diff options
Diffstat (limited to 'Doc/library/token.rst')
-rw-r--r-- | Doc/library/token.rst | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/Doc/library/token.rst b/Doc/library/token.rst new file mode 100644 index 0000000..5bf0ea8 --- /dev/null +++ b/Doc/library/token.rst @@ -0,0 +1,47 @@ + +:mod:`token` --- Constants used with Python parse trees +======================================================= + +.. module:: token + :synopsis: Constants representing terminal nodes of the parse tree. +.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org> + + +This module provides constants which represent the numeric values of leaf nodes +of the parse tree (terminal tokens). Refer to the file :file:`Grammar/Grammar` +in the Python distribution for the definitions of the names in the context of +the language grammar. The specific numeric values which the names map to may +change between Python versions. + +This module also provides one data object and some functions. The functions +mirror definitions in the Python C header files. + + +.. data:: tok_name + + Dictionary mapping the numeric values of the constants defined in this module + back to name strings, allowing more human-readable representation of parse trees + to be generated. + + +.. function:: ISTERMINAL(x) + + Return true for terminal token values. + + +.. function:: ISNONTERMINAL(x) + + Return true for non-terminal token values. + + +.. function:: ISEOF(x) + + Return true if *x* is the marker indicating the end of input. + + +.. seealso:: + + Module :mod:`parser` + The second example for the :mod:`parser` module shows how to use the + :mod:`symbol` module. + |