NCalc - Mathematical Expressions Evaluator for .NET

Created Issue: Comparison of dates throws exception [25392]

benark — Wed, 18 Nov 2009 22:31:25 GMT

Try this expression: #11/18/2009#==#11/19/2009#
Get this exception: Invalid cast from 'System.DateTime' to 'System.RuntimeType'.

I find this happens when doing any date comparison.

New Post: Parsing expressions not done correctly

sebastienros — Wed, 11 Nov 2009 17:09:02 GMT

Thank you for this information. I have corrected it and published version 1.3.2. (Both issues)

Updated Release: NCalc - 1.3.2 (nov. 11, 2009)

sebastienros — Wed, 11 Nov 2009 17:07:44 GMT

BUG: Major issue corrected with precedence (again, thanks to Keze).
BUG: Use double values when using the / operator, in order to prevent percision loss

Released: NCalc - 1.3.2 (Nov 11, 2009)

Wed, 11 Nov 2009 17:07:44 GMT

BUG: Major issue corrected with precedence (again, thanks to Keze).
BUG: Use double values when using the / operator, in order to prevent percision loss

Updated Release: NCalc - 1.3.2 (Jan 01, 2009)

sebastienros — Wed, 11 Nov 2009 17:06:56 GMT

BUG: Major issue corrected with precedence (again, thanks to Keze).
BUG: Use double values when using the / operator, in order to prevent percision loss

Created Release: NCalc - 1.3.2 (Jan 01, 2009)

sebastienros — Wed, 11 Nov 2009 17:06:31 GMT

BUG: Major issue corrected with precedence (again, thanks to Keze).
BUG: Use double values when using the / operator, in order to prevent percision loss

New Post: Parsing expressions not done correctly

keze — Wed, 11 Nov 2009 13:25:48 GMT

I guess there is a problem with gramar file.

Expression 18/2/2*3 is parsed like 18/(2/(2*3)) and not like ((18/2)/2)*3

Other problem i'm running to is when dividing two integers and the second one is less than first it returns 0 (also integer),

e.g. 3/6 = 0

Is it possible to return 0.5 (float)?

Closed Issue: Multiplication behavior [25202]

sebastienros — Tue, 03 Nov 2009 16:53:03 GMT

In version 1.3 of NCalc, the expression 2*2*2*2 produces the value 4. Is there a way to avoid this behavior other than 2*(2*(2*2))) ?
Comments:

THANK YOU !!!

Are you the only one to have tried this framework ;) I can't imagine such a bug, but actually it was there.

I have published the corrected version, i.e. NCalc 1.3.1

Updated Release: NCalc - 1.3.1 (nov. 03, 2009)

sebastienros — Tue, 03 Nov 2009 16:51:26 GMT

BUG: Major issue corrected with precedence. Could not imagine a so predictable issue to occur ! Shame on me. No test was checking it !!!

Released: NCalc - 1.3.1 (Nov 03, 2009)

Tue, 03 Nov 2009 16:51:26 GMT

BUG: Major issue corrected with precedence. Could not imagine a so predictable issue to occur ! Shame on me. No test was checking it !!!

Updated Release: NCalc - 1.3.1 (Jan 01, 2009)

sebastienros — Tue, 03 Nov 2009 16:50:38 GMT

BUG: Major issue corrected with precedence. Could not imagine a so predictable issue to occur ! Shame on me. No test was checking it !!!

Created Release: NCalc - 1.3.1 (Jan 01, 2009)

sebastienros — Tue, 03 Nov 2009 16:50:17 GMT

BUG: Major issue corrected with precedence. Could not imagine a so predictable issue to occur ! Shame on me. No test was checking it !!!

Created Issue: Multiplication behavior [25202]

wujonesj2 — Tue, 03 Nov 2009 15:36:01 GMT

In version 1.3 of NCalc, the expression 2*2*2*2 produces the value 4. Is there a way to avoid this behavior other than 2*(2*(2*2))) ?

Updated Wiki: operators

sebastienros — Tue, 27 Oct 2009 14:27:10 GMT

Operators

Expressions can be combined using operators. Each operator as a precedence priority. Here is the list of those expression's priority.

primary
unary
power
multiplicative
additive
relational
logical

Logical

These operators can do some logical comparison between other expressions:

or, ||
and, &&

  true or false and true

The and operator has more prioroty thand the or, thus in the example above, false and true is evaluated first.

Relational

=, ==, !=, <>
<, <=, >, >=

  1 < 2

Additive

+, -

  1 + 2 - 3

Multiplicative

*, /, %

 1 * 2 % 3

Bitwise

& (bitwise and), | (bitwise or), ^(bitwise xor), << (left shift), >>(right shift)

  2 >> 3

Unary

!, not, -, ~ (bitwise not)

  not true

Primary

(, )
values

  2 * ( 3 + 2 )

Updated Wiki: operators

sebastienros — Tue, 27 Oct 2009 14:26:52 GMT

Operators

Expressions can be combined using operators. Each operator as a precedence priority. Here is the list of those expression's priority.

primary
unary
power
multiplicative
additive
relational
logical

Logical

These operators can do some logical comparison between other expressions:

or, ||
and, &&

  true or false and true

The and operator has more prioroty thand the or, thus in the example above, false and true is evaluated first.

Relational

=, ==, !=, <>
<, <=, >, >=

  1 < 2

Additive

+, -

  1 + 2 - 3

Multiplicative

*, /, %

 1 * 2 % 3

Bitwise

& (bitwsie and), | (bitwise or), ^(bitwise xor), << (left shift), >>(right shift)

  2 >> 3

Unary

!, not, -, ~ (bitwise not)

  not true

Primary

(, )
values

  2 * ( 3 + 2 )

Updated Release: NCalc - 1.3.0 (oct. 27, 2009)

sebastienros — Tue, 27 Oct 2009 13:08:12 GMT

NEW: Bitwise operators (&, |, ^, ~, <<, >>).
BREAK: Removed power operator, use Pow(x,y) instead.

Released: NCalc - 1.3.0 (Oct 27, 2009)

Tue, 27 Oct 2009 13:08:12 GMT

NEW: Bitwise operators (&, |, ^, ~, <<, >>).
BREAK: Removed power operator, use Pow(x,y) instead.

Updated Release: NCalc - 1.3.0 (Jan 01, 2009)

sebastienros — Tue, 27 Oct 2009 13:06:49 GMT

NEW: Bitwise operators (&, |, ^, ~, <<, >>).
BREAK: Removed power operator, use Pow(x,y) instead.

Created Release: NCalc - 1.3.0 (Jan 01, 2009)

sebastienros — Tue, 27 Oct 2009 13:06:18 GMT

NEW: Bitwise operators (&, |, ^, ~, <<, >>).
BREAK: Removed power operator, use Pow(x,y) instead.

New Post: Call for feedback !

leeatkinson — Mon, 21 Sep 2009 11:05:52 GMT

But lets suppose I'm using this is a long-running system. The system needs to evaluate many different expressions. Some may be identical, but yet some may only be used once. If the cache does not have the ability to remove objects that have not been used, and keep the most regularly-used ones, then eventutally, the cache will use too much memory.

ASP.NET cache has the ability to mange this much better. You could right your own one with the same sophistication, but wouldn't it be better to program to an interface, and let the users to select the implementation (or write their own).

Lee