[gentoo-python] [PATCH python-any-r1] Introduce python_gen_any_dep().

[Michał Górny]

This thingie allows you to get huge, beautiful dependency blocks that
can accompany python_check_deps() in making python-any-r1 finally work
like it is supposed to.

Use like:

$(python_gen_any_dep 'dev-python/foo[${PYTHON_USEDEP}] ...')

  beware: single quotes!

and get:

|| (
    ( dev-lang/python:2.7 dev-python/foo[...2_7...] )
    ( dev-lang/python:2.6 dev-python/foo[...2_6...] )
)
---
 gx86/eclass/python-any-r1.eclass | 61 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/gx86/eclass/python-any-r1.eclass b/gx86/eclass/python-any-r1.eclass
index 3be995f..72ec914 100644
--- a/gx86/eclass/python-any-r1.eclass
+++ b/gx86/eclass/python-any-r1.eclass
@@ -156,6 +156,67 @@ _python_build_set_globals
 # python_targets_python2_7(-)?,python_single_target_python2_7(+)?
 # @CODE
 
+# @FUNCTION: python_gen_any_dep
+# @USAGE: <dependency-block>
+# @DESCRIPTION:
+# Generate an any-of dependency that enforces a version match between
+# the Python interpreter and Python packages. <dependency-block> needs
+# to list one or more dependencies with verbatim '${PYTHON_USEDEP}'
+# references (quoted!) that will get expanded inside the function.
+#
+# This should be used along with an appropriate python_check_deps()
+# that checks which of the any-of blocks were matched.
+#
+# Example use:
+# @CODE
+# DEPEND="$(python_gen_any_dep '
+#	dev-python/foo[${PYTHON_USEDEP}]
+#	|| ( dev-python/bar[${PYTHON_USEDEP}]
+#		dev-python/baz[${PYTHON_USEDEP}] )')"
+#
+# python_check_deps() {
+#	has_version "dev-python/foo[${PYTHON_USEDEP}]" \
+#		&& { has_version "dev-python/bar[${PYTHON_USEDEP}]" \
+#			|| has_version "dev-python/baz[${PYTHON_USEDEP}]"; }
+# }
+# @CODE
+#
+# Example value:
+# @CODE
+# || (
+#	(
+#		dev-lang/python:2.7
+#		dev-python/foo[python_targets_python2_7(-)?,python_single_target_python2_7(+)?]
+#		|| ( dev-python/bar[python_targets_python2_7(-)?,python_single_target_python2_7(+)?]
+#			dev-python/baz[python_targets_python2_7(-)?,python_single_target_python2_7(+)?] )
+#	)
+#	(
+#		dev-lang/python:2.6
+#		dev-python/foo[python_targets_python2_6(-)?,python_single_target_python2_6(+)?]
+#		|| ( dev-python/bar[python_targets_python2_6(-)?,python_single_target_python2_6(+)?]
+#			dev-python/baz[python_targets_python2_6(-)?,python_single_target_python2_6(+)?] )
+#	)
+# )
+# @CODE
+python_gen_any_dep() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local depstr=${1}
+	[[ ${depstr} ]] || die "No dependency string provided"
+
+	local PYTHON_PKG_DEP out=
+	for i in "${_PYTHON_ALL_IMPLS[@]}"; do
+		has "${i}" "${PYTHON_COMPAT[@]}" || continue
+
+		local PYTHON_USEDEP="python_targets_${i}(-),python_single_target_${i}(+)"
+		python_export "${i}" PYTHON_PKG_DEP
+
+		local i_depstr=${depstr//\$\{PYTHON_USEDEP\}/${PYTHON_USEDEP}}
+		out="( ${PYTHON_PKG_DEP} ${i_depstr} ) ${out}"
+	done
+	echo "|| ( ${out})"
+}
+
 # @FUNCTION: _python_EPYTHON_supported
 # @USAGE: <epython>
 # @INTERNAL
-- 
1.8.3.2