Reference · stzString

FindDupSecutiveChars()

Same as FindDupSecutiveCharsCS: ENGINE-BACKED (StzEngineStringFindDupSecutiveCharsCS): positions of each char equal to the one before it. Retires the O(len) CharAt loop. pCaseSensitive=0 compares case-insensitively (per-codepoint casefold).

also written: DupSecutiveCharsZ

Basic examples (2)

Softanza

oA = new stzString("a")
s = new stzString( oA.Repeated(1000) )
# ConsecutiveSubStrings count is 375,250
? len(s.ConsecutiveSubStrings())
# FindDupSecutiveChars is 999 (positions 2..1000)
? len(s.FindDupSecutiveChars())

Output

375250
999

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 998_engine_string_largedata_narrated.ring(opens in a new tab)

Softanza

oAB  = new stzString("ab")
big  = new stzString( oAB.Repeated(1000000) )
oaA = new stzString("aA")
mBig = new stzString( oaA.Repeated(500000) )  # "aAaA..." 1,000,000 chars
# FindDupSecutiveCharsCS(1) is 0 (a <> A)
? len(mBig.FindDupSecutiveCharsCS(1))
# FindDupSecutiveCharsCS(0) is 999,999 (a == A folded)
? len(mBig.FindDupSecutiveCharsCS(0))
oAB2 = new stzString("ab")
bigab = new stzString( oAB2.Repeated(100000) )  # "abab..." 200,000 chars
# FindDupSecutiveSubString('ab') is 99,999
? len(bigab.FindDupSecutiveSubString("ab"))

Output

0
999999
99999

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 999_engine_string_millions_narrated.ring(opens in a new tab)

Scope (1)

Softanza

oA = new stzString("a")
s = new stzString( oA.Repeated(100) )
# NumberOfSubStrings is 5,050
? s.NumberOfSubStrings()
# SubStrings() enumerates 5,050
? len(s.SubStrings())
# SubStringsU() is 100
? len(s.SubStringsU())
# DuplicatesCS(1) is 50
? len(s.DuplicatesCS(1))
# ConsecutiveSubStrings is 3,775
? len(s.ConsecutiveSubStrings())
# FindDupSecutiveChars is 99
? len(s.FindDupSecutiveChars())

Output

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 998_engine_string_largedata_narrated.ring(opens in a new tab)

The extensions of this method

Each extension, and whether it exists for this method; an extension that exists combines with the others (FindSTCS).

Extension

Exists

What it adds · The names

does what the method does, then returns the object, so the call can be chained

chains on the next, more specific type of object (the Q ladder)

QQQ

chains on the most specific type of object (the Q ladder)

QRT

returns the result as an object of the requested type

yes

takes a case-sensitivity flag · FindDupSecutiveCharsCS

takes the position to start from (StartingAt)

takes bounds that are included (IncludingBounds)

the extended form: more parameters than the base method

XTT

yet another extension: a further extended form, after XT

yes

includes the position in what it returns · DupSecutiveCharsZZ

yes

returns positions as sections, [start, end] · FindDupSecutiveCharsZZ

selects by a condition

selects by a condition, with the expressive keywords (@NextItem, @PreviousItem...)

takes a direction, forward or backward (Directional)

takes a function (the condition or the update is given as a function); the forms document also uses F for the future form, which defers the action

Many

works on a collection of items instead of one (the plural form)

Except

takes exceptions, what to leave out (the exceptional form)

returns the result without duplication

Every example is a test file of the library, run inside the library for this page; only those whose output kept every promise their file wrote are shown.

FindDupSecutiveChars()

Basic examples (2)

Scope (1)

The extensions of this method

See also