From 1710d2f67b91f130ac46d41123202cefa7f1f6e4 Mon Sep 17 00:00:00 2001
From: Miika Alonen <amiika@gmail.com>
Date: Sun, 5 Feb 2023 14:12:22 +0200
Subject: [PATCH] Refactored duration changes

Fixes cyclic duration changes
---
 ziffers/mapper.py    | 22 ++++++++++++++++++++--
 ziffers/ziffers.lark |  4 +++-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/ziffers/mapper.py b/ziffers/mapper.py
index 5e4370a..e4bfcfb 100644
--- a/ziffers/mapper.py
+++ b/ziffers/mapper.py
@@ -59,8 +59,26 @@ class ZiffersTransformer(Transformer):
         return Chord(pcs=s,text="".join([val.text for val in s]))
 
     def dur_change(self,s):
-        duration = s[0]
-        return [DurationChange(dur=duration["dur"], text=duration["text"]),s[1]]
+        durs = s[0]
+        return DurationChange(dur=durs[1], text=durs[0])
+
+    def char_change(self,s):
+        chars = ""
+        durs = 0.0
+        for (dchar,dots) in s:
+            val = default_durs[dchar]
+            if(dots>0):
+                val = val * (2.0-(1.0/(2*dots)))
+            chars = chars + (dchar+"."*dots)
+            durs = durs + val
+        return [chars,durs]
+
+    def dchar_not_prefix(self,s):
+        dur = s[0].split(".",1)
+        dots = 0
+        if len(dur)>1:
+            dots = len(dur[1])+1
+        return [dur[0],dots]
 
     def escaped_decimal(self,s):
         val = s[0]
diff --git a/ziffers/ziffers.lark b/ziffers/ziffers.lark
index 49f5558..4862661 100644
--- a/ziffers/ziffers.lark
+++ b/ziffers/ziffers.lark
@@ -52,7 +52,9 @@
     // Control characters modifying future events
     oct_mod: octave WS
     oct_change: escaped_octave WS
-    dur_change: (duration_chars | decimal) WS
+    dur_change: (decimal | char_change)
+    char_change: dchar_not_prefix+
+    dchar_not_prefix: /([mklpdcwyhnqaefsxtgujzo](\.)*)(?!\d)/
 
     // Generative rules
     random_integer: /\(-?[0-9]+,-?[0-9]+\)/