1 files changed, 82 insertions, 0 deletions
diff --git a/trunk/src/examples/parseListString.py b/trunk/src/examples/parseListString.py
new file mode 100644
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+++ b/trunk/src/examples/parseListString.py
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+# parseListString.py
+#
+# Copyright, 2006, by Paul McGuire
+#
+
+from pyparsing import *
+
+# first pass
+lbrack = Literal("[")
+rbrack = Literal("]")
+integer = Word(nums).setName("integer")
+real = Combine(Optional(oneOf("+ -")) + Word(nums) + "." +
+               Optional(Word(nums))).setName("real")
+
+listItem = real | integer | quotedString
+
+listStr = lbrack + delimitedList(listItem) + rbrack
+
+test = "['a', 100, 3.14]"
+
+print(listStr.parseString(test))
+
+
+# second pass, cleanup and add converters
+lbrack = Literal("[").suppress()
+rbrack = Literal("]").suppress()
+cvtInt = lambda s,l,toks: int(toks[0])
+integer = Word(nums).setName("integer").setParseAction( cvtInt )
+cvtReal = lambda s,l,toks: float(toks[0])
+real = Regex(r'[+-]?\d+\.\d*').setName("floating-point number").setParseAction( cvtReal )
+listItem = real | integer | quotedString.setParseAction( removeQuotes )
+
+listStr = lbrack + delimitedList(listItem) + rbrack
+
+test = "['a', 100, 3.14]"
+
+print(listStr.parseString(test))
+
+# third pass, add nested list support, and tuples, too!
+cvtInt = lambda s,l,toks: int(toks[0])
+cvtReal = lambda s,l,toks: float(toks[0])
+
+lbrack = Literal("[").suppress()
+rbrack = Literal("]").suppress()
+integer = Word(nums).setName("integer").setParseAction( cvtInt )
+real = Regex(r'[+-]?\d+\.\d*').setName("floating-point number").setParseAction( cvtReal )
+tupleStr = Forward()
+listStr = Forward()
+listItem = real | integer | quotedString.setParseAction(removeQuotes) | Group(listStr) | tupleStr
+tupleStr << ( Suppress("(") + delimitedList(listItem) + Optional(Suppress(",")) + Suppress(")") )
+tupleStr.setParseAction( lambda t:tuple(t.asList()) )
+listStr << lbrack + delimitedList(listItem) + Optional(Suppress(",")) + rbrack
+
+test = "['a', 100, ('A', [101,102]), 3.14, [ +2.718, 'xyzzy', -1.414] ]"
+print(listStr.parseString(test))
+
+# fourth pass, add parsing of dicts
+cvtInt = lambda s,l,toks: int(toks[0])
+cvtReal = lambda s,l,toks: float(toks[0])
+cvtDict = lambda s,l,toks: dict(toks[0])
+
+lbrack = Literal("[").suppress()
+rbrack = Literal("]").suppress()
+lbrace = Literal("{").suppress()
+rbrace = Literal("}").suppress()
+colon = Literal(":").suppress()
+integer = Word(nums).setName("integer").setParseAction( cvtInt )
+real = Regex(r'[+-]?\d+\.\d*').setName("real").setParseAction( cvtReal )
+
+tupleStr = Forward()
+listStr = Forward()
+dictStr = Forward()
+listItem = real | integer | quotedString.setParseAction(removeQuotes) | Group(listStr) | tupleStr | dictStr
+tupleStr <<= ( Suppress("(") + delimitedList(listItem) + Optional(Suppress(",")) + Suppress(")") )
+tupleStr.setParseAction( lambda t:tuple(t.asList()) )
+listStr <<= (lbrack + Optional(delimitedList(listItem)) + Optional(Suppress(",")) + rbrack)
+dictKeyStr = real | integer | quotedString.setParseAction(removeQuotes)
+dictStr <<= lbrace + Optional(delimitedList( Group( dictKeyStr + colon + listItem ))) + Optional(Suppress(",")) + rbrace
+dictStr.setParseAction(lambda t: dict((k_v[0],(k_v[1].asList() if isinstance(k_v[1],ParseResults) else k_v[1])) for k_v in t))
+
+test = '[{0: [2], 1: []}, {0: [], 1: [], 2: [,]}, {0: [1, 2,],}]'
+print(listStr.parseString(test))