Update fourFn.py to handle functions that take multiple args, and nested functions

1 files changed, 122 insertions, 117 deletions

diff --git a/examples/SimpleCalc.py b/examples/SimpleCalc.py
index 15a1817..d52a20f 100644
--- a/examples/SimpleCalc.py
+++ b/examples/SimpleCalc.py
@@ -1,117 +1,122 @@
-# SimpleCalc.py

-#

-# Demonstration of the parsing module,

-# Sample usage

-#

-#     $ python SimpleCalc.py

-#     Type in the string to be parse or 'quit' to exit the program

-#     > g=67.89 + 7/5

-#     69.29

-#     > g

-#     69.29

-#     > h=(6*g+8.8)-g

-#     355.25

-#     > h + 1

-#     356.25

-#     > 87.89 + 7/5

-#     89.29

-#     > ans+10

-#     99.29

-#     > quit

-#     Good bye!

-#

-#

-

-

-

-# Uncomment the line below for readline support on interactive terminal

-# import readline

-from pyparsing import ParseException, Word, alphas, alphanums

-import math

-

-# Debugging flag can be set to either "debug_flag=True" or "debug_flag=False"

-debug_flag=False

-

-variables = {}

-

-from fourFn import BNF, exprStack, fn, opn

-def evaluateStack( s ):

-    op = s.pop()

-    if op == 'unary -':

-        return -evaluateStack( s )

-    if op in "+-*/^":

-        op2 = evaluateStack( s )

-        op1 = evaluateStack( s )

-        return opn[op]( op1, op2 )

-    elif op == "PI":

-        return math.pi # 3.1415926535

-    elif op == "E":

-        return math.e  # 2.718281828

-    elif op in fn:

-        return fn[op]( evaluateStack( s ) )

-    elif op[0].isalpha():

-        if op in variables:

-            return variables[op]

-        raise Exception("invalid identifier '%s'" % op)

-    else:

-        return float( op )

-

-arithExpr = BNF()

-ident = Word(alphas, alphanums).setName("identifier")

-assignment = ident("varname") + '=' + arithExpr

-pattern = assignment | arithExpr

-

-if __name__ == '__main__':

-  # input_string

-  input_string=''

-

-  # Display instructions on how to quit the program

-  print("Type in the string to be parsed or 'quit' to exit the program")

-  input_string = input("> ")

-

-  while input_string.strip().lower() != 'quit':

-    if input_string.strip().lower() == 'debug':

-        debug_flag=True

-        input_string = input("> ")

-        continue

-

-    # Reset to an empty exprStack

-    del exprStack[:]

-

-    if input_string != '':

-      # try parsing the input string

-      try:

-        L=pattern.parseString(input_string, parseAll=True)

-      except ParseException as err:

-        L=['Parse Failure', input_string, (str(err), err.line, err.column)]

-

-      # show result of parsing the input string

-      if debug_flag: print(input_string, "->", L)

-      if len(L)==0 or L[0] != 'Parse Failure':

-        if debug_flag: print("exprStack=", exprStack)

-

-        # calculate result , store a copy in ans , display the result to user

-        try:

-          result=evaluateStack(exprStack)

-        except Exception as e:

-          print(str(e))

-        else:

-          variables['ans']=result

-          print(result)

-

-          # Assign result to a variable if required

-          if L.varname:

-            variables[L.varname] = result

-          if debug_flag: print("variables=", variables)

-      else:

-        print('Parse Failure')

-        err_str, err_line, err_col = L[-1]

-        print(err_line)

-        print(" "*(err_col-1) + "^")

-        print(err_str)

-

-    # obtain new input string

-    input_string = input("> ")

-

-  # if user type 'quit' then say goodbye

-  print("Good bye!")

+# SimpleCalc.py
+#
+# Demonstration of the parsing module,
+# Sample usage
+#
+#     $ python SimpleCalc.py
+#     Type in the string to be parse or 'quit' to exit the program
+#     > g=67.89 + 7/5
+#     69.29
+#     > g
+#     69.29
+#     > h=(6*g+8.8)-g
+#     355.25
+#     > h + 1
+#     356.25
+#     > 87.89 + 7/5
+#     89.29
+#     > ans+10
+#     99.29
+#     > quit
+#     Good bye!
+#
+#
+
+
+
+# Uncomment the line below for readline support on interactive terminal
+# import readline
+from pyparsing import ParseException, Word, alphas, alphanums
+
+# Debugging flag can be set to either "debug_flag=True" or "debug_flag=False"
+debug_flag=False
+
+variables = {}
+
+from fourFn import BNF, exprStack, fn, opn, evaluate_stack
+
+# from fourFn import BNF, exprStack, fn, opn
+# def evaluateStack( s ):
+#     op = s.pop()
+#     if op == 'unary -':
+#         return -evaluateStack( s )
+#     if op in "+-*/^":
+#         op2 = evaluateStack( s )
+#         op1 = evaluateStack( s )
+#         return opn[op]( op1, op2 )
+#     elif op == "PI":
+#         return math.pi # 3.1415926535
+#     elif op == "E":
+#         return math.e  # 2.718281828
+#     elif op in fn:
+#         return fn[op]( evaluateStack( s ) )
+#     elif op[0].isalpha():
+#         if op in variables:
+#             return variables[op]
+#         raise Exception("invalid identifier '%s'" % op)
+#     else:
+#         return float( op )
+
+arithExpr = BNF()
+ident = Word(alphas, alphanums).setName("identifier")
+assignment = ident("varname") + '=' + arithExpr
+pattern = assignment | arithExpr
+
+if __name__ == '__main__':
+  # input_string
+  input_string=''
+
+  # Display instructions on how to quit the program
+  print("Type in the string to be parsed or 'quit' to exit the program")
+  input_string = input("> ")
+
+  while input_string.strip().lower() != 'quit':
+    if input_string.strip().lower() == 'debug':
+        debug_flag=True
+        input_string = input("> ")
+        continue
+
+    # Reset to an empty exprStack
+    del exprStack[:]
+
+    if input_string != '':
+      # try parsing the input string
+      try:
+        L = pattern.parseString(input_string, parseAll=True)
+      except ParseException as err:
+        L = ['Parse Failure', input_string, (str(err), err.line, err.column)]
+
+      # show result of parsing the input string
+      if debug_flag: print(input_string, "->", L)
+      if len(L)==0 or L[0] != 'Parse Failure':
+        if debug_flag: print("exprStack=", exprStack)
+
+        for i, ob in enumerate(exprStack):
+            if isinstance(ob, str) and ob in variables:
+                exprStack[i] = str(variables[ob])
+
+        # calculate result , store a copy in ans , display the result to user
+        try:
+          result=evaluate_stack(exprStack)
+        except Exception as e:
+          print(str(e))
+        else:
+          variables['ans']=result
+          print(result)
+
+          # Assign result to a variable if required
+          if L.varname:
+            variables[L.varname] = result
+          if debug_flag: print("variables=", variables)
+      else:
+        print('Parse Failure')
+        err_str, err_line, err_col = L[-1]
+        print(err_line)
+        print(" "*(err_col-1) + "^")
+        print(err_str)
+
+    # obtain new input string
+    input_string = input("> ")
+
+  # if user type 'quit' then say goodbye
+  print("Good bye!")