Add Python 3 support.

.travis.yml

@@ -1,6 +1,7 @@
 language: python
 python:
     - "2.7"
+    - "3.4"
 install:
     - "pip install -r requirements.txt --use-mirrors"
     - "pip install coveralls"

py14/analysis.py

@@ -1,3 +1,4 @@
+import sys
 import ast
 
 
@@ -11,6 +12,21 @@ def is_void_function(fun):
     finder.visit(fun)
     return not finder.returns
 
+if sys.version_info[0] >= 3:
+    def get_id(var):
+        if isinstance(var, ast.alias):
+            return var.name
+        elif isinstance(var, ast.Name):
+            return var.id
+        elif isinstance(var, ast.arg):
+            return var.arg
+else:
+    def get_id(var):
+        if isinstance(var, ast.alias):
+            return var.name
+        elif isinstance(var, ast.Name):
+            return var.id
+
 
 class ReturnFinder(ast.NodeVisitor):
     returns = False

py14/clike.py

@@ -47,6 +47,14 @@ def visit_Name(self, node):
         if node.id in self.builtin_constants:
             return node.id.lower()
         return node.id
+
+    def visit_NameConstant(self, node):
+        if node.value is True:
+            return "true"
+        elif node.value is False:
+            return "false"
+        else:
+            return node.value
 
     def visit_Num(self, node):
         return str(node.n)

py14/context.py

@@ -1,5 +1,5 @@
 import ast
-from scope import ScopeMixin
+from .scope import ScopeMixin
 
 
 def add_list_calls(node):
@@ -55,11 +55,11 @@ def visit_Import(self, node):
 
     def visit_If(self, node):
         node.vars = []
-        map(self.visit, node.body)
+        list(map(self.visit, node.body))
         node.body_vars = node.vars
 
         node.vars = []
-        map(self.visit, node.orelse)
+        list(map(self.visit, node.orelse))
         node.orelse_vars = node.vars
 
         node.vars = []

py14/scope.py

@@ -1,6 +1,7 @@
 import ast
 from contextlib import contextmanager
 
+from .analysis import get_id
 
 def add_scope_context(node):
     """Provide to scope context to all nodes"""
@@ -42,13 +43,9 @@ class ScopeList(list):
     """
     def find(self, lookup):
         """Find definition of variable lookup."""
-        def is_match(var):
-            return ((isinstance(var, ast.alias) and var.name == lookup) or
-                    (isinstance(var, ast.Name) and var.id == lookup))
-
         def find_definition(scope, var_attr="vars"):
             for var in getattr(scope, var_attr):
-                if is_match(var):
+                if get_id(var) == lookup:
                     return var
 
         for scope in self:

py14/tests/test_transpiler.py

@@ -1,5 +1,6 @@
-from py14.transpiler import transpile
+import sys
 import pytest
+from py14.transpiler import transpile
 
 
 def parse(*args):
@@ -26,7 +27,10 @@ def test_empty_return():
 
 
 def test_print_multiple_vars():
-    source = parse('print("hi", "there" )')
+    if sys.version_info[0] >= 3:
+        source = parse('print(("hi", "there" ))')
+    else:
+        source = parse('print("hi", "there" )')
     cpp = transpile(source)
     assert cpp == ('std::cout << std::string {"hi"} '
                    '<< std::string {"there"} << std::endl;')
@@ -228,12 +232,13 @@ def test_bubble_sort():
         "    return seq",
     )
     cpp = transpile(source)
+    range_f = "range" if sys.version_info[0] < 3 else "xrange"
     assert cpp == parse(
         "template <typename T1>",
         "auto sort(T1 seq) {",
         "auto L = seq.size();",
-        "for(auto _ : rangepp::range(L)) {",
-        "for(auto n : rangepp::range(1, L)) {",
+        "for(auto _ : rangepp::{0}(L)) {{".format(range_f),
+        "for(auto n : rangepp::{0}(1, L)) {{".format(range_f),
         "if(seq[n] < seq[n - 1]) {",
         "std::tie(seq[n - 1], seq[n]) = "
         "std::make_tuple(seq[n], seq[n - 1]);",
@@ -287,6 +292,7 @@ def test_comb_sort():
         "                return seq",
     )
     cpp = transpile(source)
+    range_f = "range" if sys.version_info[0] < 3 else "xrange"
     assert cpp == parse(
         "template <typename T1>",
         "auto sort(T1 seq) {",
@@ -295,7 +301,7 @@ def test_comb_sort():
         "while (gap > 1||swap) {",
         "gap = std::max(1, py14::to_int(gap / 1.25));",
         "swap = false;",
-        "for(auto i : rangepp::range(seq.size() - gap)) {",
+        "for(auto i : rangepp::{0}(seq.size() - gap)) {{".format(range_f),
         "if(seq[i] > seq[i + gap]) {",
         "std::tie(seq[i], seq[i + gap]) = "
         "std::make_tuple(seq[i + gap], seq[i]);",

py14/tracer.py

@@ -2,7 +2,8 @@
 Trace object types that are inserted into Python list.
 """
 import ast
-from clike import CLikeTranspiler
+from .analysis import get_id
+from .clike import CLikeTranspiler
 
 
 def decltype(node):
@@ -24,7 +25,7 @@ def is_list(node):
     elif isinstance(node, ast.Assign):
         return is_list(node.value)
     elif isinstance(node, ast.Name):
-        var = node.scopes.find(node.id)
+        var = node.scopes.find(get_id(node))
         return (hasattr(var, "assigned_from") and not
                 isinstance(var.assigned_from, ast.FunctionDef) and
                 is_list(var.assigned_from.value))
@@ -59,13 +60,13 @@ def visit_Str(self, node):
         return node.s
 
     def visit_Name(self, node):
-        var = node.scopes.find(node.id)
+        var = node.scopes.find(get_id(node))
         if isinstance(var.assigned_from, ast.For):
             it = var.assigned_from.iter
             return "std::declval<typename decltype({0})::value_type>()".format(
                    self.visit(it))
         elif isinstance(var.assigned_from, ast.FunctionDef):
-            return var.id
+            return get_id(var)
         else:
             return self.visit(var.assigned_from.value)
 
@@ -99,6 +100,9 @@ def visit_Name(self, node):
         else:
             return self.visit(var.assigned_from.value)
 
+    def visit_NameConstant(self, node):
+        return CLikeTranspiler().visit(node)
+
     def visit_Call(self, node):
         params = ",".join([self.visit(arg) for arg in node.args])
         return "{0}({1})".format(node.func.id, params)

py14/transpiler.py

@@ -1,9 +1,10 @@
+import sys
 import ast
-from clike import CLikeTranspiler
-from scope import add_scope_context
-from analysis import add_imports, is_void_function
-from context import add_variable_context, add_list_calls
-from tracer import decltype, is_list, is_builtin_import, defined_before
+from .clike import CLikeTranspiler
+from .scope import add_scope_context
+from .context import add_variable_context, add_list_calls
+from .analysis import add_imports, is_void_function, get_id
+from .tracer import decltype, is_list, is_builtin_import, defined_before
 
 
 def transpile(source, headers=False, testing=False):
@@ -43,7 +44,7 @@ def generate_catch_test_case(node, body):
 def generate_template_fun(node, body):
     params = []
     for idx, arg in enumerate(node.args.args):
-        params.append(("T" + str(idx + 1), arg.id))
+        params.append(("T" + str(idx + 1), get_id(arg)))
     typenames = ["typename " + arg[0] for arg in params]
 
     template = "inline "
@@ -90,9 +91,10 @@ def visit_FunctionDef(self, node):
 
     def visit_Attribute(self, node):
         attr = node.attr
-        if is_builtin_import(node.value.id):
-            return "py14::" + node.value.id + "::" + attr
-        elif node.value.id == "math":
+        value_id = get_id(node.value)
+        if is_builtin_import(value_id):
+            return "py14::" + value_id + "::" + attr
+        elif value_id == "math":
             if node.attr == "asin":
                 return "std::asin"
             elif node.attr == "atan":
@@ -103,7 +105,7 @@ def visit_Attribute(self, node):
         if is_list(node.value):
             if node.attr == "append":
                 attr = "push_back"
-        return node.value.id + "." + attr
+        return value_id + "." + attr
 
     def visit_Call(self, node):
         fname = self.visit(node.func)
@@ -120,11 +122,24 @@ def visit_Call(self, node):
         elif fname == "max":
             return "std::max({0})".format(args)
         elif fname == "range":
-            return "rangepp::range({0})".format(args)
+            if sys.version_info[0] >= 3:
+                return "rangepp::xrange({0})".format(args)
+            else:
+                return "rangepp::range({0})".format(args)
         elif fname == "xrange":
             return "rangepp::xrange({0})".format(args)
         elif fname == "len":
             return "{0}.size()".format(self.visit(node.args[0]))
+        elif fname == "print":
+            buf = []
+            for n in node.args:
+                value = self.visit(n)
+                if isinstance(n, ast.List) or isinstance(n, ast.Tuple):
+                    buf.append("std::cout << {0} << std::endl;".format(
+                               " << ".join([self.visit(el) for el in n.elts])))
+                else:
+                    buf.append('std::cout << {0} << std::endl;'.format(value))
+            return '\n'.join(buf)
 
         return '{0}({1})'.format(fname, args)
 
@@ -157,9 +172,17 @@ def visit_Name(self, node):
         else:
             return super(CppTranspiler, self).visit_Name(node)
 
+    def visit_NameConstant(self, node):
+        if node.value is True:
+            return "true"
+        elif node.value is False:
+            return "false"
+        else:
+            return super(CppTranspiler, self).visit_NameConstant(node)
+
     def visit_If(self, node):
-        body_vars = set([v.id for v in node.scopes[-1].body_vars])
-        orelse_vars = set([v.id for v in node.scopes[-1].orelse_vars])
+        body_vars = set([get_id(v) for v in node.scopes[-1].body_vars])
+        orelse_vars = set([get_id(v) for v in node.scopes[-1].orelse_vars])
         node.common_vars = body_vars.intersection(orelse_vars)
 
         var_definitions = []
@@ -179,6 +202,16 @@ def visit_If(self, node):
             return ("".join(var_definitions) +
                     super(CppTranspiler, self).visit_If(node))
 
+    def visit_UnaryOp(self, node):
+        if isinstance(node.op, ast.USub):
+            if isinstance(node.operand, (ast.Call, ast.Num)):
+                # Shortcut if parenthesis are not needed
+                return "-{0}".format(self.visit(node.operand))
+            else:
+                return "-({0})".format(self.visit(node.operand))
+        else:
+            return super(CppTranspiler, self).visit_UnaryOp(node)
+
     def visit_BinOp(self, node):
         if (isinstance(node.left, ast.List)
                 and isinstance(node.op, ast.Mult)
@@ -197,7 +230,7 @@ def visit_alias(self, node):
 
     def visit_Import(self, node):
         imports = [self.visit(n) for n in node.names]
-        return "\n".join(filter(None, imports))
+        return "\n".join(i for i in imports if i)
 
     def visit_List(self, node):
         if len(node.elts) > 0:

regtests/test_range.py

@@ -1,16 +1,16 @@
 def test_range():
-    simple = range(0, 10)
+    simple = list(range(0, 10))
     results = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
     assert simple == results
 
 
 def test_range_with_steps():
-    with_steps = range(0, 10, 2)
+    with_steps = list(range(0, 10, 2))
     results = [0, 2, 4, 6, 8]
     assert with_steps == results
 
 
 def test_range_with_negative_steps():
-    with_steps = range(10, 0, -2)
+    with_steps = list(range(10, 0, -2))
     results = [10, 8, 6, 4, 2]
     assert with_steps == results