Using vectors and hash tables

TSF provides two types for the manipulation of set of values ; the vectors and the hash tables. A vector is an sequence of values referenced by an integer index. The lower index is 1.

  $\blacktriangleright$ V$\lbrack$i$\rbrack$

 
The expression references the element of index i in the vector V.

• V (input VECTOR).
• i (input INT).

  $\blacktriangleright$ VECTOR(v1,v2,...,vn)

 
The expression returns a vector of length n initialized with the values v1,v2,...,vn of any types.

• v1,...,vn (input ANY TYPE)

  $\blacktriangleright$ NEWVECTOR(n,v)

 
The expression returns a vector of length n. All elements are initialized with the same value v.

• n (input INT)
• v (input ANY TYPE)

The following expressions can be used to manipulate hash tables.

  $\blacktriangleright$ H$\{$k$\}$

 
The expression returns the element of key k in the hash table H. The value FALSE is returned when the key is not found in the hash table.

• H (input HASH).
• k (input ALL TYPE).

  $\blacktriangleright$ NEWHASH()

 
The expression returns an empty hash table.

  $\blacktriangleright$ CLEARHASH(H)

 
The statement remove all elements in the hash table H.

• H (input HASH)

  $\blacktriangleright$ HASHKEYS(H)

 
The expression returns a vector initialized with the keys in the hash table H.

• H (input HASH)

  $\blacktriangleright$ HASHVALUES(H)

 
The expression returns a vector initialized with the values in the hash table H. The values are given in the same order of the keys returned by the function HASHKEYS.

• H (input HASH)

The following are commons to vectors and hash tables.

  $\blacktriangleright$ LENGTH(M)

 
The expression returns the number of elements in the vector or the hash table M.

• M (input VECTOR or HASH)

$\vartriangleright$ Example 52:Print the content of a hash table.

  SCRIPT DumpHashTable(H)
    // Version with the keys
    keys := HASHKEYS(H)
    FOR i := 1,LENGTH(keys) DO
      k := keys[i]
      PRINT TOSTRING(k)+" => "+TOSTRING(H{k})
    ENDFOR
  ENDSCRIPT
  SCRIPT ShortDumpHashTable(H)
    // Version without the keys
    val := HASHVALUES(H)
    FOR i := 1,LENGTH(val) DO
      PRINT val[i]
    ENDFOR
  ENDSCRIPT

$\vartriangleright$ Example 53:A simple use of vectors and hash tables. Associate a string (in english) to its numerical value.

  SCRIPT main()
    // Create a vector of number (strings)
    v1 := VECTOR("one","two","three","four")
    // Create the equivalent vector of number (integers)
    v2 := NEWVECTOR(LENGTH(v1),FALSE)
    FOR i:=1,LENGTH(v2) DO
     v2[i] := i 
    ENDFOR
    // Associate v1 and v2 in a hash table
    h := NEWHASH 
    FOR i:=1,LENGTH(v1) DO
      h{v1[i]} := v2[i] 
    ENDFOR
    // Print the value associated to the string "two" 
    PRINT "The value of 'two' is "
    PRINT h{"two"}    
  ENDSCRIPT

In the current version of TSF, there are some syntaxical restrictions in the usage of vectors and hash tables. A element can not be used as a reference in a function call or in a script call. For example, it is not possible to write the following statement:

CALLSCRIPT my_script(&V[3])

When accessing an element (with $\lbrack\rbrack$ or $\{\}$), the left part must be a variable name. So, V[3] is allowed but not V[3][4] (i.e. the left part V[3] is not a variable name).