r4d 0.1.3

R4d (Rad)

R4d is a text oriented macro prosessor made with rust.

R4d is in very early stage, so there might be lots of undetected bugs and changes will occur fast.

Currently only binary exists.

Usage

# Usage : rad [OPTIONS] [FILE]...

# Read from file and save to file
rad input_file.txt -o out_file.txt

# Read from file and print to stdout 
rad input_file.txt

# Read from standard input and print to file
printf '...text...' | rad -o out_file.txt

# Read from stdin and print to stdout 
printf '...text...' | rad 

# Use following options to decide error behaviours
# default is stderr
rad -e FileToWriteError.txt # Log error to file
rad -s # Suppress error

Type -h or --help to see full options.

Syntax

Macro definition

Definition syntax is similar to macro invocation but requires a specific form to sucessfully register the macro.

$define(name,arg1 arg2, $arg1() $arg2())

• First argument is a macro name. Macro should start with an alphabet character and following characters should be either alphanumeric or underscore.
• Second argument is macro's arguments. Macro argument also follows same rule of naming. Multiple arguments can be declared and should be separated by a whitespace.
• Third argument is a macro body. Any text can be included in the macro body while an unbalanced right parenthesis will end the definition. Enclose the body with double quote or escape with backslash to type literal parenthesis. Any character including newlines('\n', "\r\n") are all respected. (UTF-8)

You can simply bind the value to macro with =.

$define(v_name=Simon creek)

which is technically same with

$define(v_name,,Simon creek)

Macro inovokation

Prefix is a dollar sign($)

$define(macro_name,a1 a2,$a1() $a2())
$macro_name(arg1, arg2)

Macro can be invoked anywhere after the definition.

My name is $macro_name(Simon, Creek).

converts to

My name is Simon Creek.

Special argument $_ is used for iterated value.

$foreach("John,Simon,Jane",Name : $_
)
$forloop("5,10",$_th
)

converts to

Name : John
Name : Simon
Name : Jane

5th
6th
7th
8th
9th
10th

NOTE

An unbalanced right parenthesis ends macro invocation and a non-double-quoted comma will change the number or content of arguments. If desirable content includes unbalanced right parentheses or commas, enclose the body with double quotes. Use escaped form of double quote, \" to use literal comma inside double quotes.

$define(order=first,second,third)
$order()

The result is

first

To include commas you need to enclose with double quotes

$define(order="first,second,third")
$order()

converts to

first,second,third

Goal

R4d aims to be a modern alternative to m4 processor, which means

• No trivial m4 quotes for macro definition
• Explicit rule for macro definition and usage so that de facto underscore rule is not necessary
• Easier binding with other programming languages(Rust's c binding)
• Enable combination of file stream and stdout
• As expressive as current m4 macro processor

Built-in macros (or macro-like functions)

Usages