cuelang.org/go@v0.10.1/pkg/tool/tool.cue (about)

     1  // Copyright 2018 The CUE Authors
     2  // 
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tool
    16  
    17  // A Command specifies a user-defined command.
    18  //
    19  // Descriptions are derived from the doc comment, if they are not provided
    20  // structurally, using the following format:
    21  //
    22  //    // short description on one line
    23  //    //
    24  //    // Usage: <name> usage (optional)
    25  //    //
    26  //    // long description covering the remainder of the doc comment.
    27  //
    28  Command: {
    29  	// Tasks specifies the things to run to complete a command. Tasks are
    30  	// typically underspecified and completed by the particular internal
    31  	// handler that is running them. Tasks can be a single task, or a full
    32  	// hierarchy of tasks.
    33  	//
    34  	// Tasks that depend on the output of other tasks are run after such tasks.
    35  	// Use `$after` if a task needs to run after another task but does not
    36  	// otherwise depend on its output.
    37  	Tasks
    38  
    39  	// $usage summarizes how a command takes arguments.
    40  	//
    41  	// Example:
    42  	//     mycmd [-n] names
    43  	$usage?: string
    44  
    45  	// $short is short description of what the command does.
    46  	$short?: string
    47  
    48  	// $long is a longer description that spans multiple lines and
    49  	// likely contain examples of usage of the command.
    50  	$long?: string
    51  }
    52  
    53  // TODO:
    54  // - child commands?
    55  
    56  // Tasks defines a hierarchy of tasks. A command completes if all tasks have
    57  // run to completion.
    58  Tasks: Task | {
    59  	[name=Name]: Tasks
    60  }
    61  
    62  // #Name defines a valid task or command name.
    63  Name: =~#"^\PL([-](\PL|\PN))*$"#
    64  
    65  // A Task defines a step in the execution of a command.
    66  Task: {
    67  	$type: "tool.Task" // legacy field 'kind' still supported for now.
    68  
    69  	// $id indicates the operation to run. It must be of the form
    70  	// packagePath.Operation.
    71  	$id: =~#"\."#
    72  
    73  	// $after can be used to specify a task is run after another one, when
    74  	// it does not otherwise refer to an output of that task.
    75  	$after?: Task | [...Task]
    76  }
    77  
    78  // TODO: consider these options:
    79  //   $success: bool
    80  //   $runif: a.b.$success or $guard: a.b.$success
    81  // With this `$after: a.b` would just be a shorthand for `$guard: a.b.$success`.