Updated documentation for sets

db4
Daniel Ehrenberg 2010-02-27 00:27:40 -05:00
parent 7cd3360cdd
commit 7ad324837b
6 changed files with 148 additions and 71 deletions

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@ -0,0 +1,18 @@
USING: help.markup help.syntax sequences math ;
IN: bit-sets
ARTICLE: "bit-sets" "Bit sets"
"The " { $vocab-link "bit-sets" } " vocabulary implements bit-array-backed sets. Bitsets are efficient for implementing relatively dense sets whose members are in a contiguous range of integers starting from 0. One bit is required for each integer in this range in the underlying representation."
"Bit sets are of the class"
{ $subsection bit-set }
"They can be instantiated with the word"
{ $subsection <bit-set> } ;
ABOUT: "bit-sets"
HELP: bit-set
{ $class-description "The class of bit-array-based sets. These implement the " { $link "sets" } "." } ;
HELP: <bit-set>
{ $values { "capacity" integer } { "bit-set" bit-set } }
{ $description "Creates a new bit set with the given capacity. This set is initially empty and can contain as members integers between 0 and " { $snippet "capacity" } "-1." } ;

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@ -166,6 +166,7 @@ ARTICLE: "collections" "Collections"
}
{ $heading "Other collections" }
{ $subsections
"sets"
"lists"
"disjoint-sets"
"interval-maps"

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@ -0,0 +1,18 @@
USING: help.markup help.syntax sequences ;
IN: hash-sets
ARTICLE: "hash-sets" "Hash sets"
"The " { $vocab-link "hash-sets" } " vocabulary implements hashtable-backed sets. These are of the class:"
{ $subsection hash-set }
"They can be instantiated with the word"
{ $subsection <hash-set> }
"The syntax for hash sets is described in " { $link "syntax-hash-sets" } "." ;
ABOUT: "hash-sets"
HELP: hash-set
{ $class-description "The class of hashtable-based sets. These implement the " { $link "sets" } "." } ;
HELP: <hash-set>
{ $values { "members" sequence } { "hash-set" hash-set } }
{ $description "Creates a new hash set with the given members." } ;

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@ -1,42 +1,71 @@
USING: assocs hashtables help.markup help.syntax kernel
quotations sequences ;
quotations sequences vectors ;
IN: sets
ARTICLE: "sets" "Set-theoretic operations on sequences"
"Set-theoretic operations on sequences are defined on the " { $vocab-link "sets" } " vocabulary. All of these operations use hashtables internally to achieve linear running time."
$nl
"Remove duplicates:"
{ $subsections prune }
"Test for duplicates:"
ARTICLE: "sets" "Sets"
"A set is an unordered list of elements. Words for working with sets are in the " { $vocab-link "sets" } " vocabulary."
"All sets are instances of a mixin class:"
{ $subsections
all-unique?
duplicates
set
set?
}
"Set operations on sequences:"
{ $subsections "set-operations" "set-implementations" } ;
ABOUT: "sets"
ARTICLE: "set-operations" "Operations on sets"
"To test if an object is a member of a set:"
{ $subsection member? }
"All sets can be represented as a sequence, without duplicates, of their members:"
{ $subsection members }
"Sets can have members added or removed destructively:"
{ $subsections
adjoin
delete
}
"Basic mathematical operations, which any type of set may override for efficiency:"
{ $subsections
diff
intersect
union
}
"Set-theoretic predicates:"
"Mathematical predicates on sets, which may be overridden for efficiency:"
{ $subsections
intersects?
subset?
set=
}
"A word used to implement the above:"
{ $subsections unique }
"Adding elements to sets:"
"An optional generic word for creating sets of the same class as a given set:"
{ $subsection set-like }
"An optional generic word for creating a set with a fast lookup operation, if the set itself has a slow lookup operation:"
{ $subsection fast-set }
"For set types that allow duplicates, like sequence sets, some additional words test for duplication:"
{ $subsections
adjoin
}
{ $see-also member? member-eq? any? all? "assocs-sets" } ;
all-unique?
duplicates
} ;
ABOUT: "sets"
ARTICLE: "set-implementations" "Set implementations"
"There are several implementations of sets in the Factor library. More can be added if they implement the words of the set protocol, the basic set operations."
{ $subsections
"sequence-sets"
"hash-sets"
"bit-sets"
} ;
ARTICLE: "sequence-sets" "Sequences as sets"
"Any sequence can be used as a set. The members of this set are the elements of the sequence. Calling the word " { $link members } " on a sequence returns a copy of the sequence with only one listing of each member. Destructive operations " { $link adjoin } " and " { $link delete } " only work properly on growable sequences like " { $link vector } "s."
$nl
"Care must be taken in writing efficient code using sequence sets. Testing for membership with " { $link in? } ", as well as the destructive set operations, take time proportional to the size of the sequence. Another representation, like " { $link "hash-sets" } ", would take constant time for membership tests. But binary operations like " { $link union } "are asymptotically optimal, taking time proportional to the sum of the size of the inputs."
$nl
"As one particlar example, " { $link POSTPONE: f } " is a representation of the empty set, as it represents the empty sequence." ;
HELP: set
{ $class-description "The class of all sets. Custom implementations of the set protocol should be declared as instances of this mixin for all set implementation to work correctly." } ;
HELP: adjoin
{ $values { "elt" object } { "seq" "a resizable mutable sequence" } }
{ $description "Removes all elements equal to " { $snippet "elt" } ", and adds " { $snippet "elt" } " at the end of the sequence." }
{ $values { "elt" object } { "set" set } }
{ $description "Destructively adds " { $snippet "elt" } " to " { $snippet "set" } ". For sequences, this guarantees that this element is not duplicated, and that it is at the end of the sequence." $nl "Each mutable set type is expected to implement a method on this generic word." }
{ $examples
{ $example
"USING: namespaces prettyprint sets ;"
@ -47,48 +76,36 @@ HELP: adjoin
"V{ \"beans\" \"cheese\" \"nachos\" \"salsa\" }"
}
}
{ $side-effects "seq" } ;
{ $side-effects "set" } ;
HELP: conjoin
{ $values { "elt" object } { "assoc" assoc } }
{ $description "Stores a key/value pair, both equal to " { $snippet "elt" } ", into the assoc." }
{ $examples
{ $example
"USING: kernel prettyprint sets ;"
"H{ } clone 1 over conjoin ."
"H{ { 1 1 } }"
}
}
HELP: delete
{ $values { "elt" object } { "set" set } }
{ $description "Destructively removes " { $snippet "elt" } " from " { $snippet "set" } ". If the element is not present, this does nothing." $nl "Each mutable set type is expected to implement a method on this generic word." }
{ $side-effects "set" } ;
HELP: members
{ $values { "set" set } { "seq" sequence } }
{ $description "Creates a sequence with a single copy of each member of the set." $nl "Each set type is expected to implement a method on this generic word." } ;
HELP: in?
{ $values { "elt" object } { "set" set } { "?" "a boolean" } }
{ $description "Tests whether the element is a member of the set." $nl "Each set type is expected to implement a method on this generic word as part of the set protocol." } ;
HELP: adjoin-at
{ $values { "value" object } { "key" object } { "assoc" assoc } }
{ $description "Adds " { $snippet "value" } " to the set stored at " { $snippet "key" } " of " { $snippet "assoc" } "." }
{ $side-effects "assoc" } ;
HELP: conjoin-at
{ $values { "value" object } { "key" object } { "assoc" assoc } }
{ $description "Adds " { $snippet "value" } " to the set stored at " { $snippet "key" } " of " { $snippet "assoc" } "." } ;
HELP: unique
{ $values { "seq" "a sequence" } { "assoc" assoc } }
{ $description "Outputs a new assoc where the keys and values are equal." }
{ $examples
{ $example "USING: sets prettyprint ;" "{ 1 1 2 2 3 3 } unique ." "H{ { 1 1 } { 2 2 } { 3 3 } }" }
} ;
HELP: prune
{ $values { "seq" "a sequence" } { "newseq" "a sequence" } }
{ $description "Outputs a new sequence with each distinct element of " { $snippet "seq" } " appearing only once. Elements are compared for equality using " { $link = } " and elements are ordered according to their position in " { $snippet "seq" } "." }
{ $examples
{ $example "USING: sets prettyprint ;" "{ 1 1 t 3 t } prune ." "V{ 1 t 3 }" }
} ;
HELP: duplicates
{ $values { "seq" "a sequence" } { "newseq" "a sequence" } }
{ $description "Outputs a new sequence consisting of elements which occur more than once in " { $snippet "seq" } "." }
{ $values { "set" set } { "seq" sequence } }
{ $description "Outputs a sequence consisting of elements which occur more than once in " { $snippet "set" } "." }
{ $examples
{ $example "USING: sets prettyprint ;" "{ 1 2 3 1 2 1 } duplicates ." "{ 1 2 1 }" }
{ $example "USING: sets prettyprint ;" "{ 1 2 3 1 2 1 } duplicates ." "{ 2 1 2 1 }" }
} ;
HELP: all-unique?
{ $values { "seq" sequence } { "?" "a boolean" } }
{ $description "Tests whether a sequence contains any repeated elements." }
{ $values { "set" set } { "?" "a boolean" } }
{ $description "Tests whether a set contains any repeated elements." }
{ $example
"USING: sets prettyprint ;"
"{ 0 1 1 2 3 5 } all-unique? ."
@ -96,41 +113,44 @@ HELP: all-unique?
} ;
HELP: diff
{ $values { "seq1" sequence } { "seq2" sequence } { "newseq" sequence } }
{ $description "Outputs a sequence consisting of elements present in " { $snippet "seq1" } " but not " { $snippet "seq2" } ", comparing elements for equality."
{ $values { "set1" set } { "set2" set } { "set" set } }
{ $description "Outputs a set consisting of elements present in " { $snippet "set1" } " but not " { $snippet "set2" } ", comparing elements for equality."
"This word has a default definition which works for all sets, but set implementations may override the default for efficiency."
} { $examples
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } diff ." "{ 1 }" }
} ;
HELP: intersect
{ $values { "seq1" sequence } { "seq2" sequence } { "newseq" sequence } }
{ $description "Outputs a sequence consisting of elements present in both " { $snippet "seq1" } " and " { $snippet "seq2" } "." }
{ $values { "set1" set } { "set2" set } { "set" set } }
{ $description "Outputs a set consisting of elements present in both " { $snippet "set1" } " and " { $snippet "set2" } "."
"This word has a default definition which works for all sets, but set implementations may override the default for efficiency." }
{ $examples
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } intersect ." "{ 2 3 }" }
} ;
HELP: union
{ $values { "seq1" sequence } { "seq2" sequence } { "newseq" sequence } }
{ $description "Outputs a sequence consisting of elements present in " { $snippet "seq1" } " and " { $snippet "seq2" } " which does not contain duplicate values." }
{ $values { "set1" set } { "set2" set } { "set" set } }
{ $description "Outputs a set consisting of elements present in either " { $snippet "set1" } " or " { $snippet "set2" } " which does not contain duplicate values."
"This word has a default definition which works for all sets, but set implementations may override the default for efficiency." }
{ $examples
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } union ." "V{ 1 2 3 4 }" }
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } union ." "{ 1 2 3 4 }" }
} ;
{ diff intersect union } related-words
HELP: intersects?
{ $values { "seq1" sequence } { "seq2" sequence } { "?" "a boolean" } }
{ $description "Tests if " { $snippet "seq1" } " and " { $snippet "seq2" } " have any elements in common." }
{ $notes "If one of the sequences is empty, the result is always " { $link f } "." } ;
{ $values { "set1" set } { "set2" set } { "?" "a boolean" } }
{ $description "Tests if " { $snippet "set1" } " and " { $snippet "set2" } " have any elements in common." }
{ $notes "If one of the sets is empty, the result is always " { $link f } "." } ;
HELP: subset?
{ $values { "seq1" sequence } { "seq2" sequence } { "?" "a boolean" } }
{ $description "Tests if every element of " { $snippet "seq1" } " is contained in " { $snippet "seq2" } "." }
{ $notes "If " { $snippet "seq1" } " is empty, the result is always " { $link t } "." } ;
{ $values { "set1" set } { "set2" set } { "?" "a boolean" } }
{ $description "Tests if every element of " { $snippet "set1" } " is contained in " { $snippet "set2" } "." }
{ $notes "If " { $snippet "set1" } " is empty, the result is always " { $link t } "." } ;
HELP: set=
{ $values { "seq1" sequence } { "seq2" sequence } { "?" "a boolean" } }
{ $description "Tests if both sequences contain the same elements, disregrading order and duplicates." } ;
{ $values { "set1" set } { "set2" set } { "?" "a boolean" } }
{ $description "Tests if both sets contain the same elements, disregrading order and duplicates." } ;
HELP: gather
{ $values
@ -138,3 +158,10 @@ HELP: gather
{ "newseq" sequence } }
{ $description "Maps a quotation onto a sequence, concatenates the results of the mapping, and removes duplicates." } ;
HELP: set-like
{ $values { "set" set } { "exemplar" set } { "set'" set } }
{ $description "If the conversion is defined for the exemplar, converts the set into a set of the exemplar's class. This is not guaranteed to create a new set, for example if the input set and exemplar are of the same class." $nl
"Set implementations may optionally implement a method on this generic word. The default implementation returns its input set." }
{ $examples
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } HS{ } set-like ." "HS{ 1 2 3 }" }
} ;

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@ -18,12 +18,14 @@ GENERIC: intersects? ( set1 set2 -- ? )
GENERIC: diff ( set1 set2 -- set )
GENERIC: subset? ( set1 set2 -- ? )
GENERIC: set= ( set1 set2 -- ? )
GENERIC: duplicates ( set -- sequence )
GENERIC: duplicates ( set -- seq )
GENERIC: all-unique? ( set -- ? )
! Defaults for some methods.
! Override them for efficiency
M: set set-like drop ; inline
M: set union
[ [ members ] bi@ append ] keep set-like ;

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@ -189,6 +189,10 @@ ARTICLE: "syntax-hashtables" "Hashtable syntax"
{ $subsections POSTPONE: H{ }
"Hashtables are documented in " { $link "hashtables" } "." ;
ARTICLE: "syntax-hash-sets" "Hash set syntax"
{ $subsections POSTPONE: HS{ }
"Hashtables are documented in " { $link "hash-sets" } "." ;
ARTICLE: "syntax-tuples" "Tuple syntax"
{ $subsections POSTPONE: T{ }
"Tuples are documented in " { $link "tuples" } "." ;
@ -229,6 +233,7 @@ $nl
"syntax-vectors"
"syntax-sbufs"
"syntax-hashtables"
"syntax-hash-sets"
"syntax-tuples"
"syntax-pathnames"
"syntax-effects"
@ -330,7 +335,7 @@ HELP: }
$nl
"Parsing words can use this word as a generic end delimiter." } ;
{ POSTPONE: { POSTPONE: V{ POSTPONE: H{ POSTPONE: C{ POSTPONE: T{ POSTPONE: W{ POSTPONE: } } related-words
{ POSTPONE: { POSTPONE: V{ POSTPONE: H{ POSTPONE: HS{ POSTPONE: C{ POSTPONE: T{ POSTPONE: W{ POSTPONE: } } related-words
HELP: {
{ $syntax "{ elements... }" }
@ -356,6 +361,12 @@ HELP: H{
{ $description "Marks the beginning of a literal hashtable, given as a list of two-element arrays holding key/value pairs. Literal hashtables are terminated by " { $link POSTPONE: } } "." }
{ $examples { $code "H{ { \"tuna\" \"fish\" } { \"jalapeno\" \"vegetable\" } }" } } ;
HELP: HS{
{ $syntax "HS{ members ... }" }
{ $values { "members" "a list of objects" } }
{ $description "Marks the beginning of a literal hash set, given as a list of its members. Literal hashtables are terminated by " { $link POSTPONE: } } "." }
{ $examples { $code "HS{ 3 \"foo\" }" } } ;
HELP: C{
{ $syntax "C{ real-part imaginary-part }" }
{ $values { "real-part" "a real number" } { "imaginary-part" "a real number" } }