Rewrite PackageVersionConstraint constructing

Use the TryFrom trait rather than a `::new()` constructor that can fail.
This is way more idomatic.

Signed-off-by: Matthias Beyer <matthias.beyer@atos.net>

8 files changed, 38 insertions, 21 deletions

diff --git a/src/commands/env_of.rs b/src/commands/env_of.rs
index 4ee48d1..c763a23 100644
--- a/src/commands/env_of.rs
+++ b/src/commands/env_of.rs
@@ -8,6 +8,8 @@
 // SPDX-License-Identifier: EPL-2.0
 //
 
+use std::convert::TryFrom;
+
 use anyhow::Result;
 use clap::ArgMatches;
 use log::trace;
@@ -29,8 +31,7 @@ pub async fn env_of(matches: &ArgMatches, repo: Repository) -> Result<()> {
             .unwrap();
         let constraint = matches
             .value_of("package_version_constraint")
-            .map(String::from)
-            .map(PackageVersionConstraint::new)
+            .map(PackageVersionConstraint::try_from)
             .unwrap()?;
         trace!(
             "Checking for package with name = {} and version = {:?}",
diff --git a/src/commands/find_artifact.rs b/src/commands/find_artifact.rs
index ee11229..17db563 100644
--- a/src/commands/find_artifact.rs
+++ b/src/commands/find_artifact.rs
@@ -11,6 +11,7 @@
 use std::path::PathBuf;
 use std::io::Write;
 use std::sync::Arc;
+use std::convert::TryFrom;
 
 use anyhow::Context;
 use anyhow::Error;
@@ -37,8 +38,7 @@ pub async fn find_artifact(matches: &ArgMatches, config: &Configuration, progres
 
     let package_version_constraint = matches
         .value_of("package_version_constraint")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()
         .context("Parsing package version constraint")
         .context("A valid package version constraint looks like this: '=1.0.0'")?;
diff --git a/src/commands/find_pkg.rs b/src/commands/find_pkg.rs
index e2f7b77..7190ef8 100644
--- a/src/commands/find_pkg.rs
+++ b/src/commands/find_pkg.rs
@@ -8,6 +8,8 @@
 // SPDX-License-Identifier: EPL-2.0
 //
 
+use std::convert::TryFrom;
+
 use anyhow::Context;
 use anyhow::Result;
 use clap::ArgMatches;
@@ -31,8 +33,7 @@ pub async fn find_pkg(
 
     let package_version_constraint = matches
         .value_of("package_version_constraint")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()
         .context("Parsing package version constraint")
         .context("A valid package version constraint looks like this: '=1.0.0'")?;
diff --git a/src/commands/lint.rs b/src/commands/lint.rs
index 9ad9c7d..2a54c62 100644
--- a/src/commands/lint.rs
+++ b/src/commands/lint.rs
@@ -8,6 +8,7 @@
 // SPDX-License-Identifier: EPL-2.0
 //
 
+use std::convert::TryFrom;
 use std::path::Path;
 
 use anyhow::anyhow;
@@ -36,8 +37,7 @@ pub async fn lint(
         .map(PackageName::from);
     let pvers = matches
         .value_of("package_version")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()?;
 
     let bar = progressbars.bar();
diff --git a/src/commands/source.rs b/src/commands/source.rs
index f29ce84..c3655cc 100644
--- a/src/commands/source.rs
+++ b/src/commands/source.rs
@@ -11,6 +11,7 @@
 use std::io::Write;
 use std::path::PathBuf;
 use std::sync::Arc;
+use std::convert::TryFrom;
 
 use anyhow::anyhow;
 use anyhow::Context;
@@ -60,8 +61,7 @@ pub async fn verify(
         .map(PackageName::from);
     let pvers = matches
         .value_of("package_version")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()?;
 
     let packages = repo
@@ -183,8 +183,7 @@ pub async fn url(matches: &ArgMatches, repo: Repository) -> Result<()> {
         .map(PackageName::from);
     let pvers = matches
         .value_of("package_version")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()?;
 
     repo.packages()
@@ -225,8 +224,7 @@ pub async fn download(
         .map(PackageName::from);
     let pvers = matches
         .value_of("package_version")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()?;
     let multi = {
         let mp = indicatif::MultiProgress::new();
diff --git a/src/commands/tree_of.rs b/src/commands/tree_of.rs
index 30196b7..10e51d3 100644
--- a/src/commands/tree_of.rs
+++ b/src/commands/tree_of.rs
@@ -8,6 +8,8 @@
 // SPDX-License-Identifier: EPL-2.0
 //
 
+use std::convert::TryFrom;
+
 use anyhow::Error;
 use anyhow::Result;
 use clap::ArgMatches;
@@ -31,8 +33,7 @@ pub async fn tree_of(
         .map(PackageName::from);
     let pvers = matches
         .value_of("package_version")
-        .map(String::from)
-        .map(PackageVersionConstraint::new)
+        .map(PackageVersionConstraint::try_from)
         .transpose()?;
 
     repo.packages()
diff --git a/src/package/dependency/mod.rs b/src/package/dependency/mod.rs
index f2fd80f..e58d0a0 100644
--- a/src/package/dependency/mod.rs
+++ b/src/package/dependency/mod.rs
@@ -8,6 +8,8 @@
 // SPDX-License-Identifier: EPL-2.0
 //
 
+use std::convert::TryFrom;
+
 use anyhow::anyhow;
 use anyhow::Result;
 use lazy_static::lazy_static;
@@ -60,7 +62,7 @@ pub(in crate::package::dependency) fn parse_package_dependency_string_into_name_
         .map(|m| String::from(m.as_str()))
         .ok_or_else(|| anyhow!("Could not parse version: '{}'", s))?;
 
-    let v = PackageVersionConstraint::new(vers)?;
+    let v = PackageVersionConstraint::try_from(vers)?;
     Ok((PackageName::from(name), v))
 }
 
diff --git a/src/package/version.rs b/src/package/version.rs
index 0c3f7f6..9705c8d 100644
--- a/src/package/version.rs
+++ b/src/package/version.rs
@@ -25,10 +25,6 @@ pub struct PackageVersionConstraint {
 }
 
 impl PackageVersionConstraint {
-    pub fn new(s: String) -> Result<Self> {
-        Self::parser().parse(s.as_bytes()).map_err(Error::from)
-    }
-
     fn parser<'a>() -> PomParser<'a, u8, Self> {
         (pom::parser::sym(b'=') + PackageVersion::parser())
             .convert(|(constraint, version)| {
@@ -53,6 +49,24 @@ impl PackageVersionConstraint {
     }
 }
 
+impl std::convert::TryFrom<String> for PackageVersionConstraint {
+    type Error = anyhow::Error;
+
+    fn try_from(s: String) -> Result<Self> {
+        Self::try_from(&s as &str)
+    }
+}
+
+impl std::convert::TryFrom<&str> for PackageVersionConstraint {
+    type Error = anyhow::Error;
+
+    fn try_from(s: &str) -> Result<Self> {
+        PackageVersionConstraint::parser()
+            .parse(s.as_bytes())
+            .map_err(Error::from)
+    }
+}
+
 #[derive(
     parse_display::Display,
     Serialize,