From 577991d248a2098146538f93c8fffede0acf59d0 Mon Sep 17 00:00:00 2001
From: Nicholas Robinson <nwrobins@edu.uwaterloo.ca>
Date: Sun, 9 Feb 2020 23:04:24 -0500
Subject: [PATCH] parser lastrule & node children
- condensed getting the last rule, no more need for copying the stack
- children are now right way round, not reversed
---
Parsing.py | 33 +++++++++++----------------------
Weeding.py | 23 +++++++++++++++++++++++
utils.py | 6 +++---
3 files changed, 37 insertions(+), 25 deletions(-)
create mode 100644 Weeding.py
diff --git a/Parsing.py b/Parsing.py
index 645d767..cb9c8be 100644
--- a/Parsing.py
+++ b/Parsing.py
@@ -65,9 +65,8 @@ class State():
newChildren = [] # Node[]
while (toPop != 0):
statesVisited.pop()
-
top = theStack.pop()
- newChildren.append(Node(top.children, top.name, top.lex))
+ newChildren.insert(0, Node(top.children, top.name, top.lex))
toPop -= 1
@@ -127,27 +126,16 @@ def checkSequence(tokens):
getNext = states[curState].trans(statesVisited, tokens[i].name, rulesToOutput)
- copyStack = theStack
- if copyStack:
- lastRule = copyStack[-1].name
- theRule = ''
- copyStack.pop()
-
- while copyStack:
- lastRule = copyStack[-1].name + ' ' + lastRule
- copyStack.pop()
-
- for r in cfgrules:
- if (' '.join(r)).find(lastRule) != -1:
- theRule = r
- break
-
- if theRule != '':
- rulesToOutput.append(' '.join(theRule))
- else:
- print('last rule not found')
+ lastRule = True
+ for index, token in enumerate(theStack):
+ if token.name != cfgrules[0][index+1]:
+ lastRule = False
+ break
+ if lastRule:
+ rulesToOutput.append(' '.join(cfgrules[0]))
+ else:
+ raise ValueError('last rule not found')
- # printNodeStack(theStack)
return rulesToOutput
# set up grammar from files and set up states
@@ -200,4 +188,5 @@ def parse(tokens):
except ValueError as err:
return (None, err)
+ # printNodeStack(theStack)
return (result, "success")
diff --git a/Weeding.py b/Weeding.py
new file mode 100644
index 0000000..b918cac
--- /dev/null
+++ b/Weeding.py
@@ -0,0 +1,23 @@
+import string
+
+##################### Weeding ##########################################
+
+# node: Node[]
+def oneConstructor(node, insideClass):
+ success = False
+ if not insideClass:
+ if node.name == 'classDcl':
+ for c in node.children:
+ success = oneConstructor(c, True)
+ if success:
+ return True
+ elif insideClass:
+ if node.name == 'constructorDcl':
+ return True
+
+
+# tree: Node[]
+def weed(tree):
+ # Every class must contain at least one explicit constructor
+ if oneConstructor(tree, False) == False:
+ print('a class does not have an explicit constructor')
diff --git a/utils.py b/utils.py
index 51a2a3a..623e5dd 100644
--- a/utils.py
+++ b/utils.py
@@ -13,14 +13,14 @@ def printStack(a):
def printNode(a):
print(a.name),
if (a.lex != ''):
- print(' ' + a.lex),
+ print(a.lex),
- for i in reversed(a.children):
+ for i in a.children:
print(i.name),
if a.children:
print('\n<children>')
- for i in reversed(a.children):
+ for i in a.children:
printNode(i)
print('</children>')
else:
--
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