[pypy-svn] r17879 - pypy/dist/pypy/translator/tool

[pedronis at codespeak.net]

Author: pedronis
Date: Mon Sep 26 16:59:42 2005
New Revision: 17879

Added:
   pypy/dist/pypy/translator/tool/taskengine.py   (contents, props changed)
Log:
start of a very very simple "make-like" task engine to use to make translation/translator more goal oriented



Added: pypy/dist/pypy/translator/tool/taskengine.py
==============================================================================
--- (empty file)
+++ pypy/dist/pypy/translator/tool/taskengine.py	Mon Sep 26 16:59:42 2005
@@ -0,0 +1,108 @@
+
+
+
+
+class SimpleTaskEngine:
+
+
+    def __init__(self):
+
+        self.tasks = tasks = {}
+
+        for name in dir(self):
+            if name.startswith('task_'):
+                task_name = name[len('task_'):]
+                task = getattr(self, name)
+                assert callable(task)
+                task_deps = getattr(task, 'task_deps', [])
+
+                tasks[task_name] = task, task_deps
+
+
+    def _plan(self, goal, skip=[]):
+
+        constraints = []
+
+        def subgoals(task_name):
+            taskcallable, deps = self.tasks[task_name]
+            for dep in deps:
+                if dep.startswith('?'):
+                    dep = dep[1:]
+                    if dep in skip:
+                        continue
+                yield dep
+
+
+        seen = {}
+                        
+        def consider(subgoal):
+            if subgoal in seen:
+                return
+            else:
+                seen[subgoal] = True
+            constraints.append([subgoal])
+            deps = subgoals(subgoal)
+            for dep in deps:
+                constraints.append([subgoal, dep])
+                consider(dep)
+
+        consider(goal)
+
+        #sort
+
+        plan = []
+
+        while True:
+            cands = dict.fromkeys([constr[0] for constr in constraints if constr])
+            if not cands:
+                break
+
+            for cand in cands:
+                for constr in constraints:
+                    if cand in constr[1:]:
+                        break
+                else:
+                    break
+            else:
+                raise RuntimeError, "circular dependecy"
+
+            plan.append(cand)
+            for constr in constraints:
+                if constr and constr[0] == cand:
+                    del constr[0]
+
+        plan.reverse()
+
+        return plan
+            
+            
+
+def test_simple():
+
+    class ABC(SimpleTaskEngine):
+
+        def task_A(self):
+            pass
+
+        task_A.task_deps = ['B', '?C']
+
+        def task_B(self):
+            pass
+
+        def task_C(self):
+            pass
+
+        task_C.task_deps = ['B']
+
+    abc = ABC()
+
+    assert abc._plan('B') == ['B']
+    assert abc._plan('C') == ['B', 'C']
+    assert abc._plan('A') == ['B', 'C', 'A']
+    assert abc._plan('A', skip=['C']) == ['B', 'A']
+   
+
+   
+
+        
+