terminal: clean up duplicate states in parse table

This commit is contained in:
Mitchell Hashimoto
2023-03-17 14:07:24 -07:00
parent 38cd496c82
commit 4b57a715b0

View File

@ -25,7 +25,11 @@ pub const table = genTable();
/// Table is the type of the state table. This is dynamically (comptime)
/// generated to be exactly sized.
pub const Table = genTableType();
pub const Table = genTableType(false);
/// OptionalTable is private to this file. We use this to accumulate and
/// detect invalid transitions created.
const OptionalTable = genTableType(true);
// Transition is the transition to take within the table
pub const Transition = struct {
@ -34,24 +38,23 @@ pub const Transition = struct {
};
/// Table is the type of the state transition table.
fn genTableType() type {
fn genTableType(comptime optional: bool) type {
const max_u8 = std.math.maxInt(u8);
const stateInfo = @typeInfo(State);
const max_state = stateInfo.Enum.fields.len;
return [max_u8 + 1][max_state]Transition;
const Elem = if (optional) ?Transition else Transition;
return [max_u8 + 1][max_state]Elem;
}
/// Function to generate the full state transition table for VT emulation.
fn genTable() Table {
@setEvalBranchQuota(20000);
var result: Table = undefined;
// Initialize everything so every state transition exists
var i: usize = 0;
while (i < result.len) : (i += 1) {
var j: usize = 0;
while (j < result[0].len) : (j += 1) {
result[i][j] = transition(@intToEnum(State, j), .none);
// We accumulate using an "optional" table so we can detect duplicates.
var result: OptionalTable = undefined;
for (0..result.len) |i| {
for (0..result[0].len) |j| {
result[i][j] = null;
}
}
@ -126,9 +129,6 @@ fn genTable() Table {
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
range(&result, 0x20, 0x7F, source, source, .ignore);
// => ground
single(&result, 0x9C, source, .ground, .none);
}
// escape
@ -218,9 +218,6 @@ fn genTable() Table {
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
// => ground
single(&result, 0x9C, source, .ground, .none);
}
// dcs_param
@ -256,9 +253,6 @@ fn genTable() Table {
range(&result, 0x1C, 0x1F, source, source, .put);
range(&result, 0x20, 0x7E, source, source, .put);
single(&result, 0x7F, source, source, .ignore);
// => ground
single(&result, 0x9C, source, .ground, .none);
}
// csi_param
@ -348,24 +342,38 @@ fn genTable() Table {
// events
single(&result, 0x19, source, source, .ignore);
range(&result, 0, 0x06, source, source, .ignore);
range(&result, 0x08, 0x17, source, source, .ignore);
range(&result, 0, 0x17, source, source, .ignore);
range(&result, 0x1C, 0x1F, source, source, .ignore);
range(&result, 0x20, 0x7F, source, source, .osc_put);
// => ground
single(&result, 0x07, source, .ground, .none);
single(&result, 0x9C, source, .ground, .none);
}
return result;
// Create our immutable version
var final: Table = undefined;
for (0..final.len) |i| {
for (0..final[0].len) |j| {
final[i][j] = result[i][j] orelse transition(@intToEnum(State, j), .none);
}
}
return final;
}
fn single(t: *Table, c: u8, s0: State, s1: State, a: Action) void {
t[c][@enumToInt(s0)] = transition(s1, a);
fn single(t: *OptionalTable, c: u8, s0: State, s1: State, a: Action) void {
const s0_int = @enumToInt(s0);
// TODO: enable this but it thinks we're in runtime right now
// if (t[c][s0_int]) |existing| {
// @compileLog(c);
// @compileLog(s0);
// @compileLog(s1);
// @compileLog(existing);
// @compileError("transition set multiple times");
// }
t[c][s0_int] = transition(s1, a);
}
fn range(t: *Table, from: u8, to: u8, s0: State, s1: State, a: Action) void {
fn range(t: *OptionalTable, from: u8, to: u8, s0: State, s1: State, a: Action) void {
var i = from;
while (i <= to) : (i += 1) single(t, i, s0, s1, a);
}