Type Aliases Reference


                    
                    
                    EvalFunc

A function which is used to compute the parameters of the involved symbols during the parsing progress of an invocation of a rule.

Assume that the rule has the form

L => R1 R2 ... Rn

Then the function will be called at a certain stage k, where k is the number of symbols R1 … Rk whose parameters have already been computed during previous stages.

Seealso

Rule

Declaration

Swift

public typealias EvalFunc<Param> = (_ env: EvalEnv, _ k: Int, _ params: [Param]) -> Param?

Parameters

`env`	An environment which a function can use to store information in between calls to it during the parsing progress of the rule as it progresses from stage to stage. The environment is a copy of an environment used during the previous stage.
`k`	The current stage, where `0 <= k <= n`, and `n` is the number of symbols on the right hand side of the rule.
`params`	The parameters that have been evaluated so far. We have `params.count == 1 + 2 * k` and the following layout: `params[0]`: the input parameter of `L` `params[1]`: the input parameter of `R1` `params[2]`: the output parameter of `R1` `params[3]`: the input parameter of `R2` `params[4]`: the output parameter of `R2` … `params[2k-1]`: the input parameter of `Rk` `params[2k]`: the output parameter of `Rk`

Return Value

For k < n this returns the input parameter of R(k+1). For k == n this returns the output parameter of L. In case of a return value of nil, the parsing at this particular stage is aborted.


                    
                    
                    Tokens

Represents the result of parsing a set of terminals at the same position. Each terminal and associated input parameter under consideration is mapped to its set of successfully parsed tokens.

Declaration

Swift

public typealias Tokens<Param, Result> = [TerminalKey<Param> : Set<Token<Param, Result>>] where Param : Hashable


                    
                    
                    RuleIndex

The index of a rule in the Grammar.rules array.

Declaration

Swift

public typealias RuleIndex = Int