Chain Language

Chain is serial data description language.

Use #

• cui
• argument parser
• inter-application communication
• serialize(Recursive nesting is possible)

Syntax #

For example, tiger 's cui is chain language.

tiger run --taskLocation 'abc' --taskName 'tiger_sample.yaml'

run is head.
--taskLocation 'abc' and --taskName 'tiger_sample.yaml' is option.
There is no example, -log is flag.

Chain contains only Head, Option, and Flag.

Each name must be unique #

Head name, option name, and flag name must not be duplicate.

Head #

1. head position is the beginning.
2. head prefix is no hypen.
3. head is not empty.
4. head quantity must be 1.

Option #

1. option position is free.
2. option prefix is double-hypen.
3. option is not empty.
4. option quantity is 0 or more.
5. option value quantity is 0 or more.
   • In the above example, 'abc' and 'tiger_sample.yaml' is option value.
6. option value position is right behind option or right behind option value.
   • you can make a List by placing option value in a row.
   • example, --something 'a' 'b' 'c'
7. if the option value prefix is ​​hypen, an escape is required.
   • escape sequence is \.
   • example, --something '\-\-great data'
8. option value is available empty.
   • example, --something '' 'b' 'c'

Flag #

1. flag position is free.
2. flag prefix is single-hypen.
3. flag is not empty.
4. flag quantity is 0 or more.

Delimiter #

1. delimiter is space only.
2. space quantity is 1 or more.

Include white space #

if you want to include white space in serial source, Please circle it with single or double quotation.
example: --something 'hello world'

Include quotation #

if you want to include single quotation in serial source, Please circle it with double quotation.
example: --something "abc'def'ghi"
if you want to include double quotation in serial source, Please circle it with single quotation.
example: --something 'abc"def"ghi'

Other #

Triple-hypen or more prefix

Valid as head or option value.
But, Not recommended.

Pass value that starts with a hyphen to option value

Impossible.

There is no shorthand for head, option, and flag

There is only one way to specify.

Please depend on bpriver_origin library #

When extracting values ​​from the chain, we use the Result type.

dependencies:
  bpriver_origin: ^2.1.0

Result type is available.

import 'package:bpriver_origin/logger_result.dart';

Data serialize. #

This can be achieved by storing the chain string as the option value. For Example,

A --a 'B --b \'C --c \\'something value\\'\''

--a has 'B --b \'C --c \\'something value\\'\''.
--b has \'C --c \\'something value\\'\'.
--c has \\'something value\\'.

The deeper the nesting, the more escape sequences will accumulate.
This has some drawbacks:

1. Readabilityis not good.
2. The danger of data becoming too large.
   • Because escape sequences accumulate

It is also possible to store other formats. For example json,

A --a '{ "name": "arakawa", "job": "unemployed" }'

The specific code is here. test\nested_chain\nested_chain_test.dart.

Code example #

The example code is in the example folder.