language/scan: add argument processor

artiq/language/__init__.py

@@ -1,10 +1,12 @@
-from artiq.language import core, environment, units
+from artiq.language import core, environment, units, scan
 from artiq.language.core import *
 from artiq.language.environment import *
 from artiq.language.units import *
+from artiq.language.scan import *
 
 
 __all__ = []
 __all__.extend(core.__all__)
 __all__.extend(environment.__all__)
 __all__.extend(units.__all__)
+__all__.extend(scan.__all__)

artiq/language/scan.py

@@ -1,6 +1,27 @@
 from random import Random, shuffle
+import inspect
 
 from artiq.language.core import *
+from artiq.language.environment import NoDefault, DefaultMissing
+
+
+__all__ = ["NoScan", "LinearScan", "RandomScan", "ExplicitScan", "Scannable"]
+
+
+class NoScan:
+    def __init__(self, value):
+        self.value = value
+
+    @portable
+    def _gen(self):
+        yield self.value
+
+    @portable
+    def __iter__(self):
+        return self._gen()
+
+    def describe(self):
+        return {"ty": "NoScan", "value": self.value}
 
 
 class LinearScan:
@@ -20,6 +41,10 @@ class LinearScan:
     def __iter__(self):
         return self._gen()
 
+    def describe(self):
+        return {"ty": "LinearScan",
+                "min": self.min, "max": self.max, "npoints": self.npoints}
+
 
 class RandomScan:
     def __init__(self, min, max, npoints, seed=0):
@@ -30,6 +55,11 @@ class RandomScan:
     def __iter__(self):
         return iter(self.sequence)
 
+    def describe(self):
+        return {"ty": "RandomScan",
+                "min": self.min, "max": self.max, "npoints": self.npoints}
+
+
 
 class ExplicitScan:
     def __init__(self, sequence):
@@ -38,3 +68,48 @@ class ExplicitScan:
     @portable
     def __iter__(self):
         return iter(self.sequence)
+
+    def describe(self):
+        return {"ty": "ExplicitScan", "sequence": self.sequence}
+
+
+_ty_to_scan = {
+    "NoScan": NoScan,
+    "LinearScan": LinearScan,
+    "RandomScan": RandomScan,
+    "ExplicitScan": ExplicitScan
+}
+
+
+class Scannable:
+    def __init__(self, global_min=None, global_max=None, global_step=None,
+                 unit="", default=NoDefault):
+        self.global_min = global_min
+        self.global_max = global_max
+        self.global_step = global_step
+        self.unit = unit
+        if default is not NoDefault:
+            self.default_value = default
+
+    def default(self):
+        if not hasattr(self, "default_value"):
+            raise DefaultMissing
+        return self.default_value
+
+    def process(self, x):
+        cls = _ty_to_scan[x["ty"]]
+        args = dict()
+        for arg in inspect.getargspec(cls).args[1:]:
+            if arg in x:
+                args[arg] = x[arg]
+        return cls(**args)
+
+    def describe(self):
+        d = {"ty": "Scannable"}
+        d["global_min"] = self.global_min
+        d["global_max"] = self.global_max
+        d["global_step"] = self.global_step
+        d["unit"]= self.unit
+        if hasattr(self, "default_value"):
+            d["default"] = self.default_value.describe()
+        return d