1072

1 files changed, 96 insertions, 0 deletions

diff --git a/cpp/050string.mu b/cpp/050string.mu
new file mode 100644
index 00000000..e85dc083
--- /dev/null
+++ b/cpp/050string.mu
@@ -0,0 +1,96 @@
+recipe string-equal [
+  default-space:address:space <- new location:type, 30:literal
+  a:address:array:character <- next-ingredient
+  a-len:integer <- length a:address:array:character/deref
+  b:address:array:character <- next-ingredient
+  b-len:integer <- length b:address:array:character/deref
+  # compare lengths
+  {
+    trace [string-equal], [comparing lengths]
+    length-equal?:boolean <- equal a-len:integer, b-len:integer
+    break-if length-equal?:boolean
+    reply 0:literal
+  }
+  # compare each corresponding character
+  trace [string-equal], [comparing characters]
+  i:integer <- copy 0:literal
+  {
+    done?:boolean <- greater-or-equal i:integer, a-len:integer
+    break-if done?:boolean
+    a2:character <- index a:address:array:character/deref, i:integer
+    b2:character <- index b:address:array:character/deref, i:integer
+    {
+      chars-match?:boolean <- equal a2:character, b2:character
+      break-if chars-match?:boolean
+      reply 0:literal
+    }
+    i:integer <- add i:integer, 1:literal
+    loop
+  }
+  reply 1:literal
+]
+
+scenario string-equal-reflexive [
+  run [
+    default-space:address:space <- new location:type, 30:literal
+    x:address:array:character <- new [abc]
+    3:boolean/raw <- string-equal x:address:array:character, x:address:array:character
+  ]
+  memory should contain [
+    3 <- 1  # x == x for all x
+  ]
+]
+
+scenario string-equal-identical [
+  run [
+    default-space:address:space <- new location:type, 30:literal
+    x:address:array:character <- new [abc]
+    y:address:array:character <- new [abc]
+    3:boolean/raw <- string-equal x:address:array:character, y:address:array:character
+  ]
+  memory should contain [
+    3 <- 1  # abc == abc
+  ]
+]
+
+scenario string-equal-distinct-lengths [
+  run [
+    default-space:address:space <- new location:type, 30:literal
+    x:address:array:character <- new [abc]
+    y:address:array:character <- new [abcd]
+    3:boolean/raw <- string-equal x:address:array:character, y:address:array:character
+  ]
+  memory should contain [
+    3 <- 0  # abc != abcd
+  ]
+  trace should contain [
+    string-equal: comparing lengths
+  ]
+  trace should not contain [
+    string-equal: comparing characters
+  ]
+]
+
+scenario string-equal-with-empty [
+  run [
+    default-space:address:space <- new location:type, 30:literal
+    x:address:array:character <- new []
+    y:address:array:character <- new [abcd]
+    3:boolean/raw <- string-equal x:address:array:character, y:address:array:character
+  ]
+  memory should contain [
+    3 <- 0  # "" != abcd
+  ]
+]
+
+scenario string-equal-common-lengths-but-distinct [
+  run [
+    default-space:address:space <- new location:type, 30:literal
+    x:address:array:character <- new [abc]
+    y:address:array:character <- new [abd]
+    3:boolean/raw <- string-equal x:address:array:character, y:address:array:character
+  ]
+  memory should contain [
+    3 <- 0  # abc != abd
+  ]
+]