implement function `word`

1 files changed, 12 insertions, 1 deletions

diff --git a/src/makefile/functions.rs b/src/makefile/functions.rs
index 712b944..7bb0908 100644
--- a/src/makefile/functions.rs
+++ b/src/makefile/functions.rs
@@ -3,7 +3,7 @@ use std::env;
 use std::process::{Command, Stdio};
 use std::rc::Rc;
 
-use eyre::{bail, Result};
+use eyre::{bail, Result, WrapErr};
 
 use super::pattern::r#match;
 use super::r#macro::{Set as MacroSet, Source as MacroSource};
@@ -40,6 +40,10 @@ pub fn expand_call(
             assert_eq!(args.len(), 1);
             text::sort(macros, &args[0])
         }
+        "word" => {
+            assert_eq!(args.len(), 2);
+            text::word(macros, &args[0], &args[1])
+        }
         "words" => {
             assert_eq!(args.len(), 1);
             text::words(macros, &args[0])
@@ -211,6 +215,13 @@ mod text {
         Ok(words.join(" "))
     }
 
+    pub fn word(macros: &MacroSet, n: &TokenString, text: &TokenString) -> Result<String> {
+        let n = macros.expand(n)?;
+        let n: usize = n.parse().wrap_err("while calling `word`")?;
+        let text = macros.expand(text)?;
+        Ok(text.split_whitespace().nth(n + 1).unwrap_or("").to_owned())
+    }
+
     pub fn words(macros: &MacroSet, words: &TokenString) -> Result<String> {
         let words = macros.expand(words)?;
         Ok(words.split_whitespace().count().to_string())