Crate glc

Macros

nt

Generate a non-terminal symbol from a string.

nt_seq_rule

Represents a rule that replaces one non-terminal by a sequence of non-terminals. Invoke it like this:

t_or_rule

Represents a disjunctive rule: a non-terminal that can be replaced by one of the listed terminal symbols. An invocation of this macro looks like this:

Structs

Derivation

A derivation starts with the starting non-terminal symbol of the grammar and progresses by iteratively replacing non-terminals by some sequence of symbols, according to the grammar rules.

Expression

An expression constituted of a sequence of terminal symbols. These expressions can be obtained by making a complete Derivation with the Grammar. A Derivation that has only terminal symbols can be converted into an expression.

Grammar

Represents a context-free grammar. Contains a NonTerminal which represents the starting symbol and a list of Rules.

NonTerminal

A non-terminal symbol is a symbol that must be replaced further before the final expression is complete.

Or

A disjunction of Sequences.

Rule

Represents a grammar rule. Contains a NonTerminal which represents the rule’s head, and a RuleBody.

Sequence

A sequence of Symbols.

Terminal

A terminal symbol is a symbol that is not further replaceable. It can appear in the final expression generated.

Enums

RuleBody

The body of a rule. The body can be just a Sequence (of symbols) or an Or. The latter is equivalent to a set of rules with the same head, each with a sequence as the body.

Symbol

A Symbol can be a Terminal (a symbol that can appear in the final expression generated by the grammar) or a NonTerminal (a symbol that must be replaced further).