Find words with alternating vowels and consonants: Difference between revisions

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Latest revision as of 12:21, 5 December 2023

Task

Using the dictionary unixdict.txt, find words which odd letters are consonants and even letters are vowels or vice versa.
Display the words here (on this page).

The length of any word shown should have a length > 9.

Other tasks related to string operations:

Metrics

Counting

Remove/replace

Anagrams/Derangements/shuffling

Find/Search/Determine

Formatting

Song lyrics/poems/Mad Libs/phrases

Tokenize

Sequences

11l

Translation of: Nim

V vowels = ‘aeiou’

V count = 0
L(word) File(‘unixdict.txt’).read().split("\n")
   I word.len > 9
      V first = word[0] C vowels
      L(i) (2 .< word.len).step(2)
         I (word[i] C vowels) != first
            L.break
      L.was_no_break
         L(i) (1 .< word.len).step(2)
            I (word[i] C vowels) == first
               L.break
         L.was_no_break
            count++
            print(word.rjust(14), end' I count % 7 == 0 {"\n"} E ‘ ’)
print()

Output:

    aboriginal     apologetic    bimolecular   borosilicate    calorimeter     capacitate     capacitive
    capitoline     capitulate     caricature     colatitude     coloratura    colorimeter     debilitate
    decelerate     decolonize     definitive     degenerate     deliberate     demodulate     denominate
    denotative     deregulate     desiderata    desideratum     dilapidate     diminutive     epigenetic
    facilitate    hemosiderin     heretofore    hexadecimal     homogenate    inoperative     judicature
   latitudinal     legitimate     lepidolite     literature     locomotive     manipulate     metabolite
  nicotinamide     oratorical     paragonite     pejorative     peridotite    peripatetic    polarimeter
    recitative     recuperate   rehabilitate     rejuvenate     remunerate     repetitive     reticulate
    savonarola     similitude     solicitude     tananarive    telekinesis    teratogenic     topologize
    unilateral     unimodular     uninominal verisimilitude

In the following solution the input file unixdict.txt is loaded from H6 drive. Altirra emulator automatically converts CR/LF character from ASCII into 155 character in ATASCII charset used by Atari 8-bit computer when one from H6-H10 hard drive under DOS 2.5 is used.

BYTE FUNC IsVovel(CHAR c)
  IF c='a OR c='e OR c='i OR c='o OR c='u THEN
    RETURN (1)
  FI
RETURN (0)

BYTE FUNC IsValidWord(CHAR ARRAY word)
  BYTE i,len,v

  len=word(0)
  IF len<=9 THEN RETURN (0) FI

  v=IsVovel(word(1))
  FOR i=2 TO len STEP 2
  DO
    IF IsVovel(word(i))=v THEN RETURN (0) FI
  OD
  FOR i=3 TO len STEP 2
  DO
    IF IsVovel(word(i))#v THEN RETURN (0) FI
  OD
RETURN (1)

PROC FindWords(CHAR ARRAY fname)
  CHAR ARRAY line(256)
  CHAR ARRAY tmp(256)
  BYTE pos,dev=[1]

  pos=2
  Close(dev)
  Open(dev,fname,4)
  WHILE Eof(dev)=0
  DO
    InputSD(dev,line)
    IF IsValidWord(line) THEN
      IF pos+line(0)>=39 THEN
        PutE() pos=2
      FI
      Print(line) Put(32)
      pos==+line(0)+1
    FI
  OD
  Close(dev)
RETURN

PROC Main()
  CHAR ARRAY fname="H6:UNIXDICT.TXT"

  FindWords(fname)
RETURN

Output:

Screenshot from Atari 8-bit computer

aboriginal apologetic bimolecular borosilicate calorimeter capacitate capacitive capitoline capitulate
caricature colatitude coloratura colorimeter debilitate decelerate decolonize definitive degenerate
deliberate demodulate denominate denotative deregulate desiderata desideratum dilapidate diminutive
epigenetic facilitate hemosiderin heretofore hexadecimal homogenate inoperative judicature latitudinal
legitimate lepidolite literature locomotive manipulate metabolite nicotinamide oratorical paragonite
pejorative peridotite peripatetic polarimeter recitative recuperate rehabilitate rejuvenate remunerate
repetitive reticulate savonarola similitude solicitude tananarive telekinesis teratogenic topologize
unilateral unimodular uninominal verisimilitude

Ada

with Ada.Text_Io;
with Ada.Strings.Fixed;

procedure Find_Alternating is
   use Ada.Text_Io;

   function Is_Vowel (Letter : Character) return Boolean
   is (Ada.Strings.Fixed.Index ("aeiou", "" & Letter) /= 0);

   Filename : constant String := "unixdict.txt";
   File     : File_Type;
begin
   Open (File, In_File, Filename);
   while not End_Of_File (File) loop
      declare
         Word   : constant String  := Get_Line (File);
         Failed : Boolean := False;
         Vowel  : Boolean := not Is_Vowel (Word (Word'First));
      begin
         for Letter of Word loop
            if Vowel = Is_Vowel (letter) then
               Failed := True;
               exit;
            end if;
            Vowel := not Vowel;
         end loop;
         if not Failed and Word'Length > 9 then
            Put_Line (Word);
         end if;
      end;
   end loop;
   Close (File);
end Find_Alternating;

ALGOL 68

# read the list of words and show words with alternating vowels and  #
# consonants                                                         #
IF  FILE input file;
    STRING file name = "unixdict.txt";
    open( input file, file name, stand in channel ) /= 0
THEN
    # failed to open the file #
    print( ( "Unable to open """ + file name + """", newline ) )
ELSE
    # file opened OK #
    BOOL at eof := FALSE;
    # set the EOF handler for the file #
    on logical file end( input file, ( REF FILE f )BOOL:
                                     BEGIN
                                         # note that we reached EOF on the #
                                         # latest read #
                                         at eof := TRUE;
                                         # return TRUE so processing can continue #
                                         TRUE
                                     END
                       );
    # returns the length of the string w                              #
    OP LENGTH  = ( STRING w )INT: ( UPB w - LWB w ) + 1;
    # returns TRUE if c is a vowel, FALSE otherwise                   #
    OP ISVOWEL = ( CHAR c )BOOL: ( c = "a" OR c = "e" OR c = "i" OR c = "o" OR c = "u" );
    # blank pads s on the left to width characters                    #
    PRIO PAD   = 1;
    OP   PAD   = ( INT width, STRING s )STRING: IF LENGTH s >= width THEN s ELSE ( " " * ( width - LENGTH s ) ) + s FI;
    INT    alternating count := 0;
    WHILE STRING word;
          get( input file, ( word, newline ) );
          NOT at eof
    DO
        IF LENGTH word >= 10
        THEN
            # the word is at least 10 characters                      #
            BOOL is alternating  := TRUE;
            BOOL have vowel      := ISVOWEL word[ LWB word ];
            FOR w pos FROM LWB word + 1 TO UPB word
            WHILE BOOL had vowel  = have vowel;
                  have vowel     := ISVOWEL word[ w pos ];
                  is alternating := have vowel = NOT had vowel
            DO SKIP OD;
            IF is alternating THEN
                # the characters of word alternate between vowels and #
                # non-vowels                                          #
                alternating count +:= 1;
                print( ( " ", 15 PAD word ) );
                IF LENGTH word > 15 OR alternating count MOD 6 = 0 THEN
                    print( ( newline ) )
                FI
            FI
        FI
    OD;
    close( input file );
    print( ( newline, whole( alternating count, 0 ), " words of alternating vowels and consonants found", newline ) ) 
FI

Output:

      aboriginal      apologetic     bimolecular    borosilicate     calorimeter      capacitate
      capacitive      capitoline      capitulate      caricature      colatitude      coloratura
     colorimeter      debilitate      decelerate      decolonize      definitive      degenerate
      deliberate      demodulate      denominate      denotative      deregulate      desiderata
     desideratum      dilapidate      diminutive      epigenetic      facilitate     hemosiderin
      heretofore     hexadecimal      homogenate     inoperative      judicature     latitudinal
      legitimate      lepidolite      literature      locomotive      manipulate      metabolite
    nicotinamide      oratorical      paragonite      pejorative      peridotite     peripatetic
     polarimeter      recitative      recuperate    rehabilitate      rejuvenate      remunerate
      repetitive      reticulate      savonarola      similitude      solicitude      tananarive
     telekinesis     teratogenic      topologize      unilateral      unimodular      uninominal
  verisimilitude
67 words of alternating vowels and consonants found

AppleScript

Idiomatic

The handler here is case- and diacritical-insensitive and has an option to treat "y" as a vowel. With the text file located on the computer's startup disk, it performs the set task in just under a third of a second on my machine, which is probably good enough for such a silly task.

(*
    With AppleScript's text item delimiters set to all the vowels, the 'text items' of a word with alternating
    vowels and consonants are single-character strings (the consonants), with the possibility of an empty
    string at the beginning and/or end representing a leading and/or trailing vowel.
*)

on findWordsWithAlternatingVowelsAndConsonants from theText given minLength:minLength, yAsVowel:yAsVowel
    script o
        property wordList : theText's words
        property output : {}
    end script
    
    set astid to AppleScript's text item delimiters
    if (yAsVowel) then
        set AppleScript's text item delimiters to {"a", "e", "i", "o", "u", "y"}
    else
        set AppleScript's text item delimiters to {"a", "e", "i", "o", "u"}
    end if
    ignoring case and diacriticals
        repeat with thisWord in o's wordList
            set thisWord to thisWord's contents
            if ((count thisWord) ≥ minLength) then
                set textItems to thisWord's text items
                set a to 1
                if ((count beginning of textItems) is 0) then set a to 2
                set b to (count textItems)
                if ((count end of textItems) is 0) then set b to b - 1
                repeat with i from a to b
                    set alternating to ((count item i of textItems) is 1)
                    if (not alternating) then exit repeat
                end repeat
                if (alternating) then set end of o's output to thisWord
            end if
        end repeat
    end ignoring
    set AppleScript's text item delimiters to astid
    return o's output
end findWordsWithAlternatingVowelsAndConsonants

-- Task code:
local theText
set theText to (read file ((path to desktop as text) & "unixdict.txt") as «class utf8»)
findWordsWithAlternatingVowelsAndConsonants from theText without yAsVowel given minLength:10

Output:

{"aboriginal", "apologetic", "bimolecular", "borosilicate", "calorimeter", "capacitate", "capacitive", "capitoline", "capitulate", "caricature", "colatitude", "coloratura", "colorimeter", "debilitate", "decelerate", "decolonize", "definitive", "degenerate", "deliberate", "demodulate", "denominate", "denotative", "deregulate", "desiderata", "desideratum", "dilapidate", "diminutive", "epigenetic", "facilitate", "hemosiderin", "heretofore", "hexadecimal", "homogenate", "inoperative", "judicature", "latitudinal", "legitimate", "lepidolite", "literature", "locomotive", "manipulate", "metabolite", "nicotinamide", "oratorical", "paragonite", "pejorative", "peridotite", "peripatetic", "polarimeter", "recitative", "recuperate", "rehabilitate", "rejuvenate", "remunerate", "repetitive", "reticulate", "savonarola", "similitude", "solicitude", "tananarive", "telekinesis", "teratogenic", "topologize", "unilateral", "unimodular", "uninominal", "verisimilitude"}

Or if you want to treat "y" as a vowel:

-- Task code:
local theText
set theText to (read file ((path to desktop as text) & "unixdict.txt") as «class utf8»)
findWordsWithAlternatingVowelsAndConsonants from theText with yAsVowel given minLength:10

Output:

{"aboriginal", "apologetic", "bimolecular", "borosilicate", "calorimeter", "capacitate", "capacitive", "capitoline", "capitulate", "caricature", "cohomology", "colatitude", "coloratura", "colorimeter", "debilitate", "decelerate", "decolonize", "definitive", "degeneracy", "degenerate", "dehumidify", "deliberate", "demodulate", "denominate", "denotative", "depositary", "depository", "deregulate", "deregulatory", "derogatory", "desiderata", "desideratum", "dicotyledon", "dilapidate", "diminutive", "epigenetic", "facilitate", "generosity", "hemosiderin", "hereditary", "heretofore", "heterodyne", "hexadecimal", "homogenate", "hypotenuse", "inoperative", "judicatory", "judicature", "laboratory", "latitudinal", "latitudinary", "legitimacy", "legitimate", "lepidolite", "literature", "locomotive", "locomotory", "luminosity", "manipulate", "metabolite", "mineralogy", "monocotyledon", "musicology", "nicotinamide", "numerology", "oratorical", "paragonite", "paramilitary", "pejorative", "peridotite", "peripatetic", "polarimeter", "polymerase", "pyrimidine", "pyroxenite", "recitative", "recuperate", "regulatory", "rehabilitate", "rejuvenate", "remunerate", "repetitive", "repository", "reticulate", "revelatory", "savonarola", "similitude", "solicitude", "solidarity", "tananarive", "telekinesis", "teratogenic", "teratology", "topologize", "toxicology", "unilateral", "unimodular", "uninominal", "verisimilitude", "veterinary", "vocabulary"}

Functional

Listing 'alternating' words for both {a,e,i,o,u} and {a,e,i,o,u,y} interpretations of 'vowel':

use AppleScript version "2.4"
use framework "Foundation"
use scripting additions


------------ ALTERNATING VOWELS AND CONSONANTS -----------

-- alternatingWordQuery :: String -> String
on alternatingWordQuery(vowels)
    set regex to "^.*([" & vowels & "]{2}|[^" & vowels & "]{2}).*$"
    
    "(9 < self.length) and not (self matches '" & regex & "')"
end alternatingWordQuery


-- matchingWords :: NSString -> String -> String
on matchingWords(lexicon)
    script
        on |λ|(vowels)
            set query to alternatingWordQuery(vowels)
            
            set matches to filteredLines(query, lexicon)
            set intMatches to length of matches
            
            ("Assuming " & vowels & " – " & intMatches as text) & ¬
                " matches:" & linefeed & linefeed & ¬
                inColumns(4, matches)
        end |λ|
    end script
end matchingWords


--------------------------- TEST -------------------------
on run
    set fpWordList to scriptFolder() & "unixdict.txt"
    if doesFileExist(fpWordList) then
        
        intercalate(linefeed & linefeed, ¬
            map(matchingWords(readFile(fpWordList)), ¬
                {"aeiou", "aeiouy"}))
    else
        display dialog "Word list not found in this script's folder:" & ¬
            linefeed & tab & fpWordList
    end if
end run



----------- GENERIC :: FILTERED LINES FROM FILE ----------

-- doesFileExist :: FilePath -> IO Bool
on doesFileExist(strPath)
    set ca to current application
    set oPath to (ca's NSString's stringWithString:strPath)'s ¬
        stringByStandardizingPath
    set {bln, int} to (ca's NSFileManager's defaultManager's ¬
        fileExistsAtPath:oPath isDirectory:(reference))
    bln and (int ≠ 1)
end doesFileExist


-- filteredLines :: String -> NSString -> [a]
on filteredLines(predicateString, s)
    -- A list of lines filtered by an NSPredicate string
    set ca to current application
    
    set predicate to ca's NSPredicate's predicateWithFormat:predicateString
    set array to ca's NSArray's ¬
        arrayWithArray:(s's componentsSeparatedByString:(linefeed))
    
    (array's filteredArrayUsingPredicate:(predicate)) as list
end filteredLines


-- readFile :: FilePath -> IO NSString
on readFile(strPath)
    set ca to current application
    set e to reference
    set {s, e} to (ca's NSString's ¬
        stringWithContentsOfFile:((ca's NSString's ¬
            stringWithString:strPath)'s ¬
            stringByStandardizingPath) ¬
            encoding:(ca's NSUTF8StringEncoding) |error|:(e))
    if missing value is e then
        s
    else
        (localizedDescription of e) as string
    end if
end readFile


-- scriptFolder :: () -> IO FilePath
on scriptFolder()
    -- The path of the folder containing this script
    try
        tell application "Finder" to ¬
            POSIX path of ((container of (path to me)) as alias)
    on error
        display dialog "Script file must be saved"
    end try
end scriptFolder


-------------- GENERIC :: COLUMNAR FORMATTING ------------

-- Tuple (,) :: a -> b -> (a, b)
on Tuple(a, b)
    -- Constructor for a pair of values, 
    -- possibly of two different types.
    {type:"Tuple", |1|:a, |2|:b, length:2}
end Tuple


-- chunksOf :: Int -> [a] -> [[a]]
on chunksOf(k, xs)
    script
        on go(ys)
            set ab to splitAt(k, ys)
            set a to |1| of ab
            if {} ≠ a then
                {a} & go(|2| of ab)
            else
                a
            end if
        end go
    end script
    result's go(xs)
end chunksOf


-- concatMap :: (a -> [b]) -> [a] -> [b]
on concatMap(f, xs)
    set lng to length of xs
    set acc to {}
    tell mReturn(f)
        repeat with i from 1 to lng
            set acc to acc & (|λ|(item i of xs, i, xs))
        end repeat
    end tell
    if {text, string} contains class of xs then
        acc as text
    else
        acc
    end if
end concatMap


-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
    tell mReturn(f)
        set v to startValue
        set lng to length of xs
        repeat with i from 1 to lng
            set v to |λ|(v, item i of xs, i, xs)
        end repeat
        return v
    end tell
end foldl


-- inColumns :: Int -> [String] -> String
on inColumns(n, xs)
    -- The strings in xs displayed in n columns
    -- of equal width.
    set widest to maximum(map(my |length|, xs))
    
    unlines(map(my unwords, chunksOf(n, ¬
        map(justifyLeft(widest, space), xs))))
end inColumns


-- intercalate :: String -> [String] -> String
on intercalate(delim, xs)
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, delim}
    set s to xs as text
    set my text item delimiters to dlm
    s
end intercalate


-- justifyLeft :: Int -> Char -> String -> String
on justifyLeft(n, cFiller)
    script
        on |λ|(s)
            if n > length of s then
                text 1 thru n of (s & replicate(n, cFiller))
            else
                s
            end if
        end |λ|
    end script
end justifyLeft


-- length :: [a] -> Int
on |length|(xs)
    set c to class of xs
    if list is c or string is c then
        length of xs
    else
        (2 ^ 29 - 1) -- (maxInt - simple proxy for non-finite)
    end if
end |length|


-- maximum :: Ord a => [a] -> a
on maximum(xs)
    script
        on |λ|(a, b)
            if a is missing value or b > a then
                b
            else
                a
            end if
        end |λ|
    end script
    
    foldl(result, missing value, xs)
end maximum


-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
    -- 2nd class handler function 
    -- lifted into 1st class script wrapper. 
    if script is class of f then
        f
    else
        script
            property |λ| : f
        end script
    end if
end mReturn


-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
    -- The list obtained by applying f
    -- to each element of xs.
    tell mReturn(f)
        set lng to length of xs
        set lst to {}
        repeat with i from 1 to lng
            set end of lst to |λ|(item i of xs, i, xs)
        end repeat
        return lst
    end tell
end map


-- replicate :: Int -> String -> String
on replicate(n, s)
    -- Egyptian multiplication - progressively doubling a list, 
    -- appending stages of doubling to an accumulator where needed 
    -- for binary assembly of a target length
    script p
        on |λ|({n})
            n ≤ 1
        end |λ|
    end script
    
    script f
        on |λ|({n, dbl, out})
            if (n mod 2) > 0 then
                set d to out & dbl
            else
                set d to out
            end if
            {n div 2, dbl & dbl, d}
        end |λ|
    end script
    
    set xs to |until|(p, f, {n, s, ""})
    item 2 of xs & item 3 of xs
end replicate


-- splitAt :: Int -> [a] -> ([a], [a])
on splitAt(n, xs)
    if n > 0 and n < length of xs then
        if class of xs is text then
            Tuple(items 1 thru n of xs as text, ¬
                items (n + 1) thru -1 of xs as text)
        else
            Tuple(items 1 thru n of xs, items (n + 1) thru -1 of xs)
        end if
    else
        if n < 1 then
            Tuple({}, xs)
        else
            Tuple(xs, {})
        end if
    end if
end splitAt


-- unlines :: [String] -> String
on unlines(xs)
    -- A single string formed by the intercalation
    -- of a list of strings with the newline character.
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, linefeed}
    set s to xs as text
    set my text item delimiters to dlm
    s
end unlines


-- until :: (a -> Bool) -> (a -> a) -> a -> a
on |until|(p, f, x)
    set v to x
    set mp to mReturn(p)
    set mf to mReturn(f)
    repeat until mp's |λ|(v)
        set v to mf's |λ|(v)
    end repeat
    v
end |until|


-- unwords :: [String] -> String
on unwords(xs)
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, space}
    set s to xs as text
    set my text item delimiters to dlm
    return s
end unwords

Output:

Assuming aeiou – 67 matches:

aboriginal     apologetic     bimolecular    borosilicate  
calorimeter    capacitate     capacitive     capitoline    
capitulate     caricature     colatitude     coloratura    
colorimeter    debilitate     decelerate     decolonize    
definitive     degenerate     deliberate     demodulate    
denominate     denotative     deregulate     desiderata    
desideratum    dilapidate     diminutive     epigenetic    
facilitate     hemosiderin    heretofore     hexadecimal   
homogenate     inoperative    judicature     latitudinal   
legitimate     lepidolite     literature     locomotive    
manipulate     metabolite     nicotinamide   oratorical    
paragonite     pejorative     peridotite     peripatetic   
polarimeter    recitative     recuperate     rehabilitate  
rejuvenate     remunerate     repetitive     reticulate    
savonarola     similitude     solicitude     tananarive    
telekinesis    teratogenic    topologize     unilateral    
unimodular     uninominal     verisimilitude

Assuming aeiouy – 101 matches:

aboriginal     apologetic     bimolecular    borosilicate  
calorimeter    capacitate     capacitive     capitoline    
capitulate     caricature     cohomology     colatitude    
coloratura     colorimeter    debilitate     decelerate    
decolonize     definitive     degeneracy     degenerate    
dehumidify     deliberate     demodulate     denominate    
denotative     depositary     depository     deregulate    
deregulatory   derogatory     desiderata     desideratum   
dicotyledon    dilapidate     diminutive     epigenetic    
facilitate     generosity     hemosiderin    hereditary    
heretofore     heterodyne     hexadecimal    homogenate    
hypotenuse     inoperative    judicatory     judicature    
laboratory     latitudinal    latitudinary   legitimacy    
legitimate     lepidolite     literature     locomotive    
locomotory     luminosity     manipulate     metabolite    
mineralogy     monocotyledon  musicology     nicotinamide  
numerology     oratorical     paragonite     paramilitary  
pejorative     peridotite     peripatetic    polarimeter   
polymerase     pyrimidine     pyroxenite     recitative    
recuperate     regulatory     rehabilitate   rejuvenate    
remunerate     repetitive     repository     reticulate    
revelatory     savonarola     similitude     solicitude    
solidarity     tananarive     telekinesis    teratogenic   
teratology     topologize     toxicology     unilateral    
unimodular     uninominal     verisimilitude veterinary    
vocabulary

Arturo

words: read.lines relative "unixdict.txt"
vowels: [`a` `e` `i` `o` `u`]
alternatingVC?: function [w][
    lookForConsonant: true
    if contains? vowels first w -> lookForConsonant: false

    loop w 'c [
        if xnor? lookForConsonant 
                 contains? vowels c -> return false
        lookForConsonant: not? lookForConsonant
    ]
    return true
]

loop words 'word [
    if 9 < size word [
        if alternatingVC? word ->
            print word
    ]
]

Output:

aboriginal
apologetic
bimolecular
borosilicate
calorimeter
capacitate
capacitive
capitoline
capitulate
caricature
colatitude
coloratura
colorimeter
debilitate
decelerate
decolonize
definitive
degenerate
deliberate
demodulate
denominate
denotative
deregulate
desiderata
desideratum
dilapidate
diminutive
epigenetic
facilitate
hemosiderin
heretofore
hexadecimal
homogenate
inoperative
judicature
latitudinal
legitimate
lepidolite
literature
locomotive
manipulate
metabolite
nicotinamide
oratorical
paragonite
pejorative
peridotite
peripatetic
polarimeter
recitative
recuperate
rehabilitate
rejuvenate
remunerate
repetitive
reticulate
savonarola
similitude
solicitude
tananarive
telekinesis
teratogenic
topologize
unilateral
unimodular
uninominal
verisimilitude

AutoHotkey

FileRead, db, % A_Desktop "\unixdict.txt"
vowels := {"a":1, "e":1, "i":1, "o":1, "u":1}, c := 0

Main:
for i, word in StrSplit(db, "`n", "`r")
{
    if StrLen(word) < 10
        continue
    vCount := cCount := 0
    while (letter := SubStr(word, A_Index, 1))
    {
        if vowels[letter]
            vCount++, cCount:=0
        else
            vCount:=0, cCount++
        if (vCount > 1 || cCount > 1)
            continue main
    }
    c++
    result .= word (Mod(c, 9) ? "`t" : "`n")
        
}
MsgBox, 262144, , % result
return

Output:

aboriginal	apologetic	bimolecular	borosilicate	calorimeter	capacitate	capacitive	capitoline	capitulate
caricature	colatitude	coloratura	colorimeter	debilitate	decelerate	decolonize	definitive	degenerate
deliberate	demodulate	denominate	denotative	deregulate	desiderata	desideratum	dilapidate	diminutive
epigenetic	facilitate	hemosiderin	heretofore	hexadecimal	homogenate	inoperative	judicature	latitudinal
legitimate	lepidolite	literature	locomotive	manipulate	metabolite	nicotinamide	oratorical	paragonite
pejorative	peridotite	peripatetic	polarimeter	recitative	recuperate	rehabilitate	rejuvenate	remunerate
repetitive	reticulate	savonarola	similitude	solicitude	tananarive	telekinesis	teratogenic	topologize
unilateral	unimodular	uninominal	verisimilitude

AWK

( length( $1 ) >= 10 ) \
{
    # have an appropriate length word
    word          = $1;
    haveVowel     = word ~ /^[aeiou]/;
    isAlternating = 1;
    for( wPos = 2; isAlternating && wPos <= length( word ); wPos ++ )
    {
        hadVowel  = haveVowel;
        haveVowel = substr( word, wPos, 1 ) ~ /^[aeiou]/;
        isAlternating = ( hadVowel && ! haveVowel ) || ( ! hadVowel && haveVowel );
    } # for wPos
    if( isAlternating )
    {
        printf( " %16s%s", word, ( alternatingCount % 6 == 5 ) ? "\n" : "" );
        alternatingCount += 1;
    } # if isAlternating
}

END \
{
    printf( "\n%d words with alternating vowels and consonants found\n", alternatingCount );
} # END

Output:

       aboriginal       apologetic      bimolecular     borosilicate      calorimeter       capacitate
       capacitive       capitoline       capitulate       caricature       colatitude       coloratura
      colorimeter       debilitate       decelerate       decolonize       definitive       degenerate
       deliberate       demodulate       denominate       denotative       deregulate       desiderata
      desideratum       dilapidate       diminutive       epigenetic       facilitate      hemosiderin
       heretofore      hexadecimal       homogenate      inoperative       judicature      latitudinal
       legitimate       lepidolite       literature       locomotive       manipulate       metabolite
     nicotinamide       oratorical       paragonite       pejorative       peridotite      peripatetic
      polarimeter       recitative       recuperate     rehabilitate       rejuvenate       remunerate
       repetitive       reticulate       savonarola       similitude       solicitude       tananarive
      telekinesis      teratogenic       topologize       unilateral       unimodular       uninominal
   verisimilitude
67 words with alternating vowels and consonants found

C

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_WORD_SIZE 80

bool is_vowel(char ch) {
    switch (ch) {
    case 'a': case 'A':
    case 'e': case 'E':
    case 'i': case 'I':
    case 'o': case 'O':
    case 'u': case 'U':
        return true;
    }
    return false;
}

bool alternating_vowels_and_consonants(const char* str, size_t len) {
    for (size_t i = 1; i < len; ++i) {
        if (is_vowel(str[i]) == is_vowel(str[i - 1]))
            return false;
    }
    return true;
}

int main(int argc, char** argv) {
    const char* filename = argc < 2 ? "unixdict.txt" : argv[1];
    FILE* fp = fopen(filename, "r");
    if (!fp) {
        perror(filename);
        return EXIT_FAILURE;
    }
    char line[MAX_WORD_SIZE];
    int n = 1;
    while (fgets(line, sizeof(line), fp)) {
        size_t len = strlen(line) - 1; // last character is \n
        if (len > 9 && alternating_vowels_and_consonants(line, len))
            printf("%2d: %s", n++, line);
    }
    fclose(fp);
    return EXIT_SUCCESS;
}

Output:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

C++

#include <cstdlib>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <string>

bool is_vowel(char ch) {
    switch (ch) {
    case 'a': case 'A':
    case 'e': case 'E':
    case 'i': case 'I':
    case 'o': case 'O':
    case 'u': case 'U':
        return true;
    }
    return false;
}

bool alternating_vowels_and_consonants(const std::string& str) {
    for (size_t i = 1, len = str.size(); i < len; ++i) {
        if (is_vowel(str[i]) == is_vowel(str[i - 1]))
            return false;
    }
    return true;
}

int main(int argc, char** argv) {
    const char* filename = argc < 2 ? "unixdict.txt" : argv[1];
    std::ifstream in(filename);
    if (!in) {
        std::cerr << "Cannot open file '" << filename << "'.\n";
        return EXIT_FAILURE;
    }
    std::string line;
    for (int n = 1; getline(in, line); ) {
        if (line.size() > 9 && alternating_vowels_and_consonants(line))
            std::cout << std::setw(2) << n++ << ": " << line << '\n';
    }
    return EXIT_SUCCESS;
}

Output:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

Delphi

Works with: Delphi version 6.0

Library: Classes,StdCtrls,SysUtils

Runtime = 4.3 ms.

var Dict: TStringList;	{List holds dictionary}

function IsVowel(C: char): boolean;
begin
Result:=C in ['a','e','i','o','u'];
end;

function DoesAlternate(S: string): boolean;
var I: integer;
var Vowel: boolean;
begin
Result:=False;
Vowel:=IsVowel(S[1]);
for I:=2 to Length(S) do
	begin
	if not (Vowel xor IsVowel(S[I])) then exit;
	Vowel:=IsVowel(S[I]);
	end;
Result:=True;
end;


procedure AlternateVowelConsonant(Memo: TMemo);
{Find words where the letters alternate vowel,consonant}
var I,Cnt: integer;
var S: string;
begin
S:=''; Cnt:=0;
for I:=0 to Dict.Count-1 do
 if Length(Dict[I])>9 then
	begin
	if DoesAlternate(Dict[I]) then
		begin
		Inc(Cnt);
		S:=S+Format('%-23s',[Dict[I]]);
		if (Cnt mod 4)=0 then S:=S+#$0D#$0A
		end
	end;
Memo.Lines.Add(IntToStr(Cnt)+' Alternate Vowel/Consonant words found.');
Memo.Lines.Add(S);
end;


initialization
{Create/load dictionary}
Dict:=TStringList.Create;
Dict.LoadFromFile('unixdict.txt');
Dict.Sorted:=True;
finalization
Dict.Free;
end.

Output:

67 Alternate Vowel/Consonant words found.
aboriginal             apologetic             bimolecular            borosilicate           
calorimeter            capacitate             capacitive             capitoline             
capitulate             caricature             colatitude             coloratura             
colorimeter            debilitate             decelerate             decolonize             
definitive             degenerate             deliberate             demodulate             
denominate             denotative             deregulate             desiderata             
desideratum            dilapidate             diminutive             epigenetic             
facilitate             hemosiderin            heretofore             hexadecimal            
homogenate             inoperative            judicature             latitudinal            
legitimate             lepidolite             literature             locomotive             
manipulate             metabolite             nicotinamide           oratorical             
paragonite             pejorative             peridotite             peripatetic            
polarimeter            recitative             recuperate             rehabilitate           
rejuvenate             remunerate             repetitive             reticulate             
savonarola             similitude             solicitude             tananarive             
telekinesis            teratogenic            topologize             unilateral             
unimodular             uninominal             verisimilitude

F#

// Find words with alternating vowels and consonants. Nigel Galloway: January 20th., 2020
let vowels=set['a';'e';'i';'o';'u']
let fN g=let rec fN g=function h::t->(if g<>vowels.Contains h then fN (not g) t else false)|_->true
         fN (vowels.Contains(Seq.head g)) (Seq.tail g|>List.ofSeq)
seq{use n=System.IO.File.OpenText("unixdict.txt") in while not n.EndOfStream do yield n.ReadLine()}
  |>Seq.filter(fun g->g.Length>9 && fN g)|>Seq.iter(printfn "%s")

Output:

aboriginal
apologetic
bimolecular
borosilicate
calorimeter
capacitate
capacitive
capitoline
capitulate
caricature
colatitude
coloratura
colorimeter
debilitate
decelerate
decolonize
definitive
degenerate
deliberate
demodulate
denominate
denotative
deregulate
desiderata
desideratum
dilapidate
diminutive
epigenetic
facilitate
hemosiderin
heretofore
hexadecimal
homogenate
inoperative
judicature
latitudinal
legitimate
lepidolite
literature
locomotive
manipulate
metabolite
nicotinamide
oratorical
paragonite
pejorative
peridotite
peripatetic
polarimeter
recitative
recuperate
rehabilitate
rejuvenate
remunerate
repetitive
reticulate
savonarola
similitude
solicitude
tananarive
telekinesis
teratogenic
topologize
unilateral
unimodular
uninominal
verisimilitude

Factor

group-by is used to group words by vowels and consonants. For example, "hello" [ "aeiou" member? ] group-by produces a sequence like { 'h' 'e' 'll' 'o' }. The number of elements in this grouping is the same as the length of the original word if and only if it has alternating vowels and consonants.

Works with: Factor version 0.99 2020-08-14

USING: grouping.extras io.encodings.ascii io.files kernel math
prettyprint sequences ;

"unixdict.txt" ascii file-lines
[ length 9 > ] filter
[ dup [ "aeiou" member? ] group-by [ length ] same? ] filter .

Output:

{
    "aboriginal"
    "apologetic"
    "bimolecular"
    "borosilicate"
    "calorimeter"
    "capacitate"
    "capacitive"
    "capitoline"
    "capitulate"
    "caricature"
    "colatitude"
    "coloratura"
    "colorimeter"
    "debilitate"
    "decelerate"
    "decolonize"
    "definitive"
    "degenerate"
    "deliberate"
    "demodulate"
    "denominate"
    "denotative"
    "deregulate"
    "desiderata"
    "desideratum"
    "dilapidate"
    "diminutive"
    "epigenetic"
    "facilitate"
    "hemosiderin"
    "heretofore"
    "hexadecimal"
    "homogenate"
    "inoperative"
    "judicature"
    "latitudinal"
    "legitimate"
    "lepidolite"
    "literature"
    "locomotive"
    "manipulate"
    "metabolite"
    "nicotinamide"
    "oratorical"
    "paragonite"
    "pejorative"
    "peridotite"
    "peripatetic"
    "polarimeter"
    "recitative"
    "recuperate"
    "rehabilitate"
    "rejuvenate"
    "remunerate"
    "repetitive"
    "reticulate"
    "savonarola"
    "similitude"
    "solicitude"
    "tananarive"
    "telekinesis"
    "teratogenic"
    "topologize"
    "unilateral"
    "unimodular"
    "uninominal"
    "verisimilitude"
}

Forth

Works with: Gforth

: vowel? ( c -- ? )
  case
    'a' of true endof
    'e' of true endof
    'i' of true endof
    'o' of true endof
    'u' of true endof
    0 swap
  endcase ;

: alternating-vowels-and-consonants { addr len -- ? }
  len 9 <= if false exit then
  len 1 do
    addr i + c@ vowel? addr i 1- + c@ vowel? = if
      unloop false exit
    then
  loop true ;

256 constant max-line

: main
  0 0 { count fd-in }
  s" unixdict.txt" r/o open-file throw to fd-in
  begin
    here max-line fd-in read-line throw
  while
    here swap 2dup alternating-vowels-and-consonants if
      count 1+ to count
      count 2 .r ." : " type cr
    else
      2drop
    then
  repeat
  drop
  fd-in close-file throw ;

main
bye

Output:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

FreeBASIC

dim as string s, c
dim as boolean v = false, lv = false
dim as integer i, n, a=0

open "unixdict.txt" for input as #1

while not eof(1)
    line input #1, s
    n = len(s)
    if n<10 then continue while
    for i = 1 to n
        c = mid(s,i,1)
        if c="a" or c="e" or c="i" or c="o" or c="u" then
            v = true
        else
            v = false
        end if
        'print c, v, lv
        if v = lv and i>1 then continue while
        lv = v
    next i
    a+=1
    print s;"   ";
    if a mod 10 = 0 then print
wend
close #1

Output:

aboriginal apologetic bimolecular borosilicate calorimeter capacitate capacitive capitoline capitulate caricature colatitude coloratura colorimeter debilitate decelerate decolonize definitive degenerate deliberate demodulate denominate denotative deregulate desiderata desideratum dilapidate diminutive epigenetic facilitate hemosiderin heretofore hexadecimal homogenate inoperative judicature latitudinal legitimate lepidolite literature locomotive manipulate metabolite nicotinamide oratorical paragonite pejorative peridotite peripatetic polarimeter recitative recuperate rehabilitate rejuvenate remunerate repetitive reticulate savonarola similitude solicitude tananarive telekinesis teratogenic topologize unilateral unimodular uninominal verisimilitude

Go

package main

import (
    "bytes"
    "fmt"
    "io/ioutil"
    "log"
    "strings"
    "unicode/utf8"
)

func isVowel(c rune) bool { return strings.ContainsRune("aeiou", c) }

func main() {
    wordList := "unixdict.txt"
    b, err := ioutil.ReadFile(wordList)
    if err != nil {
        log.Fatal("Error reading file")
    }
    bwords := bytes.Fields(b)
    var words []string
    for _, bword := range bwords {
        s := string(bword)
        if utf8.RuneCountInString(s) > 9 {
            words = append(words, s)
        }
    }
    count := 0
    fmt.Println("Words with alternate consonants and vowels in", wordList, "\b:\n")
    for _, word := range words {
        found := true
        for i, c := range word {
            if (i%2 == 0 && isVowel(c)) || (i%2 == 1 && !isVowel(c)) {
                found = false
                break
            }
        }
        if !found {
            found = true
            for i, c := range word {
                if (i%2 == 0 && !isVowel(c)) || (i%2 == 1 && isVowel(c)) {
                    found = false
                    break
                }
            }
        }
        if found {
            count++
            fmt.Printf("%2d: %s\n", count, word)
        }
    }
}

Output:

Words with alternate consonants and vowels in unixdict.txt:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

Haskell

import Control.Monad (join)
import Data.Bifunctor (bimap)
import Data.List.Split (chunksOf)

------- WORDS WITH ALTERNATING VOWELS AND CONSONANTS -----

isLongAlternator :: String -> Bool
isLongAlternator s =
  9 < length s
    && all alternating (zip s $ tail s)

alternating :: (Char, Char) -> Bool
alternating = uncurry (/=) . join bimap isVowel

isVowel :: Char -> Bool
isVowel = flip elem "aeiou"

--------------------------- TEST -------------------------
main :: IO ()
main =
  readFile "unixdict.txt"
    >>= mapM_ putStrLn
      . ( ((:) . (<> " matching words:\n") . show . length)
            <*> inColumns 4
        )
      . filter isLongAlternator
      . lines

------------------------ FORMATTING ----------------------

inColumns :: Int -> [String] -> [String]
inColumns n xs = unwords <$> chunksOf n (justifyLeft w ' ' <$> xs)
  where
    w = maximum (length <$> xs)

justifyLeft :: Int -> Char -> String -> String
justifyLeft n c s = take n (s <> replicate n c)

Output:

67 matching words:

aboriginal     apologetic     bimolecular    borosilicate  
calorimeter    capacitate     capacitive     capitoline    
capitulate     caricature     colatitude     coloratura    
colorimeter    debilitate     decelerate     decolonize    
definitive     degenerate     deliberate     demodulate    
denominate     denotative     deregulate     desiderata    
desideratum    dilapidate     diminutive     epigenetic    
facilitate     hemosiderin    heretofore     hexadecimal   
homogenate     inoperative    judicature     latitudinal   
legitimate     lepidolite     literature     locomotive    
manipulate     metabolite     nicotinamide   oratorical    
paragonite     pejorative     peridotite     peripatetic   
polarimeter    recitative     recuperate     rehabilitate  
rejuvenate     remunerate     repetitive     reticulate    
savonarola     similitude     solicitude     tananarive    
telekinesis    teratogenic    topologize     unilateral    
unimodular     uninominal     verisimilitude

J

We're looking for words which have more than 9 letters and where any adjacent pair of letters has both a vowel and a consonant.

   >(#~ (*/@(2 ~:/\ e.&'aeiou')*9<#)@>) cutLF fread'unixdict.txt'
aboriginal    
apologetic    
bimolecular   
borosilicate  
calorimeter   
capacitate    
capacitive    
capitoline    
capitulate    
caricature    
colatitude    
coloratura    
colorimeter   
debilitate    
decelerate    
decolonize    
definitive    
degenerate    
deliberate    
demodulate    
denominate    
denotative    
deregulate    
desiderata    
desideratum   
dilapidate    
diminutive    
epigenetic    
facilitate    
hemosiderin   
heretofore    
hexadecimal   
homogenate    
inoperative   
judicature    
latitudinal   
legitimate    
lepidolite    
literature    
locomotive    
manipulate    
metabolite    
nicotinamide  
oratorical    
paragonite    
pejorative    
peridotite    
peripatetic   
polarimeter   
recitative    
recuperate    
rehabilitate  
rejuvenate    
remunerate    
repetitive    
reticulate    
savonarola    
similitude    
solicitude    
tananarive    
telekinesis   
teratogenic   
topologize    
unilateral    
unimodular    
uninominal    
verisimilitude

JavaScript

As a standard for an embedded language which may have no access to a file-system, ECMAScript doesn't define any syntax or types for file operations.

This draft defines a readFile function for the Automation library of a macOS osascript instance of a JSContext.

(() => {
    'use strict';

    // -- WORDS WITH ALTERNATING VOWELS AND CONSONANTS ---

    // isLongAlternator :: String -> Bool
    const isLongAlternator = s =>
        9 < s.length && all(
            ab => isVowel(ab[0]) !== isVowel(ab[1])
        )(
            zip(s)(s.slice(1))
        );

    // isVowel :: Char -> Bool
    const isVowel = c =>
        'aeiou'.includes(c);


    // ---------------------- TEST -----------------------
    // main :: IO ()
    const main = () => {
        const
            matches = lines(
                readFile('unixdict.txt')
            ).filter(isLongAlternator);

        return `${matches.length} matches:\n\n` + (
            inColumns(4)(matches)
        );
    };

    // ------------------- FORMATTING --------------------

    // inColumns :: Int -> [String] -> String
    const inColumns = n =>
        xs => (
            w => unlines(
                chunksOf(n)(
                    xs.map(justifyLeft(w)(' '))
                )
                .map(unwords)
            )
        )(
            maximum(xs.map(length))
        );

    // --------------------- GENERIC ---------------------

    // Tuple (,) :: a -> b -> (a, b)
    const Tuple = a =>
        b => ({
            type: 'Tuple',
            '0': a,
            '1': b,
            length: 2
        });


    // all :: (a -> Bool) -> [a] -> Bool
    const all = p =>
        // True if p(x) holds for every x in xs.
        xs => [...xs].every(p);


    // chunksOf :: Int -> [a] -> [[a]]
    const chunksOf = n => {
        // xs split into sublists of length n.
        // The last sublist will be short if n 
        // does not evenly divide the length of xs .
        const go = xs => {
            const
                chunk = xs.slice(0, n),
                rest = xs.slice(n);
            return 0 < chunk.length ? (
                [chunk].concat(go(rest))
            ) : [];
        };
        return go;
    };


    // justifyLeft :: Int -> Char -> String -> String
    const justifyLeft = n =>
        // The string s, followed by enough padding (with
        // the character c) to reach the string length n.
        c => s => n > s.length ? (
            s.padEnd(n, c)
        ) : s;


    // length :: [a] -> Int
    const length = xs =>
        // Returns Infinity over objects without finite
        // length. This enables zip and zipWith to choose
        // the shorter argument when one is non-finite,
        // like cycle, repeat etc
        'GeneratorFunction' !== xs.constructor
        .constructor.name ? (
            xs.length
        ) : Infinity;


    // lines :: String -> [String]
    const lines = s =>
        // A list of strings derived from a single
        // string delimited by newline and or CR.
        0 < s.length ? (
            s.split(/[\r\n]+/)
        ) : [];


    // list :: StringOrArrayLike b => b -> [a]
    const list = xs =>
        // xs itself, if it is an Array,
        // or an Array derived from xs.
        Array.isArray(xs) ? (
            xs
        ) : Array.from(xs || []);


    // maximum :: Ord a => [a] -> a
    const maximum = xs => (
        // The largest value in a non-empty list.
        ys => 0 < ys.length ? (
            ys.slice(1).reduce(
                (a, y) => y > a ? (
                    y
                ) : a, ys[0]
            )
        ) : undefined
    )(list(xs));


    // readFile :: FilePath -> IO String
    const readFile = fp => {
        // The contents of a text file at the
        // filepath fp.
        const
            e = $(),
            ns = $.NSString
            .stringWithContentsOfFileEncodingError(
                $(fp).stringByStandardizingPath,
                $.NSUTF8StringEncoding,
                e
            );
        return ObjC.unwrap(
            ns.isNil() ? (
                e.localizedDescription
            ) : ns
        );
    };


    // unlines :: [String] -> String
    const unlines = xs =>
        // A single string formed by the intercalation
        // of a list of strings with the newline character.
        xs.join('\n');


    // unwords :: [String] -> String
    const unwords = xs =>
        // A space-separated string derived
        // from a list of words.
        xs.join(' ');


    // zip :: [a] -> [b] -> [(a, b)]
    const zip = xs =>
        // The paired members of xs and ys, up to
        // the length of the shorter of the two lists.
        ys => Array.from({
            length: Math.min(xs.length, ys.length)
        }, (_, i) => Tuple(xs[i])(ys[i]));


    // MAIN ---
    return main();
})();

Output:

67 matches:

aboriginal     apologetic     bimolecular    borosilicate  
calorimeter    capacitate     capacitive     capitoline    
capitulate     caricature     colatitude     coloratura    
colorimeter    debilitate     decelerate     decolonize    
definitive     degenerate     deliberate     demodulate    
denominate     denotative     deregulate     desiderata    
desideratum    dilapidate     diminutive     epigenetic    
facilitate     hemosiderin    heretofore     hexadecimal   
homogenate     inoperative    judicature     latitudinal   
legitimate     lepidolite     literature     locomotive    
manipulate     metabolite     nicotinamide   oratorical    
paragonite     pejorative     peridotite     peripatetic   
polarimeter    recitative     recuperate     rehabilitate  
rejuvenate     remunerate     repetitive     reticulate    
savonarola     similitude     solicitude     tananarive    
telekinesis    teratogenic    topologize     unilateral    
unimodular     uninominal     verisimilitude

jq

Works with: jq

Works with gojq, the Go implementation of jq

# input: an array
# output: if the $parity elements are all in $array then true, else false
def check($parity; $array):
  . as $in
  | all( range(0+$parity; length; 2); $in[.]|IN($array[]));

def alternating:
  def c: explode[0];

  ("aeiou" | explode) as $vowels
  | ([range("a"|c; ("z"|c)+1)] - $vowels)  as $consonants
  | inputs
  | select(length>9)
  | . as $word
  | explode
  | select(
      (check(0; $consonants) and check(1; $vowels)) or
      (check(1; $consonants) and check(0; $vowels)) )
  | $word ;

alternating

Output:

Invocation example: jq -nrR -f program.jq unixdict.txt

aboriginal
apologetic
bimolecular
borosilicate
calorimeter
capacitate
capacitive
capitoline
capitulate
caricature
colatitude
coloratura
colorimeter
debilitate
decelerate
decolonize
definitive
degenerate
deliberate
demodulate
denominate
denotative
deregulate
desiderata
desideratum
dilapidate
diminutive
epigenetic
facilitate
hemosiderin
heretofore
hexadecimal
homogenate
inoperative
judicature
latitudinal
legitimate
lepidolite
literature
locomotive
manipulate
metabolite
nicotinamide
oratorical
paragonite
pejorative
peridotite
peripatetic
polarimeter
recitative
recuperate
rehabilitate
rejuvenate
remunerate
repetitive
reticulate
savonarola
similitude
solicitude
tananarive
telekinesis
teratogenic
topologize
unilateral
unimodular
uninominal
verisimilitude

Julia

See Alternade_words#Julia for the foreachword function.

isvowel(c) = c in ['a', 'e', 'i', 'o', 'u'] # NB. leaves out 'α' and similar unicode vowels, and what about y?
onlyodds(f, s) = all(c -> f(c), s[1:2:length(s)]) && !any(c -> f(c), s[2:2:length(s)])
onlyevens(f, s) = !any(c -> f(c), s[1:2:length(s)]) && all(c -> f(c), s[2:2:length(s)])
eitheronlyvowels(w, _) = onlyodds(isvowel, w) || onlyevens(isvowel, w) ? w : ""

foreachword("unixdict.txt", eitheronlyvowels, minlen = 10)

Output:

Word source: unixdict.txt

aboriginal     apologetic     bimolecular    borosilicate   calorimeter    capacitate
capacitive     capitoline     capitulate     caricature     colatitude     coloratura     
colorimeter    debilitate     decelerate     decolonize     definitive     degenerate
deliberate     demodulate     denominate     denotative     deregulate     desiderata
desideratum    dilapidate     diminutive     epigenetic     facilitate     hemosiderin
heretofore     hexadecimal    homogenate     inoperative    judicature     latitudinal    
legitimate     lepidolite     literature     locomotive     manipulate     metabolite
nicotinamide   oratorical     paragonite     pejorative     peridotite     peripatetic
polarimeter    recitative     recuperate     rehabilitate   rejuvenate     remunerate
repetitive     reticulate     savonarola     similitude     solicitude     tananarive     
telekinesis    teratogenic    topologize     unilateral     unimodular     uninominal
verisimilitude

Ksh

#!/bin/ksh

# Find words with alternating vowels and consonants

#	# Variables:
#
dict='../unixdict.txt'

integer MINLENGTH=10
vowels='a|e|i|o|u'

#	# Functions:
#
#	# Function _isvowel(ch) - Return 1 if letter is a vowel
#
function _isvowel {
	typeset _ch ; typeset -l -L1 _ch="$1"

	[[ ${_ch} == @(${vowels}) ]] && return 1
	return 0
}
#	# Function _isalternating(str) - Return 1 if letter alternate vowel/const.
#
function _isalternating {
	typeset _str ; typeset -l _str="$1"
	typeset _i _rc ; integer _i _rc

	for ((_i=0; _i<${#_str}-1; _i++)); do
		_isvowel ${_str:${_i}:1} ; _rc=$?
		_isvowel ${_str:$((_i+1)):1}
		(( $? == _rc )) && return 0
	done
	return 1
}

 ######
# main #
 ######
while read; do
	(( ${#REPLY} < MINLENGTH )) && continue
	_isalternating "$REPLY"
	(( $? )) && print "$REPLY"
done < ${dict}

Output:

aboriginal apologetic bimolecular borosilicate calorimeter capacitate capacitive capitoline capitulate caricature colatitude coloratura colorimeter debilitate decelerate decolonize definitive degenerate deliberate demodulate denominate denotative deregulate desiderata desideratum dilapidate diminutive epigenetic facilitate hemosiderin heretofore hexadecimal homogenate inoperative judicature latitudinal legitimate lepidolite literature locomotive manipulate metabolite nicotinamide oratorical paragonite pejorative peridotite peripatetic polarimeter recitative recuperate rehabilitate rejuvenate remunerate repetitive reticulate savonarola similitude solicitude tananarive telekinesis teratogenic topologize unilateral unimodular uninominal

verisimilitude

Mathematica/Wolfram Language

vowels = Characters["euioa"];
consonants = DeleteCases[Alphabet[], Alternatives @@ vowels];
dict = Once[Import["https://web.archive.org/web/20180611003215/http://www.puzzlers.org/pub/wordlists/unixdict.txt"]];
dict //= StringSplit[#, "\n"] &;
dict //= Select[StringLength /* GreaterThan[9]];
dict //= 
 Select[(ContainsAll[vowels, Characters[StringTake[#, {1, -1, 2}]]] &&
       ContainsAll[consonants, 
       Characters[StringTake[#, {2, -1, 2}]]]) || (ContainsAll[
       consonants, Characters[StringTake[#, {1, -1, 2}]]] && 
      ContainsAll[vowels, Characters[StringTake[#, {2, -1, 2}]]]) &]

Output:

{aboriginal, apologetic, bimolecular, borosilicate, calorimeter, capacitate, capacitive, capitoline, capitulate, caricature, colatitude, coloratura, colorimeter, debilitate, decelerate, decolonize, definitive, degenerate, deliberate, demodulate, denominate, denotative, deregulate, desiderata, desideratum, dilapidate, diminutive, epigenetic, facilitate, hemosiderin, heretofore, hexadecimal, homogenate, inoperative, judicature, latitudinal, legitimate, lepidolite, literature, locomotive, manipulate, metabolite, nicotinamide, oratorical, paragonite, pejorative, peridotite, peripatetic, polarimeter, recitative, recuperate, rehabilitate, rejuvenate, remunerate, repetitive, reticulate, savonarola, similitude, solicitude, tananarive, telekinesis, teratogenic, topologize, unilateral, unimodular, uninominal, verisimilitude}

MiniScript

This implementation is for use with the Mini Micro version of MiniScript. The command-line version does not include a HTTP library. The script can be modified to use the file class to read a local copy of the word list.

isVowel = function(c)
	return "aeiou".indexOf(c) != null
end function

isAlternating = function(word)
	compVowelState= isVowel(word[0])
	for i in range(1, word.len - 1)
		if isVowel(word[i]) == compVowelState then return false
		compVowelState = not compVowelState
	end for
	return true
end function

wordList = http.get("http://wiki.puzzlers.org/pub/wordlists/unixdict.txt").split(char(10))
results = []

for word in wordList
	if word.len >9 and isAlternating(word) then results.push(word)
end for
c = 0

for word in results
	word = (word + " " * 5)[:15] // padded for printing
	print word, ""
	c = c + 1
	if c % 4 == 0 then print
end for

Output:

aboriginal     apologetic     bimolecular    borosilicate
calorimeter    capacitate     capacitive     capitoline
capitulate     caricature     colatitude     coloratura
colorimeter    debilitate     decelerate     decolonize
definitive     degenerate     deliberate     demodulate
denominate     denotative     deregulate     desiderata
desideratum    dilapidate     diminutive     epigenetic
facilitate     hemosiderin    heretofore     hexadecimal
homogenate     inoperative    judicature     latitudinal
legitimate     lepidolite     literature     locomotive
manipulate     metabolite     nicotinamide   oratorical
paragonite     pejorative     peridotite     peripatetic
polarimeter    recitative     recuperate     rehabilitate
rejuvenate     remunerate     repetitive     reticulate
savonarola     similitude     solicitude     tananarive
telekinesis    teratogenic    topologize     unilateral
unimodular     uninominal     verisimilitude

Nim

import strutils

const Vowels = {'a', 'e', 'i', 'o', 'u'}

var count = 0
for word in "unixdict.txt".lines:
  if word.len > 9:
    block checkWord:
      let first = word[0] in Vowels
      for i in countup(2, word.high, 2):
        if word[i] in Vowels != first: break checkWord
      for i in countup(1, word.high, 2):
        if word[i] in Vowels == first: break checkWord
      inc count
      stdout.write word.align(14), if count mod 7 == 0: '\n' else: ' '
echo()

Output:

    aboriginal     apologetic    bimolecular   borosilicate    calorimeter     capacitate     capacitive
    capitoline     capitulate     caricature     colatitude     coloratura    colorimeter     debilitate
    decelerate     decolonize     definitive     degenerate     deliberate     demodulate     denominate
    denotative     deregulate     desiderata    desideratum     dilapidate     diminutive     epigenetic
    facilitate    hemosiderin     heretofore    hexadecimal     homogenate    inoperative     judicature
   latitudinal     legitimate     lepidolite     literature     locomotive     manipulate     metabolite
  nicotinamide     oratorical     paragonite     pejorative     peridotite    peripatetic    polarimeter
    recitative     recuperate   rehabilitate     rejuvenate     remunerate     repetitive     reticulate
    savonarola     similitude     solicitude     tananarive    telekinesis    teratogenic     topologize
    unilateral     unimodular     uninominal verisimilitude

Perl

Translated from AWK

Used a2p.

Translation of: AWK

# 20210104 added Perl programming solution

use strict;
use warnings;

my $alternatingCount = 0;

while (<>) {
   (my $Fld1) = split(' ', $_, -1);
   if ((length($Fld1) >= 10)) { # have an arpropriate length word
      my $word = $Fld1;
      my $haveVowel = $word =~ /^[aeiou]/;
      my $isAlternating = 1;
      for (my $wPos = 2; $isAlternating && $wPos <= length($word); $wPos++) {
         my $hadVowel = $haveVowel;
         $haveVowel = substr($word, ($wPos)-1, 1) =~ /^[aeiou]/;
         $isAlternating = ($hadVowel && !$haveVowel) || (!$hadVowel && $haveVowel);
      } # for wPos
      if ($isAlternating) {
          printf ' %16s%s', $word, ($alternatingCount % 6 == 5) ? "\n" : '';
          $alternatingCount += 1;
      } # if isAlternating
   }
}

printf "\n%d words with alternating vowels and consonants found\n", $alternatingCount;

Output:

       aboriginal       apologetic      bimolecular     borosilicate      calorimeter       capacitate
       capacitive       capitoline       capitulate       caricature       colatitude       coloratura
      colorimeter       debilitate       decelerate       decolonize       definitive       degenerate
       deliberate       demodulate       denominate       denotative       deregulate       desiderata
      desideratum       dilapidate       diminutive       epigenetic       facilitate      hemosiderin
       heretofore      hexadecimal       homogenate      inoperative       judicature      latitudinal
       legitimate       lepidolite       literature       locomotive       manipulate       metabolite
     nicotinamide       oratorical       paragonite       pejorative       peridotite      peripatetic
      polarimeter       recitative       recuperate     rehabilitate       rejuvenate       remunerate
       repetitive       reticulate       savonarola       similitude       solicitude       tananarive
      telekinesis      teratogenic       topologize       unilateral       unimodular       uninominal
   verisimilitude
67 words with alternating vowels and consonants found

Regex solution

I've heard rumors that there are more than 5 vowels...

$vowels = 'aeiou';
$v = qr/[$vowels]/;
$c = qr/[^$vowels]/;

/^ ( ($c$v)+ $c? | ($v$c)+ $v? ) $/ix and say for grep { /.{10}/ } split "\n",  do { (@ARGV, $/) = 'unixdict.txt'; <> };

Output:

aboriginal
apologetic
bimolecular
...
verisimilitude

Phix

with javascript_semantics
function vowel(integer ch) return find(ch,"aeiou")!=0 end function
function oddeven(string word)
    if length(word)<=9 then return false end if
    sequence consonants = apply(word,vowel),
             ohoneohone = apply(tagset(length(word)),odd)
    return find(consonants,{ohoneohone,sq_not(ohoneohone)})
end function
sequence words = filter(unix_dict(),oddeven)
printf(1,"%d avac words found: %s\n",{length(words),join(shorten(words,"",3),", ")})

Output:

67 avac words found: aboriginal, apologetic, bimolecular, ..., unimodular, uninominal, verisimilitude

Plain English

To run:
Start up.
Put "c:\unixdict.txt" into a path.
Read the path into a buffer.
Slap a rider on the buffer.
Loop.
Move the rider (text file rules).
Subtract 1 from the rider's token's last. \remove the newline
Put the rider's token into a word string.
If the word is blank, break.
If the word's length is less than 10, repeat.
If the word is alternating between vowels and consonants, write the word on the console.
Repeat.
Wait for the escape key.
Shut down.

To decide if a string is alternating between vowels and consonants:
Slap a substring on the string.
Put the substring's first plus 1 into the substring's last.
Loop.
If the substring's last's target is noise, say yes.
If the substring is double, say no.
Add 1 to the substring's first.
Add 1 to the substring's last.
Repeat.

To decide if a string is double:
If the string's first's target is any consonant, set a flag.
If the string's last's target is any consonant, set another flag.
If the flag is the other flag, say yes.
Say no.

Output:

aboriginal
apologetic
bimolecular
borosilicate
calorimeter
capacitate
capacitive
capitoline
capitulate
caricature
colatitude
coloratura
colorimeter
debilitate
decelerate
decolonize
definitive
degenerate
deliberate
demodulate
denominate
denotative
deregulate
desiderata
desideratum
dilapidate
diminutive
epigenetic
facilitate
hemosiderin
heretofore
hexadecimal
homogenate
inoperative
judicature
latitudinal
legitimate
lepidolite
literature
locomotive
manipulate
metabolite
nicotinamide
oratorical
paragonite
pejorative
peridotite
peripatetic
polarimeter
recitative
recuperate
rehabilitate
rejuvenate
remunerate
repetitive
reticulate
savonarola
similitude
solicitude
tananarive
telekinesis
teratogenic
topologize
unilateral
unimodular
uninominal
verisimilitude

Prolog

Works with: SWI Prolog

main:-
    open("unixdict.txt", read, Stream),
    main(Stream, 0),
    close(Stream).

main(Stream, Count):-
    read_line_to_string(Stream, String),
    String \= end_of_file,
    !,
    process_line(String, Count, Count1),
    main(Stream, Count1).
main(_, _).

process_line(String, Count, Count1):-
    string_chars(String, Chars),
    length(Chars, Length),
    Length > 9,
    alternating_vowels_and_consonants(Chars),
    !,
    Count1 is Count + 1,
    writef('%3r: %w\n', [Count1, String]).
process_line(_, Count, Count).

vowel('a').
vowel('e').
vowel('i').
vowel('o').
vowel('u').

alternating_vowels_and_consonants([_]):-!.
alternating_vowels_and_consonants([Ch1, Ch2|Chars]):-
    (vowel(Ch1) -> \+vowel(Ch2) ; vowel(Ch2)),
    alternating_vowels_and_consonants([Ch2|Chars]).

Output:

  1: aboriginal
  2: apologetic
  3: bimolecular
  4: borosilicate
  5: calorimeter
  6: capacitate
  7: capacitive
  8: capitoline
  9: capitulate
 10: caricature
 11: colatitude
 12: coloratura
 13: colorimeter
 14: debilitate
 15: decelerate
 16: decolonize
 17: definitive
 18: degenerate
 19: deliberate
 20: demodulate
 21: denominate
 22: denotative
 23: deregulate
 24: desiderata
 25: desideratum
 26: dilapidate
 27: diminutive
 28: epigenetic
 29: facilitate
 30: hemosiderin
 31: heretofore
 32: hexadecimal
 33: homogenate
 34: inoperative
 35: judicature
 36: latitudinal
 37: legitimate
 38: lepidolite
 39: literature
 40: locomotive
 41: manipulate
 42: metabolite
 43: nicotinamide
 44: oratorical
 45: paragonite
 46: pejorative
 47: peridotite
 48: peripatetic
 49: polarimeter
 50: recitative
 51: recuperate
 52: rehabilitate
 53: rejuvenate
 54: remunerate
 55: repetitive
 56: reticulate
 57: savonarola
 58: similitude
 59: solicitude
 60: tananarive
 61: telekinesis
 62: teratogenic
 63: topologize
 64: unilateral
 65: unimodular
 66: uninominal
 67: verisimilitude

Python

'''Words with alternating vowels and consonants'''


# isLongAlternator :: String -> Bool
def isLongAlternator(s):
    '''True if s has 10 or more characters,
       and no two successive characters that are
       both vowels, or both consonants.
    '''
    def p(a, b):
        return isVowel(a) != isVowel(b)
    return 9 < len(s) and all(map(p, s, s[1:]))


def isVowel(c):
    '''True if c is in the set {a, e, i, o, u}
    '''
    return c in 'aeiou'


# ------------------------- TEST -------------------------
# main :: IO ()
def main():
    '''Words without successive vowels or consonants
       found in the file 'unixdict.txt'
    '''
    matches = [
        x for x in readFile('unixdict.txt').splitlines()
        if isLongAlternator(x)
    ]
    w = max(len(x) for x in matches)
    print(str(len(matches)) + ' matching words:\n')
    print(
        '\n'.join(
            ' '.join(s) for s in chunksOf(4)([
                x.ljust(w, ' ') for x in matches
            ])
        )
    )


# ----------------------- GENERIC ------------------------

# chunksOf :: Int -> [a] -> [[a]]
def chunksOf(n):
    '''A series of lists of length n, subdividing the
       contents of xs. Where the length of xs is not evenly
       divible, the final list will be shorter than n.
    '''
    def go(xs):
        return (
            xs[i:n + i] for i in range(0, len(xs), n)
        ) if 0 < n else None
    return go


# readFile :: FilePath -> IO String
def readFile(fp):
    '''The contents of any file at the path.
    '''
    with open(fp, 'r', encoding='utf-8') as f:
        return f.read()


# MAIN ---
if __name__ == '__main__':
    main()

Output:

67 matching words:

aboriginal     apologetic     bimolecular    borosilicate  
calorimeter    capacitate     capacitive     capitoline    
capitulate     caricature     colatitude     coloratura    
colorimeter    debilitate     decelerate     decolonize    
definitive     degenerate     deliberate     demodulate    
denominate     denotative     deregulate     desiderata    
desideratum    dilapidate     diminutive     epigenetic    
facilitate     hemosiderin    heretofore     hexadecimal   
homogenate     inoperative    judicature     latitudinal   
legitimate     lepidolite     literature     locomotive    
manipulate     metabolite     nicotinamide   oratorical    
paragonite     pejorative     peridotite     peripatetic   
polarimeter    recitative     recuperate     rehabilitate  
rejuvenate     remunerate     repetitive     reticulate    
savonarola     similitude     solicitude     tananarive    
telekinesis    teratogenic    topologize     unilateral    
unimodular     uninominal     verisimilitude

Quackery

  [ [] swap ]'[ swap
    witheach
      [ dup nested
        unrot over do
        iff [ dip join ]
        else nip ]
    drop ]                         is filter      ( [ --> [ )

  [ [ 0
      26 times
        [ i^ char A +
          bit | ]
      26 times
        [ i^ char a +
          bit | ] ] constant ]     is letters     (   --> n )

  [ [ 0 $ "AEIUOaeiou"
      witheach [ bit | ] ]
      constant ]                   is vowels      (   --> n )

  [ [ letters vowels ~ & ]
    constant ]                     is consonants  (   --> n )

  [ true swap
    witheach
      [ bit letters & 0 =
        if [ conclude not ] ] ]    is onlyletters ( $ --> b )

  [ stack [ ] ]                    is chartest    ( $ --> b )

  [ bit vowels & 0 > ]             is isvowel     ( c --> b )

  [ bit consonants & 0 > ]         is isconsonant ( c --> b )

  forward                          is constest    ( c --> b )

  [ isvowel
    ' constest
    chartest replace ]             is voweltest   ( c --> b )

  [ isconsonant
    ' voweltest
    chartest replace ]       resolves constest    ( c --> b )

  [ behead isvowel iff
      [ ' constest ]
    else [ ' voweltest ]
    chartest put
    true swap witheach
      [ chartest share do
        not if
          [ conclude not ] ] ]     is alternating ( $ --> b )

  [ dup size 10 < iff
      [ drop false ] done
    dup onlyletters not iff
      [ drop false ] done
    alternating ]                  is allcriteria ( $ --> b )


   $ "rosetta/unixdict.txt" sharefile
   drop nest$
   filter allcriteria
   80 wrap$

Output:

aboriginal apologetic bimolecular borosilicate calorimeter capacitate capacitive
capitoline capitulate caricature colatitude coloratura colorimeter debilitate
decelerate decolonize definitive degenerate deliberate demodulate denominate
denotative deregulate desiderata desideratum dilapidate diminutive epigenetic
facilitate hemosiderin heretofore hexadecimal homogenate inoperative judicature
latitudinal legitimate lepidolite literature locomotive manipulate metabolite
nicotinamide oratorical paragonite pejorative peridotite peripatetic polarimeter
recitative recuperate rehabilitate rejuvenate remunerate repetitive reticulate
savonarola similitude solicitude tananarive telekinesis teratogenic topologize
unilateral unimodular uninominal verisimilitude

Racket

Echoing #Raku ... this is another one that can be done with a regex.

Here's a bit of variety; the match-lambda for the regex version could also be simplified to regexp-match.

#lang racket

(define alternating?/re
  (match-lambda
    ((regexp #rx"^[aeiou]?([^aeiou][aeiou])*[^aeiou]?$") #t)
    (_ #f)))

(define/match (vowel? v)
  [((or #\a #\e #\i #\o #\u)) #t]
  [(_) #f])

(define consonant? (negate vowel?))

(define (alternating?/for w)
  (or (string=? "" w)
      (let/ec fail (or (for/fold ((expect-vowel? (consonant? (string-ref w 0))))
                                 ((c (in-string w 1)))
                         (if (eq? (vowel? c) expect-vowel?)
                             (not expect-vowel?)
                             (fail #f)))
                       #t))))

(define (alternating?/loop w)
  (define w-len-- (sub1 (string-length w)))
  (or (negative? w-len--)
      (let loop ((expect-vowel? (consonant? (string-ref w w-len--))) (i w-len--))
        (or (zero? i)
            (let* ((i-- (sub1 i)) (c (string-ref w i--)))
              (and (eq? (vowel? c) expect-vowel?)
                   (loop (not expect-vowel?) i--)))))))

(define (alternating?/letrec w)
  (letrec ((l (string-length w))
           (c (λ (i) (string-ref w i)))
           (vc-alt? (match-lambda
                      [(== l) #t]
                      [(and (app c (? vowel?)) (app add1 i)) (cv-alt? i)]
                      [_ #f]))
           (cv-alt? (match-lambda
                      [(== l) #t]
                      [(and (app c (? consonant?))(app add1 i)) (vc-alt? i)]
                      [_ #f])))
    (or (vc-alt? 0) (cv-alt? 0))))

(define (filtered-word? pred)
  (match-lambda [(and (? pred) (? (λ (w) (> (string-length w) 9)))) #t] [_ #f]))

(define all-words (file->lines "../../data/unixdict.txt"))

(module+ main
  (filter (filtered-word? alternating?/re) all-words))

(module+ test
  (require rackunit)
  (define words/re (filter (filtered-word? alternating?/re) all-words))
  (define words/fold (filter (filtered-word? alternating?/for) all-words))
  (define words/loop (filter (filtered-word? alternating?/loop) all-words))
  (define words/letrec (filter (filtered-word? alternating?/letrec) all-words))

  (check-equal? words/re words/fold)
  (check-equal? words/re words/loop)
  (check-equal? words/re words/letrec))

Output:

'("aboriginal" "apologetic" "bimolecular" "borosilicate" "calorimeter" "capacitate" "capacitive" "capitoline" "capitulate" "caricature" "colatitude" "coloratura" "colorimeter" "debilitate" "decelerate" "decolonize" "definitive" "degenerate" "deliberate" "demodulate" "denominate" "denotative" "deregulate" "desiderata" "desideratum" "dilapidate" "diminutive" "epigenetic" "facilitate" "hemosiderin" "heretofore" "hexadecimal" "homogenate" "inoperative" "judicature" "latitudinal" "legitimate" "lepidolite" "literature" "locomotive" "manipulate" "metabolite" "nicotinamide" "oratorical" "paragonite" "pejorative" "peridotite" "peripatetic" "polarimeter" "recitative" "recuperate" "rehabilitate" "rejuvenate" "remunerate" "repetitive" "reticulate" "savonarola" "similitude" "solicitude" "tananarive" "telekinesis" "teratogenic" "topologize" "unilateral" "unimodular" "uninominal" "verisimilitude")

Raku

Sigh. Yet another "Filter a word list" task. In a effort to make it a little more interesting, rather than just doing a one-liner, build a grammar and use that to filter.

grammar VOWCON {
    token       TOP { <|w> <vowel>? ( <consonant> <vowel> )* <consonant>? <|w> }
    token     vowel { <[aeiou]> }
    token consonant { <[a..z] - [aeiou]> }
}

say ( grep { VOWCON.parse: .lc }, grep { .chars > 9 }, 'unixdict.txt'.IO.words ).batch(6)».fmt('%-15s').join: "\n";

Output:

aboriginal      apologetic      bimolecular     borosilicate    calorimeter     capacitate     
capacitive      capitoline      capitulate      caricature      colatitude      coloratura     
colorimeter     debilitate      decelerate      decolonize      definitive      degenerate     
deliberate      demodulate      denominate      denotative      deregulate      desiderata     
desideratum     dilapidate      diminutive      epigenetic      facilitate      hemosiderin    
heretofore      hexadecimal     homogenate      inoperative     judicature      latitudinal    
legitimate      lepidolite      literature      locomotive      manipulate      metabolite     
nicotinamide    oratorical      paragonite      pejorative      peridotite      peripatetic    
polarimeter     recitative      recuperate      rehabilitate    rejuvenate      remunerate     
repetitive      reticulate      savonarola      similitude      solicitude      tananarive     
telekinesis     teratogenic     topologize      unilateral      unimodular      uninominal     
verisimilitude

REXX

/*REXX program finds all the  caseless words  (within an identified dictionary)  that   */
/*──────────────────────────────────────── either have odd letters that are vowels, and */
/*──────────────────────────────────────── even letters that consonants,  or vice versa.*/
parse arg minL iFID .                            /*obtain optional arguments from the CL*/
if minL=='' | minL=="," then minL= 10            /*Not specified?  Then use the default.*/
if iFID=='' | iFID=="," then iFID='unixdict.txt' /* "      "         "   "   "     "    */

              do #=1  while lines(iFID)\==0      /*read each word in the file  (word=X).*/
              x= strip( linein( iFID) )          /*pick off a word from the input line. */
              $.#= x                             /*save: original case and the semaphore*/
              end   /*#*/                        /* [↑]   semaphore name is uppercased. */
#= # - 1                                         /*adjust the record count  (DO loop).  */
say copies('─', 30)     #     "words in the dictionary file: "       iFID;       say
finds= 0                                         /*count of the words found  (so far).  */
vow= 'aeiou';     con= "bcdfghjklmnpqrstvwxyz"   /*list of vowels;  list of consonants. */
@@@=;             upper vow con                  /*@@@:  list of words found  (so far). */
w= 0                                             /*the maximum length of any word found.*/
    do j=1  for #;           L= length($.j)      /*process all the words that were found*/
    if L<minL  then iterate                      /*Is word too short?   Then ignore it. */
    y= $.j;    upper y                           /*obtain a word; and also uppercase it.*/
    ovec= 1;   ocev= 1                           /*for now, set both test cases: passed.*/
                                                 /*only scan odd indexed letters in word*/
      do ov=1  by 2  to  L;  z= substr(y, ov, 1) /*examine the odd letters in the word. */
      if verify(z, vow)>0  then ovec= 0          /*Odd letter not a vowel?  Then flunk. */
      end   /*k*/
                                                 /*only scan eve indexed letters in word*/
      do ev=2  by 2  to  L;  z= substr(y, ev, 1) /*examine the odd letters in the word. */
      if verify(z, con)>0  then ovec= 0          /*Even letter not a consonant?  Flunk. */
      end   /*k*/
                                                 /*only scan odd indexed letters in word*/
      do oc=1  by 2  to  L;  z= substr(y, oc, 1) /*examine the odd letters in the word. */
      if verify(z, con)>0  then ocev= 0          /*Odd letter not a consonant?   Flunk. */
      end   /*k*/
                                                 /*only scan eve indexed letters in word*/
      do ec=2  by 2  to  L;  z= substr(y, ec, 1) /*examine the odd letters in the word. */
      if verify(z, vow)>0  then ocev= 0          /*Even letter not a vowel?  Then flunk.*/
      end   /*k*/

    if ovec==0  &  ocev==0  then iterate         /*Did the word pass any test?  No, skip*/
    finds= finds + 1                             /*bump the count of "odd words" found. */
    w= max(w, L)                                 /*obtain the maximum length word found.*/
    @@@= @@@  $.j                                /*add a word to the list of words found*/
    end      /*j*/
                                                 /*stick a fork in it,  we're all done. */
say copies('─', 30)  finds     " words found with a minimum length of "      minL
_=
    do out=1  for finds;     z= word(@@@, out)   /*build a list that will be displayed. */
    if length(_ right(z, w))>130  then do;  say substr(_, 2);  _=;  end   /*show a line.*/
    _= _  right(z, w)                            /*append (aligned word) to output line.*/
    end   /*out*/
                                                 /*stick a fork in it,  we're all done. */
if _\==''  then say substr(_, 2)                 /*Any residual words?  Then show a line*/

output when using the default inputs:

────────────────────────────── 25104 words in the dictionary file:  unixdict.txt

────────────────────────────── 67  words found with a minimum length of  10
    aboriginal     apologetic    bimolecular   borosilicate    calorimeter     capacitate     capacitive     capitoline
    capitulate     caricature     colatitude     coloratura    colorimeter     debilitate     decelerate     decolonize
    definitive     degenerate     deliberate     demodulate     denominate     denotative     deregulate     desiderata
   desideratum     dilapidate     diminutive     epigenetic     facilitate    hemosiderin     heretofore    hexadecimal
    homogenate    inoperative     judicature    latitudinal     legitimate     lepidolite     literature     locomotive
    manipulate     metabolite   nicotinamide     oratorical     paragonite     pejorative     peridotite    peripatetic
   polarimeter     recitative     recuperate   rehabilitate     rejuvenate     remunerate     repetitive     reticulate
    savonarola     similitude     solicitude     tananarive    telekinesis    teratogenic     topologize     unilateral
    unimodular     uninominal verisimilitude

Ring

cStr = read("unixdict.txt")
wordList = str2list(cStr)
words = []
num = 0
vowels = "aeiou"
consonants = "bcdfghjklmnpqrstvwxyz"

see "working..." + nl

ln = len(wordList)
for n = ln to 1 step -1
    if len(wordList[n]) < 10
       del(wordList,n)
    ok
next

see "Words are:" + nl + nl

for n = 1 to len(wordList)
    cflag = 0
    vflag = 0
    len = len(wordList[n])
    for m = 1 to len
        if m % 2 = 1
           cons = substr(consonants,wordList[n][m])
           if cons > 0
              cflag = 1
           else
              cflag = 0
              exit
           ok           
        ok
        if m % 2 = 0
           cons = substr(vowels,wordList[n][m])
           if cons > 0
              vflag = 1
           else
              vflag = 0
              exit
           ok           
        ok
    next
    if cflag = 1 and vflag = 1
       add(words,wordList[n])
    ok
next

for n = 1 to len(wordList)
    cflag = 0
    vflag = 0
    len = len(wordList[n])
    for m = 1 to len
        if m % 2 = 1
           cons = substr(vowels,wordList[n][m])
           if cons > 0
              cflag = 1
           else
              cflag = 0
              exit
           ok           
        ok
        if m % 2 = 0
           cons = substr(consonants,wordList[n][m])
           if cons > 0
              vflag = 1
           else
              vflag = 0
              exit
           ok           
        ok
    next
    if cflag = 1 and vflag = 1
       add(words,wordList[n])
    ok
next

words = sort(words)

for n = 1 to len(words)
    see "" + n + ". " + words[n] + nl
next

see "done..." + nl

Output:

working...
Words are:

1. aboriginal
2. apologetic
3. bimolecular
4. borosilicate
5. calorimeter
6. capacitate
7. capacitive
8. capitoline
9. capitulate
10. caricature
11. colatitude
12. coloratura
13. colorimeter
14. debilitate
15. decelerate
16. decolonize
17. definitive
18. degenerate
19. deliberate
20. demodulate
21. denominate
22. denotative
23. deregulate
24. desiderata
25. desideratum
26. dilapidate
27. diminutive
28. epigenetic
29. facilitate
30. hemosiderin
31. heretofore
32. hexadecimal
33. homogenate
34. inoperative
35. judicature
36. latitudinal
37. legitimate
38. lepidolite
39. literature
40. locomotive
41. manipulate
42. metabolite
43. nicotinamide
44. oratorical
45. paragonite
46. pejorative
47. peridotite
48. peripatetic
49. polarimeter
50. recitative
51. recuperate
52. rehabilitate
53. rejuvenate
54. remunerate
55. repetitive
56. reticulate
57. savonarola
58. similitude
59. solicitude
60. tananarive
61. telekinesis
62. teratogenic
63. topologize
64. unilateral
65. unimodular
66. uninominal
67. verisimilitude
done...

Ruby

VOWELS =%w(a e i o u).map(&:freeze)

res = File.open("unixdict.txt").each_line.select do |line|
  word = line.chomp
  word.size > 9 && word.chars.each_cons(2).all?{|c1, c2| VOWELS.include?(c1) != VOWELS.include?(c2) }
end
puts res

Output:

aboriginal
apologetic
bimolecular
borosilicate
calorimeter
capacitate
capacitive
capitoline
capitulate
caricature
colatitude
coloratura
colorimeter
debilitate
decelerate
decolonize
definitive
degenerate
deliberate
demodulate
denominate
denotative
deregulate
desiderata
desideratum
dilapidate
diminutive
epigenetic
facilitate
hemosiderin
heretofore
hexadecimal
homogenate
inoperative
judicature
latitudinal
legitimate
lepidolite
literature
locomotive
manipulate
metabolite
nicotinamide
oratorical
paragonite
pejorative
peridotite
peripatetic
polarimeter
recitative
recuperate
rehabilitate
rejuvenate
remunerate
repetitive
reticulate
savonarola
similitude
solicitude
tananarive
telekinesis
teratogenic
topologize
unilateral
unimodular
uninominal
verisimilitude

sed

#!/bin/sed -f

/^.\{10\}/!d
/^[aeiou]\{0,1\}\([^aeiou][aeiou]\)*[^aeiou]\{0,1\}$/!d

Output:

aboriginal
apologetic
bimolecular
[...]
unimodular
uninominal
verisimilitude

Seed7

$include "seed7_05.s7i";

const func boolean: vowel (in char: letter) is
  return letter in {'A', 'E', 'I', 'O', 'U'} |
                   {'a', 'e', 'i', 'o', 'u'};
   
const func boolean: consonant (in char: letter) is
  return letter in {'B', 'C', 'D'} | {'F', 'G', 'H'} |
                   {'J' .. 'N'} | {'P' .. 'T'} | {'V' .. 'Z'} |
                   {'b', 'c', 'd'} | {'f', 'g', 'h'} |
                   {'j' .. 'n'} | {'p' .. 't'} | {'v' .. 'z'};

const func boolean: opposite (in char: letter1, in char: letter2) is
  return vowel(letter1) and consonant(letter2) or
         (consonant(letter1) and vowel(letter2));

const func boolean: alternating (in string: word) is func
  result
    var boolean: isAlternating is TRUE;
  local
    var integer: i is 2;
  begin
    while i <= length(word) and isAlternating do
      isAlternating := opposite(word[i - 1], word[i]);
      incr(i);
    end while;
  end func;

const proc: main is func
  local
    var file: dictionary is STD_NULL;
    var string: word is "";
    var integer: count is 1;
  begin
    dictionary := open("unixdict.txt", "r");
    if dictionary <> STD_NULL then
      while not eof(dictionary) do
        readln(dictionary, word);
        if length(word) > 9 and alternating(word) then
          writeln(count lpad 2 <& ": " <& word);
          incr(count);
        end if;
      end while;
      close(dictionary);
    end if;
  end func;

Output:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

Swift

import Foundation

func isVowel(_ char: Character) -> Bool {
    switch (char) {
    case "a", "A", "e", "E", "i", "I", "o", "O", "u", "U":
        return true
    default:
        return false
    }
}

func alternatingVowelsAndConsonants(word: String) -> Bool {
    return zip(word, word.dropFirst()).allSatisfy{isVowel($0.0) != isVowel($0.1)}
}

do {
    try String(contentsOfFile: "unixdict.txt", encoding: String.Encoding.ascii)
        .components(separatedBy: "\n")
        .filter{$0.count > 9 && alternatingVowelsAndConsonants(word: $0)}
        .enumerated()
        .forEach{print(String(format: "%2d. %@", $0.0 + 1, $0.1))}
} catch {
    print(error.localizedDescription)
}

Output:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

Wren

Library: Wren-fmt

import "io" for File
import "./fmt" for Fmt

var isVowel = Fn.new { |c| "aeiou".contains(c) }

var wordList = "unixdict.txt" // local copy
var words = File.read(wordList).trimEnd().split("\n").where { |w| w.count > 9 }
var count = 0
System.print("Words with alternate consonants and vowels in %(wordList):\n")
for (word in words) {
    var found = true
    for (i in 0...word.count) {
        var c = word[i]
        if ((i%2 == 0 && isVowel.call(c)) || (i%2 == 1 && !isVowel.call(c))) {
            found = false
            break
        }
    }
    if (!found) {
        found = true
        for (i in 0...word.count) {
            var c = word[i]
            if ((i%2 == 0 && !isVowel.call(c)) || (i%2 == 1 && isVowel.call(c))) {
                found = false
                break
            }
        }
    }
    if (found) {
        count = count + 1
        Fmt.print("$2d: $s", count, word)
    }
}

Output:

Words with alternate consonants and vowels in unixdict.txt:

 1: aboriginal
 2: apologetic
 3: bimolecular
 4: borosilicate
 5: calorimeter
 6: capacitate
 7: capacitive
 8: capitoline
 9: capitulate
10: caricature
11: colatitude
12: coloratura
13: colorimeter
14: debilitate
15: decelerate
16: decolonize
17: definitive
18: degenerate
19: deliberate
20: demodulate
21: denominate
22: denotative
23: deregulate
24: desiderata
25: desideratum
26: dilapidate
27: diminutive
28: epigenetic
29: facilitate
30: hemosiderin
31: heretofore
32: hexadecimal
33: homogenate
34: inoperative
35: judicature
36: latitudinal
37: legitimate
38: lepidolite
39: literature
40: locomotive
41: manipulate
42: metabolite
43: nicotinamide
44: oratorical
45: paragonite
46: pejorative
47: peridotite
48: peripatetic
49: polarimeter
50: recitative
51: recuperate
52: rehabilitate
53: rejuvenate
54: remunerate
55: repetitive
56: reticulate
57: savonarola
58: similitude
59: solicitude
60: tananarive
61: telekinesis
62: teratogenic
63: topologize
64: unilateral
65: unimodular
66: uninominal
67: verisimilitude

XPL0

string  0;              \Use zero-terminated strings
int  Cnt, I, Ch, Len;
char Word(100); \(longest word in unixdict.txt is 22 chars)
def  Tab=$09, LF=$0A, CR=$0D, EOF=$1A;

        func Vowel(Ch); \Return 'true' if character is a vowel
        int  Ch;
        case Ch of ^a, ^e, ^i, ^o, ^u: return true
        other return false;

        func Alternates; \Return 'true' if Word alternates vowel/consonant
        int  Sense, I;
        [Sense:= Vowel(Word(0));
        for I:= 0 to Len-1 do
            [if Vowel(Word(I)) # Sense then return false;
            Sense:= not Sense;
            ];
        return true;
        ];

[FSet(FOpen("unixdict.txt", 0), ^I);    \open dictionary and set it to device 3
OpenI(3);
Cnt:= 0;
repeat  I:= 0;
        loop    [repeat Ch:= ChIn(3) until Ch # CR;     \remove possible CR
                if Ch=LF or Ch=EOF then quit;
                Word(I):= Ch;
                I:= I+1;
                ];
        Word(I):= 0;                    \terminate string
        Len:= I;
        if Len > 9 then
            [if Alternates then
                [Text(0, Word);
                Cnt:= Cnt+1;
                if rem(Cnt/5) then ChOut(0, Tab) else CrLf(0);
                ];
            ];
until   Ch = EOF;
]

Output:

aboriginal      apologetic      bimolecular     borosilicate    calorimeter
capacitate      capacitive      capitoline      capitulate      caricature
colatitude      coloratura      colorimeter     debilitate      decelerate
decolonize      definitive      degenerate      deliberate      demodulate
denominate      denotative      deregulate      desiderata      desideratum
dilapidate      diminutive      epigenetic      facilitate      hemosiderin
heretofore      hexadecimal     homogenate      inoperative     judicature
latitudinal     legitimate      lepidolite      literature      locomotive
manipulate      metabolite      nicotinamide    oratorical      paragonite
pejorative      peridotite      peripatetic     polarimeter     recitative
recuperate      rehabilitate    rejuvenate      remunerate      repetitive
reticulate      savonarola      similitude      solicitude      tananarive
telekinesis     teratogenic     topologize      unilateral      unimodular
uninominal      verisimilitude