// Copyright 2021 The Jujutsu Authors// // Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at// // https://www.apache.org/licenses/LICENSE-2.0// // Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License. identifier_part = @{ (ASCII_ALPHANUMERIC | "_" | "/")+ }identifier = @{  identifier_part ~ ("." | "-" | "+" ) ~ identifier  | identifier_part}symbol = {  identifier  | literal_string}literal_string = { "\"" ~ (!"\"" ~ ANY)* ~ "\"" }whitespace = _{ " " | "\t" | "\r" | "\n" | "\x0c" } at_op = { "@" }pattern_kind_op = { ":" } parents_op = { "-" }children_op = { "+" }compat_parents_op = { "^" } dag_range_op = { "::" }dag_range_pre_op = { "::" }dag_range_post_op = { "::" }dag_range_all_op = { "::" }compat_dag_range_op = { ":" }compat_dag_range_pre_op = { ":" }compat_dag_range_post_op = { ":" }range_op = { ".." }range_pre_op = { ".." }range_post_op = { ".." }range_all_op = { ".." }range_ops = _{ dag_range_op | compat_dag_range_op | range_op }range_pre_ops = _{ dag_range_pre_op | compat_dag_range_pre_op | range_pre_op }range_post_ops = _{ dag_range_post_op | compat_dag_range_post_op | range_post_op }range_all_ops = _{ dag_range_all_op | range_all_op } negate_op = { "~" }union_op = { "|" }intersection_op = { "&" }difference_op = { "~" }compat_add_op = { "+" }compat_sub_op = { "-" }infix_op = _{ union_op | intersection_op | difference_op | compat_add_op | compat_sub_op } function_name = @{ (ASCII_ALPHANUMERIC | "_")+ }keyword_argument = { identifier ~ whitespace* ~ "=" ~ whitespace* ~ expression }argument = _{ keyword_argument | expression }function_arguments = {  argument ~ (whitespace* ~ "," ~ whitespace* ~ argument)* ~ (whitespace* ~ ",")?  | ""}formal_parameters = {  identifier ~ (whitespace* ~ "," ~ whitespace* ~ identifier)* ~ (whitespace* ~ ",")?  | ""} // TODO: change rhs to literal_string to require quoting? #2101string_pattern = { identifier ~ pattern_kind_op ~ symbol } primary = {  function_name ~ "(" ~ whitespace* ~ function_arguments ~ whitespace* ~ ")"  | "(" ~ whitespace* ~ expression ~ whitespace* ~ ")"  | string_pattern  // "@" operator cannot be nested  | symbol ~ at_op ~ symbol  | symbol ~ at_op  | symbol  | at_op} neighbors_expression = _{ primary ~ (parents_op | children_op | compat_parents_op)* } range_expression = _{  neighbors_expression ~ range_ops ~ neighbors_expression  | neighbors_expression ~ range_post_ops  | range_pre_ops ~ neighbors_expression  | neighbors_expression  | range_all_ops} expression = {  (negate_op ~ whitespace*)* ~ range_expression  ~ (whitespace* ~ infix_op ~ whitespace* ~ (negate_op ~ whitespace*)* ~ range_expression)*} program = _{ SOI ~ whitespace* ~ expression ~ whitespace* ~ EOI } alias_declaration_part = _{  function_name ~ "(" ~ whitespace* ~ formal_parameters ~ whitespace* ~ ")"  | identifier}alias_declaration = _{  SOI ~ alias_declaration_part ~ EOI}