Merge branch 'master' of https://github.com/redpony/cdec

1 files changed, 0 insertions, 1335 deletions

diff --git a/jam-files/boost-build/build/feature.jam b/jam-files/boost-build/build/feature.jam
deleted file mode 100644
index 6f54adef..00000000
--- a/jam-files/boost-build/build/feature.jam
+++ /dev/null
@@ -1,1335 +0,0 @@
-# Copyright 2001, 2002, 2003 Dave Abrahams
-# Copyright 2002, 2006 Rene Rivera
-# Copyright 2002, 2003, 2004, 2005, 2006 Vladimir Prus
-# Distributed under the Boost Software License, Version 1.0.
-# (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
-
-import assert : * ;
-import "class" : * ;
-import errors : lol->list ;
-import indirect ;
-import modules ;
-import regex ;
-import sequence ;
-import set ;
-import utility ;
-
-
-local rule setup ( )
-{
-    .all-attributes =
-        implicit
-        composite
-        optional
-        symmetric
-        free
-        incidental
-        path
-        dependency
-        propagated
-        link-incompatible
-        subfeature
-        order-sensitive
-    ;
-
-    .all-features = ;
-    .all-subfeatures = ;
-    .all-top-features = ;  # non-subfeatures
-    .all-implicit-values = ;
-}
-setup ;
-
-
-# Prepare a fresh space to test in by moving all global variable settings into
-# the given temporary module and erasing them here.
-#
-rule prepare-test ( temp-module )
-{
-    DELETE_MODULE $(temp-module) ;
-
-    # Transfer globals to temp-module.
-    for local v in [ VARNAMES feature ]
-    {
-        if [ MATCH (\\.) : $(v) ]
-        {
-            modules.poke $(temp-module) : $(v) : $($(v)) ;
-            $(v) = ;
-        }
-    }
-    setup ;
-}
-
-
-# Clear out all global variables and recover all variables from the given
-# temporary module.
-#
-rule finish-test ( temp-module )
-{
-    # Clear globals.
-    for local v in [ VARNAMES feature ]
-    {
-        if [ MATCH (\\.) : $(v) ]
-        {
-            $(v) = ;
-        }
-    }
-
-    for local v in [ VARNAMES $(temp-module) ]
-    {
-        $(v) = [ modules.peek $(temp-module) : $(v) ] ;
-    }
-    DELETE_MODULE $(temp-module) ;
-}
-
-
-# Transform features by bracketing any elements which are not already bracketed
-# by "<>".
-#
-local rule grist ( features * )
-{
-    local empty = "" ;
-    return $(empty:G=$(features)) ;
-}
-
-
-# Declare a new feature with the given name, values, and attributes.
-#
-rule feature (
-      name          # Feature name.
-    : values *      # Allowable values - may be extended later using feature.extend.
-    : attributes *  # Feature attributes (e.g. implicit, free, propagated...).
-)
-{
-    name = [ grist $(name) ] ;
-
-    local error ;
-
-    # Check for any unknown attributes.
-    if ! ( $(attributes) in $(.all-attributes) )
-    {
-        error = unknown attributes:
-            [ set.difference $(attributes) : $(.all-attributes) ] ;
-    }
-    else if $(name) in $(.all-features)
-    {
-        error = feature already defined: ;
-    }
-    else if implicit in $(attributes) && free in $(attributes)
-    {
-        error = free features cannot also be implicit ;
-    }
-    else if free in $(attributes) && propagated in $(attributes)
-    {
-        error = free features cannot be propagated ;
-    }
-    else
-    {
-        local m = [ MATCH (.*=.*) : $(values) ] ;
-        if $(m[1])
-        {
-            error = "feature value may not contain '='" ;
-        }
-    }
-
-    if $(error)
-    {
-        errors.error $(error)
-              : "in" feature declaration:
-              : feature [ lol->list $(1) : $(2) : $(3) ] ;
-    }
-
-    $(name).values ?= ;
-    $(name).attributes = $(attributes) ;
-    $(name).subfeatures ?= ;
-    $(attributes).features += $(name) ;
-
-    .all-features += $(name) ;
-    if subfeature in $(attributes)
-    {
-        .all-subfeatures += $(name) ;
-    }
-    else
-    {
-        .all-top-features += $(name) ;
-    }
-    extend $(name) : $(values) ;
-}
-
-
-# Sets the default value of the given feature, overriding any previous default.
-#
-rule set-default ( feature : value )
-{
-    local f = [ grist $(feature) ] ;
-    local a = $($(f).attributes) ;
-    local bad-attribute = ;
-    if free in $(a)
-    {
-        bad-attribute = free ;
-    }
-    else if optional in $(a)
-    {
-        bad-attribute = optional ;
-    }
-    if $(bad-attribute)
-    {
-        errors.error "$(bad-attribute) property $(f) cannot have a default." ;
-    }
-    if ! $(value) in $($(f).values)
-    {
-        errors.error "The specified default value, '$(value)' is invalid"
-          : "allowed values are: " $($(f).values) ;
-    }
-    $(f).default = $(value) ;
-}
-
-
-# Returns the default property values for the given features.
-#
-rule defaults ( features * )
-{
-    local result ;
-    for local f in $(features)
-    {
-        local gf = $(:E=:G=$(f)) ;
-        local a = $($(gf).attributes) ;
-        if ( free in $(a) ) || ( optional in $(a) )
-        {
-        }
-        else
-        {
-            result += $(gf)$($(gf).default) ;
-        }
-    }
-    return $(result) ;
-}
-
-
-# Returns true iff all 'names' elements are valid features.
-#
-rule valid ( names + )
-{
-    if $(names) in $(.all-features)
-    {
-        return true ;
-    }
-}
-
-
-# Returns the attibutes of the given feature.
-#
-rule attributes ( feature )
-{
-    return $($(:E=:G=$(feature)).attributes) ;
-}
-
-
-# Returns the values of the given feature.
-#
-rule values ( feature )
-{
-    return $($(:E=:G=$(feature)).values) ;
-}
-
-
-# Returns true iff 'value-string' is a value-string of an implicit feature.
-#
-rule is-implicit-value ( value-string )
-{
-    local v = [ regex.split $(value-string) - ] ;
-    local failed ;
-    if ! $(v[1]) in $(.all-implicit-values)
-    {
-        failed = true ;
-    }
-    else
-    {
-        local feature = $($(v[1]).implicit-feature) ;
-        for local subvalue in $(v[2-])
-        {
-            if ! [ find-implied-subfeature $(feature) $(subvalue) : $(v[1]) ]
-            {
-                failed = true ;
-            }
-        }
-    }
-
-    if ! $(failed)
-    {
-        return true ;
-    }
-}
-
-
-# Returns the implicit feature associated with the given implicit value.
-#
-rule implied-feature ( implicit-value )
-{
-    local components = [ regex.split $(implicit-value) "-" ] ;
-
-    local feature = $($(components[1]).implicit-feature) ;
-    if ! $(feature)
-    {
-        errors.error \"$(implicit-value)\" is not a value of an implicit feature ;
-        feature = "" ;  # Keep testing happy; it expects a result.
-    }
-    return $(feature) ;
-}
-
-
-local rule find-implied-subfeature ( feature subvalue : value-string ? )
-{
-    # Feature should be of the form <feature-name>.
-    if $(feature) != $(feature:G)
-    {
-        errors.error invalid feature $(feature) ;
-    }
-
-    return $($(feature)$(value-string:E="")<>$(subvalue).subfeature) ;
-}
-
-
-# Given a feature and a value of one of its subfeatures, find the name of the
-# subfeature. If value-string is supplied, looks for implied subfeatures that
-# are specific to that value of feature
-#
-rule implied-subfeature (
-      feature         # The main feature name.
-      subvalue        # The value of one of its subfeatures.
-    : value-string ?  # The value of the main feature.
-)
-{
-    local subfeature = [ find-implied-subfeature $(feature) $(subvalue)
-        : $(value-string) ] ;
-    if ! $(subfeature)
-    {
-        value-string ?= "" ;
-        errors.error \"$(subvalue)\" is not a known subfeature value of
-            $(feature)$(value-string) ;
-    }
-    return $(subfeature) ;
-}
-
-
-# Generate an error if the feature is unknown.
-#
-local rule validate-feature ( feature )
-{
-    if ! $(feature) in $(.all-features)
-    {
-        errors.error unknown feature \"$(feature)\" ;
-    }
-}
-
-
-# Given a feature and its value or just a value corresponding to an implicit
-# feature, returns a property set consisting of all component subfeatures and
-# their values. For example all the following calls:
-#
-#   expand-subfeatures-aux <toolset>gcc-2.95.2-linux-x86
-#   expand-subfeatures-aux gcc-2.95.2-linux-x86
-#
-# return:
-#
-#   <toolset>gcc <toolset-version>2.95.2 <toolset-os>linux <toolset-cpu>x86
-#
-local rule expand-subfeatures-aux (
-      feature ?        # Feature name or empty if value corresponds to an
-                       # implicit property.
-    : value            # Feature value.
-    : dont-validate ?  # If set, no value string validation will be done.
-)
-{
-    if $(feature)
-    {
-        feature = $(feature) ;
-    }
-
-    if ! $(feature)
-    {
-        feature = [ implied-feature $(value) ] ;
-    }
-    else
-    {
-        validate-feature $(feature) ;
-    }
-    if ! $(dont-validate)
-    {
-        validate-value-string $(feature) $(value) ;
-    }
-
-    local components = [ regex.split $(value) "-" ] ;
-
-    # Get the top-level feature's value.
-    local value = $(components[1]:G=) ;
-
-    local result = $(components[1]:G=$(feature)) ;
-
-    local subvalues = $(components[2-]) ;
-    while $(subvalues)
-    {
-        local subvalue = $(subvalues[1]) ;  # Pop the head off of subvalues.
-        subvalues = $(subvalues[2-]) ;
-
-        local subfeature = [ find-implied-subfeature $(feature) $(subvalue) :
-            $(value) ] ;
-
-        # If no subfeature was found reconstitute the value string and use that.
-        if ! $(subfeature)
-        {
-            result = $(components:J=-) ;
-            result = $(result:G=$(feature)) ;
-            subvalues = ;  # Stop looping.
-        }
-        else
-        {
-            local f = [ MATCH ^<(.*)>$ : $(feature) ] ;
-            result += $(subvalue:G=$(f)-$(subfeature)) ;
-        }
-    }
-
-    return $(result) ;
-}
-
-
-# Make all elements of properties corresponding to implicit features explicit,
-# and express all subfeature values as separate properties in their own right.
-# For example, all of the following properties
-#
-#    gcc-2.95.2-linux-x86
-#    <toolset>gcc-2.95.2-linux-x86
-#
-# might expand to
-#
-#   <toolset>gcc <toolset-version>2.95.2 <toolset-os>linux <toolset-cpu>x86
-#
-rule expand-subfeatures (
-    properties *       # Property set with elements of the form
-                       # <feature>value-string or just value-string in the case
-                       # of implicit features.
-    : dont-validate ?
-)
-{
-    local result ;
-    for local p in $(properties)
-    {
-        # Don't expand subfeatures in subfeatures
-        if ! [ MATCH "(:)" : $(p:G) ]
-        {
-            result += [ expand-subfeatures-aux $(p:G) : $(p:G=) : $(dont-validate) ] ;
-        }
-        else
-        {
-            result += $(p) ;
-        }
-    }
-    return $(result) ;
-}
-
-
-# Helper for extend, below. Handles the feature case.
-#
-local rule extend-feature ( feature : values * )
-{
-    feature = [ grist $(feature) ] ;
-    validate-feature $(feature) ;
-    if implicit in $($(feature).attributes)
-    {
-        for local v in $(values)
-        {
-            if $($(v).implicit-feature)
-            {
-                errors.error $(v) is already associated with the \"$($(v).implicit-feature)\" feature ;
-            }
-            $(v).implicit-feature = $(feature) ;
-        }
-
-        .all-implicit-values += $(values) ;
-    }
-    if ! $($(feature).values)
-    {
-        # This is the first value specified for this feature so make it be the
-        # default.
-        $(feature).default = $(values[1]) ;
-    }
-    $(feature).values += $(values) ;
-}
-
-
-# Checks that value-string is a valid value-string for the given feature.
-#
-rule validate-value-string ( feature value-string )
-{
-    if ! (
-        free in $($(feature).attributes)
-        || ( $(value-string) in $(feature).values )
-    )
-    {
-        local values = $(value-string) ;
-
-        if $($(feature).subfeatures)
-        {
-            if ! ( $(value-string) in $($(feature).values) )
-               && ! ( $(value-string) in $($(feature).subfeatures) ) 
-            {
-                values = [ regex.split $(value-string) - ] ;
-            }
-        }
-
-        if ! ( $(values[1]) in $($(feature).values) ) &&
-
-            # An empty value is allowed for optional features.
-            ( $(values[1]) || ! ( optional in $($(feature).attributes) ) )
-        {
-            errors.error \"$(values[1])\" is not a known value of feature $(feature)
-                : legal values: \"$($(feature).values)\" ;
-        }
-
-        for local v in $(values[2-])
-        {
-            # This will validate any subfeature values in value-string.
-            implied-subfeature $(feature) $(v) : $(values[1]) ;
-        }
-    }
-}
-
-
-# A helper that computes:
-#  * name(s) of module-local variable(s) used to record the correspondence
-#    between subvalue(s) and a subfeature
-#  * value of that variable when such a subfeature/subvalue has been defined and
-# returns a list consisting of the latter followed by the former.
-#
-local rule subvalue-var (
-    feature         # Main feature name.
-    value-string ?  # If supplied, specifies a specific value of the main
-                    # feature for which the subfeature values are valid.
-    : subfeature    # Subfeature name.
-    : subvalues *   # Subfeature values.
-)
-{
-    feature = [ grist $(feature) ] ;
-    validate-feature $(feature) ;
-    if $(value-string)
-    {
-        validate-value-string $(feature) $(value-string) ;
-    }
-
-    local subfeature-name = [ get-subfeature-name $(subfeature) $(value-string) ] ;
-
-    return $(subfeature-name)
-    $(feature)$(value-string:E="")<>$(subvalues).subfeature ;
-}
-
-
-# Extends the given subfeature with the subvalues. If the optional value-string
-# is provided, the subvalues are only valid for the given value of the feature.
-# Thus, you could say that <target-platform>mingw is specific to
-# <toolset>gcc-2.95.2 as follows:
-#
-#       extend-subfeature toolset gcc-2.95.2 : target-platform : mingw ;
-#
-rule extend-subfeature (
-    feature         # The feature whose subfeature is being extended.
-
-    value-string ?  # If supplied, specifies a specific value of the main
-                    # feature for which the new subfeature values are valid.
-
-    : subfeature    # Subfeature name.
-    : subvalues *   # Additional subfeature values.
-)
-{
-    local subfeature-vars = [ subvalue-var $(feature) $(value-string)
-        : $(subfeature) : $(subvalues) ] ;
-
-    local f = [ utility.ungrist [ grist $(feature) ] ] ;
-    extend $(f)-$(subfeature-vars[1]) : $(subvalues) ;
-
-    # Provide a way to get from the given feature or property and subfeature
-    # value to the subfeature name.
-    $(subfeature-vars[2-]) = $(subfeature-vars[1]) ;
-}
-
-
-# Returns true iff the subvalues are valid for the feature. When the optional
-# value-string is provided, returns true iff the subvalues are valid for the
-# given value of the feature.
-#
-rule is-subvalue ( feature : value-string ? : subfeature : subvalue )
-{
-    local subfeature-vars = [ subvalue-var $(feature) $(value-string)
-        : $(subfeature) : $(subvalue) ] ;
-
-    if $($(subfeature-vars[2])) = $(subfeature-vars[1])
-    {
-        return true ;
-    }
-}
-
-
-# Can be called three ways:
-#
-#    1. extend feature : values *
-#    2. extend <feature> subfeature : values *
-#    3. extend <feature>value-string subfeature : values *
-#
-# * Form 1 adds the given values to the given feature.
-# * Forms 2 and 3 add subfeature values to the given feature.
-# * Form 3 adds the subfeature values as specific to the given property
-#   value-string.
-#
-rule extend ( feature-or-property subfeature ? : values * )
-{
-    local feature ;       # If a property was specified this is its feature.
-    local value-string ;  # E.g., the gcc-2.95-2 part of <toolset>gcc-2.95.2.
-
-    # If a property was specified.
-    if $(feature-or-property:G) && $(feature-or-property:G=)
-    {
-        # Extract the feature and value-string, if any.
-        feature = $(feature-or-property:G) ;
-        value-string = $(feature-or-property:G=) ;
-    }
-    else
-    {
-        feature = [ grist $(feature-or-property) ] ;
-    }
-
-    # Dispatch to the appropriate handler.
-    if $(subfeature)
-    {
-        extend-subfeature $(feature) $(value-string) : $(subfeature)
-            : $(values) ;
-    }
-    else
-    {
-        # If no subfeature was specified, we do not expect to see a
-        # value-string.
-        if $(value-string)
-        {
-            errors.error can only specify a property as the first argument when
-                extending a subfeature
-                : usage:
-                : "    extend" feature ":" values...
-                : "  | extend" <feature>value-string subfeature ":" values...
-                ;
-        }
-
-        extend-feature $(feature) : $(values) ;
-    }
-}
-
-
-local rule get-subfeature-name ( subfeature value-string ? )
-{
-    local prefix = $(value-string): ;
-    return $(prefix:E="")$(subfeature) ;
-}
-
-
-# Declares a subfeature.
-#
-rule subfeature (
-    feature         # Root feature that is not a subfeature.
-    value-string ?  # A value-string specifying which feature or subfeature
-                    # values this subfeature is specific to, if any.
-    : subfeature    # The name of the subfeature being declared.
-    : subvalues *   # The allowed values of this subfeature.
-    : attributes *  # The attributes of the subfeature.
-)
-{
-    feature = [ grist $(feature) ] ;
-    validate-feature $(feature) ;
-
-    # Add grist to the subfeature name if a value-string was supplied.
-    local subfeature-name = [ get-subfeature-name $(subfeature) $(value-string) ] ;
-
-    if $(subfeature-name) in $($(feature).subfeatures)
-    {
-        errors.error \"$(subfeature)\" already declared as a subfeature of \"$(feature)\"
-            "specific to "$(value-string) ;
-    }
-    $(feature).subfeatures += $(subfeature-name) ;
-
-    # First declare the subfeature as a feature in its own right.
-    local f = [ utility.ungrist $(feature) ] ;
-    feature $(f)-$(subfeature-name) : $(subvalues) : $(attributes) subfeature ;
-
-    # Now make sure the subfeature values are known.
-    extend-subfeature $(feature) $(value-string) : $(subfeature) : $(subvalues) ;
-}
-
-
-# Set components of the given composite property.
-#
-rule compose ( composite-property : component-properties * )
-{
-    local feature = $(composite-property:G) ;
-    if ! ( composite in [ attributes $(feature) ] )
-    {
-        errors.error "$(feature)" is not a composite feature ;
-    }
-
-    $(composite-property).components ?= ;
-    if $($(composite-property).components)
-    {
-        errors.error components of "$(composite-property)" already set:
-            $($(composite-property).components) ;
-    }
-
-    if $(composite-property) in $(component-properties)
-    {
-        errors.error composite property "$(composite-property)" cannot have itself as a component ;
-    }
-    $(composite-property).components = $(component-properties) ;
-}
-
-
-local rule expand-composite ( property )
-{
-    return $(property)
-        [ sequence.transform expand-composite : $($(property).components) ] ;
-}
-
-
-# Return all values of the given feature specified by the given property set.
-#
-rule get-values ( feature : properties * )
-{
-    local result ;
-
-    feature = $(:E=:G=$(feature)) ;  # Add <> if necessary.
-    for local p in $(properties)
-    {
-        if $(p:G) = $(feature)
-        {
-            # Use MATCH instead of :G= to get the value, in order to preserve
-            # the value intact instead of having bjam treat it as a decomposable
-            # path.
-            result += [ MATCH ">(.*)" : $(p) ] ;
-        }
-    }
-    return $(result) ;
-}
-
-
-rule free-features ( )
-{
-    return $(free.features) ;
-}
-
-
-# Expand all composite properties in the set so that all components are
-# explicitly expressed.
-#
-rule expand-composites ( properties * )
-{
-    local explicit-features = $(properties:G) ;
-    local result ;
-
-    # Now expand composite features.
-    for local p in $(properties)
-    {
-        local expanded = [ expand-composite $(p) ] ;
-
-        for local x in $(expanded)
-        {
-            if ! $(x) in $(result)
-            {
-                local f = $(x:G) ;
-
-                if $(f) in $(free.features)
-                {
-                    result += $(x) ;
-                }
-                else if ! $(x) in $(properties)  # x is the result of expansion
-                {
-                    if ! $(f) in $(explicit-features)  # not explicitly-specified
-                    {
-                        if $(f) in $(result:G)
-                        {
-                            errors.error expansions of composite features result
-                                in conflicting values for $(f)
-                                : values: [ get-values $(f) : $(result) ] $(x:G=)
-                                : one contributing composite property was $(p) ;
-                        }
-                        else
-                        {
-                            result += $(x) ;
-                        }
-                    }
-                }
-                else if $(f) in $(result:G)
-                {
-                    errors.error explicitly-specified values of non-free feature
-                        $(f) conflict :
-                        "existing values:" [ get-values $(f) : $(properties) ] :
-                        "value from expanding " $(p) ":" $(x:G=) ;
-                }
-                else
-                {
-                    result += $(x) ;
-                }
-            }
-        }
-    }
-    return $(result) ;
-}
-
-
-# Return true iff f is an ordinary subfeature of the parent-property's feature,
-# or if f is a subfeature of the parent-property's feature specific to the
-# parent-property's value.
-#
-local rule is-subfeature-of ( parent-property f )
-{
-    if subfeature in $($(f).attributes)
-    {
-        local specific-subfeature = [ MATCH <(.*):(.*)> : $(f) ] ;
-        if $(specific-subfeature)
-        {
-            # The feature has the form <topfeature-topvalue:subfeature>, e.g.
-            # <toolset-msvc:version>.
-            local feature-value = [ split-top-feature $(specific-subfeature[1])
-                ] ;
-            if <$(feature-value[1])>$(feature-value[2]) = $(parent-property)
-            {
-                return true ;
-            }
-        }
-        else
-        {
-            # The feature has the form <topfeature-subfeature>, e.g.
-            # <toolset-version>
-            local top-sub = [ split-top-feature [ utility.ungrist $(f) ] ] ;
-            if $(top-sub[2]) && <$(top-sub[1])> = $(parent-property:G)
-            {
-                return true ;
-            }
-        }
-    }
-}
-
-
-# As for is-subfeature-of but for subproperties.
-#
-local rule is-subproperty-of ( parent-property p )
-{
-    return [ is-subfeature-of $(parent-property) $(p:G) ] ;
-}
-
-
-# Given a property, return the subset of features consisting of all ordinary
-# subfeatures of the property's feature, and all specific subfeatures of the
-# property's feature which are conditional on the property's value.
-#
-local rule select-subfeatures ( parent-property : features * )
-{
-    return [ sequence.filter is-subfeature-of $(parent-property) : $(features) ] ;
-}
-
-
-# As for select-subfeatures but for subproperties.
-#
-local rule select-subproperties ( parent-property : properties * )
-{
-    return [ sequence.filter is-subproperty-of $(parent-property) : $(properties) ] ;
-}
-
-
-# Given a property set which may consist of composite and implicit properties
-# and combined subfeature values, returns an expanded, normalized property set
-# with all implicit features expressed explicitly, all subfeature values
-# individually expressed, and all components of composite properties expanded.
-# Non-free features directly expressed in the input properties cause any values
-# of those features due to composite feature expansion to be dropped. If two
-# values of a given non-free feature are directly expressed in the input, an
-# error is issued.
-#
-rule expand ( properties * )
-{
-    local expanded = [ expand-subfeatures $(properties) ] ;
-    return [ expand-composites $(expanded) ] ;
-}
-
-
-# Helper rule for minimize. Returns true iff property's feature is present in
-# the contents of the variable named by feature-set-var.
-#
-local rule in-features ( feature-set-var property )
-{
-    if $(property:G) in $($(feature-set-var))
-    {
-        return true ;
-    }
-}
-
-
-# Helper rule for minimize. Returns the list with the same properties, but with
-# all subfeatures moved to the end of the list.
-#
-local rule move-subfeatures-to-the-end ( properties * )
-{
-    local x1 ;
-    local x2 ;
-    for local p in $(properties)
-    {
-        if subfeature in $($(p:G).attributes)
-        {
-            x2 += $(p) ;
-        }
-        else
-        {
-            x1 += $(p) ;
-        }
-    }
-    return $(x1) $(x2) ;
-}
-
-
-# Given an expanded property set, eliminate all redundancy: properties that are
-# elements of other (composite) properties in the set will be eliminated.
-# Non-symmetric properties equal to default values will be eliminated unless
-# they override a value from some composite property. Implicit properties will
-# be expressed without feature grist, and sub-property values will be expressed
-# as elements joined to the corresponding main property.
-#
-rule minimize ( properties * )
-{
-    # Precondition checking
-    local implicits = [ set.intersection $(p:G=) : $(p:G) ] ;
-    if $(implicits)
-    {
-        errors.error minimize requires an expanded property set, but
-            \"$(implicits[1])\" appears to be the value of an un-expanded
-            implicit feature ;
-    }
-
-    # Remove properties implied by composite features.
-    local components = $($(properties).components) ;
-    local x = [ set.difference $(properties) : $(components) ] ;
-
-    # Handle subfeatures and implicit features.
-    x = [ move-subfeatures-to-the-end $(x) ] ;
-    local result ;
-    while $(x)
-    {
-        local p fullp = $(x[1]) ;
-        local f = $(p:G) ;
-        local v = $(p:G=) ;
-
-        # Eliminate features in implicit properties.
-        if implicit in [ attributes $(f) ]
-        {
-            p = $(v) ;
-        }
-
-        # Locate all subproperties of $(x[1]) in the property set.
-        local subproperties = [ select-subproperties $(fullp) : $(x) ] ;
-        if $(subproperties)
-        {
-            # Reconstitute the joined property name.
-            local sorted = [ sequence.insertion-sort $(subproperties) ] ;
-            result += $(p)-$(sorted:G="":J=-) ;
-
-            x = [ set.difference $(x[2-]) : $(subproperties) ] ;
-        }
-        else
-        {
-            # Eliminate properties whose value is equal to feature's default,
-            # which are not symmetric and which do not contradict values implied
-            # by composite properties.
-
-            # Since all component properties of composites in the set have been
-            # eliminated, any remaining property whose feature is the same as a
-            # component of a composite in the set must have a non-redundant
-            # value.
-            if $(fullp) != [ defaults $(f) ]
-                || symmetric in [ attributes $(f) ]
-                || $(fullp:G) in $(components:G)
-            {
-                result += $(p) ;
-            }
-
-            x = $(x[2-]) ;
-        }
-    }
-    return $(result) ;
-}
-
-
-# Combine all subproperties into their parent properties
-#
-# Requires: for every subproperty, there is a parent property. All features are
-# explicitly expressed.
-#
-# This rule probably should not be needed, but build-request.expand-no-defaults
-# is being abused for unintended purposes and it needs help.
-#
-rule compress-subproperties ( properties * )
-{
-    local all-subs ;
-    local matched-subs ;
-    local result ;
-
-    for local p in $(properties)
-    {
-        if ! $(p:G)
-        {
-            # Expecting fully-gristed properties.
-            assert.variable-not-empty p:G ;
-        }
-
-        if ! subfeature in $($(p:G).attributes)
-        {
-            local subs = [ sequence.insertion-sort
-                [ sequence.filter is-subproperty-of $(p) : $(properties) ] ] ;
-
-            matched-subs += $(subs) ;
-
-            local subvalues = -$(subs:G=:J=-) ;
-            subvalues ?= "" ;
-            result += $(p)$(subvalues) ;
-        }
-        else
-        {
-            all-subs += $(p) ;
-        }
-    }
-    assert.result true : set.equal $(all-subs) : $(matched-subs) ;
-    return $(result) ;
-}
-
-
-# Given an ungristed string, finds the longest prefix which is a top-level
-# feature name followed by a dash, and return a pair consisting of the parts
-# before and after that dash. More interesting than a simple split because
-# feature names may contain dashes.
-#
-local rule split-top-feature ( feature-plus )
-{
-    local e = [ regex.split $(feature-plus) - ] ;
-    local f = $(e[1]) ;
-    local v ;
-    while $(e)
-    {
-        if <$(f)> in $(.all-top-features)
-        {
-            v = $(f) $(e[2-]:J=-) ;
-        }
-        e = $(e[2-]) ;
-        f = $(f)-$(e[1]) ;
-    }
-    return $(v) ;
-}
-
-
-# Given a set of properties, add default values for features not represented in
-# the set.
-#
-# Note: if there's an ordinary feature F1 and a composite feature F2 which
-# includes some value for F1 and both feature have default values then the
-# default value of F1 will be added (as opposed to the value in F2). This might
-# not be the right idea, e.g. consider:
-#
-#   feature variant : debug ... ;
-#        <variant>debug : .... <runtime-debugging>on
-#   feature <runtime-debugging> : off on ;
-#
-#   Here, when adding default for an empty property set, we'll get
-#
-#     <variant>debug <runtime_debugging>off
-#
-#   and that's kind of strange.
-#
-rule add-defaults ( properties * )
-{
-    for local v in $(properties:G=)
-    {
-        if $(v) in $(properties)
-        {
-            errors.error add-defaults requires explicitly specified features,
-                but \"$(v)\" appears to be the value of an un-expanded implicit
-                feature ;
-        }
-    }
-    # We don't add default for elements with ":" inside. This catches:
-    # 1. Conditional properties --- we don't want <variant>debug:<define>DEBUG
-    #    to be takes as specified value for <variant>
-    # 2. Free properties with ":" in values. We don't care, since free
-    #    properties don't have defaults.
-    local xproperties = [ MATCH "^([^:]+)$" : $(properties) ] ;
-    local missing-top = [ set.difference $(.all-top-features) : $(xproperties:G) ] ;
-    local more =  [ defaults $(missing-top) ] ;
-    properties += $(more) ;
-    xproperties += $(more) ;
-
-    # Add defaults for subfeatures of features which are present.
-    for local p in $(xproperties)
-    {
-        local s = $($(p:G).subfeatures) ;
-        local f = [ utility.ungrist $(p:G) ] ;
-        local missing-subs = [ set.difference <$(f)-$(s)> : $(properties:G) ] ;
-        properties += [ defaults [ select-subfeatures $(p) : $(missing-subs) ] ] ;
-    }
-
-    return $(properties)  ;
-}
-
-
-# Given a property-set of the form
-#       v1/v2/...vN-1/<fN>vN/<fN+1>vN+1/...<fM>vM
-#
-# Returns
-#       v1 v2 ... vN-1 <fN>vN <fN+1>vN+1 ... <fM>vM
-#
-# Note that vN...vM may contain slashes. This needs to be resilient to the
-# substitution of backslashes for slashes, since Jam, unbidden, sometimes swaps
-# slash direction on NT.
-#
-rule split ( property-set )
-{
-    local pieces = [ regex.split $(property-set) [\\/] ] ;
-    local result ;
-
-    for local x in $(pieces)
-    {
-        if ( ! $(x:G) ) && $(result[-1]:G)
-        {
-            result = $(result[1--2]) $(result[-1])/$(x) ;
-        }
-        else
-        {
-            result += $(x) ;
-        }
-    }
-
-    return $(result) ;
-}
-
-
-# Tests of module feature.
-#
-rule __test__ ( )
-{
-    # Use a fresh copy of the feature module.
-    prepare-test feature-test-temp ;
-
-    import assert ;
-    import errors : try catch ;
-
-    # These are local rules and so must be explicitly reimported into the
-    # testing module.
-    import feature : extend-feature validate-feature select-subfeatures ;
-
-    feature toolset : gcc : implicit ;
-    feature define : : free ;
-    feature runtime-link : dynamic static : symmetric ;
-    feature optimization : on off ;
-    feature variant : debug release profile : implicit composite symmetric ;
-    feature stdlib : native stlport ;
-    feature magic : : free ;
-
-    compose <variant>debug : <define>_DEBUG <optimization>off ;
-    compose <variant>release : <define>NDEBUG <optimization>on ;
-
-    assert.result dynamic static : values <runtime-link> ;
-    assert.result dynamic static : values runtime-link ;
-
-    try ;
-    {
-        compose <variant>profile : <variant>profile ;
-    }
-    catch composite property <variant>profile cannot have itself as a component ;
-
-    extend-feature toolset : msvc metrowerks ;
-    subfeature toolset gcc : version : 2.95.2 2.95.3 2.95.4 3.0 3.0.1 3.0.2 ;
-
-    assert.true is-subvalue toolset : gcc : version : 2.95.3 ;
-    assert.false is-subvalue toolset : gcc : version : 1.1 ;
-
-    assert.false is-subvalue toolset : msvc : version : 2.95.3 ;
-    assert.false is-subvalue toolset : : version : yabba ;
-
-    feature yabba ;
-    subfeature yabba : version : dabba ;
-    assert.true is-subvalue yabba : : version : dabba ;
-
-    subfeature toolset gcc : platform : linux cygwin : optional ;
-
-    assert.result <toolset-gcc:version>
-        : select-subfeatures <toolset>gcc
-        : <toolset-gcc:version>
-          <toolset-msvc:version>
-          <toolset-version>
-          <stdlib> ;
-
-    subfeature stdlib : version : 3 4 : optional ;
-
-    assert.result <stdlib-version>
-        : select-subfeatures <stdlib>native
-        : <toolset-gcc:version>
-          <toolset-msvc:version>
-          <toolset-version>
-          <stdlib-version> ;
-
-    assert.result <toolset>gcc <toolset-gcc:version>3.0.1
-        : expand-subfeatures <toolset>gcc-3.0.1 ;
-
-    assert.result <toolset>gcc <toolset-gcc:version>3.0.1 <toolset-gcc:platform>linux
-        : expand-subfeatures <toolset>gcc-3.0.1-linux ;
-
-    assert.result <toolset>gcc <toolset-gcc:version>3.0.1
-        : expand <toolset>gcc <toolset-gcc:version>3.0.1  ;
-
-    assert.result <define>foo=x-y
-        : expand-subfeatures <define>foo=x-y ;
-
-    assert.result <toolset>gcc <toolset-gcc:version>3.0.1
-        : expand-subfeatures gcc-3.0.1 ;
-
-    assert.result a c e
-        : get-values <x> : <x>a <y>b <x>c <y>d <x>e ;
-
-    assert.result <toolset>gcc <toolset-gcc:version>3.0.1
-        <variant>debug <define>_DEBUG <optimization>on
-        : expand gcc-3.0.1 debug <optimization>on ;
-
-    assert.result <variant>debug <define>_DEBUG <optimization>on
-        : expand debug <optimization>on ;
-
-    assert.result <optimization>on <variant>debug <define>_DEBUG
-        : expand <optimization>on debug ;
-
-    assert.result <runtime-link>dynamic <optimization>on
-        : defaults <runtime-link> <define> <optimization> ;
-
-    # Make sure defaults is resilient to missing grist.
-    assert.result <runtime-link>dynamic <optimization>on
-        : defaults runtime-link define optimization ;
-
-    feature dummy : dummy1 dummy2 ;
-    subfeature dummy : subdummy : x y z : optional ;
-
-    feature fu : fu1 fu2 : optional ;
-    subfeature fu : subfu : x y z : optional ;
-    subfeature fu : subfu2 : q r s ;
-
-    assert.result optional : attributes <fu> ;
-    assert.result optional : attributes fu ;
-
-    assert.result <runtime-link>static <define>foobar <optimization>on
-        <toolset>gcc:<define>FOO <toolset>gcc <variant>debug <stdlib>native
-        <dummy>dummy1 <toolset-gcc:version>2.95.2
-        : add-defaults <runtime-link>static <define>foobar <optimization>on
-          <toolset>gcc:<define>FOO ;
-
-    assert.result <runtime-link>static <define>foobar <optimization>on
-        <toolset>gcc:<define>FOO <fu>fu1 <toolset>gcc <variant>debug
-        <stdlib>native <dummy>dummy1 <fu-subfu2>q <toolset-gcc:version>2.95.2
-        : add-defaults <runtime-link>static <define>foobar <optimization>on
-          <toolset>gcc:<define>FOO <fu>fu1 ;
-
-    set-default <runtime-link> : static ;
-    assert.result <runtime-link>static : defaults <runtime-link> ;
-
-    assert.result gcc-3.0.1 debug <optimization>on
-        : minimize [ expand gcc-3.0.1 debug <optimization>on <stdlib>native ] ;
-
-    assert.result gcc-3.0.1 debug <runtime-link>dynamic
-        : minimize
-          [ expand gcc-3.0.1 debug <optimization>off <runtime-link>dynamic ] ;
-
-    assert.result gcc-3.0.1 debug
-        : minimize [ expand gcc-3.0.1 debug <optimization>off ] ;
-
-    assert.result debug <optimization>on
-        : minimize [ expand debug <optimization>on ] ;
-
-    assert.result gcc-3.0
-        : minimize <toolset>gcc <toolset-gcc:version>3.0 ;
-
-    assert.result gcc-3.0
-        : minimize <toolset-gcc:version>3.0 <toolset>gcc ;
-
-    assert.result <x>y/z <a>b/c <d>e/f
-        : split <x>y/z/<a>b/c/<d>e/f ;
-
-    assert.result <x>y/z <a>b/c <d>e/f
-        : split <x>y\\z\\<a>b\\c\\<d>e\\f ;
-
-    assert.result a b c <d>e/f/g <h>i/j/k
-        : split a/b/c/<d>e/f/g/<h>i/j/k ;
-
-    assert.result a b c <d>e/f/g <h>i/j/k
-        : split a\\b\\c\\<d>e\\f\\g\\<h>i\\j\\k ;
-
-    # Test error checking.
-
-    try ;
-    {
-        expand release <optimization>off <optimization>on ;
-    }
-    catch explicitly-specified values of non-free feature <optimization> conflict ;
-
-    try ;
-    {
-        validate-feature <foobar> ;
-    }
-    catch unknown feature ;
-
-    validate-value-string <toolset> gcc ;
-    validate-value-string <toolset> gcc-3.0.1 ;
-
-    try ;
-    {
-        validate-value-string <toolset> digital_mars ;
-    }
-    catch \"digital_mars\" is not a known value of <toolset> ;
-
-    try ;
-    {
-        feature foobar : : baz ;
-    }
-    catch unknown attributes: baz ;
-
-    feature feature1 ;
-    try ;
-    {
-        feature feature1 ;
-    }
-    catch feature already defined: ;
-
-    try ;
-    {
-        feature feature2 : : free implicit ;
-    }
-    catch free features cannot also be implicit ;
-
-    try ;
-    {
-        feature feature3 : : free propagated ;
-    }
-    catch free features cannot be propagated ;
-
-    try ;
-    {
-        implied-feature lackluster ;
-    }
-    catch \"lackluster\" is not a value of an implicit feature ;
-
-    try ;
-    {
-        implied-subfeature <toolset> 3.0.1 ;
-    }
-    catch \"3.0.1\" is not a known subfeature value of <toolset> ;
-
-    try ;
-    {
-        implied-subfeature <toolset> not-a-version : gcc ;
-    }
-    catch \"not-a-version\" is not a known subfeature value of <toolset>gcc ;
-
-    # Leave a clean copy of the features module behind.
-    finish-test feature-test-temp ;
-}