Matchmaker, Matchmaker, make me a match

Question

(we won't be finding a Find or catching a tryCatch, though)

This is part two of a multi-part series of implementing some interesting R functions. Part one can be found here.

The task:

You are to implement R's match function in as few bytes as possible.

Input:

• x, a possibly empty list/array of integers
• table, a possibly empty list/array of integers
• nomatch, a single integer value
• incomparables, a possibly empty list/array of integers

Output:

• a single array/list of integers O of equal length to x, where each value O[i] represents either:
  • The index j of the first value in table where table[j]==x[i]
  • nomatch, indicating that no value in table is equal to x[i] OR that x[i] is in the list of incomparables.

Test Cases

All in the form x, table, nomatch, incomparables -> output
outputs 

[], [1,2,3], 0, [5] -> []

[1, 2, 3], [], 0, [5] -> [0, 0, 0]

[9, 4, 3, 6, 3], [9, 8, 7, 6, 5, 4, 3, 2, 1], -1, [4] -> [1, -1, 7, 4, 7]

[8, 6, 7, 5, 3, 0, 9], [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8, 9, 7, 9, 3, 2, 3, 8, 4, 6, 2, 6], 1000, [1] -> [12, 8, 14, 5, 1, 1000, 6]

More test cases can be generated as needed.

Additional rules:

• R has 1-based indices, but a consistent alternative-based indices are acceptable. So you can use indices that start at 3 or 17 or whatever, but this must be consistent, and you must indicate this in your answer.
• If you chosen language has a builtin that does this, please also implement your own solution.
• Explanations are appreciated.

This is code-golf, so shortest solution in bytes wins!

Answer 1

R, 83 bytes

function(x,t,n,i)sapply(x,function(a)c(which(a==t/!rowSums(outer(t,i,`==`))),n)[1])

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Avoids match, %in% and setdiff.

Answer 2

Jelly,  10  8 bytes

-2 thanks to Erik the Outgolfer

,⁷y⁵iⱮ⁶o

A full program accepting four command line arguments, incomparables nomatch table x which prints a Jelly representation* of the list of R's match function results.

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How?

e.g. with incomparables nomatch table x = [1,4], 2, [2,4], [4,3,2,1,0]:

,⁷y⁵iⱮ⁶o - Main Link: list, incomparables; list, nomatch
 ⁷       - newline character                                '\n'
,        - pair (incompararables) with (right)              [[1,4],'\n']
   ⁵     - 5th argument (3rd input = table)                 [2,4]
  y      - translate (right) with lookup (left)             [2,'\n']             
      ⁶  - 6th argument (4th input = x)                     [4,3,2,1,0]
     Ɱ   - map with:
    i    -   first index of (right) in (left)               [0,0,1,0,0]
       o - logical OR                                       [2,2,1,2,2]

---

* An empty list is represented as nothing, a list of lenth one is represented as just the item, while other lists are enclosed in [] and delimited by ,

Answer 3

R, 55 bytes

In this case, the code doesn't use match with its full functionality, it is just used as an index function. First R answer, so probably incredibly inefficient byte-wise!

Note (thanks to Giuseppe for the info): %in% and setdiff are also both internally implemented using match, so completely getting rid of this surprisingly useful function will result in a mess. Therefore, there is a 150-rep bounty with no deadline for this! (note that setdiff is allowed, though)

function(x,t,n,i)ifelse(x%in%setdiff(t,i),match(x,t),n)

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or...

R, 5 bytes

match

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Answer 4

Jelly, 9 8 bytes

ṣK¥ƒiⱮo⁶

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A full program that takes three arguments: [[table], incomparables], x, nomatch in that order.

Answer 5

C# (Visual C# Interactive Compiler), 60 bytes

(a,b,c,d)=>a.Select(x=>d.Contains(x)|(x=b.IndexOf(x))<0?c:x)

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Answer 6

Ruby, 44 bytes

Zero-indexed.

->x,t,n,i{x.map{|e|i-[e]==i&&t.index(e)||n}}

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Answer 7

R, 79 bytes

function(x,t,n,i)sapply(x,function(y)`if`(any(z<-y==t)&all(y-i),which(z)[1],n))

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R, 66 bytes

function(x,t,n,i)sapply(x,function(y)c(which(y==t&all(y-i)),n)[1])

Combining my solution with parts of Nick's solution.

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Answer 8

Japt, 14 bytes

Ë!XøD ©ÒVbD ªW

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Answer 9

Python 3, 60 bytes

lambda x,t,n,i:[v in{*t}-{*i}and-~t.index(v)or n for v in x]

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Answer 10

PowerShell, 63 bytes

param($x,$t,$n,$o)$x|%{($n,$t.indexof($_))[$_-in$t*!($_-in$o)]}

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0-indexed

Answer 11

JavaScript (ES6), 53 bytes

(x,t,n,i)=>x.map(v=>!~i.indexOf(v)*-~t.indexOf(v)||n)

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Answer 12

Perl 6, 45 bytes

->\b,\c,\d{*>>.&{$_∉d&&~b.first($_,:k)||c}}

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Anonymous code block that takes input curried, like f(table, nomatch, incomparables)(x) and returns the matches 0 indexed.

Explanation:

->\b,\c,\d{                               }    # Anonymous code block taking 3 inputs
           *           # Return an anonymous Whatever lambda
            >>.&{                        }  # Mapping input to
                 $_∉d                       # If the element is not an uncomparable
                     && b.first($_,:k)      # Return the first index in the table
                       ~                    # Stringified so Nils are false
                                      ||c   # Else the nomatch element
~~

Answer 13

Charcoal, 14 bytes

ＩＥθ∨∧¬№ει⊕⌕ηιζ

Try it online! Link is to verbose version of code. 1-indexed. Explanation:

  θ             First input (x)
 Ｅ              Map over elements
       ε        Fourth input (incomparables)
      №         Count occurrences of
        ι       Current element
     ¬          Is zero
    ∧           Logical And
           η    Second input (table)
          ⌕     Find 0-based index of
            ι   Current element
         ⊕      Convert to 1-indexed
   ∨            Logical Or
             ζ  Third input (nomatch)
Ｉ               Cast to string
                Implicitly print on separate lines

Answer 14

C (gcc), 125 bytes

1-indexed.

Given that I can't use a sentinel value in the passed arrays, I need to give the array bounds for each array.

f(x,c,t,d,n,i,e,j,f)int*x,*t,*i;{for(;f=0,c-->0;x[c]=--f?n:j){for(j=e;!f&j;x[c]-i[--j]||--f);for(;!f&j<d;x[c]-t[j++]||++f);}}

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Answer 15

Attache, 39 bytes

${{[_,y][nil=_or x@_in z]}=>x&Index@_4}

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Pretty simple verification. Note that the argument order differs from that of match; specifically, x is the last argument rather than the first, and corresponds to _4 in the above snippet.

Explanation

${{[_,y][nil=_or x@_in z]}=>x&Index@_4}
${                                    }   named lambda, taking parameters x, y, z, and _4
                            x&Index@_4    short for Index[x, _4];
                                              calculates where each element in _4 occurs in x
                                              returns `nil` for no match
  {                      }=>              over each index:
   [_,y][               ]                     choose y (`nomatch`) if
         nil=_                                    the index is nil
              or x@_in z                          or the element is in `incomparables`
    _                                         otherwise, choose the index

Answer 16

Haskell, 57 56 bytes

(t#n)i=map$maybe n id.($zip i[n,n..]++zip t[1..]).lookup

Argument order is: table, nomatch, incomparables, x.

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Answer 17

05AB1E, 7 bytes

õ:Ik®I:

0-indexed. Inputs are in the order: incomparables, table, x, nomatch.

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Explanation:

õ:       # Replace all values of the (implicit) first incomparables-list in
         # the (implicit) second table-list with an empty string
         #  i.e. incomparables=[4] and table=[9,8,7,6,5,4,3,2,1] → [9,8,7,6,5,"",3,2,1]
  Ik     # Get the index of each value in the third x-list in this list (-1 if not found)
         #  i.e. x=[9,4,3,6,3] → [0,-1,6,3,6]
    ®I:  # Replace all -1 with the fourth input-integer
         #  i.e. nomatch=-99 → [0,-99,6,3,6]
         # (and output the mapped list implicitly as result)