Kotlin and general Gradle support. (#745)

autoload/ale/gradle.vim

@@ -0,0 +1,54 @@
+" Author: Michael Pardo <michael@michaelpardo.com>
+" Description: Functions for working with Gradle projects.
+
+let s:script_path = fnamemodify(resolve(expand('<sfile>:p')), ':h')
+
+" Given a buffer number, find a Gradle project root.
+function! ale#gradle#FindProjectRoot(buffer) abort
+    let l:gradlew_path = ale#path#FindNearestFile(a:buffer, 'gradlew')
+    if !empty(l:gradlew_path)
+        return fnamemodify(l:gradlew_path, ':h')
+    endif
+
+    let l:settings_path = ale#path#FindNearestFile(a:buffer, 'settings.gradle')
+    if !empty(l:settings_path)
+        return fnamemodify(l:settings_path, ':h')
+    endif
+
+    let l:build_path = ale#path#FindNearestFile(a:buffer, 'build.gradle')
+    if !empty(l:build_path)
+        return fnamemodify(l:build_path, ':h')
+    endif
+
+    return ''
+endfunction
+
+" Given a buffer number, find the path to the executable.
+" First search on the path for 'gradlew', if nothing is found, try the global
+" command. Returns an empty string if cannot find the executable.
+function! ale#gradle#FindExecutable(buffer) abort
+    let l:gradlew_path = ale#path#FindNearestFile(a:buffer, 'gradlew')
+    if !empty(l:gradlew_path)
+        return l:gradlew_path
+    endif
+
+    if executable('gradle')
+        return 'gradle'
+    endif
+
+    return ''
+endfunction
+
+" Given a buffer number, build a command to print the classpath of the root
+" project. Returns an empty string if cannot build the command.
+function! ale#gradle#BuildClasspathCommand(buffer) abort
+    let l:executable = ale#gradle#FindExecutable(a:buffer)
+    let l:project_root = ale#gradle#FindProjectRoot(a:buffer)
+
+    if !empty(l:executable) && !empty(l:project_root)
+        return ale#path#CdString(l:project_root)
+        \   . l:executable . ' -I ' . s:script_path . '/gradle/init.gradle -q printClasspath'
+    endif
+
+    return ''
+endfunction

autoload/ale/gradle/init.gradle

@@ -0,0 +1,23 @@
+class ClasspathPlugin implements Plugin<Project> {
+    void apply(Project project) {
+        project.task('printClasspath') {
+            doLast {
+                project
+                    .rootProject
+                    .allprojects
+                    .configurations
+                    .flatten()
+                    .findAll { it.name.endsWith('Classpath') }
+                    .collect { it.resolve() }
+                    .flatten()
+                    .unique()
+                    .findAll { it.exists() }
+                    .each { println it }
+            }
+        }
+    }
+}
+
+rootProject {
+    apply plugin: ClasspathPlugin
+}