Parsing Text into Joy Expressions¶
TODO: example…
joy.parser
¶
This module exports a single function for converting text to a joy expression as well as a single Symbol class and a single Exception type.
The Symbol string class is used by the interpreter to recognize literals by the fact that they are not Symbol objects.
A crude grammar:
joy = term*
term = int | float | string | '[' joy ']' | symbol
A Joy expression is a sequence of zero or more terms. A term is a literal value (integer, float, string, or Joy expression) or a function symbol. Function symbols are unquoted strings and cannot contain square brackets. Terms must be separated by blanks, which can be omitted around square brackets.
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joy.parser.
text_to_expression
(text)[source]¶ Convert a string to a Joy expression.
When supplied with a string this function returns a Python datastructure that represents the Joy datastructure described by the text expression. Any unbalanced square brackets will raise a ParseError.
Parameters: text (str) – Text to convert. Return type: stack Raises: ParseError – if the parse fails.
Parser Internals¶
TODO: Document things like the regular expressions used for tokenizing, and the re.Scanner, etc…