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| author | ptmcg <ptmcg@9bf210a0-9d2d-494c-87cf-cfb32e7dff7b> | 2016-08-09 00:23:49 +0000 |
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| committer | ptmcg <ptmcg@9bf210a0-9d2d-494c-87cf-cfb32e7dff7b> | 2016-08-09 00:23:49 +0000 |
| commit | b2c3ade75384efe76b8774b607e17fe98fab92ef (patch) | |
| tree | b162262f3f0a4bc976d45bed08ccfc6cc9a2eb23 /trunk/src/examples/apicheck.py | |
| parent | 0be19d2d8545f1ac4b93ffd0d10524613837ba39 (diff) | |
| download | pyparsing-b2c3ade75384efe76b8774b607e17fe98fab92ef.tar.gz | |
TagTag for 2.1.6 release
git-svn-id: svn://svn.code.sf.net/p/pyparsing/code/tags/pyparsing_2.1.6@402 9bf210a0-9d2d-494c-87cf-cfb32e7dff7b
Diffstat (limited to 'trunk/src/examples/apicheck.py')
| -rw-r--r-- | trunk/src/examples/apicheck.py | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/trunk/src/examples/apicheck.py b/trunk/src/examples/apicheck.py new file mode 100644 index 0000000..4315ac9 --- /dev/null +++ b/trunk/src/examples/apicheck.py @@ -0,0 +1,55 @@ +# apicheck.py
+# A simple source code scanner for finding patterns of the form
+# [ procname1 $arg1 $arg2 ]
+# and verifying the number of arguments
+
+from pyparsing import *
+
+# define punctuation and simple tokens for locating API calls
+LBRACK,RBRACK,LBRACE,RBRACE = map(Suppress,"[]{}")
+ident = Word(alphas,alphanums+"_") | QuotedString("{",endQuoteChar="}")
+arg = "$" + ident
+
+# define an API call with a specific number of arguments - using '-'
+# will ensure that after matching procname, an incorrect number of args will
+# raise a ParseSyntaxException, which will interrupt the scanString
+def apiProc(name, numargs):
+ return LBRACK + Keyword(name)("procname") - arg*numargs + RBRACK
+
+# create an apiReference, listing all API functions to be scanned for, and
+# their respective number of arguments. Beginning the overall expression
+# with FollowedBy allows us to quickly rule out non-api calls while scanning,
+# since all of the api calls begin with a "["
+apiRef = FollowedBy("[") + MatchFirst([
+ apiProc("procname1", 2),
+ apiProc("procname2", 1),
+ apiProc("procname3", 2),
+ ])
+
+test = """[ procname1 $par1 $par2 ]
+ other code here
+ [ procname1 $par1 $par2 $par3 ]
+ more code here
+ [ procname1 $par1 ]
+ [ procname3 ${arg with spaces} $par2 ]"""
+
+
+# now explicitly iterate through the scanner using next(), so that
+# we can trap ParseSyntaxException's that would be raised due to
+# an incorrect number of arguments. If an exception does occur,
+# then see how we reset the input text and scanner to advance to the
+# next line of source code
+api_scanner = apiRef.scanString(test)
+while 1:
+ try:
+ t,s,e = next(api_scanner)
+ print("found %s on line %d" % (t.procname, lineno(s,test)))
+ except ParseSyntaxException as pe:
+ print("invalid arg count on line", pe.lineno)
+ print(pe.lineno,':',pe.line)
+ # reset api scanner to start after this exception location
+ test = "\n"*(pe.lineno-1)+test[pe.loc+1:]
+ api_scanner = apiRef.scanString(test)
+ except StopIteration:
+ break
+
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