sclass _PrintIndent extends F1 { S prefix; bool beginningOfLine = true; *() {} *(S *prefix) {} Bool get(S s) { if (empty(s)) false; bool nl = s.endsWith("\n"); if (nl) s = dropLast(s); s = s.replace("\n", "\n" + prefix); print_raw(beginningOfLine ? prefix + s : s); if (nl) print_raw("\n"); beginningOfLine = nl; false; } }