add Primitve for the 'square root' block

2 files changed, 29 insertions, 16 deletions

diff --git a/TurtleArt/tabasics.py b/TurtleArt/tabasics.py
index f6ea917..97ce4fd 100644
--- a/TurtleArt/tabasics.py
+++ b/TurtleArt/tabasics.py
@@ -99,6 +99,8 @@ class Palettes():
             "convert_value_for_move": Primitive(self.convert_value_for_move, 
                 export_me=False),
             "convert_for_cmp": Primitive(Primitive.convert_for_cmp,
+                constant_args={'decimal_point': self.tw.decimal_point}),
+            "convert_to_number": Primitive(Primitive.convert_to_number,
                 constant_args={'decimal_point': self.tw.decimal_point})
         } # avoid several Primitives of the same function
 
@@ -685,7 +687,6 @@ blocks'))
                             lambda self, x, y:
                             primitive_dictionary['remainder'](x, y))
 
-        primitive_dictionary['sqrt'] = self._prim_sqrt
         palette.add_block('sqrt',
                           style='number-style-1arg',
                           label=_('√'),
@@ -694,7 +695,13 @@ blocks'))
                           logo_command='tasqrt',
                           help_string=_('calculates square root'))
         self.tw.lc.def_prim('sqrt', 1,
-                            lambda self, x: primitive_dictionary['sqrt'](x))
+            Primitive(sqrt,
+                slot_wrappers={0: Primitive(self.check_non_negative,
+                    slot_wrappers={0: Primitive(self.check_number,
+                        slot_wrappers={0:
+                            self.prim_cache["convert_to_number"]},
+                        export_me=False)},
+                    export_me=False)}))
 
         primitive_dictionary['random'] = self._prim_random
         palette.add_block('random',
@@ -1183,11 +1190,27 @@ variable'))
     
     def check_number(self, value):
         ''' Check if value is a number. If yes, return the value. If no,
-        raise an error. '''
+        raise a logoerror. '''
         if not _num_type(value):
             raise logoerror("#notanumber")
         return value
 
+    def check_non_negative(self, x, msg="#negroot"):
+        ''' Raise a logoerror iff x is negative. Otherwise, return x
+        unchanged.
+        msg -- the name of the logoerror message '''
+        if x < 0:
+            raise logoerror(msg)
+        return x
+
+    def check_non_zero(self, x, msg="#zerodivide"):
+        ''' Raise a logoerror iff x is zero. Otherwise, return x
+        unchanged.
+        msg -- the name of the logoerror message '''
+        if x == 0:
+            raise logoerror(msg)
+        return x
+
     def after_right(self, *ignored_args):
         if self.tw.lc.update_values:
             self.tw.lc.update_label_value(
@@ -1366,19 +1389,6 @@ variable'))
         except ValueError:
             raise logoerror("#syntaxerror")
 
-    def _prim_sqrt(self, x):
-        ''' Square root '''
-        if _num_type(x):
-            if x < 0:
-                raise logoerror("#negroot")
-            return sqrt(x)
-        try:
-            return sqrt(self._string_to_num(x))
-        except ValueError:
-            raise logoerror("#negroot")
-        except TypeError:
-            raise logoerror("#notanumber")
-
     def _prim_random(self, x, y):
         ''' Random integer '''
         if _num_type(x) and _num_type(y):
diff --git a/TurtleArt/taexportpython.py b/TurtleArt/taexportpython.py
index 0816d9f..c87757d 100644
--- a/TurtleArt/taexportpython.py
+++ b/TurtleArt/taexportpython.py
@@ -38,6 +38,9 @@ from tautils import (debug_output, find_group, find_top_block)
 _SETUP_CODE_START = """\
 #!/usr/bin/env python
 
+from math import sqrt
+from random import uniform
+
 from pyexported.window_setup import *