From 58e2ab61df35578320f4abe912cb794739407cfa Mon Sep 17 00:00:00 2001
From: Mark Skilbeck <markskilbeck@gmail.com>
Date: Mon, 7 Dec 2020 16:07:24 +0000
Subject: [PATCH] native pragma support

---
 pyquil/pragmas.py | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 pyquil/pragmas.py

diff --git a/pyquil/pragmas.py b/pyquil/pragmas.py
new file mode 100644
index 000000000..5effcd8be
--- /dev/null
+++ b/pyquil/pragmas.py
@@ -0,0 +1,53 @@
+##############################################################################
+# Copyright 2016-2018 Rigetti Computing
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+##############################################################################
+
+from typing import List, Iterable
+
+from pyquil.quilbase import AbstractInstruction, Pragma
+from pyquil.quil import Program
+
+
+class InitialRewiring(Pragma):
+    def __init__(self, rewiring: str):
+        self.rewiring = rewiring
+
+    def out(self) -> str:
+        return f'PRAGMA INITIAL_REWIRING "{self.rewiring}"'
+
+
+NAIVE_REWIRING = InitialRewiring("NAIVE")
+RANDOM_REWIRING = InitialRewiring("RANDOM")
+GREEDY_REWIRING = InitialRewiring("GREEDY")
+PARTIAL_REWIRING = InitialRewiring("PARTIAL")
+
+
+class PreserveBlock(Pragma):
+    def __init__(self, *instructions: Iterable[AbstractInstruction]):
+        self.instructions = Program(instructions)
+
+    def out(self) -> str:
+        return "PRAGMA PRESERVE_BLOCK\n{}\nPRAGMA END_PRESERVE_BLOCK".format(
+            "\n".join([str(instr) for instr in self.instructions]),
+        )
+
+
+class CommutingBlocks(Pragma):
+    def __init__(self, blocks: List[Iterable[AbstractInstruction]]):
+        self.blocks = blocks
+
+    def out(self) -> str:
+        blocks = "\n".join([f"PRAGMA BLOCK\n{block}PRAGMA END_BLOCK" for block in self.blocks])
+        return f"PRAGMA COMMUTING_BLOCKS\n{blocks}\nPRAGMA END_COMMUTING_BLOCKS"