From bd4ca514538157e4300169821e867e4c4051affc Mon Sep 17 00:00:00 2001
From: Melody Horn <melody@boringcactus.com>
Date: Sun, 4 Apr 2021 15:02:48 -0600
Subject: implement `and` function

---
 src/makefile/functions.rs | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/makefile/functions.rs b/src/makefile/functions.rs
index 750d56a..45ef925 100644
--- a/src/makefile/functions.rs
+++ b/src/makefile/functions.rs
@@ -54,20 +54,21 @@ pub fn expand_call(
             assert!(args.len() == 2 || args.len() == 3);
             conditional::r#if(macros, &args[0], &args[1], args.get(2))
         }
+        "and" => {
+            assert!(!args.is_empty());
+            conditional::and(macros, args.iter())
+        }
 
-        // foreach
         "foreach" => {
             assert_eq!(args.len(), 3);
             foreach(macros, &args[0], &args[1], &args[2])
         }
 
-        // call
         "call" => {
             assert!(!args.is_empty());
             call(macros, args.iter())
         }
 
-        // eval
         "eval" => {
             assert_eq!(args.len(), 1);
             let should_eval = eval(macros, &args[0])?;
@@ -84,7 +85,6 @@ pub fn expand_call(
             origin(macros, &args[0])
         }
 
-        // shell
         "shell" => {
             assert_eq!(args.len(), 1);
             shell(macros, &args[0])
@@ -250,6 +250,20 @@ mod conditional {
             macros.expand(if_true)
         }
     }
+
+    pub fn and<'a>(
+        macros: &MacroSet,
+        args: impl Iterator<Item = &'a TokenString>,
+    ) -> Result<String> {
+        let mut last = String::new();
+        for arg in args {
+            last = macros.expand(arg)?;
+            if last.is_empty() {
+                return Ok(String::new());
+            }
+        }
+        Ok(last)
+    }
 }
 
 pub fn foreach(
-- 
cgit v1.2.3