diff options
| -rw-r--r-- | src/CHANGES | 4 | ||||
| -rw-r--r-- | src/examples/fourFn.py | 12 |
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 )
|