The following functions perform text processing operations:

1  –  ADDPREFIX

    $(ADDPREFIX prefix,text)

    Prepends to text. 'prefix' is prepended to the start of each word
    in 'text'.

2  –  ADDSUFFIX

    $(ADDSUFFIX suffix,text)

    Appends to text. 'suffix' is appended to the end of each word in
    'text'.

3  –  FILTER

    $(FILTER pattern...,text)

    Filters text. Any word in 'text' that does not match any 'pattern'
    word is removed. 'pattern' words may contain the wildcard
    characters * and %.

4  –  FILTER-OUT

    $(FILTER-OUT pattern...,text)

    Filters text. Any word in 'text' that matches any 'pattern' word
    is removed. 'pattern' words may contain the wildcard characters
    * and %.

5  –  FINDSTRING

    $(FINDSTRING find,text)
    String search. If 'find' occurs in 'text', the value is 'find';
    otherwise, the value is empty.

6  –  FIRSTWORD

    $(FIRSTWORD text)

    Returns the first word in 'text'.

7  –  FOREACH

    $(FOREACH macro,list,text)

    Repeatedly expands text. For each word in 'list', 'text' is
    repeated with the value of 'macro' defined as the word from 'list'.

8  –  JOIN

    $(JOIN list,text)

    Concatenates word by word. Each word in 'text' is appended to the
    corresponding word in 'list' to form a word in the result. When
    the number of words in 'list' and 'text' are not the same, the
    remaining words from the longer list are simply appended to the
    result.

9  –  PATSUBST

    $(PATSUBST pattern...,to,text)

    Pattern substitution. Each word in 'text' that matches any
    'pattern'    word is replaced by 'to'. 'pattern' words may contain
    the wildcard characters * and %. If 'to' also contains wildcard
    characters, they will be replaced by the text that matched the
    wildcard characters in 'pattern'.

10  –  SORT

    $(SORT text)

    Sorts text. Words in 'text' are sorted into lexical order;
    duplicated words are removed.

11  –  STRIP

    $(STRIP text)

    White-space compression. Leading and trailing white-space is
    removed from 'text' and each internal sequence of white-space
    characters is replaced by a single space.

12  –  SUBST

    $(SUBST from,to,text)

    String substitution. Each occurrence of 'from' in 'text' is
    replaced by 'to'.

13  –  WORD

    $(WORD n,text)

    Returns the n'th word from 'text'. 'n' should be in the range 1 to the
    number of words in the list; when 'n' is not in this range, the result
    is empty.

14  –  WORDS

    $(WORDS text)

    Returns the number of words in 'text'.