feat : add max size parameter for string and truncate output

[youen]

Problem

Column definition in database have a max size definition. Trying to insert a bigger value with lino push failed.

Proposal

Define a template with max size parameter that truncate string longer than max size definition.

$ jl -t '{"name": "string(4)"}' <<EOF
{"name": "Martin"}
EOF
{"name":"Mart"}

[adrienaury]

The proposed syntax will conflict with the way to define the raw type (for example jl -t '{"value":"binary(int64)"}' < file.jsonl)

So we need another notation.

[youen]

What is a raw type for a string ?

[adrienaury]

For example :

jl -t '{"value":"string([]byte)"}' < file.jsonl

The string value read from JSON will be transformed and the database driver will receive a []byte instead of a string.

[adrienaury]

Here is a syntax with possibility to extend to other parameters

jl -t '{"name": "string(size=4)"}'
jl -t '{"name": "string([]byte,size=4)"}'