feat(spdx-licenses): implement is_valid_license_string SPDX expression parser

PHP matches the SPDX license-expression grammar with a single recursive
PCRE pattern ((?(DEFINE) subpatterns plus (?&name) recursion), which the
regex crate cannot express, so port it as a hand-written recursive-descent
parser instead. licenseid/licenseexceptionid dictionary lookups use
longest-match-first, guarded against accepting a short entry that is only
a coincidental prefix of a longer identifier run (e.g. "DOC" prefixing
"DocumentRef-..."), which a length-sorted greedy match alone would
misparse.

Un-ignores the two validating_array_loader tests that were blocked on
this todo!().

1 files changed, 0 insertions, 2 deletions

diff --git a/crates/shirabe/tests/package/loader/validating_array_loader_test.rs b/crates/shirabe/tests/package/loader/validating_array_loader_test.rs
index 419f703c..07f3e4a6 100644
--- a/crates/shirabe/tests/package/loader/validating_array_loader_test.rs
+++ b/crates/shirabe/tests/package/loader/validating_array_loader_test.rs
@@ -959,7 +959,6 @@ fn warning_provider() -> Vec<(
 }
 
 /// ref: ValidatingArrayLoaderTest::testLoadWarnings
-#[ignore = "license warning cases need the SPDX license-expression grammar (recursive PCRE), not yet ported: spdx_licenses todo!()"]
 #[test]
 fn test_load_warnings() {
     for (cfg, mut expected_warnings, _must_check, _expected_array) in warning_provider() {
@@ -981,7 +980,6 @@ fn test_load_warnings() {
 }
 
 /// ref: ValidatingArrayLoaderTest::testLoadSkipsWarningDataWhenIgnoringErrors
-#[ignore = "must_check license cases need the SPDX license-expression grammar (recursive PCRE), not yet ported: spdx_licenses todo!()"]
 #[test]
 fn test_load_skips_warning_data_when_ignoring_errors() {
     for (mut cfg, _expected_warnings, must_check, expected_array) in warning_provider() {