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lexer: add support for binary number literals

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This commit is contained in:
Zack Buhman 2023-08-23 19:34:09 -07:00
parent 118942521e
commit c2c59495b3
2 changed files with 36 additions and 5 deletions
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15
grammar.txt
View File

@ -6,12 +6,19 @@ unary → ( "~" | "+" | "-" ) unary
shift → andl ( ( "<<" | ">>" ) andl )*
andl → orl ( "&" orl )*
orl → andl ( ( "|" | "^" ) andl )*
primary → NUMBER
primary → number
| "(" expression ")"
uimm8 → expression
uimm19 → expression
uimm25 → expression
number → "%" base2-number
| "$" base16-number
| "0b" base2-number
| "0x" base16-number
| base10-number
imm → ("#")? expression
uimm8 → imm
uimm19 → imm
uimm25 → imm
alu → and | or | xor | add | sub | ad2 | sr | rr | sl | rl | rl8

26
lexer.cpp
View File

@ -53,6 +53,19 @@ constexpr static N parse_number(const std::string_view s)
return n;
}
struct bin_t {
constexpr static bool pred(const char c)
{
return c >= '0' && c <= '1';
}
template <typename N>
constexpr static N parse(const std::string_view s)
{
return parse_number<N, 2>(s);
}
};
struct dec_t {
constexpr static bool pred(const char c)
{
@ -159,7 +172,6 @@ std::optional<token_t> lexer_t::lex_token()
case '-': return {{pos, minus, lexeme()}};
case '*': return {{pos, star, lexeme()}};
case '/': return {{pos, slash, lexeme()}};
case '%': return {{pos, percent, lexeme()}};
case '~': return {{pos, tilde, lexeme()}};
case '&': return {{pos, ampersand, lexeme()}};
case '|': return {{pos, bar, lexeme()}};
@ -188,6 +200,13 @@ std::optional<token_t> lexer_t::lex_token()
return {{tmp, eol, lexeme()}};
}
break;
case '%':
if (bin_t::pred(peek())) {
start_ix += 1;
return {_number<bin_t>()};
} else {
return {{pos, percent, lexeme()}};
}
case '$':
if (hex_t::pred(peek())) {
start_ix += 1;
@ -200,6 +219,11 @@ std::optional<token_t> lexer_t::lex_token()
start_ix += 2;
return {_number<hex_t>()};
}
} else if (match('b')) {
if (bin_t::pred(peek())) {
start_ix += 2;
return {_number<bin_t>()};
}
}
[[fallthrough]];
default: