file.cpp

// Read all lines from a file, applying an ad-hoc mutation to them
 
#include <iostream>
#include <z/all.hpp>
 
using z::file::lines, z::file::execdir;
 
int main() {
    const auto filename = execdir() + "/../data/in1.txt";
 
    "Original file contents:"_zs.writeln(std::cout);
    for (auto line : lines(filename)) {
        line.writeln(std::cout);
    }
 
    // Create a lambda that mutates each line of the file while they're read.
    auto mutated_lines = lines(filename).map<zstring>([](auto line) {
        auto result = line;
        result.replace(' ', "˽");
        result.replace('\n', "˥\n");
        result.replace('\r', "˿");
        result.replace('\t', "˾");
        return result;
    });
 
    "\nMutated file contents:"_zs.writeln(std::cout);
    for (auto line : mutated_lines) {
        line.writeln(std::cout);
    }
 
    return 0;
}