2 files changed, 113 insertions, 0 deletions
diff --git a/mu.arc b/mu.arc
index 236024b5..a1d7c2f0 100644
--- a/mu.arc
+++ b/mu.arc
@@ -1891,6 +1891,36 @@
   (result:boolean <- equal full:integer curr:integer)
   (reply result:boolean))
 
+(init-fn string-equal
+  (default-space:space-address <- new space:literal 30:literal)
+  (a:string-address <- next-input)
+  (a-len:integer <- length a:string-address/deref)
+  (b:string-address <- next-input)
+  (b-len:integer <- length b:string-address/deref)
+  ; compare lengths
+  { begin
+    (length-equal?:boolean <- equal a-len:integer b-len:integer)
+    (break-if length-equal?:boolean)
+    (reply nil:literal)
+  }
+  ; compare each corresponding byte
+  (i:integer <- copy 0:literal)
+  { begin
+    (done?:boolean <- greater-or-equal i:integer a-len:integer)
+    (break-if done?:boolean)
+    (a-char:byte <- index a:string-address/deref i:integer)
+    (b-char:byte <- index b:string-address/deref i:integer)
+    { begin
+      (chars-match?:boolean <- equal a-char:byte b-char:byte)
+      (break-if chars-match?:boolean)
+      (reply nil:literal)
+    }
+    (i:integer <- add i:integer 1:literal)
+    (loop)
+  }
+  (reply t:literal)
+)
+
 (init-fn strcat
   (default-space:space-address <- new space:literal 30:literal)
   ; result = new string[a.length + b.length]
diff --git a/mu.arc.t b/mu.arc.t
index a1fd7b3f..f529f72e 100644
--- a/mu.arc.t
+++ b/mu.arc.t
@@ -4000,6 +4000,89 @@
       (prn "F - 'new' initializes allocated memory to string literal"))))
 
 (reset)
+(new-trace "string-equal")
+(add-code
+  '((function main [
+      (1:string-address <- new "hello")
+      (2:string-address <- new "hello")
+      (3:boolean <- string-equal 1:string-address 2:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 t)
+  (prn "F - 'string-equal'"))
+
+(reset)
+(new-trace "string-equal-empty")
+(add-code
+  '((function main [
+      (1:string-address <- new "")
+      (2:string-address <- new "")
+      (3:boolean <- string-equal 1:string-address 2:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 t)
+  (prn "F - 'string-equal' works on empty strings"))
+
+(reset)
+(new-trace "string-equal-compare-with-empty")
+(add-code
+  '((function main [
+      (1:string-address <- new "a")
+      (2:string-address <- new "")
+      (3:boolean <- string-equal 1:string-address 2:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 nil)
+  (prn "F - 'string-equal' compares correctly with empty strings"))
+
+(reset)
+(new-trace "string-equal-compares-length")
+(add-code
+  '((function main [
+      (1:string-address <- new "a")
+      (2:string-address <- new "ab")
+      (3:boolean <- string-equal 1:string-address 2:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 nil)
+  (prn "F - 'string-equal' handles differing lengths"))
+
+(reset)
+(new-trace "string-equal-compares-initial-element")
+(add-code
+  '((function main [
+      (1:string-address <- new "aa")
+      (2:string-address <- new "ba")
+      (3:boolean <- string-equal 1:string-address 2:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 nil)
+  (prn "F - 'string-equal' handles inequal final byte"))
+
+(reset)
+(new-trace "string-equal-compares-final-element")
+(add-code
+  '((function main [
+      (1:string-address <- new "ab")
+      (2:string-address <- new "aa")
+      (3:boolean <- string-equal 1:string-address 2:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 nil)
+  (prn "F - 'string-equal' handles inequal final byte"))
+
+(reset)
+(new-trace "string-equal-reflexive")
+(add-code
+  '((function main [
+      (1:string-address <- new "ab")
+      (3:boolean <- string-equal 1:string-address 1:string-address)
+     ])))
+(run 'main)
+(when (~iso memory*.3 t)
+  (prn "F - 'string-equal' handles identical pointer"))
+
+(reset)
 (new-trace "strcat")
 (add-code
   '((function main [