From 8f5d8adf4862eaaa37cb441a224cd387e3c37fb1 Mon Sep 17 00:00:00 2001
From: Miika Alonen <amiika@gmail.com>
Date: Wed, 26 Apr 2023 21:14:21 +0300
Subject: [PATCH] Added pick and select for lists

Pick: (1 2 3 4)?4 or (1 2 3 4)?(3 2)
Select: (1 2 3 4)~2 or (1 2 3 4)~(2 3)
---
 ziffers/classes/items.py     |  2 +-
 ziffers/classes/sequences.py | 49 +++++++++++++++++++++++++++++++++++-
 ziffers/defaults.py          |  4 ++-
 ziffers/mapper.py            |  2 +-
 ziffers/parser.py            |  1 -
 ziffers/spec/ziffers.lark    |  6 +++--
 6 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/ziffers/classes/items.py b/ziffers/classes/items.py
index c3ada80..a4e405b 100644
--- a/ziffers/classes/items.py
+++ b/ziffers/classes/items.py
@@ -433,7 +433,7 @@ class RomanNumeral(Event):
     pitch_classes: list = field(default=None, init=False)
     inversions: int = field(default=None)
     evaluated_chord: Chord = None
-
+    
     def set_notes(self, chord_notes: list[int]):
         """Set notes to roman numeral
 
diff --git a/ziffers/classes/sequences.py b/ziffers/classes/sequences.py
index 5b66b17..cd6b8f6 100644
--- a/ziffers/classes/sequences.py
+++ b/ziffers/classes/sequences.py
@@ -2,6 +2,7 @@
 from dataclasses import dataclass, field, replace
 from itertools import product
 from math import floor
+import random
 from types import LambdaType
 from copy import deepcopy
 import operator
@@ -403,6 +404,47 @@ class ListOperation(Sequence):
 
             return flattened_list
 
+        def _pick_from_list(left, right, options):
+            """Pick random numbers from a list"""
+            if isinstance(left, Sequence):
+                left = _filter_operation(left, options)
+            
+            if isinstance(right, Sequence):
+                right = _filter_operation(right, options)
+            
+            if not isinstance(right, (list, Sequence)):
+                right = Sequence(values=[right])
+            
+            result = []
+
+            for num in right.values:
+                for _ in range(num.get_value(options)):
+                    result.append(random.choice(left.values))
+            return flatten(result)
+        
+
+        def _select_from_list(left, right, options):
+            """Select number of items from shuffled list"""
+            if isinstance(left, Sequence):
+                left = _filter_operation(left, options)
+            
+            if isinstance(right, Sequence):
+                right = _filter_operation(right, options)
+            
+            if not isinstance(right, (list, Sequence)):
+                right = Sequence(values=[right])
+            
+            result = []
+            left = left.values
+
+            for num in right.values:
+                random.shuffle(left)
+                num = num.get_value(options)
+                new_list = [left[i % len(left)] for i in range(num)]
+                result += new_list
+                
+            return flatten(result)
+
         def _vertical_arpeggio(left, right, options):
             """Vertical arpeggio operation, eg. (135)@(q 1 2 021)"""
             left = _filter_operation(left, options)
@@ -537,8 +579,13 @@ class ListOperation(Sequence):
                     left = _vertical_arpeggio(left, right, options)
                 elif operation == "horizontal":
                     left = _horizontal_arpeggio(left, right, options)
-                if operation == "zip":
+                elif operation == "zip":
                     left = _cyclic_zip(left, right, options)
+                elif operation == "pick":
+                    left = _pick_from_list(left, right, options)
+                elif operation == "select":
+                    left = _select_from_list(left, right, options)
+                
             else:
                 left = _python_operations(left, right, options)
         return left
diff --git a/ziffers/defaults.py b/ziffers/defaults.py
index e184796..92ca46b 100644
--- a/ziffers/defaults.py
+++ b/ziffers/defaults.py
@@ -62,7 +62,9 @@ OPERATORS = MappingProxyType({
     ">>": operator.irshift,
     "@": "vertical",
     "#": "horizontal",
-    "<>": "zip"
+    "<>": "zip",
+    "?": "pick",
+    "~": "select"
 })
 
 
diff --git a/ziffers/mapper.py b/ziffers/mapper.py
index 0443838..949329a 100644
--- a/ziffers/mapper.py
+++ b/ziffers/mapper.py
@@ -431,7 +431,7 @@ class ZiffersTransformer(Transformer):
     def lisp_operation(self, items):
         """Parse lisp like list operation"""
         op = items[0]
-        values = items[1:]
+        values = items[2]
         return LispOperation(
             operator=op,
             values=values,
diff --git a/ziffers/parser.py b/ziffers/parser.py
index 4fb12db..d0f083c 100644
--- a/ziffers/parser.py
+++ b/ziffers/parser.py
@@ -73,7 +73,6 @@ def zparse(expr: str, **opts) -> Ziffers:
     parsed.init_opts(opts)
     return parsed
 
-
 # pylint: disable=invalid-name
 
 
diff --git a/ziffers/spec/ziffers.lark b/ziffers/spec/ziffers.lark
index 03466b9..bfb760f 100644
--- a/ziffers/spec/ziffers.lark
+++ b/ziffers/spec/ziffers.lark
@@ -56,8 +56,9 @@
     right_op: list | number
     // Operators that work only on lists: | << >>
     list_operator: /(\||<<|>>|<>|#|@)(?=[(\d])/
+    // /(\||<<|>>|<>|#|@)(?=[(\d])/
     // Common operators that works with numbers 3+5 3-5 etc.
-    operator: /([\+\-\*\/%\&])/
+    operator: /(\+|-|\*|\/|%|&|\?|~)/
 
     // Euclidean cycles
     // TODO: Support randomization etc.
@@ -66,7 +67,8 @@
     ?euclid_operator: /<[0-9]+,[0-9]+(,[0-9])?>/
     
     // Lisp like list operation
-    lisp_operation:  "(" operator WS sequence ")"
+    lisp_operator: /([\+\-\*\/%\&])/ 
+    lisp_operation:  "(" lisp_operator WS sequence ")"
 
     // Subdivision
     subdivision: "[" subitems "]"