Function Repository Resource:

SplitByPatterns

Split a list into sublists that match the same pattern from an ordered list of patterns

Contributed by: Ian Ford (Wolfram Research)

ResourceFunction["SplitByPatterns"][list,{patt₁,patt₂,…}]

splits list into sublists consisting of runs of successive elements that match the same patt_i.

Details and Options

ResourceFunction["SplitByPatterns"][list,{patt₁,patt₂,…}] uses the first patt_i that an element matches to determine whether to split.

Split into runs of either integers or strings:

In[1]:=

$ResourceFunction[ "SplitByPatterns"][{1, "a", 2, 3, "b", "c", "d"}, {_Integer, _String}]$

Out[1]=

The first pattern that matches an element is used:

In[2]:=

$ResourceFunction[ "SplitByPatterns"][{2, 4, 3, 6, 7}, {_Integer?EvenQ, _Integer}]$

Out[2]=

If the patterns are reversed, the result may differ:

In[3]:=

$ResourceFunction[ "SplitByPatterns"][{2, 4, 3, 6, 7}, {_Integer, _Integer?EvenQ}]$

Out[3]=

SplitByPatterns[list,{patt₁,…}] is equivalent to SplitByPatterns[list,{patt₁,…,_}]:

In[4]:=

$ResourceFunction[ "SplitByPatterns"][{1, "a", 2, 3, "b", "c", "d"}, {_Integer}]$

Out[4]=