From e92c82e2c9ff541cd321ad7a8aedcf34e615197c Mon Sep 17 00:00:00 2001
From: Lars-Dominik Braun <lars@6xq.net>
Date: Sun, 14 Jun 2015 20:35:08 +0200
Subject: First public version

---
 src/Codec/Pesto/Serialize.lhs | 69 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 src/Codec/Pesto/Serialize.lhs

(limited to 'src/Codec/Pesto/Serialize.lhs')

diff --git a/src/Codec/Pesto/Serialize.lhs b/src/Codec/Pesto/Serialize.lhs
new file mode 100644
index 0000000..5b3007e
--- /dev/null
+++ b/src/Codec/Pesto/Serialize.lhs
@@ -0,0 +1,69 @@
+Serializing
+-----------
+
+.. class:: nodoc
+
+> module Codec.Pesto.Serialize (serialize) where
+> import Data.Char (isSpace, toLower, isLetter)
+> import Data.Ratio (numerator, denominator)
+>
+> import {-# SOURCE #-} Codec.Pesto.Parse
+
+> class Serializeable a where
+> 	serialize :: a -> String
+
+.. class:: todo
+
+- Add instance for graph
+- use :math:`\mathcal{O}(1)` string builder
+
+
+Finally transform linear stream of operations into a string again:
+
+> instance Serializeable a => Serializeable [a] where
+> 	serialize ops = unlines $ map serialize ops
+
+> instance Serializeable Operation where
+> 	serialize (Annotation s) = quote '(' ')' s
+> 	serialize (Ingredient q) = '+':serialize q
+> 	serialize (Tool q) = '&':serialize q
+> 	serialize (Action s) = quote '[' ']' s
+> 	serialize (Reference q) = '*':serialize q
+> 	serialize (Result s) = '>':serializeQstr s
+> 	serialize (Alternative s) = '|':serializeQstr s
+
+> instance Serializeable Quantity where
+> 	serialize (Quantity a b "") = serialize a ++ " " ++ serializeQstr b
+> 	serialize (Quantity (Exact (AmountStr "")) "" c) = serializeQstr c
+> 	serialize (Quantity a "" c) = serialize a ++ " _ " ++ serializeQstr c
+> 	serialize (Quantity a b c) = serialize a ++ " " ++ serializeQstr b ++ " " ++ serializeQstr c
+
+> instance Serializeable Approximately where
+> 	serialize (Range a b) = serialize a ++ "-" ++ serialize b
+> 	serialize (Approx a) = '~':serialize a
+> 	serialize (Exact a) = serialize a
+
+There are two special cases here, both for aesthetic reasons:
+
+1) If the denominator is one we can just skip printing it, because
+   :math:`\frac{2}{1} = 2` and
+2) if the numerator is larger than the denominator use mixed fraction notation,
+   because :math:`\frac{7}{2} = 3+\frac{1}{2}`
+
+> instance Serializeable Amount where
+> 	serialize (AmountRatio a) | denominator a == 1 = show (numerator a)
+> 	serialize (AmountRatio a) | numerator a > denominator a =
+> 		show full ++ "/" ++ show num ++ "/" ++ show denom
+> 		where
+> 			full = numerator a `div` denom
+> 			num = numerator a - full * denom
+> 			denom = denominator a
+> 	serialize (AmountRatio a) = show (numerator a) ++ "/" ++ show (denominator a)
+> 	serialize (AmountStr s) = serializeQstr s
+
+> serializeQstr "" = "_"
+> serializeQstr s | (not . isLetter . head) s || hasSpaces s = quote '"' '"' s
+> serializeQstr s = s
+> hasSpaces = any isSpace
+> quote start end s = [start] ++ concatMap (\c -> if c == end then ['\\', end] else [c]) s ++ [end]
+
-- 
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