r4d 0.1.2

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.

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 (without error print)
rad input_file.txt 2>/dev/null

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

# Read from stdin and print to stdout (without error print)
printf '...text...' | rad 2>/dev/null

Syntax

Macro definition

Definition is also a macro. However it requires specific form not like other macros.

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

• First argument is a macro name. Macro should start with alphabets 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)

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 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.

Goal

R4d aims to be a modern m4 alternative, 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

In-built macros(WIP)

Implemented

• define
• undef
• include
• repeat
• foreach
• forloop
• ifelse
• syscmd
• rsub, rdel
• eval
• trim, chomp, comp
• lipsum
• time, date
• ifdef

Not implemented

• csv sql query
• csv formatting(gfm table, wititext table, latex table)
• Macro automation

Possibly

• Web request macro There would many caveats implementing web request macro, because it is inherently insecure + r4d targets gnu linux, windows and possibly musl linux(alpine linux), thus configuing libcurl and libssl compatible global interface might not be easy, I guess