trotter 1.0.2

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Welcome to trotter, a Dart library that simplifies working with meta-arrangements commonly encountered in combinatorics such as arrangements of combinations and permutations.

trotter gives the developer access to pseudo-lists that "contain" an arrangement of all arrangements (combinations, permutations, etc.) of objects taken from a specified list of items.

The order of arrangements is based on the the order produced by the Steinhaus–Johnson–Trotter algorithm for ordering permutations, which has been generalized in this library to combinations and arrangements that allow for replacement after item selection.

The pseudo-list classes available are:

  • Combinations.
  • Permutations.
  • Compositions (combinations with replacement).
  • Amalgams (permutations with replacement).
  • Subsets (combinations of unspecified size).
  • Compounds (permutations of unspecified size).

Demo

Take a look at Falco Shapes, a trotter demo based on Marsha Falco's combinatorics game Set, that uses trotter to search through items for combinations with certain characteristics.

The basic classes

Combinations

A combination is a selection of items for which order is not important and items are not replaced after being selected.

The Combinations class defines a pseudo-list that "contains" an arrangement of all combinations of a set of items.

Example:

    List bagOfItems = characters("abcde");
    var combos = Combinations(3, bagOfItems);
    for (var combo in combos()) {
      print(combo);
    }

Output:


[a, b, c]
[a, b, d]
[a, b, e]
[a, c, d]
[a, c, e]
[a, d, e]
[b, c, d]
[b, c, e]
[b, d, e]
[c, d, e]

Permutations

A permutation is a selection of items for which order is important and items are not replaced after being selected.

The Permutations class defines a pseudo-list that "contains" an arrangement of all permutations of a set of items.

Example:

    List bagOfItems = characters("abcde");
    var perms = Permutations(3, bagOfItems);
    for (var perm in perms()) {
      print(perm);
    }

Output:


[a, b, c]
[a, c, b]
[c, a, b]
[c, b, a]
[b, c, a]
[b, a, c]
[a, b, d]
[a, d, b]
[d, a, b]
[d, b, a]
[b, d, a]
[b, a, d]
[a, b, e]
[a, e, b]
[e, a, b]
[e, b, a]
[b, e, a]
[b, a, e]
[a, c, d]
[a, d, c]
[d, a, c]
[d, c, a]
[c, d, a]
[c, a, d]
[a, c, e]
[a, e, c]
[e, a, c]
[e, c, a]
[c, e, a]
[c, a, e]
[a, d, e]
[a, e, d]
[e, a, d]
[e, d, a]
[d, e, a]
[d, a, e]
[b, c, d]
[b, d, c]
[d, b, c]
[d, c, b]
[c, d, b]
[c, b, d]
[b, c, e]
[b, e, c]
[e, b, c]
[e, c, b]
[c, e, b]
[c, b, e]
[b, d, e]
[b, e, d]
[e, b, d]
[e, d, b]
[d, e, b]
[d, b, e]
[c, d, e]
[c, e, d]
[e, c, d]
[e, d, c]
[d, e, c]
[d, c, e]

(Notice that this library arranges permutations similarly to the way the Steinhaus-Johnson-Trotter algorithm arranges permutations. In fact, if we get the permutations of all the specified items, e.g. var perms = Permutations(5, bagOfItems); in the above code, the arrangement of permutations is exactly what would have resulted from applying the S-J-T algorithm. The algorithms in this library have an advantage in that they do not iterate through all k - 1 permutations in order to determint the kth permutation, however.)

Compositions

A composition (or combination with replacement) is a selection of items for which order is not important and items are replaced after being selected.

The Compositions class defines a pseudo-list that "contains" an arrangement of all compositions of a set of items.

Here are all the compositions of three items taken from a bag of five items:

Example:

    List bagOfItems = characters("abcde");
    var comps = Compositions(3, bagOfItems);
    for (var comp in comps()) {
      print(comp);
    }

Output:


[a, a, a]
[a, a, b]
[a, a, c]
[a, a, d]
[a, a, e]
[a, b, b]
[a, b, c]
[a, b, d]
[a, b, e]
[a, c, c]
[a, c, d]
[a, c, e]
[a, d, d]
[a, d, e]
[a, e, e]
[b, b, b]
[b, b, c]
[b, b, d]
[b, b, e]
[b, c, c]
[b, c, d]
[b, c, e]
[b, d, d]
[b, d, e]
[b, e, e]
[c, c, c]
[c, c, d]
[c, c, e]
[c, d, d]
[c, d, e]
[c, e, e]
[d, d, d]
[d, d, e]
[d, e, e]
[e, e, e]

Amalgams

An amalgam (or permutation with replacement) is a selection of items for which order is important and items are replaced after being selected.

The Amalgams class defines a pseudo-list that "contains" an arrangement of all amalgams of a set of items.

Example:

    List bagOfItems = characters("abcde");
    var amals = Amalgams(3, bagOfItems);
    for (var amal in amals()) {
      print(amal);
    }

Output:


[a, a, a]
[a, a, b]
[a, a, c]
[a, a, d]
[a, a, e]
[a, b, a]
[a, b, b]
[a, b, c]
[a, b, d]
[a, b, e]
[a, c, a]
[a, c, b]
[a, c, c]
[a, c, d]
[a, c, e]
[a, d, a]
[a, d, b]
[a, d, c]
[a, d, d]
[a, d, e]
[a, e, a]
[a, e, b]
[a, e, c]
[a, e, d]
[a, e, e]
[b, a, a]
[b, a, b]
[b, a, c]
[b, a, d]
[b, a, e]
[b, b, a]
[b, b, b]
[b, b, c]
[b, b, d]
[b, b, e]
[b, c, a]
[b, c, b]
[b, c, c]
[b, c, d]
[b, c, e]
[b, d, a]
[b, d, b]
[b, d, c]
[b, d, d]
[b, d, e]
[b, e, a]
[b, e, b]
[b, e, c]
[b, e, d]
[b, e, e]
[c, a, a]
[c, a, b]
[c, a, c]
[c, a, d]
[c, a, e]
[c, b, a]
[c, b, b]
[c, b, c]
[c, b, d]
[c, b, e]
[c, c, a]
[c, c, b]
[c, c, c]
[c, c, d]
[c, c, e]
[c, d, a]
[c, d, b]
[c, d, c]
[c, d, d]
[c, d, e]
[c, e, a]
[c, e, b]
[c, e, c]
[c, e, d]
[c, e, e]
[d, a, a]
[d, a, b]
[d, a, c]
[d, a, d]
[d, a, e]
[d, b, a]
[d, b, b]
[d, b, c]
[d, b, d]
[d, b, e]
[d, c, a]
[d, c, b]
[d, c, c]
[d, c, d]
[d, c, e]
[d, d, a]
[d, d, b]
[d, d, c]
[d, d, d]
[d, d, e]
[d, e, a]
[d, e, b]
[d, e, c]
[d, e, d]
[d, e, e]
[e, a, a]
[e, a, b]
[e, a, c]
[e, a, d]
[e, a, e]
[e, b, a]
[e, b, b]
[e, b, c]
[e, b, d]
[e, b, e]
[e, c, a]
[e, c, b]
[e, c, c]
[e, c, d]
[e, c, e]
[e, d, a]
[e, d, b]
[e, d, c]
[e, d, d]
[e, d, e]
[e, e, a]
[e, e, b]
[e, e, c]
[e, e, d]
[e, e, e]

Subsets

A subset (or combination of unspecified length) is a selection of items for which order is not important, items are not replaced and the number of items is not specified.

The Subsets class defines a pseudo-list that "contains" an arrangement of all subsets of a set of items.

Example:

    List bagOfItems = characters("abcde");
    var subs = Subsets(bagOfItems);
    for (var sub in subs()) {
      print(sub);
    }

Output:


[]
[a]
[b]
[a, b]
[c]
[a, c]
[b, c]
[a, b, c]
[d]
[a, d]
[b, d]
[a, b, d]
[c, d]
[a, c, d]
[b, c, d]
[a, b, c, d]
[e]
[a, e]
[b, e]
[a, b, e]
[c, e]
[a, c, e]
[b, c, e]
[a, b, c, e]
[d, e]
[a, d, e]
[b, d, e]
[a, b, d, e]
[c, d, e]
[a, c, d, e]
[b, c, d, e]
[a, b, c, d, e]

Compounds

A compound (or permutation of unspecified length) is a selection of items for which order is important, items are not replaced and the number of items is not specified.

The Compounds class defines a pseudo-list that "contains" an arrangement of all compounds of a set of items.

Example:

    List bagOfItems = characters("abcde");
    var comps = Compounds(bagOfItems);
    for (var comp in comps()) {
      print(comp);
    }

Output:


[]
[a]
[b]
[c]
[d]
[e]
[a, b]
[b, a]
[a, c]
[c, a]
[a, d]
[d, a]
[a, e]
[e, a]
[b, c]
[c, b]
[b, d]
[d, b]
[b, e]
[e, b]
[c, d]
[d, c]
[c, e]
[e, c]
[d, e]
[e, d]
[a, b, c]
[a, c, b]
[c, a, b]
[c, b, a]
[b, c, a]
[b, a, c]
[a, b, d]
[a, d, b]
[d, a, b]
[d, b, a]
[b, d, a]
[b, a, d]
[a, b, e]
[a, e, b]
[e, a, b]
[e, b, a]
[b, e, a]
[b, a, e]
[a, c, d]
[a, d, c]
[d, a, c]
[d, c, a]
[c, d, a]
[c, a, d]
[a, c, e]
[a, e, c]
[e, a, c]
[e, c, a]
[c, e, a]
[c, a, e]
[a, d, e]
[a, e, d]
[e, a, d]
[e, d, a]
[d, e, a]
[d, a, e]
[b, c, d]
[b, d, c]
[d, b, c]
[d, c, b]
[c, d, b]
[c, b, d]
[b, c, e]
[b, e, c]
[e, b, c]
[e, c, b]
[c, e, b]
[c, b, e]
[b, d, e]
[b, e, d]
[e, b, d]
[e, d, b]
[d, e, b]
[d, b, e]
[c, d, e]
[c, e, d]
[e, c, d]
[e, d, c]
[d, e, c]
[d, c, e]
[a, b, c, d]
[a, b, d, c]
[a, d, b, c]
[d, a, b, c]
[d, a, c, b]
[a, d, c, b]
[a, c, d, b]
[a, c, b, d]
[c, a, b, d]
[c, a, d, b]
[c, d, a, b]
[d, c, a, b]
[d, c, b, a]
[c, d, b, a]
[c, b, d, a]
[c, b, a, d]
[b, c, a, d]
[b, c, d, a]
[b, d, c, a]
[d, b, c, a]
[d, b, a, c]
[b, d, a, c]
[b, a, d, c]
[b, a, c, d]
[a, b, c, e]
[a, b, e, c]
[a, e, b, c]
[e, a, b, c]
[e, a, c, b]
[a, e, c, b]
[a, c, e, b]
[a, c, b, e]
[c, a, b, e]
[c, a, e, b]
[c, e, a, b]
[e, c, a, b]
[e, c, b, a]
[c, e, b, a]
[c, b, e, a]
[c, b, a, e]
[b, c, a, e]
[b, c, e, a]
[b, e, c, a]
[e, b, c, a]
[e, b, a, c]
[b, e, a, c]
[b, a, e, c]
[b, a, c, e]
[a, b, d, e]
[a, b, e, d]
[a, e, b, d]
[e, a, b, d]
[e, a, d, b]
[a, e, d, b]
[a, d, e, b]
[a, d, b, e]
[d, a, b, e]
[d, a, e, b]
[d, e, a, b]
[e, d, a, b]
[e, d, b, a]
[d, e, b, a]
[d, b, e, a]
[d, b, a, e]
[b, d, a, e]
[b, d, e, a]
[b, e, d, a]
[e, b, d, a]
[e, b, a, d]
[b, e, a, d]
[b, a, e, d]
[b, a, d, e]
[a, c, d, e]
[a, c, e, d]
[a, e, c, d]
[e, a, c, d]
[e, a, d, c]
[a, e, d, c]
[a, d, e, c]
[a, d, c, e]
[d, a, c, e]
[d, a, e, c]
[d, e, a, c]
[e, d, a, c]
[e, d, c, a]
[d, e, c, a]
[d, c, e, a]
[d, c, a, e]
[c, d, a, e]
[c, d, e, a]
[c, e, d, a]
[e, c, d, a]
[e, c, a, d]
[c, e, a, d]
[c, a, e, d]
[c, a, d, e]
[b, c, d, e]
[b, c, e, d]
[b, e, c, d]
[e, b, c, d]
[e, b, d, c]
[b, e, d, c]
[b, d, e, c]
[b, d, c, e]
[d, b, c, e]
[d, b, e, c]
[d, e, b, c]
[e, d, b, c]
[e, d, c, b]
[d, e, c, b]
[d, c, e, b]
[d, c, b, e]
[c, d, b, e]
[c, d, e, b]
[c, e, d, b]
[e, c, d, b]
[e, c, b, d]
[c, e, b, d]
[c, b, e, d]
[c, b, d, e]
[a, b, c, d, e]
[a, b, c, e, d]
[a, b, e, c, d]
[a, e, b, c, d]
[e, a, b, c, d]
[e, a, b, d, c]
[a, e, b, d, c]
[a, b, e, d, c]
[a, b, d, e, c]
[a, b, d, c, e]
[a, d, b, c, e]
[a, d, b, e, c]
[a, d, e, b, c]
[a, e, d, b, c]
[e, a, d, b, c]
[e, d, a, b, c]
[d, e, a, b, c]
[d, a, e, b, c]
[d, a, b, e, c]
[d, a, b, c, e]
[d, a, c, b, e]
[d, a, c, e, b]
[d, a, e, c, b]
[d, e, a, c, b]
[e, d, a, c, b]
[e, a, d, c, b]
[a, e, d, c, b]
[a, d, e, c, b]
[a, d, c, e, b]
[a, d, c, b, e]
[a, c, d, b, e]
[a, c, d, e, b]
[a, c, e, d, b]
[a, e, c, d, b]
[e, a, c, d, b]
[e, a, c, b, d]
[a, e, c, b, d]
[a, c, e, b, d]
[a, c, b, e, d]
[a, c, b, d, e]
[c, a, b, d, e]
[c, a, b, e, d]
[c, a, e, b, d]
[c, e, a, b, d]
[e, c, a, b, d]
[e, c, a, d, b]
[c, e, a, d, b]
[c, a, e, d, b]
[c, a, d, e, b]
[c, a, d, b, e]
[c, d, a, b, e]
[c, d, a, e, b]
[c, d, e, a, b]
[c, e, d, a, b]
[e, c, d, a, b]
[e, d, c, a, b]
[d, e, c, a, b]
[d, c, e, a, b]
[d, c, a, e, b]
[d, c, a, b, e]
[d, c, b, a, e]
[d, c, b, e, a]
[d, c, e, b, a]
[d, e, c, b, a]
[e, d, c, b, a]
[e, c, d, b, a]
[c, e, d, b, a]
[c, d, e, b, a]
[c, d, b, e, a]
[c, d, b, a, e]
[c, b, d, a, e]
[c, b, d, e, a]
[c, b, e, d, a]
[c, e, b, d, a]
[e, c, b, d, a]
[e, c, b, a, d]
[c, e, b, a, d]
[c, b, e, a, d]
[c, b, a, e, d]
[c, b, a, d, e]
[b, c, a, d, e]
[b, c, a, e, d]
[b, c, e, a, d]
[b, e, c, a, d]
[e, b, c, a, d]
[e, b, c, d, a]
[b, e, c, d, a]
[b, c, e, d, a]
[b, c, d, e, a]
[b, c, d, a, e]
[b, d, c, a, e]
[b, d, c, e, a]
[b, d, e, c, a]
[b, e, d, c, a]
[e, b, d, c, a]
[e, d, b, c, a]
[d, e, b, c, a]
[d, b, e, c, a]
[d, b, c, e, a]
[d, b, c, a, e]
[d, b, a, c, e]
[d, b, a, e, c]
[d, b, e, a, c]
[d, e, b, a, c]
[e, d, b, a, c]
[e, b, d, a, c]
[b, e, d, a, c]
[b, d, e, a, c]
[b, d, a, e, c]
[b, d, a, c, e]
[b, a, d, c, e]
[b, a, d, e, c]
[b, a, e, d, c]
[b, e, a, d, c]
[e, b, a, d, c]
[e, b, a, c, d]
[b, e, a, c, d]
[b, a, e, c, d]
[b, a, c, e, d]
[b, a, c, d, e]

Large indices

Arrangement numbers often grow very quickly. For example, consider the number of 10-permutations of the letters of the alphabet:

Example:

    List largeBagOfItems = characters("abcdefghijklmnopqrstuvwxyz");
    var perms = Permutations(10, largeBagOfItems);
    print(perms);

Output:


Pseudo-list containing all 19275223968000 10-permutations of items from [a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z].

Wow! That's a lot of permutations! It's most likely a bad idea to iterate over them all!

Notice that the word algorithms is a 10-permutation of the letters of the alphabet. What is the index of this permutation in our list of permutations?

Example:

    List largeBagOfItems = characters("abcdefghijklmnopqrstuvwxyz");
    var perms = Permutations(10, largeBagOfItems);
    List permutationOfInterest = characters("algorithms");
    BigInt index = perms.indexOf(permutationOfInterest);
    print("The index of $permutationOfInterest is $index.");
    print("perms[$index]: ${perms[index]}");

Output:


The index of [a, l, g, o, r, i, t, h, m, s] is 6831894769563.
perms[6831894769563]: [a, l, g, o, r, i, t, h, m, s]

Wow! That's almost seven trillion! Luckily we didn't need to perform that search using brute force!

Be aware that we sometimes can be working with indexes so large that they cannot be represented using Dart's 64 bit int, in which case we need to use BigInt objects.

Example:

    var largeBagOfItems = characters("abcdefghijklmnopqrstuvwxyz");
    var comps = Compounds(largeBagOfItems);
    print("There are ${comps.length} compounds of these letters!");
    BigInt lastCompoundIndex = comps.length - BigInt.one;
    print("The last compound is ${comps[lastCompoundIndex]}.");

Output:


There are 1096259850353149530222034277 compounds of these letters!
The last compound is [b, a, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z].

Unless you're immortal, don't try to use comps().last to access the last compound in the previous example!

trotter in Dart 2

In Dart 1, at least on the Dart VM, int instances could be used to represent arbitrary precision integers, and the classes above could conveniently extend ListBase, which made the analogy with a list of arrangements very strong. As of Dart 2, int instances can only be used to represent up to 64 bit integers. Although Dart 2 does provide the BigInt class for dealing with very large integers, BigInt instances cannot be used to index List instances, and the classes above had to drop the extension.

The first version of trotter that can be used for large structures in Dart 2 is trotter 0.9.5. In general, only slight modifications need be made to code written for previous versions. Here are some examples.

Instances are no longer iterable

Instances are no longer iterable, list-like structures. An Iterable "containing" all the arrangements is available through directly calling the instance, calling the range method or accessing the iterable property, however.

trotter < 0.9.5

var combos = Combinations(3, characters("abcde"));
for (var combo in combos) { // combos is iterable
...
}

trotter >= 0.9.5

var combos = Combinations(3, characters("abcde"));
for (var combo in combos()) { // combos is callable, returns an iterable
...
}

Filters, mappings and other tasks associated with Iterable instances can no longer be applied directly to instances of the classes above, but can, of course be applied to the Iterable returned by direct calling, the range method or the iterable property.

Example:

    var items = characters("abc");
    var subsets = Subsets(items);
    print(subsets().where((subset) => subset.length == 2).join(" "));

Output:


[a, b] [a, c] [b, c]

The Selections class has been renamed

In combinatorics literature the term selection is often used as a generic word that can refer to permutations or combinations in different contexts. The use of the term for combinations with replacement could thus be confusing. As of trotter 0.9.5, the class Compositions is used to represent combinations. I feel that composition is a fitting word: if a body is composed of items A, B and C then it is also composed of C, B and A, so composition suggests that order is not important. Further a body can be composed of two parts of A to one part of B, which suggests that items are replaced after being selected.

trotter was written by Richard Ambler.

Thanks for your interest in this library. Please file any bugs, issues and suggestions here.

Change log

1.0.2

  • Cleaned up the type declaration for the iterables.
  • Link to Falco-shapes demo.

1.0.1

Made the abstract, parent class Combinatorics visible to the user for those cases in which the combinatorics type is not known at the time of declaration.

1.0.0

  • Cleaned up code to be more in line with Dart 2.
  • Added example.dart (and an example output, fun-with-mastermind.md) to example/.

0.9.5

  • As of Dart 2, int instances represent 64 bit, as opposed to arbitrary length, integers. Since trotter often works with very large integers, it needed an overhaul so as to incorporate the BigInt class. This resulted in several breaking changes, most notably that the base _Combinatoric class no longer extends ListBase. I have made the class instances callable, however, to address this: code that needs an instance of one of the classes to behave like an iterable just need to call the instance. For example, if perms is an instance of Permutations, we would now use something like for (var p in perms()) (as opposed to for (var p in perms), which worked in previous versions). The instances can still be thought of as pseudo-lists in that they can be indexed and have several properties and methods that might be expected in a list, such as length and indexOf.

  • I took advantage of the necessity of making breaking changes mentioned above to make one more: I have renamed the Selections class Compositions. In combinatorics literature, the term selection is often use as a generic word to mean either combination or permutation. This might have caused confusion in the way I had used the term in previous versions of the library. I think that composition is more appropriate to mean a selection in which order is not important (if a body is composed of materials A, B and C then it is also composed of materials C, B and A) and items are "replaced" (it makes sense to say that a body is composed of two parts A to one part B, for example).

0.9.1

  • Fixed an error introduced during the changes made for 0.9.0.

0.9.0

  • Cleaned up and simplified the code so that the structures extend Lists more naturally. (Structures extend ListBase now instead of Iterable.)
  • Should be backwards compatible in that code that works in previous versions should also work in this version.
  • Structures should now behave better with List methods like map, where, every and so on.

0.8.5

  • Cleaned up the code so that the library may be used in strong mode.
  • Added subset of the functionality associated with Iterables (first, last, any, every, forEach etc.). Some functionality that would be redundant (e.g. isEmpty) or less meaningful/useful (e.g. fold) neglected. Since structures we can represent can "contain" a huge number of arrangements, we need to be careful about using methods that iterate over the structures (like any, every, forEach).

0.8.1

  • Added the Compounds class (permutations of unspecified size).
  • Added the contains method for all classes.
  • Corrected indexOf behaviour for when arrangements that don't exist are passed as arguments; returns -1 if the arrangement is not in the pseudo-list.

0.8.0

  • Added inverses to all the functions so that we can look up arrangements non iteratively (now possible to look up values in arbitrarily large pseudo-lists; this library was incomplete without this functionality!).
  • Made the code more readable. Made a few minor tweaks to the existing code.

0.5.1

Improved the documentation; minor bug fixes.

0.5.0

First Dart release: support for classes:

  • Permutations
  • Combinations
  • Amalgams (permutations with replacement during arranging)
  • Selections (combinations with replacement during arranging)
  • Subsets

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:


dependencies:
  trotter: ^1.0.2

2. Install it

You can install packages from the command line:

with pub:


$ pub get

with Flutter:


$ flutter packages get

Alternatively, your editor might support pub get or flutter packages get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:


import 'package:trotter/trotter.dart';
  
Version Uploaded Documentation Archive
1.0.2 Aug 10, 2018 Go to the documentation of trotter 1.0.2 Download trotter 1.0.2 archive
1.0.1 Aug 8, 2018 Go to the documentation of trotter 1.0.1 Download trotter 1.0.1 archive
1.0.0 Aug 3, 2018 Go to the documentation of trotter 1.0.0 Download trotter 1.0.0 archive
0.9.5 May 7, 2018 Go to the documentation of trotter 0.9.5 Download trotter 0.9.5 archive
0.9.1 Dec 10, 2017 Go to the documentation of trotter 0.9.1 Download trotter 0.9.1 archive
0.9.0 Dec 7, 2017 Go to the documentation of trotter 0.9.0 Download trotter 0.9.0 archive
0.8.5 Jan 13, 2017 Go to the documentation of trotter 0.8.5 Download trotter 0.8.5 archive
0.8.1 Feb 10, 2016 Go to the documentation of trotter 0.8.1 Download trotter 0.8.1 archive
0.8.0 Feb 8, 2016 Go to the documentation of trotter 0.8.0 Download trotter 0.8.0 archive
0.5.2 Nov 26, 2014 Go to the documentation of trotter 0.5.2 Download trotter 0.5.2 archive

All 12 versions...

Popularity:
Describes how popular the package is relative to other packages. [more]
70
Health:
Code health derived from static analysis. [more]
100
Maintenance:
Reflects how tidy and up-to-date the package is. [more]
100
Overall:
Weighted score of the above. [more]
85
Learn more about scoring.

We analyzed this package on Aug 10, 2018, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.0.0
  • pana: 0.11.8

Platforms

Detected platforms: Flutter, web, other

No platform restriction found in primary library package:trotter/trotter.dart.

Suggestions

Maintain an example.

None of the files in your example/ directory matches a known example patterns. Common file name patterns include: main.dart, example.dart or you could also use trotter.dart.

Dependencies

Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.0.0 <3.0.0