Advanced Configuration

Overview

The Eta compiler takes many command line options that you may want to use for your Gradle build. We provide an Options DSL to allow you to configure compiler options easily.

The following table lists the properties that are available for the options property of the compile[SourceSet]Eta task:

language

This specifies the language to use for the build. A language consists of a set of predefined language extensions are are defined by the compiler. Currently, there are only two values you can put for this field:

• 'Haskell98'
• 'Haskell2010'

Default: 'Haskell2010'

Example

Sets the language to Haskell98 for all the Eta source files in the main sourceSet.

1
2
3

compileEta {
  options.language = 'Haskell98'
}

extensions

The set of language extensions to enable or disable for the build.

Example 1

Enables the DataKinds language extension by default for all the Eta source files in the main sourceSet.

1
2
3
4
5
6
7

compileEta {
  options {
    extensions {
      DataKinds
    }
  }
}

Example 2

Disables the DataKinds language extension by default for all the Eta source files in the test sourceSet.

1
2
3
4
5
6
7

compileTestEta {
  options {
    extensions {
      NoDataKinds
    }
  }
}

args

The direct flags to send to the Eta compiler. You would typically use this property to set warning flags.

Example

Enables all warnings and converts warnings to errors.

1
2
3

compileEta {
  options.args = ['-Wall', '-Werror']
}

cpp

The flags to send to the preprocessor used by the Eta compiler to preprocess files that enable the CPP extension.

Example

Enables the CPP language extension for all the Eta source files in the test sourceSet and sends some flags to the preprocessor that define the MY_VERSION constant to be 1200.

1
2
3
4
5
6
7
8
9

compileTestEta {
  
  options {
    extensions {
      CPP
    }
    cpp = ['-DMY_VERSION=1200']
  }
}

includeDirs

Paths to directories which contain include files that can later be referenced with #include directives.

Example

Locates header files in /path/to/includes so that the files in the main sourceSet can access the include files they need.

1
2
3
4
5

compileEta {
  options {
    includeDirs = ['/path/to/includes']
  }
}

installIncludes

Names of include files to install along with the package being built.

Example

Configures the CTypes.h header file to be installed along with the package defined by the main sourceSet.

1
2
3

compileEta {
  options.installIncludes = ['CTypes.h']
}

Configuring Multiple Tasks

Sometimes we want to share configuration across multiple tasks. Here's a quick example of how to use Groovy's language features to configure multiple tasks at a time.

1
2
3
4
5
6
7
8

[compileEta, compileTestEta].each {
  options {
    args = ['-Werror','-Wall']
    extensions {
      DataKinds
    }
  }
}