Conform Semver and Range to fmt::Display

lib/src/range/mod.rs

@@ -1,5 +1,8 @@
 use crate::semver::Semver;
-use std::hash::{Hash, Hasher};
+use std::{
+    fmt,
+    hash::{Hash, Hasher},
+};
 
 pub mod intersect;
 pub mod max;
@@ -43,3 +46,82 @@ impl Hash for Semver {
         self.components.hash(state);
     }
 }
+
+impl fmt::Display for Range {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let str = self
+            .set
+            .iter()
+            .map(|v| match v {
+                Constraint::Any => "*".to_string(),
+                Constraint::Single(v) => format!("={}", v),
+                Constraint::Contiguous(v1, v2) => {
+                    if v2.major == v1.major + 1 && v2.minor == 0 && v2.patch == 0 {
+                        let v = chomp(v1);
+                        if v1.major == 0 {
+                            if v1.components.len() == 1 {
+                                "^0".to_string()
+                            } else {
+                                format!(">={}<1", v)
+                            }
+                        } else {
+                            format!("^{}", v)
+                        }
+                    } else if v2.major == v1.major && v2.minor == v1.minor + 1 && v2.patch == 0 {
+                        let v = chomp(v1);
+                        format!("~{}", v)
+                    } else if v2.major == usize::MAX {
+                        let v = chomp(v1);
+                        format!(">={}", v)
+                    } else if at(v1, v2) {
+                        format!("@{}", v1)
+                    } else {
+                        format!(">={}<{}", chomp(v1), chomp(v2))
+                    }
+                }
+            })
+            .collect::<Vec<_>>()
+            .join(",");
+        write!(f, "{}", str)
+    }
+}
+
+/// checks @ syntax, eg. [email protected]
+fn at(v1: &Semver, v2: &Semver) -> bool {
+    let mut cc1 = v1.components.clone();
+    let cc2 = &v2.components;
+
+    if cc1.len() > cc2.len() {
+        return false;
+    }
+
+    // Ensure cc1 and cc2 have the same length by appending 0s to cc1
+    while cc1.len() < cc2.len() {
+        cc1.push(0);
+    }
+
+    if last(&cc1) != last(cc2) - 1 {
+        return false;
+    }
+
+    for i in 0..cc1.len() - 1 {
+        if cc1[i] != cc2[i] {
+            return false;
+        }
+    }
+
+    true
+}
+
+fn last(arr: &[usize]) -> usize {
+    *arr.last().unwrap()
+}
+
+fn chomp(v: &Semver) -> String {
+    let result = v.raw.trim_end_matches(".0");
+    if result.is_empty() {
+        "0".to_string()
+    } else {
+        result.to_string()
+    }
+}

lib/src/semver/mod.rs

@@ -1,3 +1,5 @@
+use std::fmt;
+
 pub mod bump;
 pub mod compare;
 pub mod parse;
@@ -28,3 +30,17 @@ impl Semver {
         }
     }
 }
+
+impl fmt::Display for Semver {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            self.components
+                .iter()
+                .map(|c| c.to_string())
+                .collect::<Vec<_>>()
+                .join(".")
+        )
+    }
+}