Merge lp:~jelmer/storm/cast into lp:storm

[Jelmer Vernooij]

Add storm.expr.Cast.

This branch adds storm.expr.Cast.

[Gustavo Niemeyer (niemeyer)]

Looks good. +1!

review: Approve

[Jamu Kakar (jkakar)]

[1]

Please add docstrings to the various bits you've added.

[2]

Maybe it's overkill, but I wonder if we should allow the second
parameter to optionally be a Python type? In such a case, we'd pick
the appropriate database type, depending on the backend.

+1 on this branch! If [2] seems interesting please file a bug about
it.

review: Approve

[lp:~jelmer/storm/cast]

385. By Jelmer Vernooij on 2010-11-30

Add docstrings.

[Jelmer Vernooij (jelmer)]

I've added the docstring and filed a bug about supporting Python type objects. Is there anything else I need to do to help land this?

[Jamu Kakar (jkakar)]

Harassment was all that was needed, I've merged the changes. :)

=== modified file 'storm/expr.py'
--- storm/expr.py	2009-11-02 11:11:20 +0000
+++ storm/expr.py	2010-11-30 12:31:36 +0000
@@ -1286,6 +1286,26 @@
     name = "COALESCE"
 
 
+class Cast(FuncExpr):
+    """A representation of "CAST" clauses. e.g., CAST(bar AS TEXT).
+    """
+    __slots__ = ("column", "type")
+    name = "CAST"
+
+    def __init__(self, column, type):
+        """Create a cast of C{column} as C{type}."""
+        self.column = column
+        self.type = type
+
+
[e-mail](Cast)
+def compile_cast(compile, cast, state):
+    state.push("context", EXPR)
+    column = compile(cast.column, state)
+    state.pop()
+    return "CAST(%s AS %s)" % (column, cast.type)
+
+
 # --------------------------------------------------------------------
 # Prefix and suffix expressions
 

=== modified file 'tests/expr.py'
--- tests/expr.py	2009-11-02 11:11:20 +0000
+++ tests/expr.py	2010-11-30 12:31:36 +0000
@@ -1380,6 +1380,13 @@
     def test_count_distinct_all(self):
         self.assertRaises(ValueError, Count, distinct=True)
 
+    def test_cast(self):
+        expr = Cast(Func1(), "TEXT")
+        state = State()
+        statement = compile(expr, state)
+        self.assertEquals(statement, "CAST(func1() AS TEXT)")
+        self.assertEquals(state.parameters, [])
+
     def test_max(self):
         expr = Max(Func1())
         state = State()