Different CLI param cast depending on syntax parser

[jorgee]

Bug report

Expected behavior and actual behavior

Depending on the number passed through the CLI, the syntax parser v2 is not working as the syntax parser v1.

Steps to reproduce the problem

A pipeline like the following has a different behaviour depending on the syntax parser

params.num_consumers  = 1 

workflow {

    Channel.of( 1..params.num_consumers ).view()

}

Depending on the number passed through the CLI, it has different behaviours

$ NXF_SYNTAX_PARSER=v2 nextflow run main.nf --num_consumers 1

 N E X T F L O W   ~  version 26.04.0

Launching `main.nf` [happy_mirzakhani] revision: 1e32e4174a

1
2
...
48
49

$ NXF_SYNTAX_PARSER=v1 nextflow run main.nf --num_consumers 1

 N E X T F L O W   ~  version 26.04.0

Launching `main.nf` [scruffy_sanger] revision: 1e32e4174a

1

$ NXF_SYNTAX_PARSER=v2 nextflow run main.nf --num_consumers 10

 N E X T F L O W   ~  version 26.04.0

Launching `main.nf` [modest_kowalevski] revision: 1e32e4174a

ERROR ~ Unable to create range due to incompatible types: Integer..String (possible missing brackets around range?)

 -- Check script 'main.nf' at line: 7 or see '.nextflow.log' file for more details

$ NXF_SYNTAX_PARSER=v1 nextflow run main.nf --num_consumers 10

 N E X T F L O W   ~  version 26.04.0

Launching `main.nf` [chaotic_caravaggio] revision: 1e32e4174a

1
2
...
9
10

Environment

• Nextflow version: 26.04.0
• Java version: [21]
• Operating system: Linux]
• Bash version: (use the command $SHELL --version)

Additional context

(Add any other context about the problem here)

[jorgee]

I have noted that legacy cast is disabled in syntax parser v2. So, it requires defining the params block with type or cast the parameter.

params{
 num_consumers : Integer   = 1
}

However, the case of '1' is very weird, and I was expecting to get an error, as in the case of '10'. It is silently converting to the ASCII code