Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of Boost. Click here to view this page for the latest version.

Nonterminals

Notation

RT: Synthesized attribute. The rule or grammar's return type.
Arg1, Arg2, ArgN: Inherited attributes. Zero or more arguments.
L1, L2, LN: Zero or more local variables.
r, r2: Rules
g: A grammar
p: A parser expression
my_grammar: A user defined grammar

Terminology

Signature: RT(Arg1, Arg2 ... ,ArgN). The signature specifies the synthesized (return value) and inherited (arguments) attributes.
Locals: locals<L1, L2 ..., LN>. The local variables.
Skipper: The skip-parser type

Template Arguments

Iterator: The iterator type you will use for parsing.
A1, A2, A3: Can be one of 1) Signature 2) Locals 3) Skipper.

Expression	Description
`rule<Iterator, A1, A2, A3> r(name);`	Rule declaration. `Iterator` is required. `A1, A2, A3` are optional and can be specified in any order. `name` is an optional string that gives the rule its name, useful for debugging and error handling.
`rule<Iterator, A1, A2, A3> r(r2);`	Copy construct rule `r` from rule `r2`.
`r = r2;`	Assign rule `r2` to `r`.
`r.alias()`	return an alias of `r`. The alias is a parser that holds a reference to `r`. Reference semantics.
`r.copy()`	Get a copy of `r`.
`r.name(name)`	Naming a rule
`r.name()`	Getting the name of a rule
debug(r)	Debug rule `r`
`r = p;`	Rule definition
`r %= p;`	Auto-rule definition. The attribute of `p` should be compatible with the synthesized attribute of `r`. When `p` is successful, its attribute is automatically propagated to `r`'s synthesized attribute.
template <typename Iterator> struct my_grammar : grammar<Iterator, A1, A2, A3> { my_grammar() : my_grammar::base_type(start, name) { // Rule definitions start = /* ... */; } rule<Iterator, A1, A2, A3> start; // more rule declarations... };	Grammar definition. `name` is an optional string that gives the grammar its name, useful for debugging and error handling.
`g.name(name)`	Naming a grammar
`g.name()`	Getting the name of a grammar