Macro hcl::body

macro_rules! body {
    ($($body:tt)*) => { ... };
}

Construct an hcl::Body from HCL blocks and attributes.

The macro supports a subset of the HCL syntax. If you need more flexibility, use the BlockBuilder instead.

Supported Syntax

• Attribute keys and block identifiers can be raw identifiers (identifier) or parenthesized expressions ((expr)).
• Block labels can be string literals ("label"), identifiers (label) or parenthesized expressions ((label_expr)).
• Object keys can be string literals ("key"), identifiers (key), parenthesized expressions ((key_expr)) or raw HCL expressions (#{raw_expr}).
• Attribute expression values can be any valid primitive, collection, expression or raw HCL expression (#{raw_expr}).

Please note that HCL actually uses ${} for interpolating expression, but since rust macros do not support matching on $ it was chosen to use #{} instead to support raw expressions.

Unsupported syntax

Heredocs are not supported by the hcl::body macro.

Related macros

The body! macro is composed out of different other macros that can be used on their own to construct HCL data structures:

• attribute!: constructs an Attribute
• block!: constructs a Block
• expression!: constructs an Expression
• structure!: constructs a Structure

Additionally the value! macro is provided for constructing a Value.

Example

use hcl::{Block, Body};

let body = hcl::body!({
    resource "aws_sns_topic" "topic" {
        name = "my-topic"
    }
});

let expected = Body::builder()
    .add_block(
        Block::builder("resource")
            .add_label("aws_sns_topic")
            .add_label("topic")
            .add_attribute(("name", "my-topic"))
            .build()
    )
    .build();

assert_eq!(body, expected);

Attribute keys, block identifiers and object keys can be expressions by wrapping them in parenthesis:

use hcl::{Block, Body};

let block_identifier = "resource";
let attribute_key = "name";

let body = hcl::body!({
    (block_identifier) "aws_sns_topic" "topic" {
        (attribute_key) = "my-topic"
    }
});

let expected = Body::builder()
    .add_block(
        Block::builder(block_identifier)
            .add_label("aws_sns_topic")
            .add_label("topic")
            .add_attribute((attribute_key, "my-topic"))
            .build()
    )
    .build();

assert_eq!(body, expected);