Summary

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	File:     tables.icn

	Subject:  Procedures for table manipulation

	Author:   Ralph E. Griswold

	Date:     August 20, 1996

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   This file is in the public domain.

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	Contributor:  Alan Beale

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 	keylist(T)	  produces list of keys in table T.

	kvallist(T)	  produces values in T ordered by sorted order
			  of keys.

	tbleq(T1, T2)	  tests equivalences of tables T1 amd T2.
  
	tblunion(T1, T2)  approximates T1 ++ T2.

	tblinter(T1, T2)  approximates T1 ** T2.

	tbldiff(T1, T2)	  approximates T1 -- T2.

	tblinvrt(T)	  produces a table whose keys are T's values and
			  whose values are T's keys.

	tbldflt(T)	  produces the default value for T.

	twt(T)		  produces a two-way table based on T.

	vallist(T)	  produces list of values in table T.

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  For the operations on tables that mimic set operations, the
  correspondences are only approximate and do not have the mathematical
  properties of the corresponding operations on  sets.  For example, table
  "union" is not symmetric or transitive.

  Where there is potential asymmetry, the procedures "favor" their
  first argument.

  All the procedures that return tables return new tables and do not
  modify their arguments.

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This file is part of the (main) package.

keylist(tbl)

: list of keys in table

kvallist(T)

tbldflt(T)

: table default

tbldiff(T1, T2)

: table difference

tbleq(tbl1, tbl2)

: table equivalence

tblinter(T1, T2)

: table intersection

tblinvrt(T)

: table inversion

tblunion(T1, T2)

: table union

twt(T)

: two-way table

vallist(tbl)

: list of table values

valset(tbl)

: set of table values