diff options
Diffstat (limited to 'lib/spack/spack/parse.py')
| -rw-r--r-- | lib/spack/spack/parse.py | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/lib/spack/spack/parse.py b/lib/spack/spack/parse.py index 8adf957e7f..1b88db2d7c 100644 --- a/lib/spack/spack/parse.py +++ b/lib/spack/spack/parse.py @@ -29,6 +29,7 @@ import spack.error class Token: """Represents tokens; generated from input by lexer and fed to parse().""" + def __init__(self, type, value='', start=0, end=0): self.type = type self.value = value @@ -51,11 +52,13 @@ class Token: class Lexer(object): """Base class for Lexers that keep track of line numbers.""" + def __init__(self, lexicon): self.scanner = re.Scanner(lexicon) def token(self, type, value=''): - return Token(type, value, self.scanner.match.start(0), self.scanner.match.end(0)) + return Token(type, value, + self.scanner.match.start(0), self.scanner.match.end(0)) def lex(self, text): tokens, remainder = self.scanner.scan(text) @@ -66,10 +69,11 @@ class Lexer(object): class Parser(object): """Base class for simple recursive descent parsers.""" + def __init__(self, lexer): - self.tokens = iter([]) # iterators over tokens, handled in order. Starts empty. - self.token = Token(None) # last accepted token starts at beginning of file - self.next = None # next token + self.tokens = iter([]) # iterators over tokens, handled in order. + self.token = Token(None) # last accepted token + self.next = None # next token self.lexer = lexer self.text = None @@ -82,11 +86,12 @@ class Parser(object): def push_tokens(self, iterable): """Adds all tokens in some iterable to the token stream.""" - self.tokens = itertools.chain(iter(iterable), iter([self.next]), self.tokens) + self.tokens = itertools.chain( + iter(iterable), iter([self.next]), self.tokens) self.gettok() def accept(self, id): - """Puts the next symbol in self.token if we like it. Then calls gettok()""" + """Put the next symbol in self.token if accepted, then call gettok()""" if self.next and self.next.is_a(id): self.token = self.next self.gettok() @@ -124,9 +129,9 @@ class Parser(object): return self.do_parse() - class ParseError(spack.error.SpackError): """Raised when we don't hit an error while parsing.""" + def __init__(self, message, string, pos): super(ParseError, self).__init__(message) self.string = string @@ -135,5 +140,6 @@ class ParseError(spack.error.SpackError): class LexError(ParseError): """Raised when we don't know how to lex something.""" + def __init__(self, message, string, pos): super(LexError, self).__init__(message, string, pos) |