# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1485033064 -3600
# Node ID de5b7fb29457eceb2763d7457b25d61b22c62ffd
# Parent  5a82b12d3f7b4ddaf847adc7c5c921651a3d1ac3
Exposed result objects to the attribute access instruction encoding mechanism.

diff -r 5a82b12d3f7b -r de5b7fb29457 common.py
--- a/common.py	Sat Jan 21 18:22:20 2017 +0100
+++ b/common.py	Sat Jan 21 22:11:04 2017 +0100
@@ -795,6 +795,21 @@
             l.append(arg)
     return l
 
+# Result classes.
+
+class InstructionSequence:
+
+    "A generic sequence of instructions."
+
+    def __init__(self, instructions):
+        self.instructions = instructions
+
+    def get_value_instruction(self):
+        return self.instructions[-1]
+
+    def get_init_instructions(self):
+        return self.instructions[:-1]
+
 # Dictionary utilities.
 
 def init_item(d, key, fn):
diff -r 5a82b12d3f7b -r de5b7fb29457 encoders.py
--- a/encoders.py	Sat Jan 21 18:22:20 2017 +0100
+++ b/encoders.py	Sat Jan 21 22:11:04 2017 +0100
@@ -249,7 +249,7 @@
             a[0] = "&%s" % a[0]
             a[1] = "&%s" % a[1]
 
-        argstr = "(%s)" % ", ".join(a)
+        argstr = "(%s)" % ", ".join(map(str, a))
 
     # Substitute the first element of the instruction, which may not be an
     # operation at all.
@@ -319,6 +319,15 @@
 
     return "__new_%s" % encode_path(path)
 
+def encode_instructions(instructions):
+
+    "Encode 'instructions' as a sequence."
+
+    if len(instructions) == 1:
+        return instructions[0]
+    else:
+        return "(\n%s\n)" % ",\n".join(instructions)
+
 def encode_literal_constant(n):
 
     "Encode a name for the literal constant with the number 'n'."
diff -r 5a82b12d3f7b -r de5b7fb29457 translator.py
--- a/translator.py	Sat Jan 21 18:22:20 2017 +0100
+++ b/translator.py	Sat Jan 21 22:11:04 2017 +0100
@@ -19,11 +19,13 @@
 this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
-from common import CommonModule, CommonOutput, first, get_builtin_module, \
-                   get_builtin_type, init_item, predefined_constants
+from common import CommonModule, CommonOutput, InstructionSequence, \
+                   first, get_builtin_module, get_builtin_type, init_item, \
+                   predefined_constants
 from encoders import encode_access_instruction, encode_bound_reference, \
                      encode_function_pointer, encode_literal_constant, \
                      encode_literal_instantiator, encode_instantiator_pointer, \
+                     encode_instructions, \
                      encode_path, encode_symbol, encode_type_attribute, \
                      is_type_attribute
 from os.path import exists, join
@@ -183,12 +185,12 @@
     def __repr__(self):
         return "TrResolvedInstanceRef(%r, %r)" % (self.ref, self.expr)
 
-class AttrResult(Expression, TranslationResult):
+class AttrResult(Expression, TranslationResult, InstructionSequence):
 
     "A translation result for an attribute access."
 
-    def __init__(self, s, refs, accessor_kinds):
-        Expression.__init__(self, s)
+    def __init__(self, instructions, refs, accessor_kinds):
+        InstructionSequence.__init__(self, instructions)
         self.refs = refs
         self.accessor_kinds = accessor_kinds
 
@@ -206,10 +208,13 @@
     def get_accessor_kinds(self):
         return self.accessor_kinds
 
+    def __str__(self):
+        return encode_instructions(self.instructions)
+
     def __repr__(self):
-        return "AttrResult(%r, %r, %r)" % (self.s, self.refs, self.accessor_kinds)
-
-class PredefinedConstantRef(AttrResult):
+        return "AttrResult(%r, %r, %r)" % (self.instructions, self.refs, self.accessor_kinds)
+
+class PredefinedConstantRef(Expression, TranslationResult):
 
     "A predefined constant reference."
 
@@ -701,8 +706,8 @@
         # Generate access instructions.
 
         subs = {
-            "<expr>" : str(attr_expr),
-            "<assexpr>" : str(self.in_assignment),
+            "<expr>" : attr_expr,
+            "<assexpr>" : self.in_assignment,
             }
 
         temp_subs = {
@@ -738,15 +743,8 @@
             if temp_subs.has_key(sub):
                 self.record_temp(temp_subs[sub])
 
-        # Format the output.
-
-        if len(output) == 1:
-            out = output[0]
-        else:
-            out = "(\n%s\n)" % ",\n".join(output)
-
         del self.attrs[0]
-        return AttrResult(out, refs, self.get_accessor_kinds(location))
+        return AttrResult(output, refs, self.get_accessor_kinds(location))
 
     def get_referenced_attributes(self, location):