Search results
Results From The WOW.Com Content Network
This computer-programming -related article is a stub. You can help Wikipedia by expanding it.
In the C standard library, the character-reading functions such as getchar return a value equal to the symbolic value (macro) EOF to indicate that an end-of-file condition has occurred. The actual value of EOF is implementation-dependent and must be negative (it is commonly −1, such as in glibc [2]).
The most vexing parse is a counterintuitive form of syntactic ambiguity resolution in the C++ programming language. In certain situations, the C++ grammar cannot distinguish between the creation of an object parameter and specification of a function's type.
The most common syntax for here documents, originating in Unix shells, is << followed by a delimiting identifier (often the word EOF or END [2]), followed, starting on the next line, by the text to be quoted, and then closed by the same delimiting identifier on its own line.
Parsing a number, for example, can require five function calls: one for each non-terminal in the grammar until reaching primary. An operator-precedence parser can do the same more efficiently. [ 1 ] The idea is that we can left associate the arithmetic operations as long as we find operators with the same precedence, but we have to save a ...
The recursive-descent approach tends to lend itself to keeping data as typed local variables in the code doing the parsing, while SAX, for instance, typically requires a parser to manually maintain intermediate data within a stack of elements that are parent elements of the element being parsed.
A parsing expression is a kind of pattern that each string may either match or not match.In case of a match, there is a unique prefix of the string (which may be the whole string, the empty string, or something in between) which has been consumed by the parsing expression; this prefix is what one would usually think of as having matched the expression.
The parser then repeats the following loop step until done, or stuck on a syntax error: The topmost state on the parse stack is some state s , and the current lookahead is some terminal symbol t . Look up the next parser action from row s and column t of the Lookahead Action table.