5485 - promote SubX to top-level

1 files changed, 0 insertions, 61 deletions

diff --git a/exception1.mu b/exception1.mu
deleted file mode 100644
index df4754e5..00000000
--- a/exception1.mu
+++ /dev/null
@@ -1,61 +0,0 @@
-# Example program showing exceptions built out of delimited continuations.
-
-# Since Mu is statically typed, we can't build an all-purpose higher-order
-# function called 'try'; it wouldn't know how many arguments the function
-# passed to it needs to take, what their types are, etc. Instead, until Mu
-# gets macros we'll directly use the continuation primitives.
-
-def main [
-  local-scope
-  foo false/no-exception
-  foo true/raise-exception
-]
-
-# example showing exception handling
-def foo raise-exception?:bool [
-  local-scope
-  load-inputs
-  # To run an instruction of the form:
-  #   try f ...
-  # write this:
-  #   call-with-continuation-mark 999/exception-tag, f, ...
-  # By convention we reserve tag 999 for exceptions.
-  #
-  # 'f' above may terminate at either a regular 'return' or a 'return-with-continuation-mark'.
-  # We never re-call the continuation returned in the latter case;
-  # its existence merely signals that an exception was raised.
-  # So just treat it as a boolean.
-  # The other inputs and outputs to 'call-with-continuation-mark' depend on
-  # the function it is called with.
-  exception-raised?:bool, err:text, result:num <- call-with-continuation-mark 999/exception-tag, f, raise-exception?
-  {
-    break-if exception-raised?
-    $print [normal exit; result ] result 10/newline
-  }
-  {
-    break-unless exception-raised?
-    $print [error caught: ] err 10/newline
-  }
-]
-
-# A callee function that can raise an exception has some weird constraints at
-# the moment.
-#
-# The caller's 'call-with-continuation-mark' instruction may return with
-# either a regular 'return' or a 'return-continuation-until-mark'.
-# To handle both cases, regular 'return' instructions in the callee must
-# prepend an extra 0 result, in place of the continuation that may have been
-# returned.
-# This change to number of outputs violates our type system, so the call has
-# to be dynamically typed. The callee can't have a header.
-def f [
-  local-scope
-  raise-exception?:bool <- next-input
-  {
-    break-unless raise-exception?
-    # throw/raise: 2 results + implicit continuation (ignoring the continuation tag)
-    return-continuation-until-mark 999/exception-tag, [error will robinson!], 0/unused
-  }
-  # normal return: 3 results including 0 continuation placeholder at start
-  return 0/continuation-placeholder, null/no-error, 34/regular-result
-]