Category: Uncategorized

Posted on

Loci v1.4 Released

The latest version of the Loci compiler is now available. See the release notes for detailed information about what’s included.

The main feature in this release is a brand new compiler diagnostics system with a rewritten lexer and parser. Here’s an example of errors from the old compiler:

Parser Error: Failed to parse file 'MultipleElse.loci' with 2 errors:
Parser Error (at SourceLocation(filename = MultipleElse.loci, range = (line 11, column 4) to (line 11, column 8))): syntax error, unexpected ELSE
Parser Error (at SourceLocation(filename = MultipleElse.loci, range = (line 11, column 4) to (line 11, column 8))): Invalid statement.

And here’s how it looks with the new diagnostics system:

MultipleElse.loci:11:4: error: 'else' without a previous 'if'
  } else {
    ^~~~
1 error generated.

This release is therefore an enormous improvement in the usability of the compiler and the cause of errors/warnings should be very clear to the user.

Posted on

atoi() vs std::stringstream

I was recently asked to compare the functionality of atoi() and std::stringstream.

Here’s the code:

#include <stdio.h>
#include <stdlib.h>
#include <sstream>

void strToInt(const char* str) {
    {
        // Set to garbage value.
        int val = 479894;

        std::stringstream stream;
        stream << str;
        stream >> std::dec >> val;
        printf("stream: '%s' -> %d\n", str, val);
    }

    {
        const int val = atoi(str);
        printf("atoi: '%s' -> %d\n", str, val);
    }

    printf("\n");
}

int main() {
    strToInt("");
    strToInt("0");
    strToInt("a");
    strToInt("1");
    strToInt("44a");
    strToInt("a44");
    return 0;
}

And here’s the output:

stream: '' -> 479894
atoi: '' -> 0

stream: '0' -> 0
atoi: '0' -> 0

stream: 'a' -> 0
atoi: 'a' -> 0

stream: '1' -> 1
atoi: '1' -> 1

stream: '44a' -> 44
atoi: '44a' -> 44

stream: 'a44' -> 0
atoi: 'a44' -> 0

So it looks like the functionality of both is actually very similar (though note std::stringstream has many ways to modify its behaviour); unfortunately it seems the stream doesn’t set the result to zero when given an empty string.