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-rw-r--r--vendor/memchr/src/tests/substring/prop.rs126
1 files changed, 126 insertions, 0 deletions
diff --git a/vendor/memchr/src/tests/substring/prop.rs b/vendor/memchr/src/tests/substring/prop.rs
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+/*!
+This module defines a few quickcheck properties for substring search.
+
+It also provides a forward and reverse macro for conveniently defining
+quickcheck tests that run these properties over any substring search
+implementation.
+*/
+
+use crate::tests::substring::naive;
+
+/// $fwd is a `impl FnMut(haystack, needle) -> Option<Option<usize>>`. When the
+/// routine returns `None`, then it's skipped, which is useful for substring
+/// implementations that don't work for all inputs.
+#[macro_export]
+macro_rules! define_substring_forward_quickcheck {
+ ($fwd:expr) => {
+ #[cfg(not(miri))]
+ quickcheck::quickcheck! {
+ fn qc_fwd_prefix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+ crate::tests::substring::prop::prefix_is_substring(&bs, $fwd)
+ }
+
+ fn qc_fwd_suffix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+ crate::tests::substring::prop::suffix_is_substring(&bs, $fwd)
+ }
+
+ fn qc_fwd_matches_naive(
+ haystack: alloc::vec::Vec<u8>,
+ needle: alloc::vec::Vec<u8>
+ ) -> bool {
+ crate::tests::substring::prop::same_as_naive(
+ false,
+ &haystack,
+ &needle,
+ $fwd,
+ )
+ }
+ }
+ };
+}
+
+/// $rev is a `impl FnMut(haystack, needle) -> Option<Option<usize>>`. When the
+/// routine returns `None`, then it's skipped, which is useful for substring
+/// implementations that don't work for all inputs.
+#[macro_export]
+macro_rules! define_substring_reverse_quickcheck {
+ ($rev:expr) => {
+ #[cfg(not(miri))]
+ quickcheck::quickcheck! {
+ fn qc_rev_prefix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+ crate::tests::substring::prop::prefix_is_substring(&bs, $rev)
+ }
+
+ fn qc_rev_suffix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+ crate::tests::substring::prop::suffix_is_substring(&bs, $rev)
+ }
+
+ fn qc_rev_matches_naive(
+ haystack: alloc::vec::Vec<u8>,
+ needle: alloc::vec::Vec<u8>
+ ) -> bool {
+ crate::tests::substring::prop::same_as_naive(
+ true,
+ &haystack,
+ &needle,
+ $rev,
+ )
+ }
+ }
+ };
+}
+
+/// Check that every prefix of the given byte string is a substring.
+pub(crate) fn prefix_is_substring(
+ bs: &[u8],
+ mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>,
+) -> bool {
+ for i in 0..bs.len().saturating_sub(1) {
+ let prefix = &bs[..i];
+ let result = match search(bs, prefix) {
+ None => continue,
+ Some(result) => result,
+ };
+ if !result.is_some() {
+ return false;
+ }
+ }
+ true
+}
+
+/// Check that every suffix of the given byte string is a substring.
+pub(crate) fn suffix_is_substring(
+ bs: &[u8],
+ mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>,
+) -> bool {
+ for i in 0..bs.len().saturating_sub(1) {
+ let suffix = &bs[i..];
+ let result = match search(bs, suffix) {
+ None => continue,
+ Some(result) => result,
+ };
+ if !result.is_some() {
+ return false;
+ }
+ }
+ true
+}
+
+/// Check that naive substring search matches the result of the given search
+/// algorithm.
+pub(crate) fn same_as_naive(
+ reverse: bool,
+ haystack: &[u8],
+ needle: &[u8],
+ mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>,
+) -> bool {
+ let result = match search(haystack, needle) {
+ None => return true,
+ Some(result) => result,
+ };
+ if reverse {
+ result == naive::rfind(haystack, needle)
+ } else {
+ result == naive::find(haystack, needle)
+ }
+}