export python

1 files changed, 232 insertions, 0 deletions

diff --git a/TurtleArt/taexportpython.py b/TurtleArt/taexportpython.py
new file mode 100644
index 0000000..88a73a0
--- /dev/null
+++ b/TurtleArt/taexportpython.py
@@ -0,0 +1,232 @@
+#Copyright (c) 2013 Marion Zepf
+
+#Permission is hereby granted, free of charge, to any person obtaining a copy
+#of this software and associated documentation files (the "Software"), to deal
+#in the Software without restriction, including without limitation the rights
+#to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+#copies of the Software, and to permit persons to whom the Software is
+#furnished to do so, subject to the following conditions:
+
+#The above copyright notice and this permission notice shall be included in
+#all copies or substantial portions of the Software.
+
+#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+#OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+#THE SOFTWARE.
+
+""" Python export tool """
+
+import ast
+from gettext import gettext as _
+from os import linesep
+import re
+import traceback
+import util.codegen as codegen
+
+#from ast_pprint import * # only used for debugging, safe to comment out
+
+from talogo import LogoCode
+from taprimitive import (Primitive, PyExportError, value_to_ast)
+from tautils import (debug_output, find_group, find_top_block, get_stack_name)
+
+
+
+_SETUP_CODE_START = """\
+#!/usr/bin/env python
+
+from math import sqrt
+from random import uniform
+
+from pyexported.window_setup import *
+
+
+tw = get_tw()
+
+BOX = {}
+ACTION = {}
+
+
+
+"""
+_SETUP_CODE_END = """\
+
+
+
+if __name__ == '__main__':
+    tw.lc.icall(start)
+    gobject.idle_add(tw.lc.doevalstep)
+    gtk.main()
+
+
+"""
+_ACTION_STACK_START = """\
+def %s():
+    turtle = tw.turtles.get_active_turtle()
+    turtles = tw.turtles
+    canvas = tw.canvas
+    logo = tw.lc
+
+"""
+_ACTION_STACK_END = """\
+ACTION["%s"] = %s
+"""
+# character that is illegal in a Python identifier
+PAT_IDENTIFIER_ILLEGAL_CHAR = re.compile("[^A-Za-z0-9_]")
+
+
+
+def save_python(tw):
+    """ Find all the action stacks and turn each into python code """
+    all_blocks = tw.just_blocks()
+    blocks_covered = set()
+    tops_of_stacks = []
+    for block in all_blocks:
+        if block not in blocks_covered:
+            top = find_top_block(block)
+            tops_of_stacks.append(top)
+            block_stack = find_group(top)
+            blocks_covered.update(set(block_stack))
+
+    snippets = [_SETUP_CODE_START]
+    for block in tops_of_stacks:
+        stack_name = get_stack_name(block)
+        if stack_name:
+            pythoncode = _action_stack_to_python(block, tw.lc, name=stack_name)
+            snippets.append(pythoncode)
+            snippets.append(linesep)
+    snippets.append(_SETUP_CODE_END)
+    return "".join(snippets)
+
+def _action_stack_to_python(block, lc, name="start"):
+    """ Turn a stack of blocks into python code
+    name -- the name of the action stack (defaults to "start") """
+    # traverse the block stack and get the AST for every block
+    ast_list = _walk_action_stack(block, lc)
+    ast_list.append(_ast_yield_true())
+    action_stack_ast = ast.Module(body=ast_list)
+    #debug_output(str(action_stack_ast))
+
+    # serialize the ASTs into python code
+    generated_code = codegen.to_source(action_stack_ast)
+
+    # wrap the action stack setup code around everything
+    name_id = _make_identifier(name)
+    generated_code = _indent(generated_code, 1)
+    if generated_code.endswith(linesep):
+        newline = ""
+    else:
+        newline = linesep
+    snippets = [_ACTION_STACK_START % (name_id),
+        generated_code,
+        newline,
+        _ACTION_STACK_END % (name, name_id)]
+    return "".join(snippets)
+
+def _walk_action_stack(top_block, lc):
+    """ Turn a stack of blocks into a list of ASTs """
+    block = top_block
+
+    # value blocks don't have a primitive
+    if block.is_value_block():
+        raw_value = block.get_value(add_type_prefix=False)
+        value_ast = value_to_ast(raw_value)
+        if value_ast is not None:
+            return [value_ast]
+        else:
+            return []
+
+    def _get_prim(block):
+        prim = lc.get_prim_callable(block.primitive)
+        # fail gracefully if primitive is not a Primitive object
+        if not isinstance(prim, Primitive):
+            raise PyExportError(_("block is not exportable"), block=block)
+        return prim
+
+    prim = _get_prim(block)
+
+    ast_list = []
+    arg_asts = []
+
+    def _finish_off(block, prim=None):
+        """ Convert block to an AST and add it to the ast_list. Raise a
+        PyExportError on failure. """
+        if prim is None:
+            prim = _get_prim(block)
+        if prim.export_me:
+            try:
+                new_ast = prim.get_ast(*arg_asts)
+            except ValueError:
+                traceback.print_exc()
+                raise PyExportError(_("error while exporting block"),
+                                    block=block)
+            if isinstance(new_ast, (list, tuple)):
+                ast_list.extend(new_ast)
+            elif new_ast is not None:
+                ast_list.append(new_ast)
+        elif arg_asts:
+            new_ast = ast.List(elts=arg_asts, ctx=ast.Load)
+            ast_list.append(new_ast)
+
+    # skip the very first dock/ connection - it's either the previous block or
+    # the return value of this block
+    dock_queue = block.docks[1:]
+    conn_queue = block.connections[1:]
+    while dock_queue and conn_queue:
+        dock = dock_queue.pop(0)
+        conn = conn_queue.pop(0)
+        if conn is None or dock[0] == 'unavailable':
+            continue
+        elif not dock_queue and dock[0] == 'flow':
+            # finish off this block
+            _finish_off(block, prim)
+            arg_asts = []
+            # next block
+            block = conn
+            prim = _get_prim(block)
+            dock_queue = block.docks[1:]
+            conn_queue = block.connections[1:]
+        else:
+            # embedded stack of blocks (body of conditional or loop) or
+            # argument block
+            new_arg_asts = _walk_action_stack(conn, lc)
+            if dock[0] == 'flow':
+                # body of conditional or loop
+                if prim == LogoCode.prim_loop:
+                    new_arg_asts.append(_ast_yield_true())
+                arg_asts.append(new_arg_asts)
+            else:
+                # argument block
+                arg_asts.append(*new_arg_asts)
+
+    # finish off last block
+    _finish_off(block, prim)
+
+    return ast_list
+
+def _make_identifier(name):
+    """ Turn name into a Python identifier name by replacing illegal
+    characters """
+    replaced = re.sub(PAT_IDENTIFIER_ILLEGAL_CHAR, "_", name)
+    # TODO find better strategy to avoid number at beginning
+    if re.match("[0-9]", replaced):
+        replaced = "_" + replaced
+    return replaced
+
+def _indent(code, num_levels=1):
+    """ Indent each line of code with num_levels * 4 spaces
+    code -- some python code as a (multi-line) string """
+    indentation = " " * (4 * num_levels)
+    line_list = code.split(linesep)
+    new_line_list = []
+    for line in line_list:
+        new_line_list.append(indentation + line)
+    return linesep.join(new_line_list)
+
+def _ast_yield_true():
+    return ast.Yield(value=ast.Name(id='True', ctx=ast.Load))
+
+