeric, precision) as numeric argument, function does not evaluate it to specified precision, if precision is less than 17.

1. Example. Precision = 15

ExprEvaluator evaluator = new ExprEvaluator();
IExpr result = evaluator.eval("N(1/7, 15)");
System.out.println(result); 
System.out.println(result.fullFormString());

Output:

0.142857
0.14285714285714285`

Expected output:

0.142857142857143
0.142857142857143`

2. Example. Precision = 3

ExprEvaluator evaluator = new ExprEvaluator();
IExpr result = evaluator.eval("N(1/7, 3)");
System.out.println(result); 
System.out.println(result.fullFormString());

Output:

0.142857
0.14285714285714285`

Expected output:

0.143
0.143

3. Example. Precision = 17

ExprEvaluator evaluator = new ExprEvaluator();
IExpr result = evaluator.eval("N(1/7, 17)");
System.out.println(result); 
System.out.println(result.fullFormString());

Output:

1.4285714285714285*10^-1
1.4285714285714285`17*^-1

Expected output:

1.4285714285714285
1.4285714285714285 (basically, exactly what was expected).

I believe this is a bug, since matheclipse.org and NCalc+ both produce Expected outputs on the same inputs:

Summary
precision of less than 17 in N() evaluates number to actual precision of 16 (as seemingly evident by .fullFormString() and even more confusingly, toString() representation has precision of 5 or sometimes 6.

Prerequisites

• Java 17
• Matheclipse 3.1.0-SNAPSHOT