diff --git a/src/eval.rs b/src/eval.rs
index fe8a8f06..7d0e9473 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -31,30 +31,34 @@ pub(crate) fn matches_comparator(cmp: &Comparator, ver: &Version) -> bool {
     matches_impl(cmp, ver) && (ver.pre.is_empty() || pre_is_compatible(cmp, ver))
 }
 // If VersionReq missing Minor, Patch, then filling them with 0
-fn fill_partial_req(cmp: &mut Comparator) {
+fn fill_partial_req(cmp: &Comparator) -> Comparator {
+    let mut cmp = cmp.clone();
     if cmp.minor.is_none() {
         cmp.minor = Some(0);
         cmp.patch = Some(0);
     } else if cmp.patch.is_none() {
         cmp.patch = Some(0);
     }
+    cmp
 }
 
 fn matches_prerelease_impl(cmp: &Comparator, ver: &Version) -> bool {
-    let cmp = &{
-        let mut cmp = cmp.clone();
-        match cmp.op {
-            Op::Greater | Op::GreaterEq | Op::Less | Op::LessEq => fill_partial_req(&mut cmp),
-            _ => {}
-        }
-        cmp
-    };
     match cmp.op {
         Op::Exact | Op::Wildcard => matches_exact_prerelease(cmp, ver),
         Op::Greater => matches_greater(cmp, ver),
-        Op::GreaterEq => matches_exact(cmp, ver) || matches_greater(cmp, ver),
-        Op::Less => matches_less(cmp, ver),
-        Op::LessEq => matches_exact(cmp, ver) || matches_less(cmp, ver),
+        Op::GreaterEq => {
+            if matches_exact_prerelease(cmp, ver) {
+                return true;
+            }
+            matches_greater(cmp, ver)
+        }
+        Op::Less => matches_less(&fill_partial_req(cmp), ver),
+        Op::LessEq => {
+            if matches_exact_prerelease(cmp, ver) {
+                return true;
+            }
+            matches_less(&fill_partial_req(cmp), ver)
+        }
         Op::Tilde => matches_tilde_prerelease(cmp, ver),
         Op::Caret => matches_caret_prerelease(cmp, ver),
         #[cfg(no_non_exhaustive)]
@@ -87,12 +91,7 @@ fn matches_exact_prerelease(cmp: &Comparator, ver: &Version) -> bool {
         return false;
     }
 
-    let mut lower = Comparator {
-        op: Op::Less,
-        ..cmp.clone()
-    };
-    fill_partial_req(&mut lower);
-    if !matches_greater(&lower, ver) {
+    if !matches_greater(&fill_partial_req(cmp), ver) {
         return false;
     }
 
@@ -200,9 +199,7 @@ fn matches_tilde_prerelease(cmp: &Comparator, ver: &Version) -> bool {
         return true;
     }
 
-    let mut lower = cmp.clone();
-    fill_partial_req(&mut lower);
-    if !matches_greater(&lower, ver) {
+    if !matches_greater(&fill_partial_req(cmp), ver) {
         return false;
     }
 
@@ -252,9 +249,8 @@ fn matches_caret_prerelease(cmp: &Comparator, ver: &Version) -> bool {
     if matches_exact(cmp, ver) {
         return true;
     }
-    let mut lower = cmp.clone();
-    fill_partial_req(&mut lower);
-    if !matches_greater(&lower, ver) {
+
+    if !matches_greater(&fill_partial_req(cmp), ver) {
         return false;
     }
 
diff --git a/tests/test_matches_prerelease.rs b/tests/test_matches_prerelease.rs
index 5ec93417..6515357e 100644
--- a/tests/test_matches_prerelease.rs
+++ b/tests/test_matches_prerelease.rs
@@ -126,16 +126,115 @@ fn major_caret() {
     assert_prerelease_match_none(r, &["1.2.0", "2.0.0-0", "2.0.0"]);
 }
 
+#[test]
+fn test_exact() {
+    // =I.J.K equivalent to >=I.J.K, <I.J.(K+1)-0
+    let ref r = req("=4.2.1");
+    assert_prerelease_match_all(r, &["4.2.1"]);
+    assert_prerelease_match_none(r, &["1.2.3", "4.2.1-pre", "4.2.2", "5.0.0"]);
+
+    // =I.J equivalent to >=I.J.0, <I.(J+1).0-0
+    let ref r = req("=4.2");
+    // Match >= 4.2.0, < 4.3.0-0
+    assert_prerelease_match_all(r, &["4.2.0", "4.2.1", "4.2.4-pre", "4.2.9"]);
+    // Not Match < 4.2.0
+    assert_prerelease_match_none(r, &["0.0.1", "2.1.2-pre", "4.0.0-pre"]);
+    // Not Match >= 4.3.0-0
+    assert_prerelease_match_none(r, &["4.3.0-0", "4.3.0", "5.0.0-0", "5.0.0"]);
+
+    // =I equivalent to >=I.0.0, <(I+1).0.0-0
+    let ref r = req("=4");
+    // Match >= 4.0.0, < 5.0.0-0
+    assert_prerelease_match_all(r, &["4.0.0", "4.2.1", "4.2.4-pre", "4.9.9"]);
+    // Not Match < 4.0.0
+    assert_prerelease_match_none(r, &["0.0.1", "2.1.2-pre", "4.0.0-pre"]);
+    // Not Match >= 5.0.0-0
+    assert_prerelease_match_none(r, &["5.0.0-0", "5.0.0", "5.0.1"]);
+
+    // =I.J.K-pre only match I.J.K-pre
+    let ref r = req("=4.2.1-0");
+    // Only exactly match 4.2.1-0
+    assert_prerelease_match_all(r, &["4.2.1-0"]);
+    // Not match others
+    assert_prerelease_match_none(r, &["1.2.3", "4.2.0", "4.2.1-1", "4.2.2", "4.3.5"]);
+}
+
+#[test]
+fn test_greater() {
+    // >I.J.K
+    let ref r = req(">4.2.1");
+    assert_prerelease_match_all(r, &["4.2.2", "5.0.0-0", "5.0.0"]);
+    assert_prerelease_match_none(r, &["0.0.0", "4.2.1-pre", "4.2.1"]);
+    // >I.J equivalent to >=I.(J+1).0-0
+    let ref r = req(">4.2");
+    assert_prerelease_match_all(r, &["4.3.0-pre", "4.3.0", "5.0.0"]);
+    assert_prerelease_match_none(r, &["0.0.0", "4.2.1"]);
+    // >I equivalent to >=(I+1).0.0-0
+    let ref r = req(">4");
+    assert_prerelease_match_all(r, &["5.0.0-0", "5.0.0-1", "5.0.0"]);
+    assert_prerelease_match_none(r, &["0.0.0", "4.2.1"]);
+}
+
+#[test]
+fn test_greater_eq() {
+    // >=I.J.K
+    let ref r = req(">=4.2.1");
+    assert_prerelease_match_all(r, &["4.2.1", "5.0.0-0", "5.0.0"]);
+    assert_prerelease_match_none(r, &["0.0.0", "4.2.1-pre"]);
+    // >=I.J equivalent to >=I.J.0
+    let ref r = req(">=4.2");
+    assert_prerelease_match_all(r, &["4.2.0", "4.2.1-pre", "4.3.0", "5.0.0"]);
+    assert_prerelease_match_none(r, &["0.0.0", "4.1.1", "4.2.0-0"]);
+    // >=I equivalent to >=I.0.0
+    let ref r = req(">=4");
+    assert_prerelease_match_all(r, &["4.0.0", "4.1.0-1", "5.0.0"]);
+    assert_prerelease_match_none(r, &["0.0.0", "4.0.0-pre"]);
+}
+
+#[test]
+fn test_less() {
+    // <I.J.K
+    let ref r = req("<4.2.1");
+    assert_prerelease_match_all(r, &["0.0.0", "4.0.0", "4.2.1-pre"]);
+    assert_prerelease_match_none(r, &["4.2.2", "5.0.0-0", "5.0.0"]);
+    // <I.J equivalent to <I.J.0
+    let ref r = req("<4.2");
+    assert_prerelease_match_all(r, &["0.0.0", "4.2.0-pre"]);
+    assert_prerelease_match_none(r, &["4.2.0", "4.3.0-pre", "4.3.0"]);
+    // <I equivalent to <I.0.0
+    let ref r = req("<4");
+    assert_prerelease_match_all(r, &["0.0.0", "4.0.0-pre"]);
+    assert_prerelease_match_none(r, &["4.0.0", "5.0.0-1", "5.0.0"]);
+}
+
+#[test]
+fn test_less_eq() {
+    // <=I.J.K
+    let ref r = req("<=4.2.1");
+    assert_prerelease_match_all(r, &["0.0.0", "4.2.1-pre", "4.2.1"]);
+    assert_prerelease_match_none(r, &["4.2.2", "5.0.0-0", "5.0.0"]);
+    // <=I.J equivalent to <I.(J+1).0-0
+    let ref r = req("<=4.2");
+    assert_prerelease_match_all(r, &["0.0.0", "4.2.0-pre"]);
+    assert_prerelease_match_none(r, &["4.3.0-0", "4.3.0", "4.4.0"]);
+    // <=I equivalent to <(I+1).0.0-0
+    let ref r = req("<=4");
+    assert_prerelease_match_all(r, &["0.0.0", "4.0.0-pre", "4.0.0"]);
+    assert_prerelease_match_none(r, &["5.0.0-1", "5.0.0"]);
+}
+
 #[test]
 fn test_tilde() {
-    let ref r = req("~0.0.24");
-    // Match >= 0.0.24, < 0.1.0-0
-    assert_prerelease_match_all(r, &["0.0.24", "0.0.25-0", "0.0.25"]);
-    // Not Match < 0.0.24
-    assert_prerelease_match_none(r, &["0.0.1", "0.0.9", "0.0.24-pre"]);
-    // Not Match >= 0.1.0-0
-    assert_prerelease_match_none(r, &["0.1.0-0", "0.1.0", "1.2.3", "2.0.0"]);
+    // ~I.J.K — equivalent to >=I.J.K, <I.(J+1).0-0
+    let ref r = req("~1.2.3");
+    // Match >= 1.2.3, < 1.3.0-0
+    assert_prerelease_match_all(r, &["1.2.3", "1.2.4-pre", "1.2.4"]);
+    // Not Match < 1.2.3
+    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-pre", "1.1.0-0", "1.1.0"]);
+    // Not Match >= 1.3.0-0
+    assert_prerelease_match_none(r, &["1.3.0-0", "1.3.0", "1.3.1-0", "1.3.1", "2.0.0"]);
 
+    // ~I.J — equivalent to >=I.J.0, <I.(J+1).0-0
     let ref r = req("~0.24");
     // Match >= 0.24.0, < 0.25.0-0
     assert_prerelease_match_all(r, &["0.24.0", "0.24.1-pre", "0.24.1", "0.24.9"]);
@@ -144,6 +243,7 @@ fn test_tilde() {
     // Not Match >= 0.25.0-0
     assert_prerelease_match_none(r, &["0.25.0-0", "1.1.0", "1.2.3", "2.0.0"]);
 
+    // ~I — >=I.0.0, <(I+1).0.0-0
     let ref r = req("~1");
     // Match >= 1.0.0, < 2.0.0-0
     assert_prerelease_match_all(r, &["1.0.0", "1.1.0-0", "1.1.0", "1.2.3"]);
@@ -152,22 +252,7 @@ fn test_tilde() {
     // Not Match >= 2.0.0-0
     assert_prerelease_match_none(r, &["2.0.0-0", "2.0.0", "2.0.1"]);
 
-    let ref r = req("~1.2");
-    // Match >= 1.2.0, < 1.3.0-0
-    assert_prerelease_match_all(r, &["1.2.0", "1.2.1", "1.2.2-pre", "1.2.9"]);
-    // Not Match < 1.2.0
-    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-pre", "1.1.0-0", "1.1.0"]);
-    // Not Match >= 1.3.0-0
-    assert_prerelease_match_none(r, &["1.3.0-0", "1.3.0", "1.4.3-pre", "1.8.9", "2.0.0"]);
-
-    let ref r = req("~1.2.3");
-    // Match >= 1.2.3, < 1.3.0-0
-    assert_prerelease_match_all(r, &["1.2.3", "1.2.4-pre", "1.2.4"]);
-    // Not Match < 1.2.3
-    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-pre", "1.1.0-0", "1.1.0"]);
-    // Not Match >= 1.3.0-0
-    assert_prerelease_match_none(r, &["1.3.0-0", "1.3.0", "1.3.1-0", "1.3.1", "2.0.0"]);
-
+    // ~I.J.K-[pre] — equivalent to >=I.J.K-[pre], <I.J.(K+1).0
     let ref r = req("~1.2.3-0");
     // Match >= 1.2.3-0, < 1.3.0-0
     assert_prerelease_match_all(r, &["1.2.3-0", "1.2.3", "1.2.4-pre", "1.2.4"]);
@@ -178,82 +263,47 @@ fn test_tilde() {
 }
 
 #[test]
-fn test_range() {
-    let ref r = req(">=1.0.0");
-    assert_prerelease_match_all(r, &["1.0.0", "1.0.1-pre", "2.0.0-0", "2.0.0"]);
-    assert_prerelease_match_none(r, &["0.9.9", "0.10.0", "1.0.0-pre.0"]);
-
-    let ref r = req(">=1.0.0-pre.1");
-    assert_prerelease_match_all(r, &["1.0.0-pre.1", "1.0.0", "1.0.1-pre", "2.0.0-0"]);
-    assert_prerelease_match_none(r, &["0.9.9", "0.10.0", "1.0.0-pre.0"]);
-
-    let ref r = req("<=1.0.0");
-    assert_prerelease_match_all(r, &["0.9.9", "0.10.0", "1.0.0-pre", "1.0.0"]);
-    assert_prerelease_match_none(r, &["1.0.1", "1.0.1-pre", "1.1.0", "2.0.0-0"]);
-
-    let ref r = req("<=1.0.0-0");
-    assert_prerelease_match_all(r, &["0.9.9", "0.1.0", "0.10.0", "1.0.0-0"]);
-    assert_prerelease_match_none(r, &["1.0.0-pre", "1.0.1-pre", "1.1.0", "2.0.0-0"]);
-
-    let ref r = req(">1.0.0-0,<=1.1.0-0");
-    assert_prerelease_match_all(r, &["1.0.0-pre", "1.0.0", "1.0.9", "1.1.0-0"]);
-    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-0", "1.2.3-pre", "2.0.0"]);
-
-    let ref r = req(">=1.0.0,<1.1.0-0");
-    assert_prerelease_match_all(r, &["1.0.0", "1.0.0", "1.0.9"]);
-    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-pre", "1.1.0-0", "1.1.0", "2.0.0"]);
+fn test_caret() {
+    // ^I.J.K (for I>0) — equivalent to >=I.J.K, <(I+1).0.0-0
+    let ref r = req("^1.2.3");
+    assert_prerelease_match_all(r, &["1.2.3", "1.2.4-0", "1.8.9"]);
+    assert_prerelease_match_none(r, &["0.0.9", "1.1.1-0", "1.2.3-0", "2.0.0-pre", "2.1.1"]);
+
+    // ^0.J.K (for J>0) — equivalent to >=0.J.K, <0.(J+1).0-0
+    let ref r = req("^0.2.3");
+    assert_prerelease_match_all(r, &["0.2.3", "0.2.9-0", "0.2.9"]);
+    assert_prerelease_match_none(r, &["0.0.9", "0.2.3-0", "0.3.0-0", "0.3.11", "1.1.1"]);
+
+    // ^0.0.K — equivalent to >=0.0.K, <0.0.(K+1)-0
+    let ref r = req("^0.0.3");
+    assert_prerelease_match_all(r, &["0.0.3"]);
+    assert_prerelease_match_none(
+        r,
+        &["0.0.1", "0.0.4-0", "0.0.9", "0.3.0-0", "0.4.0-0", "1.1.1"],
+    );
+
+    // ^I.J (for I>0 or J>0) — equivalent to >=I.J.0, <(I+1).0.0-0)
+    let ref r = req("^1.2");
+    assert_prerelease_match_all(r, &["1.2.0", "1.9.0-0", "1.9.9"]);
+    assert_prerelease_match_none(r, &["0.0.1", "0.0.4-0", "1.2.0-0", "2.0.0-0", "4.0.1"]);
+
+    // ^0.0 — equivalent to >=0.0.0, <0.1.0-0
+    let ref r = req("^0.0");
+    assert_prerelease_match_all(r, &["0.0.0", "0.0.1", "0.0.4-0"]);
+    assert_prerelease_match_none(r, &["0.1.0-0", "0.1.0", "1.1.1"]);
+
+    // ^I — equivalent to >=I.0.0, <(I+1).0.0-0
+    let ref r = req("^1");
+    assert_prerelease_match_all(r, &["1.0.0", "1.0.1", "1.0.4-0"]);
+    assert_prerelease_match_none(r, &["0.1.0-0", "0.1.0", "2.0.0-0", "3.1.2"]);
 }
 
 #[test]
-fn test_range_partial() {
-    let ref r = req(">=0.24");
-    assert_prerelease_match_all(r, &["0.24.0", "0.24.1", "2.0.0-0", "2.0.0"]);
-    assert_prerelease_match_none(r, &["0.9.9", "0.10.0", "0.24.0-pre.0"]);
-
-    let ref r = req(">=1");
-    assert_prerelease_match_all(r, &["1.0.0", "1.0.1-pre", "2.0.0-0", "2.0.0"]);
-    assert_prerelease_match_none(r, &["0.9.9", "0.10.0", "1.0.0-pre.0"]);
-
-    let ref r = req("<1");
-    assert_prerelease_match_none(r, &["1.0.0", "1.0.1-pre", "2.0.0-0", "2.0.0"]);
-    assert_prerelease_match_all(r, &["0.9.9", "0.10.0", "1.0.0-pre.0"]);
-
-    let ref r = req(">=1.1");
-    assert_prerelease_match_all(r, &["1.1.0", "1.1.1-pre", "2.0.0-0"]);
-    assert_prerelease_match_none(r, &["0.9.9", "0.10.0", "1.0.0-pre.0"]);
-
-    let ref r = req("<1.1");
-    assert_prerelease_match_none(r, &["1.1.0", "1.1.1-pre", "2.0.0-0"]);
-    assert_prerelease_match_all(r, &["0.9.9", "0.10.0", "1.0.0-pre.0"]);
-
-    let ref r = req(">1,<=1.1");
-    assert_prerelease_match_all(r, &["1.0.9", "1.1.0-0"]);
-    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-0", "1.2.3-pre", "2.0.0"]);
-
-    let ref r = req(">=1.1,<2");
-    assert_prerelease_match_all(r, &["1.1.0", "1.2.9-pre", "1.2.9", "2.0.0-pre"]);
-    assert_prerelease_match_none(r, &["0.0.1", "1.0.0-pre", "1.1.0-pre"]);
-
-    let ref r = req("*");
-    assert_prerelease_match_all(r, &["0.0.1", "1.0.0", "1.2.9", "2.0.0-pre"]);
-
-    let ref r = req("^1, <=1.9");
-    assert_prerelease_match_all(r, &["1.1.1-pre", "1.1.1"]);
-    let ref r = req("^0, <=0.0.1-z0");
-    assert_prerelease_match_all(r, &["0.0.1-z0"]);
-}
-
-#[test]
-fn test_exact() {
-    let ref r = req("=4");
-    // Match >= 4.0.0, < 5.0.0-0
-    assert_prerelease_match_all(r, &["4.0.0", "4.2.1", "4.2.4-pre", "4.9.9"]);
-    // Not Match < 4.0.0
-    assert_prerelease_match_none(r, &["0.0.1", "2.1.2-pre", "4.0.0-pre"]);
-    // Not Match >= 5.0.0-0
-    assert_prerelease_match_none(r, &["5.0.0-0", "5.0.0", "5.0.1"]);
-
-    let ref r = req("=4.2");
+fn test_wildcard() {
+    // I.J.* — equivalent to =I.J
+    //
+    // =I.J equivalent to >=I.J.0, <I.(J+1).0-0
+    let ref r = req("4.2.*");
     // Match >= 4.2.0, < 4.3.0-0
     assert_prerelease_match_all(r, &["4.2.0", "4.2.1", "4.2.4-pre", "4.2.9"]);
     // Not Match < 4.2.0
@@ -261,22 +311,15 @@ fn test_exact() {
     // Not Match >= 4.3.0-0
     assert_prerelease_match_none(r, &["4.3.0-0", "4.3.0", "5.0.0-0", "5.0.0", "5.0.1"]);
 
-    let ref r = req("=4.2.1");
-    assert_prerelease_match_all(r, &["4.2.1"]);
-    assert_prerelease_match_none(r, &["1.2.3", "4.2.1-pre", "4.2.2", "5.0.0"]);
-
-    let ref r = req("=4.2.1-0");
-    // Only exactly match 4.2.1-0
-    assert_prerelease_match_all(r, &["4.2.1-0"]);
-    // Not match others
-    assert_prerelease_match_none(r, &["1.2.3", "4.2.0", "4.2.1-1", "4.2.2", "4.3.5"]);
-
-    // Speicial Case
-    let ref r = req("=0");
-    // Match >= 0.0.0, < 1.0.0-0
-    assert_prerelease_match_all(r, &["0.0.0", "0.1.1", "0.9.9"]);
-    // Not Match < 0.0.0
-    assert_prerelease_match_none(r, &["0.0.0-0", "0.0.0-pre"]);
-    // Not Match >= 1.0.0-0
-    assert_prerelease_match_none(r, &["1.0.0-0", "1.0.0", "2.0.1"]);
+    // I.* or I.*.* — equivalent to =I
+    //
+    // =I equivalent to >=I.0.0, <(I+1).0.0-0
+    for r in &[req("4.*"), req("4.*.*")] {
+        // Match >= 4.0.0, < 5.0.0-0
+        assert_prerelease_match_all(r, &["4.0.0", "4.2.1", "4.2.4-pre", "4.9.9"]);
+        // Not Match < 4.0.0
+        assert_prerelease_match_none(r, &["0.0.1", "2.1.2-pre", "4.0.0-pre"]);
+        // Not Match >= 5.0.0-0
+        assert_prerelease_match_none(r, &["5.0.0-0", "5.0.0", "5.0.1"]);
+    }
 }