NAME

stringinttab - string table lookup module

SYNOPSIS

include "strinttab.m";
StringInt: import StringIntTab;

strinttab := load StringIntTab StringIntTab->PATH;

StringInt: adt{
    key: string;
    val: int;
};

lookup:    fn(tab: array of StringInt, key: string) : (int, int);
revlookup: fn(tab: array of StringInt, val: int)    : string;

DESCRIPTION

Stringinttab provides functions that perform forward and reverse searches of an ordered table of key-value pairs.

A table should be constructed as an array of StringInt entries, ordered by increasing key value. Keys ordering is determined by comparison of the Unicode value of their characters.

Lookup performs a binary search of tab for the StringInt entry whose key field has a value equal to key and returns a tuple: an int whose value is non-zero if a match has been found and zero otherwise, and an int whose value is equal to the val field of the matching StringInt entry.

Revlookup searches tab for the first StringInt entry whose val field has a value equal to val and returns the corresponding key string.

EXAMPLES

T := load StringIntTab StringIntTab->PATH;

fmtstringtab := array[] of { Strinttab->StringInt
	("html", FHtml),
	("latex", FLatex),
	("latexbook", FLatexBook),
	("latexpart", FLatexPart),
	("latexproc", FLatexProc),
	("latexslides", FLatexSlides),
};

(fnd, fmt) := T->lookup(fmtstringtab, "latexbook");
fmtstring := T->revlookup(fmtstringtab, FLatex);

SOURCE

/appl/lib/strinttab.b

SEE ALSO

hash(2)

BUGS

Revlookup performs a sequential search of the table.

STRINGINTTAB(2 )

Rev:  Tue Mar 31 02:42:39 GMT 2015