feat: add Haskell Stack support (#546)

Add a Haskell Stack module when a stack.yaml file is detected

1 files changed, 40 insertions, 0 deletions

diff --git a/src/modules/haskell.rs b/src/modules/haskell.rs
new file mode 100644
index 000000000..ce0918cca
--- /dev/null
+++ b/src/modules/haskell.rs
@@ -0,0 +1,40 @@
+use super::{Context, Module, RootModuleConfig, SegmentConfig};
+
+use crate::configs::haskell::HaskellConfig;
+use crate::utils;
+
+/// Creates a module with the current Haskell Stack version
+///
+/// Will display the Haskell version if any of the following criteria are met:
+///     - Current directory contains a `stack.yaml` file
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let is_haskell_project = context
+        .try_begin_scan()?
+        .set_files(&["stack.yaml"])
+        .is_match();
+
+    if !is_haskell_project {
+        return None;
+    }
+
+    let haskell_version = utils::exec_cmd(
+        "stack",
+        &["ghc", "--", "--numeric-version", "--no-install-ghc"],
+    )?
+    .stdout;
+    let formatted_version = format_haskell_version(&haskell_version)?;
+
+    let mut module = context.new_module("haskell");
+    let config: HaskellConfig = HaskellConfig::try_load(module.config);
+    module.set_style(config.style);
+
+    module.create_segment("symbol", &config.symbol);
+    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+
+    Some(module)
+}
+
+fn format_haskell_version(haskell_version: &str) -> Option<String> {
+    let formatted_version = format!("v{}", haskell_version.trim());
+    Some(formatted_version)
+}