Fixed bug in fourFn.py example code, where pi and e were defined using CaselessLiteral instead of CaselessKeyword

git-svn-id: svn://svn.code.sf.net/p/pyparsing/code/trunk@282 9bf210a0-9d2d-494c-87cf-cfb32e7dff7b

2 files changed, 13 insertions, 3 deletions

diff --git a/src/CHANGES b/src/CHANGES
index 31e68a1..dc01844 100644
--- a/src/CHANGES
+++ b/src/CHANGES
@@ -14,6 +14,10 @@ Version 2.0.4 -
   only of an unnamed array of sub-structure results. Reported by Robin

   Siebler, thanks for your patience and persistence, Robin!

 

+- Fixed bug in fourFn.py example code, where pi and e were defined using

+  CaselessLiteral instead of CaselessKeyword. This was not a problem until

+  adding a new function 'exp', and the leading 'e' of 'exp' was accidentally

+  parsed as the mathematical constant 'e'. Nice catch, Tom Grydeland - thanks!

 

 

 Version 2.0.3 - 

diff --git a/src/examples/fourFn.py b/src/examples/fourFn.py
index 8ea4609..2b8c28b 100644
--- a/src/examples/fourFn.py
+++ b/src/examples/fourFn.py
@@ -10,7 +10,7 @@
 # Copyright 2003-2009 by Paul McGuire

 #

 from pyparsing import Literal,CaselessLiteral,Word,Group,Optional,\

-    ZeroOrMore,Forward,nums,alphas,Regex,ParseException

+    ZeroOrMore,Forward,nums,alphas,Regex,ParseException,CaselessKeyword

 import math

 import operator

 

@@ -42,7 +42,11 @@ def BNF():
     global bnf

     if not bnf:

         point = Literal( "." )

-        e     = CaselessLiteral( "E" )

+        # use CaselessKeyword for e and pi, to avoid accidentally matching

+        # functions that start with 'e' or 'pi' (such as 'exp'); Keyword

+        # and CaselessKeyword only match whole words

+        e     = CaselessKeyword( "E" )

+        pi    = CaselessKeyword( "PI" )

         #~ fnumber = Combine( Word( "+-"+nums, nums ) + 

                            #~ Optional( point + Optional( Word( nums ) ) ) +

                            #~ Optional( e + Word( "+-"+nums, nums ) ) )

@@ -58,7 +62,6 @@ def BNF():
         addop  = plus | minus

         multop = mult | div

         expop = Literal( "^" )

-        pi    = CaselessLiteral( "PI" )

         

         expr = Forward()

         atom = ((0,None)*minus + ( pi | e | fnumber | ident + lpar + expr + rpar | ident ).setParseAction( pushFirst ) | 

@@ -84,6 +87,7 @@ opn = { "+" : operator.add,
 fn  = { "sin" : math.sin,

         "cos" : math.cos,

         "tan" : math.tan,

+        "exp" : math.exp,

         "abs" : abs,

         "trunc" : lambda a: int(a),

         "round" : round,

@@ -149,6 +153,8 @@ if __name__ == "__main__":
     test( "round(E)", round(math.e) )

     test( "round(-E)", round(-math.e) )

     test( "E^PI", math.e**math.pi )

+    test( "exp(0)", 1 )

+    test( "exp(1)", math.e )

     test( "2^3^2", 2**3**2 )

     test( "2^3+2", 2**3+2 )

     test( "2^3+5", 2**3+5 )