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// High-concurrency API Gateway DSL (Rails/Kong-style routing surface)
grammar ApiGateway;
token Id = Identifier;
token Num = Number;
token Str = QuotedString;
token Ws = " " -> skip;
token Tab = "\t" -> skip;
token Nl = "\n" -> skip;
rule gateway {
"gateway"
Id
"{"
repeat {
route_block
}
"}"
}
rule route_block {
"route"
path
"{"
optional { methods_clause }
optional { rate_limit }
optional { balance_clause }
optional { auth_chain }
repeat {
nested_resource
}
"}"
}
rule path {
"/"
path_segment
repeat {
"/"
path_segment
}
}
rule path_segment {
match Id | param
}
rule param {
":"
Id
}
rule methods_clause {
"methods"
Id
repeat {
Id
}
}
rule rate_limit {
"limit"
Num
"per"
Id
}
rule balance_clause {
"balance"
match "RoundRobin" | "LeastConn"
}
rule auth_chain {
"auth"
Id
repeat {
Id
}
}
rule nested_resource {
"nested"
Id
"{"
optional { constraint_clause }
optional { methods_clause }
optional { rate_limit }
optional { balance_clause }
optional { auth_chain }
"}"
}
rule constraint_clause {
"constraint"
Str
}