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authorCalvin <calvin@EESI>2013-05-28 10:47:11 -0400
committerCalvin <calvin@EESI>2013-05-28 10:47:11 -0400
commitdd38d0d1dda2be42bf280aeca110542f2f2fef1b (patch)
treec921dc0690e29f1b7b913aaa72b9c12539faa5a1 /src/nbc/history.sml
parent2f33e34ae06b96c3f3e4456ce960172903f60bfb (diff)
removed files
Diffstat (limited to 'src/nbc/history.sml')
-rw-r--r--src/nbc/history.sml74
1 files changed, 0 insertions, 74 deletions
diff --git a/src/nbc/history.sml b/src/nbc/history.sml
deleted file mode 100644
index 52c1bb2..0000000
--- a/src/nbc/history.sml
+++ /dev/null
@@ -1,74 +0,0 @@
-structure History :> sig
- type history
- val create: int -> history
- val clear: history -> history
- val push: history * char -> string option * history
-end = struct
- type history = {maximumSize: int, content: string}
- fun create maximumSize = {maximumSize = maximumSize, content = ""}
- fun clear {maximumSize, content = _} =
- {maximumSize = maximumSize, content = ""}
- fun addToString (string, newCharacter) =
- let
- val size = size string
- in
- CharVector.tabulate (
- size + 1
- , fn index =>
- if index = size then newCharacter
- else String.sub (string, index)
- )
- end
- fun shiftIntoString (string, newCharacter) =
- let
- val size = size string
- in
- CharVector.tabulate (
- size
- , fn index =>
- if index = size - 1 then newCharacter
- else String.sub (string, index + 1)
- )
- end
- fun push ({maximumSize, content}, newCharacter) =
- let
- val currentSize = size content
- in
- if currentSize = maximumSize then
- let
- val newContent = shiftIntoString (
- content
- , newCharacter
- )
- in (
- SOME newContent
- , {
- maximumSize = maximumSize
- , content = newContent
- }
- ) end
- else if currentSize = maximumSize - 1 then
- let
- val newContent = addToString (
- content
- , newCharacter
- )
- in (
- SOME newContent
- , {
- maximumSize = maximumSize
- , content = newContent
- }
- ) end
- else (
- NONE
- , {
- maximumSize = maximumSize
- , content = addToString (
- content
- , newCharacter
- )
- }
- )
- end
-end