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xo-reader: exprreplxx example program, now with line editing

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This commit is contained in:
Roland Conybeare 2025-07-05 16:16:16 -05:00
commit 0af7a50810
9 changed files with 170 additions and 11 deletions
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31
xo-reader/examples/exprrepl/exprrepl.cpp
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@ -4,18 +4,35 @@
#include <iostream>
#include <unistd.h> // for isatty
bool repl_getline(bool interactive, std::istream& in, std::ostream& out, std::string& input)
bool repl_getline(bool interactive, std::size_t parser_stack_size, std::istream& in, std::ostream& out, std::string& input)
{
using namespace std;
if (interactive) {
out << "> ";
if (parser_stack_size <= 1)
out << "> ";
else
out << ". ";
std::flush(out);
}
bool retval = static_cast<bool>(std::getline(in, input));
bool retval = static_cast<bool>(getline(in, input));
if (retval) {
cerr << "got reval->true" << endl;
// interactive only: treat ^@ (C-RET) as ;RET
if ((input.size() > 0) && ((*input.rbegin()) == '\0'))
{
cerr << "got ^@" << endl;
*input.rbegin() = ';';
}
// want reader to see newline, it's syntax
input.push_back('\n');
} else {
cerr << "got retval->false" << endl;
}
return retval;
@ -38,22 +55,24 @@ main() {
bool eof = false;
span_type input;
std::size_t parser_stack_size = 0;
while (repl_getline(interactive, cin, cout, input_str)) {
while (repl_getline(interactive, parser_stack_size, cin, cout, input_str)) {
input = span_type::from_string(input_str);
while (!input.empty()) {
auto [expr, consumed] = rdr.read_expr(input, eof);
auto [expr, consumed, psz] = rdr.read_expr(input, eof);
if (expr) {
cout << expr << endl;
}
input = input.after_prefix(consumed);
parser_stack_size = psz;
}
}
auto [expr, _] = rdr.read_expr(input, true /*eof*/);
auto [expr, _1, _2] = rdr.read_expr(input, true /*eof*/);
if (expr) {
cout << expr << endl;