TreeDelete

TreeDelete[tree,pos]

deletes the subtree of tree at the position specified by pos.

TreeDelete[tree,{pos1,pos2,…}]

deletes subtrees at several positions.

TreeDelete[pos]

represents an operator form of TreeDelete that can be applied to a tree.

Details

  • TreeDelete allows removal of subtrees at any position in a Tree object.
  • TreeDelete[tree,{i,j,…}] deletes the subtree at position {i,j,…}.
  • TreeDelete can use the position specifications returned by TreePosition as well as extended forms as used in functions such as TreeExtract and TreeReplacePart. »
  • An individual position specification pos can be given as {part1,part2,…}, where part specifications parti include:
  • ithe i^(th) child
    -ithe i^(th) child from the end
    {i1,i2,…}the list of children with part numbers i1, i2, …
    "key"the child whose key is "key"
    Key[k]the child with an arbitrary key k
  • In TreeDelete[tree,{p1,p2,…}], {p1,p2,…} is interpreted as a list of individual position specifications if all the pi are lists. Otherwise, {p1,p2,…} will be taken to be an individual position specification. »
  • TreeDelete works on trees containing an Association of subtrees, using the same specification for keys as in Part. »
  • TreeDelete[pos][tree] is equivalent to TreeDelete[tree,pos].

Examples

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Basic Examples  (3)

Delete the second child of a tree:

Delete a subtree at any position:

Delete subtrees at several positions:

Use the operator form of TreeDelete:

Scope  (5)

Associations  (5)

Delete a subtree of a tree containing an association by key:

If the key is a string, the Key wrapper is optional:

Delete a subtree of a tree containing an association by key:

Delete a subtree of a tree containing an association by position:

Delete several subtrees of a tree containing an association:

Delete a nested subtree of a tree containing an association:

Delete several nested subtrees of a tree containing an association:

Properties & Relations  (7)

Subtrees can be deleted, as well as inserted or replaced:

Construct a tree from the heads in an expression:

TreeDelete deletes a subtree of a tree:

This corresponds to deleting a subexpression of an expression:

Delete can delete subexpressions directly:

If pos is not a list, pos and {pos} are equivalent specifications:

Deleting position {} deletes the whole tree:

TreeDelete ignores repeated positions:

TreeDelete can use the lists of positions returned by TreePosition:

These are the subtrees returned by TreeExtract:

TreeDelete[tree,{p1,p2,…}] treats {p1,p2,…} as a list of individual position specifications if all the pi are lists:

For {{1,2},{3,4}}, the subtrees at positions {1,2} and {3,4} are deleted:

If any pi is not a list, {p1,p2,…} is treated as a list of part specifications:

For {{{1,2},{3,4}}}, parts 3 and 4 of parts 1 and 2 are deleted:

Possible Issues  (1)

TreeDelete[tree,{}] does not delete any subtrees because the list of positions is empty:

TreeDelete[tree,{{}}] deletes position {}, which corresponds to the whole tree:

Wolfram Research (2021), TreeDelete, Wolfram Language function, https://reference.wolfram.com/language/ref/TreeDelete.html (updated 2022).

Text

Wolfram Research (2021), TreeDelete, Wolfram Language function, https://reference.wolfram.com/language/ref/TreeDelete.html (updated 2022).

CMS

Wolfram Language. 2021. "TreeDelete." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2022. https://reference.wolfram.com/language/ref/TreeDelete.html.

APA

Wolfram Language. (2021). TreeDelete. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/TreeDelete.html

BibTeX

@misc{reference.wolfram_2022_treedelete, author="Wolfram Research", title="{TreeDelete}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/TreeDelete.html}", note=[Accessed: 02-June-2023 ]}

BibLaTeX

@online{reference.wolfram_2022_treedelete, organization={Wolfram Research}, title={TreeDelete}, year={2022}, url={https://reference.wolfram.com/language/ref/TreeDelete.html}, note=[Accessed: 02-June-2023 ]}