Chemical calculator: Difference between revisions

{{draft task}}

 

 

;Introduction

* An atom name consists of one upper-case letter followed by zero, one or two lower-case letters.

* The number of atoms is stated behind the atom or atom group

 

 

;Background

 

 

 

 

 

;Examples:

 

 

=={{header|CoffeeScript}}==

===No Regular Expression===

 

molar_mass = (s) ->

assert 176.124, molar_mass 'C6H4O2(OH)4' # Vitamin C

assert 386.664, molar_mass 'C27H46O' # Cholesterol

 

===Regular Expression===

{{trans|Julia}}

 

mul = (match, p1, offset, string) -> '*' + p1

assert 176.124, molar_mass('C6H4O2(OH)4') # Vitamin C

assert 386.664, molar_mass('C27H46O') # Cholesterol

 

=={{header|Factor}}==

{{works with|Factor|0.98}}

infix.private kernel math.functions math.parser multiline

peg.ebnf qw sequences splitting strings words words.constant ;

} [ molar-mass 1e-5 approx-assert= ] assoc-each ;

 

 

No assertion errors.

 

=={{header|Go}}==

This doesn't use regular expressions, RPN or eval (which Go doesn't have). It's just a simple molar mass evaluator written from scratch.

 

import (

fmt.Printf("%17s -> %7.3f\n", molecule, mass)

}

 

{{out}}

C27H46O -> 386.664

Uue -> 315.000

</pre>

 

=={{header|Julia}}==

Note that Julia's 64-bit floating point gets a slightly different result for one of the assertions, hence a small change in the last example. The function uses Julia's own language parser to evaluate the compound as an arithmetic expression.

const He = 4.002602

const Li = 6.94

@assert 84.162 == molar_mass("C6H12")

@assert 186.29500000000002 == molar_mass("COOH(C(CH3)2)3CH3")

No assertion errors.

 

=={{header|Nim}}==

 

 

import tables, strutils, sequtils, math

while stack.len > 0: result.add stack.pop()

 

let rpn: seq[string] = pass2 s

var stack: seq[Table[string,int]] = @[]

return stack.pop()

 

let atoms: Table[string,int] = pass3 s

for key in atoms.keys:

assert 176.124 == molar_mass "C6H4O2(OH)4" # Vitamin C

assert 386.664 == molar_mass "C27H46O" # Cholesterol

=={{header|Perl}}==

use warnings;

use List::Util;

 

for (<H H2 H2O Na2SO4 C6H12 COOH(C(CH3)2)3CH3>) {

{{out}}

 

H => 1.008 , Fe => 55.845 , Te => 127.60 , Ir => 192.217 ,

He => 4.002602 , Co => 58.933194 , I => 126.90447 , Pt => 195.084 ,

return $/.made.[0];

}

{{Out}}

<pre> 1.008 H

84.162 C6H12

186.295 COOH(C(CH3)2)3CH3</pre>