###############################################################################
#
# auxiliary.eagle --
#
# Extensible Adaptable Generalized Logic Engine (Eagle)
# Eagle Auxiliary Package File
#
# Copyright (c) 2007-2012 by Joe Mistachkin. All rights reserved.
#
# See the file "license.terms" for information on usage and redistribution of
# this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: $
#
###############################################################################
#
# NOTE: Use our own namespace here because even though we do not directly
# support namespaces ourselves, we do not want to pollute the global
# namespace if this script actually ends up being evaluated in Tcl.
#
namespace eval ::Eagle {
#
# NOTE: This procedure returns the value of an environment variable, if
# it actually exists; otherwise, an empty string is returned.
#
proc getEnvironmentVariable { name } {
global env
return [expr {[info exists env($name)] ? $env($name) : ""}]
}
#
# NOTE: This procedure accepts an any number of arguments. The arguments
# are appended into one big string, verbatim. The resulting string
# is returned. Normally, this procedure is used to avoid undesired
# string interpolation operations.
#
proc appendArgs { args } {
set result ""; eval append result $args
}
#
# NOTE: This procedure attempts to locate the first named value we are
# interested in. The dictionary argument must be a list with an
# even number of elements in the following format:
#
# <name1> <value1> <name2> <value2> ... <nameN> <valueN>
#
proc getDictionaryValue { dictionary name {default ""} {wrap ""} } {
foreach {pairName pairValue} $dictionary {
#
# NOTE: Does this name match the one specified by the caller?
#
if {$pairName eq $name} then {
#
# NOTE: Return the value, optionally wrapped.
#
return [appendArgs $wrap $pairValue $wrap]
}
}
#
# NOTE: No match was found, return the default value.
#
return $default
}
#
# NOTE: This procedure exports one or more commands from the specified
# namespace and imports them into the global namespace, optionally
# forgetting all previous imports from the specified namespace.
#
proc exportAndImportPackageCommands { namespace exports forget force } {
#
# NOTE: Forget any previous commands that were imported from
# this namespace into the global namespace?
#
if {$forget} then {
namespace eval :: [list namespace forget [appendArgs $namespace ::*]]
}
#
# NOTE: Process each command to be exported from the specified
# namespace and import it into the global namespace, if
# necessary.
#
foreach export $exports {
#
# NOTE: Force importing of our exported commands into the global
# namespace? Otherwise, see if the command is already
# present in the global namespace before trying to import
# it.
#
if {$force || \
[llength [info commands [appendArgs :: $export]]] == 0} then {
#
# NOTE: Export the specified command from the specified namespace.
#
namespace eval $namespace [list namespace export $export]
#
# NOTE: Import the specified command into the global namespace.
#
set namespaceExport [appendArgs $namespace :: $export]
if {$force} then {
namespace eval :: [list namespace import -force $namespaceExport]
} else {
namespace eval :: [list namespace import $namespaceExport]
}
}
}
}
#
# NOTE: Provide the Eagle "auxiliary" package to the interpreter.
#
package provide Eagle.Auxiliary \
[expr {[isEagle] ? [info engine PatchLevel] : "1.0"}]
}
