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Refactor some of Lexer.attempt_lex_token() into find_longest_match()

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This commit is contained in:
Josh Holtrop 2023-03-12 21:19:03 -04:00
parent b92679e0c2
commit 64974cc1e2
1 changed files with 61 additions and 47 deletions
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112
assets/parser.d.erb
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@ -190,6 +190,14 @@ class <%= @classname %>
<% end %>
];
struct MatchInfo
{
size_t length;
size_t delta_row;
size_t delta_col;
const(State) * accepting_state;
}
struct Result
{
enum Type
@ -264,14 +272,55 @@ class <%= @classname %>
result.row = m_input_row;
result.col = m_input_col;
result.token = _TOKEN_COUNT;
struct MatchInfo
MatchInfo match_info;
find_longest_match(&result, &match_info);
if (result.token != _TOKEN_COUNT)
{
size_t length;
size_t delta_row;
size_t delta_col;
const(State) * accepting_state;
return result;
}
MatchInfo longest_match_info;
if (match_info.accepting_state != null)
{
uint token_to_accept = match_info.accepting_state.token;
if (match_info.accepting_state.code_id != 0xFFFF_FFFFu)
{
uint user_code_token = user_code(match_info.accepting_state.code_id, m_input[m_input_position..(m_input_position + match_info.length)], &result);
/* A return of _TOKEN_COUNT from user_code() means
* that the user code did not explicitly return a
* token. So only override the token to return if the
* user code does explicitly return a token. */
if (user_code_token != _TOKEN_COUNT)
{
token_to_accept = user_code_token;
}
}
/* Update the input position tracking. */
m_input_position += match_info.length;
m_input_row += match_info.delta_row;
if (match_info.delta_row != 0u)
{
m_input_col = match_info.delta_col;
}
else
{
m_input_col += match_info.delta_col;
}
result.token = token_to_accept;
result.length = match_info.length;
if (result.token == _TOKEN_DROP)
{
result.type = Result.Type.DROP;
}
else
{
result.type = Result.Type.TOKEN;
}
}
return result;
}
private void find_longest_match(Result * result, MatchInfo * match_info)
{
MatchInfo attempt_match_info;
uint current_state = modes[m_mode].state_table_offset;
for (;;)
@ -281,7 +330,7 @@ class <%= @classname %>
{
result.type = Result.Type.DECODE_ERROR;
result.token = _TOKEN_DECODE_ERROR;
return result;
return;
}
bool lex_continue = false;
if (!decoded.is_eof())
@ -305,56 +354,21 @@ class <%= @classname %>
(states[current_state].code_id != 0xFFFF_FFFFu))
{
attempt_match_info.accepting_state = &states[current_state];
longest_match_info = attempt_match_info;
*match_info = attempt_match_info;
}
}
}
else if (attempt_match_info.length == 0u)
{
result.token = TOKEN_0EOF;
break;
}
if (!lex_continue && (longest_match_info.accepting_state != null))
{
uint token_to_accept = longest_match_info.accepting_state.token;
if (longest_match_info.accepting_state.code_id != 0xFFFF_FFFFu)
{
uint user_code_token = user_code(longest_match_info.accepting_state.code_id, m_input[m_input_position..(m_input_position + longest_match_info.length)], &result);
/* A return of _TOKEN_COUNT from user_code() means
* that the user code did not explicitly return a
* token. So only override the token to return if the
* user code does explicitly return a token. */
if (user_code_token != _TOKEN_COUNT)
{
token_to_accept = user_code_token;
}
}
/* Update the input position tracking. */
m_input_position += longest_match_info.length;
m_input_row += longest_match_info.delta_row;
if (longest_match_info.delta_row != 0u)
{
m_input_col = longest_match_info.delta_col;
}
else
{
m_input_col += longest_match_info.delta_col;
}
result.token = token_to_accept;
result.length = longest_match_info.length;
break;
}
}
if (result.token == _TOKEN_DROP)
{
result.type = Result.Type.DROP;
}
else
{
result.type = Result.Type.TOKEN;
return;
}
if (!lex_continue)
{
return;
}
}
return result;
}
private uint transition(uint current_state, uint code_point)