implement function `firstword`

1 files changed, 9 insertions, 0 deletions

diff --git a/src/makefile/functions.rs b/src/makefile/functions.rs
index 51bf0f9..feb0e54 100644
--- a/src/makefile/functions.rs
+++ b/src/makefile/functions.rs
@@ -52,6 +52,10 @@ pub fn expand_call(
             assert_eq!(args.len(), 1);
             text::words(macros, &args[0])
         }
+        "firstword" => {
+            assert_eq!(args.len(), 1);
+            text::firstword(macros, &args[0])
+        }
         "lastword" => {
             assert_eq!(args.len(), 1);
             text::lastword(macros, &args[0])
@@ -266,6 +270,11 @@ mod text {
         Ok(words.split_whitespace().count().to_string())
     }
 
+    pub fn firstword(macros: &MacroSet, words: &TokenString) -> Result<String> {
+        let words = macros.expand(words)?;
+        Ok(words.split_whitespace().nth(0).unwrap_or("").to_owned())
+    }
+
     pub fn lastword(macros: &MacroSet, words: &TokenString) -> Result<String> {
         let words = macros.expand(words)?;
         Ok(words.split_whitespace().last().unwrap_or("").to_owned())