shithub: purgatorio

ref: 3efb5bbb4061056e523858b134c555949591efe2
dir: /man/2/stringinttab/

.TH STRINGINTTAB 2
.SH NAME
stringinttab \- string table lookup module
.SH SYNOPSIS
.EX
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;
.EE
.SH DESCRIPTION
.B Stringinttab
provides functions that perform forward and reverse searches of an ordered table of
.I key\-value
pairs.
.PP
A table should be constructed as an array of
.B StringInt
entries, ordered by increasing
.I key
value.  Keys ordering is determined by comparison of the Unicode
value of their characters.
.PP
.B Lookup
performs a binary search of
.I tab
for the
.B StringInt
entry whose
.B key
field has a value equal to
.I key
and returns a tuple: an
.B int
whose value is non-zero if a match has been found and zero otherwise,
and an
.B int
whose value is equal to the
.B val
field of the matching
.B StringInt
entry.
.PP
.B Revlookup
searches
.I tab
for the first
.B StringInt
entry whose
.B val
field has a value equal to
.I val
and returns the corresponding
.B key
string.
.SH EXAMPLES
.EX
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);
.EE
.SH SOURCE
.B /appl/lib/strinttab.b
.SH SEE ALSO
.IR hash (2)
.SH BUGS
.B Revlookup
performs a sequential search of the table.