77 lines
1.2 KiB
Ragel
77 lines
1.2 KiB
Ragel
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#include "value.h"
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#include <stdexcept>
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void value::expect_number() const {
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std::string error;
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error = "Expected a number when \"";
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error += string;
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error += "\" was encountered";
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throw std::domain_error(error);
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}
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void value::scan_number(void) noexcept {
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%%{
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machine scanner;
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hexnumber =
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('$' | '0x' | '0X')
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(
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[0-9] ${ value = (value << 4) + fc - '0'; }
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[A-Fa-f] ${value = (value << 4) + (fc | 0x20) - 'a' + 10; }
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)+
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;
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binnumber =
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('0b' | '0B')
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[01]+ ${ value = (value << 1) + fc - '0'; }
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;
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octalnumber =
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'0'
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[0-7]+ ${ value = (value << 3) + fc - '0'; }
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;
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# a leading 0 is ambiguous since it could also
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# be part of the binary or hex prefix.
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# however, setting it to 0 is safe.
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decnumber =
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'0'
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([1-9] [0-9]*) ${ value = value * 10 + fc - '0'; }
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;
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main :=
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( hexnumber | decnumber |binnumber)
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%{
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status = valid;
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number = value;
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return;
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}
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;
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}%%
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if (string.empty()) {
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// special case.
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status = valid;
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number = 0;
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return;
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}
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const char *p = string.data();
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const char *pe = string.data() + string.size();
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const char *eof = pe;
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int cs;
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int32_t value = 0;
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%%write data;
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%%write init;
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%%write exec;
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status = invalid;
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}
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