# HG changeset patch
# User paulb
# Date 1106563001 0
# Node ID e7ecb820d8ef4912c113c5ccd81384f3df8457f8
# Parent  5a430aba00c780a9deaaacc2bcb88fe3f4404e28
[project @ 2005-01-24 10:36:41 by paulb]
Added prefix definition using special import statements.

diff -r 5a430aba00c7 -r e7ecb820d8ef libxml2macro.py
--- a/libxml2macro.py	Mon Jan 24 02:16:16 2005 +0000
+++ b/libxml2macro.py	Mon Jan 24 10:36:41 2005 +0000
@@ -33,7 +33,7 @@
 
 # Processing functions.
 
-def process_nodes(root_node, prefix):
+def process_nodes(root_node, prefix=None):
 
     """
     Under the 'root_node', process all suitable expression nodes which employ
@@ -41,14 +41,40 @@
     """
 
     for node in root_node.getChildNodes():
-        # Identify suitable names and add such nodes
-        if isinstance(node, compiler.ast.CallFunc):
+
+        # Find imports and discover if they are really used to define the
+        # special prefix.
+
+        if isinstance(node, compiler.ast.Import):
+            prefix = process_import(node, root_node) or prefix
+
+        # Identify suitable names and add replacement nodes.
+
+        elif isinstance(node, compiler.ast.CallFunc):
             process_callfunc(node, prefix)
         elif isinstance(node, compiler.ast.Getattr):
             process_getattr(node, prefix, root_node)
         else:
             process_nodes(node, prefix)
 
+def process_import(node, parent):
+
+    """
+    Process the Import 'node' searching for the special incantation required to
+    set the prefix. Remove compliant nodes from their 'parent' node. If no new
+    prefix is found, return None.
+    """
+
+    for name, alias in node.names:
+        if name == "libxml2macro":
+
+            # Remove this node from its parent.
+
+            parent.nodes.remove(node)
+            return alias
+
+    return None
+
 def process_callfunc(node, prefix):
 
     """
@@ -56,7 +82,13 @@
     'prefix'.
     """
 
+    # Check the prefix.
+
+    if prefix is None:
+        return
+
     # Check the target.
+
     target = node.node
     if isinstance(target, compiler.ast.Getattr):
         if process_getattr(target, prefix, node):
@@ -95,6 +127,11 @@
     processed and where a replacement of such arguments is occurring.
     """
 
+    # Check the prefix.
+
+    if prefix is None:
+        return
+
     # Detected cases:
     # node.attr plus node.attr.attr
     # (obj.node).attr plus (obj.node).attr.attr
@@ -167,16 +204,27 @@
 
     # Check the expression as a simple name:
     # node.attr
+
     if isinstance(node.expr, compiler.ast.Name) and node.expr.name.startswith(prefix):
         return 1
+
     # Check the attribute name of child expressions:
     # (obj.node).attr
+
     elif isinstance(node.expr, compiler.ast.Getattr) and node.expr.attrname.startswith(prefix):
         return 1
     else:
         return 0
 
-def process_file(filename, prefix="x2_"):
+def include_import(module):
+
+    """
+    Include an import statement in 'module' so make the macro library available.
+    """
+
+    module.node.nodes.insert(0, compiler.ast.From("libxml2dom.macrolib", [("*", None)]))
+
+def process_file(filename):
 
     """
     Process the module given by the specified 'filename'. The optional special
@@ -189,7 +237,11 @@
 
     # Find references to special variables.
 
-    process_nodes(module, prefix)
+    process_nodes(module)
+
+    # Add necessary imports.
+
+    include_import(module)
 
     # Write the module.