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//! Lua's Table Library
use crate::LuaType;
use crate::State;
use crate::error::{ErrorKind, TypeError};
pub(crate) fn open_table(state: &mut State) {
// Create the table table
state.new_table_with_capacity(8);
// Helper to add a function to the table at stack index -1.
macro_rules! add_fn {
($name:expr, $func:expr) => {
state
.set_table_str_key_rust_fn(-1, $name, $func)
.expect("table library registration cannot fail");
};
}
// table.insert(t, [pos,] value) - costs 1
// Inserts value at position pos in t, shifting elements up.
// If pos is omitted, inserts at the end.
add_fn!("insert", |state| {
state.consume_cost(1)?;
state.check_type(1, LuaType::Table)?;
let num_args = state.get_top();
if num_args == 2 {
// table.insert(t, value) - append at end
let len = state.table_len(1);
// Stack: [t, value]
state.push_number((len + 1) as f64);
// Stack: [t, value, pos]
// Swap to get [t, pos, value]
state.insert(-2)?;
state.table_insert_at(1)?;
} else if num_args >= 3 {
// table.insert(t, pos, value)
state.check_type(2, LuaType::Number)?;
// Stack: [t, pos, value]
state.table_insert_at(1)?;
}
state.set_top(0);
Ok(0)
});
// table.remove(t [, pos]) - costs 1
// Removes and returns the element at position pos.
// If pos is omitted, removes the last element.
add_fn!("remove", |state| {
state.consume_cost(1)?;
state.check_type(1, LuaType::Table)?;
let num_args = state.get_top();
let pos = if num_args >= 2 {
state.check_type(2, LuaType::Number)?;
state.to_number(2)? as usize
} else {
state.table_len(1)
};
state.set_top(1);
// Stack: [t]
state.table_remove_at(1, pos)?;
// Stack: [t, removed_value]
state.remove(1)?; // Remove table, leave value
Ok(1)
});
// table.sort(t [, comp]) - costs n (array length)
// Sorts the array portion of t in place.
// comp is an optional comparison function.
add_fn!("sort", |state| {
state.check_type(1, LuaType::Table)?;
let num_args = state.get_top();
let has_comp = num_args >= 2;
if has_comp {
state.check_type(2, LuaType::Function)?;
}
let n = state.table_sort(1, has_comp)?;
state.consume_cost(n.max(1) as u64)?;
state.set_top(0);
Ok(0)
});
// table.unpack(list [, i [, j]])
// Returns list[i], list[i+1], ..., list[j].
// Default: i=1, j=#list
add_fn!("unpack", |state| {
state.check_type(1, LuaType::Table)?;
let num_args = state.get_top();
let len = state.table_len(1);
let i = if num_args >= 2 {
state.check_type(2, LuaType::Number)?;
state.to_number(2)? as usize
} else {
1
};
let j = if num_args >= 3 {
state.check_type(3, LuaType::Number)?;
state.to_number(3)? as usize
} else {
len
};
state.set_top(1);
// Stack: [t]
if i > j {
state.set_top(0);
return Ok(0);
}
let count = j - i + 1;
for idx in i..=j {
state.push_number(idx as f64);
state.get_table(1)?;
}
// Stack: [t, list[i], list[i+1], ..., list[j]]
state.remove(1)?; // Remove table
Ok(count as u8)
});
// table.pack(...) - costs 1
// Returns a new table with all arguments stored into keys 1, 2, etc.
// and with a field "n" with the total number of arguments.
add_fn!("pack", |state| {
state.consume_cost(1)?;
let num_args = state.get_top();
// Create new table
state.new_table();
let table_idx = state.get_top() as isize;
// Insert all arguments into the table
for i in 1..=num_args {
state.push_number(i as f64); // push the index (key)
state.push_value(i as isize)?; // push the argument (value)
state.set_table_raw(table_idx)?;
}
// Add the "n" field
state.push_string("n");
state.push_number(num_args as f64);
state.set_table_raw(table_idx)?;
// Remove all original arguments, leave just the table
// Table is at position (num_args + 1)
for _ in 0..num_args {
state.remove(1)?;
}
Ok(1)
});
// table.concat(list [, sep [, i [, j]]]) - costs 1
// Returns list[i]..sep..list[i+1]..sep..list[j].
// Default: sep="", i=1, j=#list
add_fn!("concat", |state| {
state.consume_cost(1)?;
state.check_type(1, LuaType::Table)?;
let num_args = state.get_top();
let len = state.table_len(1);
let sep = if num_args >= 2 {
state.check_type(2, LuaType::String)?;
state.to_bytes(2)?.to_vec()
} else {
Vec::new()
};
let i = if num_args >= 3 {
state.check_type(3, LuaType::Number)?;
state.to_number(3)? as usize
} else {
1
};
let j = if num_args >= 4 {
state.check_type(4, LuaType::Number)?;
state.to_number(4)? as usize
} else {
len
};
state.set_top(1);
if i > j || len == 0 {
state.set_top(0);
state.push_bytes(b"");
return Ok(1);
}
let mut result = Vec::new();
for idx in i..=j {
if idx > i {
result.extend_from_slice(&sep);
}
state.push_number(idx as f64);
state.get_table(1)?;
let typ = state.typ(-1);
match typ {
LuaType::String | LuaType::Number => {
result.extend_from_slice(state.to_bytes_coerce(-1)?.as_ref());
}
_ => return Err(state.error(ErrorKind::TypeError(TypeError::Concat(typ)))),
}
state.pop(1);
}
state.set_top(0);
state.push_bytes(result);
Ok(1)
});
// table.move(a1, f, e, t [, a2]) - costs 1
// Moves elements from table a1 to table a2 (or a1 if not given).
// Copies a1[f..e] to a2[t..t+(e-f)]. Returns a2.
add_fn!("move", |state| {
state.consume_cost(1)?;
state.check_type(1, LuaType::Table)?;
state.check_type(2, LuaType::Number)?;
state.check_type(3, LuaType::Number)?;
state.check_type(4, LuaType::Number)?;
let f = state.to_number(2)? as isize;
let e = state.to_number(3)? as isize;
let t = state.to_number(4)? as isize;
// Determine destination table (a2 or a1)
let has_a2 = state.get_top() >= 5 && state.typ(5) == LuaType::Table;
let dest_idx: isize = if has_a2 { 5 } else { 1 };
// Copy elements (if any). Same-table moves that shift the range right
// must copy backwards so earlier writes do not clobber later reads.
if f <= e {
let count = e - f + 1;
let same_table = state.raw_equal(1, dest_idx);
if same_table && t > f {
for i in (0..count).rev() {
let src_key = (f + i) as f64;
let dest_key = (t + i) as f64;
state.push_number(dest_key);
state.push_number(src_key);
state.get_table(1)?;
state.set_table_raw(dest_idx)?;
}
} else {
for i in 0..count {
let src_key = (f + i) as f64;
let dest_key = (t + i) as f64;
state.push_number(dest_key);
state.push_number(src_key);
state.get_table(1)?;
state.set_table_raw(dest_idx)?;
}
}
}
// Return destination table - push it first, then clear below it
state.push_value(dest_idx)?;
// Now move it to position 1 and clear rest
state.replace(1)?;
state.set_top(1);
Ok(1)
});
// Set the table table as a global
state.set_global("table");
}