add helpers aggregating settings from all libraries

Fix #28

Cargo.toml

@@ -19,6 +19,7 @@ strum = "0.20"
 strum_macros = "0.20"
 thiserror = "1"
 anyhow = "1.0"
+itertools = "0.10"
 
 [dev-dependencies]
 lazy_static = "1"

src/lib.rs

@@ -141,6 +141,7 @@ extern crate lazy_static;
 mod test;
 
 use heck::{ShoutySnakeCase, SnakeCase};
+use itertools::Itertools;
 use std::collections::HashMap;
 use std::env;
 use std::fmt;
@@ -213,6 +214,67 @@ impl Libraries {
         self.libs.iter().map(|(k, v)| (k.as_str(), v))
     }
 
+    fn aggregate_str<F: Fn(&Library) -> &Vec<String>>(
+        &self,
+        getter: F,
+    ) -> impl Iterator<Item = &str> {
+        self.libs
+            .values()
+            .map(|l| getter(l))
+            .flatten()
+            .map(|s| s.as_str())
+            .sorted()
+            .dedup()
+    }
+
+    fn aggregate_path_buf<F: Fn(&Library) -> &Vec<PathBuf>>(
+        &self,
+        getter: F,
+    ) -> impl Iterator<Item = &PathBuf> {
+        self.libs
+            .values()
+            .map(|l| getter(l))
+            .flatten()
+            .sorted()
+            .dedup()
+    }
+
+    /// An iterator returning each [Library::libs] of each library, removing duplicates.
+    pub fn all_libs(&self) -> impl Iterator<Item = &str> {
+        self.aggregate_str(|l| &l.libs)
+    }
+
+    /// An iterator returning each [Library::link_paths] of each library, removing duplicates.
+    pub fn all_link_paths(&self) -> impl Iterator<Item = &PathBuf> {
+        self.aggregate_path_buf(|l| &l.link_paths)
+    }
+
+    /// An iterator returning each [Library::frameworks] of each library, removing duplicates.
+    pub fn all_frameworks(&self) -> impl Iterator<Item = &str> {
+        self.aggregate_str(|l| &l.frameworks)
+    }
+
+    /// An iterator returning each [Library::framework_paths] of each library, removing duplicates.
+    pub fn all_framework_paths(&self) -> impl Iterator<Item = &PathBuf> {
+        self.aggregate_path_buf(|l| &l.framework_paths)
+    }
+
+    /// An iterator returning each [Library::include_paths] of each library, removing duplicates.
+    pub fn all_include_paths(&self) -> impl Iterator<Item = &PathBuf> {
+        self.aggregate_path_buf(|l| &l.include_paths)
+    }
+
+    /// An iterator returning each [Library::defines] of each library, removing duplicates.
+    pub fn all_defines(&self) -> impl Iterator<Item = (&str, &Option<String>)> {
+        self.libs
+            .values()
+            .map(|l| l.defines.iter())
+            .flatten()
+            .map(|(k, v)| (k.as_str(), v))
+            .sorted()
+            .dedup()
+    }
+
     fn add(&mut self, name: &str, lib: Library) {
         self.libs.insert(name.to_string(), lib);
     }

src/test.rs

@@ -784,3 +784,40 @@ fn optional() {
     // testlib is no longer optional if enabling v5
     toml_pkg_config_err_version("toml-optional", "5.0", vec![("CARGO_FEATURE_V5", "")]);
 }
+
+#[test]
+fn aggregate() {
+    let (libraries, _) = toml("toml-two-libs", vec![]).unwrap();
+
+    assert_eq!(
+        libraries.all_libs().collect::<Vec<&str>>(),
+        vec!["test", "test2"]
+    );
+    assert_eq!(
+        libraries.all_link_paths().collect::<Vec<&PathBuf>>(),
+        vec![Path::new("/usr/lib"), Path::new("/usr/lib64")]
+    );
+    assert_eq!(
+        libraries.all_frameworks().collect::<Vec<&str>>(),
+        vec!["someframework", "someotherframework"]
+    );
+    assert_eq!(
+        libraries.all_framework_paths().collect::<Vec<&PathBuf>>(),
+        vec![Path::new("/usr/lib"), Path::new("/usr/lib64")]
+    );
+    assert_eq!(
+        libraries.all_include_paths().collect::<Vec<&PathBuf>>(),
+        vec![
+            Path::new("/usr/include/testanotherlib"),
+            Path::new("/usr/include/testlib")
+        ]
+    );
+    assert_eq!(
+        libraries.all_defines().collect::<Vec<_>>(),
+        vec![
+            ("AWESOME", &None),
+            ("BADGER", &Some("yes".into())),
+            ("GREAT", &None)
+        ]
+    );
+}

src/tests/testanotherlib.pc

@@ -0,0 +1,12 @@
+prefix=/usr
+exec_prefix=${prefix}
+libdir=${exec_prefix}/lib/
+libdir2=${exec_prefix}/lib64/
+includedir=${prefix}/include/testlib
+includedir2=${prefix}/include/testanotherlib
+
+Name: Test Another Library
+Description: Another fake library to test pkg-config.
+Version: 1.2.3
+Libs: -L${libdir} -ltest -L${libdir2} -ltest2 -F${libdir} -framework someframework -F${libdir2} -framework someotherframework
+Cflags: -I${includedir} -I${includedir2} -DBADGER=yes -DAWESOME -DGREAT

src/tests/toml-two-libs/Cargo.toml

@@ -0,0 +1,3 @@
+[package.metadata.system-deps]
+testlib = { version = "1" }
+testanotherlib = { version = "1" }