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Encode Abi Parameters

Definition

Generates Abi encoded data using the contract ABI specification by a given set of inputs or outputs and the associated values.

Zabi supports encoding AbiParameters that are either comptime know or runtime know. It is advised that if you know the specification you are working with is comptime know to use encodeAbiParametersComptime.

Usage

encodeAbiParameters takes in 3 parameters.

  • an allocator used to perform any sort of memory allocations.
  • a set of Abi Parameters.
  • a tuple of values that the type corresponds to the given set of parameters.

All memory will be managed by a ArenaAllocator. You must call deinit() after this call.

const std = @import("std");
const encoder = @import("zabi").encoder;
const abi_parameters: []const AbiParameter = &.{ .{.type = .{.string = {} }, .name = "foo"} };
 
const encoded = try encoder.encodeAbiParameters(std.testing.allocator, abi_parameters, .{"Hello World"})
defer encoded.deinit();
 
// Result
// 00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003666f6f0000000000000000000000000000000000000000000000000000000000

This same example of usage could be used with encodeAbiParametersComptime because here the Abi Parameter is comptime know.

const std = @import("std");
const encoder = @import("zabi").encoder;
const abi_parameters: []const AbiParameter = &.{ .{.type = .{.string = {} }, .name = "foo"} };
 
const encoded = try encoder.encodeAbiParametersComptime(std.testing.allocator, abi_parameters, .{"Hello World"})
defer encoded.deinit();
 
// Result
// 00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003666f6f0000000000000000000000000000000000000000000000000000000000

The main benifit of using this is that we can infer which is the expected type of the values to encode. This leads to better help from the compiler on what are the expected types instead of having it solely rely on type reflection

You could also use the encode method that the Abi Parameter type has.

const std = @import("std");
const encoder = @import("zabi").encoder;
const abi_parameters: AbiParameter =  .{.type = .{.string = {} }, .name = "foo"};
 
const encoded = try abi_parameters.encode(std.testing.allocator, .{"Hello World"})
defer encoded.deinit();
 
// Result
// 00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003666f6f0000000000000000000000000000000000000000000000000000000000

In this example you will not need to pass in the params arguments and it will use self for this.

Returns

Type: AbiEncoded

A struct with the following fields.

  • arena: *ArenaAllocator
  • data: []u8. This is not hex encoded. You must do this after.