add ?? maybe unwrapping binary operator

add null literal
fix number literal / maybe interactions

2 files changed, 26 insertions, 0 deletions

diff --git a/std/std.zig b/std/std.zig
index a53dbb6027..333896cadc 100644
--- a/std/std.zig
+++ b/std/std.zig
@@ -1,5 +1,6 @@
 use "syscall.zig";
 
+const stdin_fileno : isize = 0;
 const stdout_fileno : isize = 1;
 const stderr_fileno : isize = 2;
 
@@ -38,6 +39,26 @@ pub fn print_i64(x: i64) -> isize {
     return write(stdout_fileno, buf.ptr, len);
 }
 
+/*
+// TODO error handling
+pub fn readline(buf: []u8) -> ?[]u8 {
+    var index = 0;
+    while (index < buf.len) {
+        // TODO unknown size array indexing operator
+        const err = read(stdin_fileno, &buf.ptr[index], 1);
+        if (err != 0) {
+            return null;
+        }
+        // TODO unknown size array indexing operator
+        if (buf.ptr[index] == '\n') {
+            return buf[0...index + 1];
+        }
+        index += 1;
+    }
+    return null;
+}
+*/
+
 fn digit_to_char(digit: u64) -> u8 {
     '0' + (digit as u8)
 }
diff --git a/std/syscall.zig b/std/syscall.zig
index 1bcbcdbe31..97542363cb 100644
--- a/std/syscall.zig
+++ b/std/syscall.zig
@@ -1,3 +1,4 @@
+const SYS_read : usize = 0;
 const SYS_write : usize = 1;
 const SYS_exit : usize = 60;
 const SYS_getrandom : usize = 318;
@@ -16,6 +17,10 @@ fn syscall3(number: usize, arg1: usize, arg2: usize, arg3: usize) -> usize {
         : "rcx", "r11")
 }
 
+pub fn read(fd: isize, buf: &u8, count: usize) -> isize {
+    syscall3(SYS_read, fd as usize, buf as usize, count) as isize
+}
+
 pub fn write(fd: isize, buf: &const u8, count: usize) -> isize {
     syscall3(SYS_write, fd as usize, buf as usize, count) as isize
 }