R4d (Rad)
- Explicit rule for macro definition and usage so that de facto underscore rule is not necessary
- Easier binding with other programming languages
- Enable combination of file stream and stdout
- As expressive as current m4 macro processor
Implementation
No library
I tried pest, however I didn't like the limitation of the syntax. Plus, other parser generator libraries recommend using custom parser for programming languages.
The reason stock library doesn't fit well comes from the expressiveness and complexity of m4 macro processor. Technical difficulties are followed,
- M4 syntax allows string literal in its file which is not allowed in many programming languages
- M4 allows macro definition in any location of given input, even among string literal
- M4 allows shell execution in any location of given input.
Thus there are too much caveats to with exsiting library that can differentiate string literal and macro definitio and macro usages at the same time.
Syntax (This is a plan, not the real specification)
Macro definition
Definition is also a macro.
Definition should start from the first of the line
// Define with json form
$define({name: "", args: [""], contents: [""]})
// Define with simple form
$define("",[""],[""])
Macro inovokation
Prefix(default is $, dollar sign) can be changed by end user.
$macro_name(arg1, arg2)
Macro can be invoked anywhere
My name is $macro_name(Simon, Creek).
In-built macros
- Include
- Foreach, for loop
