Add ParseDependency trait

This patch adds a trait "ParseDependency" which can be used to transform
a stringly typed dependency object into a (PackageName, PackageVersion).

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

5 files changed, 74 insertions, 24 deletions

diff --git a/src/package/dependency/build.rs b/src/package/dependency/build.rs
index 0f8c0c1..9d67051 100644
--- a/src/package/dependency/build.rs
+++ b/src/package/dependency/build.rs
@@ -1,6 +1,10 @@
 use serde::Deserialize;
+use anyhow::Result;
 
 use crate::package::dependency::StringEqual;
+use crate::package::dependency::ParseDependency;
+use crate::package::PackageName;
+use crate::package::PackageVersionConstraint;
 
 /// A dependency that is packaged and is only required during build time
 #[derive(Deserialize, Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
@@ -12,3 +16,10 @@ impl StringEqual for BuildDependency {
         self.0 == s
     }
 }
+
+impl ParseDependency for BuildDependency {
+    fn parse_into_name_and_version(self) -> Result<(PackageName, PackageVersionConstraint)> {
+        crate::package::dependency::parse_package_dependency_string_into_name_and_version(&self.0)
+    }
+}
+
diff --git a/src/package/dependency/mod.rs b/src/package/dependency/mod.rs
index f2f0b8a..6df8b6a 100644
--- a/src/package/dependency/mod.rs
+++ b/src/package/dependency/mod.rs
@@ -1,3 +1,11 @@
+use lazy_static::lazy_static;
+use anyhow::anyhow;
+use anyhow::Result;
+use regex::Regex;
+
+use crate::package::PackageName;
+use crate::package::PackageVersionConstraint;
+
 mod system;
 pub use system::*;
 
@@ -14,6 +22,36 @@ pub trait StringEqual {
     fn str_equal(&self, s: &str) -> bool;
 }
 
+pub trait ParseDependency {
+    fn parse_into_name_and_version(self) -> Result<(PackageName, PackageVersionConstraint)>;
+}
+
+lazy_static! {
+    pub(in crate::package::dependency)  static ref DEPENDENCY_PARSING_RE: Regex =
+        Regex::new("^(?P<name>[[:alpha:]]([[[:alnum:]]-_])*) (?P<version>([\\*=><])?[[:alnum:]]([[[:alnum:]][[:punct:]]])*)$").unwrap();
+}
+
+/// Helper function for the actual implementation of the ParseDependency trait.
+///
+/// TODO: Reimplement using pom crate
+pub(in crate::package::dependency) fn parse_package_dependency_string_into_name_and_version(s: &str)
+    -> Result<(PackageName, PackageVersionConstraint)>
+{
+    let caps = crate::package::dependency::DEPENDENCY_PARSING_RE
+        .captures(s)
+        .ok_or_else(|| anyhow!("Could not parse into package name and package version constraint: '{}'", s))?;
+
+    let name = caps.name("name")
+        .ok_or_else(|| anyhow!("Could not parse name: '{}'", s))?;
+
+    let vers = caps.name("version")
+        .ok_or_else(|| anyhow!("Could not parse version: '{}'", s))?;
+
+    let constraint = PackageVersionConstraint::parse(vers.as_str())?;
+
+    Ok((PackageName::from(String::from(name.as_str())), constraint))
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/src/package/dependency/runtime.rs b/src/package/dependency/runtime.rs
index 5096469..de445b3 100644
--- a/src/package/dependency/runtime.rs
+++ b/src/package/dependency/runtime.rs
@@ -1,12 +1,10 @@
-use std::result::Result as RResult;
 use serde::Deserialize;
-use regex::Regex;
-use lazy_static::lazy_static;
-use anyhow::anyhow;
+use anyhow::Result;
 
 use crate::package::PackageName;
 use crate::package::PackageVersionConstraint;
 use crate::package::dependency::StringEqual;
+use crate::package::dependency::ParseDependency;
 
 
 /// A dependency that is packaged and is required during runtime
@@ -26,26 +24,9 @@ impl From<String> for Dependency {
     }
 }
 
-impl std::convert::TryInto<(PackageName, PackageVersionConstraint)> for Dependency {
-    type Error = anyhow::Error;
-
-    fn try_into(self) -> RResult<(PackageName, PackageVersionConstraint), Self::Error> {
-        lazy_static! {
-            static ref RE: Regex = Regex::new("^(?P<name>[[:alpha:]]([[[:alnum:]]-_])*) (?P<version>([\\*=><])?[[:alnum:]]([[[:alnum:]][[:punct:]]])*)$").unwrap();
-        }
-
-        let caps = RE.captures(&self.0)
-            .ok_or_else(|| anyhow!("Could not parse into package name and package version constraint: '{}'", self.0))?;
-
-        let name = caps.name("name")
-            .ok_or_else(|| anyhow!("Could not parse name: '{}'", self.0))?;
-
-        let vers = caps.name("version")
-            .ok_or_else(|| anyhow!("Could not parse version: '{}'", self.0))?;
-
-        let constraint = PackageVersionConstraint::parse(vers.as_str())?;
-
-        Ok((PackageName::from(String::from(name.as_str())), constraint))
+impl ParseDependency for Dependency {
+    fn parse_into_name_and_version(self) -> Result<(PackageName, PackageVersionConstraint)> {
+        crate::package::dependency::parse_package_dependency_string_into_name_and_version(&self.0)
     }
 }
 
diff --git a/src/package/dependency/system.rs b/src/package/dependency/system.rs
index aa5241c..9e731f7 100644
--- a/src/package/dependency/system.rs
+++ b/src/package/dependency/system.rs
@@ -1,6 +1,10 @@
 use serde::Deserialize;
+use anyhow::Result;
 
 use crate::package::dependency::StringEqual;
+use crate::package::dependency::ParseDependency;
+use crate::package::PackageName;
+use crate::package::PackageVersionConstraint;
 
 /// A dependency that can be installed from the system and is only required during build
 #[derive(Deserialize, Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
@@ -13,3 +17,9 @@ impl StringEqual for SystemBuildDependency {
     }
 }
 
+impl ParseDependency for SystemBuildDependency {
+    fn parse_into_name_and_version(self) -> Result<(PackageName, PackageVersionConstraint)> {
+        crate::package::dependency::parse_package_dependency_string_into_name_and_version(&self.0)
+    }
+}
+
diff --git a/src/package/dependency/system_runtime.rs b/src/package/dependency/system_runtime.rs
index 1764102..75942d0 100644
--- a/src/package/dependency/system_runtime.rs
+++ b/src/package/dependency/system_runtime.rs
@@ -1,6 +1,10 @@
 use serde::Deserialize;
+use anyhow::Result;
 
 use crate::package::dependency::StringEqual;
+use crate::package::dependency::ParseDependency;
+use crate::package::PackageName;
+use crate::package::PackageVersionConstraint;
 
 /// A dependency that can be installed from the system and is required during runtime
 #[derive(Deserialize, Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
@@ -13,3 +17,9 @@ impl StringEqual for SystemDependency {
     }
 }
 
+impl ParseDependency for SystemDependency {
+    fn parse_into_name_and_version(self) -> Result<(PackageName, PackageVersionConstraint)> {
+        crate::package::dependency::parse_package_dependency_string_into_name_and_version(&self.0)
+    }
+}
+