Haxe: investigating string interpolation and macros

InterpolatedMacroPlay.hx

// Haxe’s macro support makes for a golden opportunity for building
// program metadata during compiletime. I think it would be very cool
// to be able to preprocess itnerpolated strings so that text can be
// extracted and analyzed separately (NLS?) or, e.g., to do JavaScript-style
// tagged string stuff/C#-style FormattableString stuff like automatically
// escaping expressions when building HTML, etc.
//
// However, it looks to me like right now macros are given CStrings
// which don’t even let you know if the string will be interpolated
// or not.

import haxe.macro.Expr;

class InterpolatedMacroPlay {
    static function main() {
        trace(intr('asdf'));
        trace(intr('asdf${2*3}'));
        trace(intr('asdf${{}}asdf'));
        trace(intr("as${2*3}df"));
    }

    public macro static function intr(e:Expr) {
        switch (e.expr) {
        case ExprDef.EConst(c):
            switch (c) {
            case CString(s): trace('str: ${s}');
            default:
            }
        case ExprDef.EBinop(op, e1, e2):
            trace('binop: ${e1} ${op} ${e2}');
        default:
        }
        return e;
    }
}

output.txt

$ haxe --run InterpolatedMacroPlay
InterpolatedMacroPlay.hx:26: str: asdf
InterpolatedMacroPlay.hx:26: str: asdf${2*3}
InterpolatedMacroPlay.hx:26: str: asdf${{}}asdf
InterpolatedMacroPlay.hx:26: str: as${2*3}df
InterpolatedMacroPlay.hx:16: asdf
InterpolatedMacroPlay.hx:17: asdf6
InterpolatedMacroPlay.hx:18: asdf{}asdf
InterpolatedMacroPlay.hx:19: as${2*3}df