Module macros

The macro module provides helpers that simplify writing proc macros that take format strings and arguments. This is accomplish with three main constructs:

• FormatAndArgsFlavor: A struct that implements syn::parse::Parse to parse a format string and its following arguments.
• FormatMacroGenerator: A trait used to implement the macro specific logic to generate code.
• generate: A function to handle the execution of the proc macro by calling into a FormatMacroGenerator.

Additionally PrintfFormatMacroGenerator trait and generate_printf function are provided to help when implementing generators that need to produce printf style format strings as part of their code generation.

Example

An example of implementing a proc macro is provided in the pw_format_example_macro crate

Structs

CoreFmtFormatStringParser

An implementation of FormatStringParser that parsers core::fmt style format strings.

Error

An error occurring during proc macro evaluation.

FormatAndArgs

A parsed format string and it’s arguments.

FormatAndArgsFlavor

A variant of FormatAndArgs that is generic over format string flavor.

FormatParams

Formatting parameters passed to an untyped conversion.

PrintfFormatStringParser

An implementation of FormatStringParser that parsers printf style format strings.

Enums

Arg

An argument to a pw_format backed macro.

PrintfFormatStringFragment

A fragment of a printf format string.

Traits

CoreFmtFormatMacroGenerator

A specialized generator for proc macros that produce core::fmt style format strings.

FormatMacroGenerator

A code generator for implementing a pw_format style macro.

FormatStringParser

A trait for parsing a string into a FormatString.

PrintfFormatMacroGenerator

A specialized generator for proc macros that produce printf style format strings.

Functions

generate

Generate code for a pw_format style proc macro.

generate_core_fmt

Generate code for a pw_format style proc macro that needs a core::fmt format string.

generate_printf

Generate code for a pw_format style proc macro that needs a printf format string.

Type Aliases

Result

An alias for a Result with an Error