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Accept &&/and for &, ||/or for |, and not for !. Also improved error

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reporting in the tokenizer.
This commit is contained in:
John Wiegley 2009-01-22 17:01:46 -04:00
parent 0b9f22b4d2
commit fac5a95a48
2 changed files with 119 additions and 48 deletions
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158
src/token.cc
View file

@ -34,46 +34,77 @@
namespace ledger {
int expr_t::token_t::parse_reserved_word(std::istream& in)
{
char c = in.peek();
if (c == 'a' || c == 'f' || c == 'o' || c == 'n' || c == 't') {
length = 0;
char buf[256];
READ_INTO_(in, buf, 255, c, length,
std::isalnum(c) || c == '_' || c == '.' || c == '-');
switch (buf[0]) {
case 'a':
if (std::strcmp(buf, "and") == 0) {
symbol[0] = '&';
symbol[1] = '\0';
kind = KW_AND;
return 1;
}
break;
case 'f':
if (std::strcmp(buf, "false") == 0) {
kind = VALUE;
value = false;
return 1;
}
break;
case 'o':
if (std::strcmp(buf, "or") == 0) {
symbol[0] = '|';
symbol[1] = '\0';
kind = KW_OR;
return 1;
}
break;
case 'n':
if (std::strcmp(buf, "not") == 0) {
symbol[0] = '!';
symbol[1] = '\0';
kind = EXCLAM;
return 1;
}
break;
case 't':
if (std::strcmp(buf, "true") == 0) {
kind = VALUE;
value = true;
return 1;
}
break;
}
return 0;
}
return -1;
}
void expr_t::token_t::parse_ident(std::istream& in)
{
if (in.eof()) {
kind = TOK_EOF;
return;
}
assert(in.good());
char c = peek_next_nonws(in);
if (in.eof()) {
kind = TOK_EOF;
return;
}
assert(in.good());
kind = IDENT;
length = 0;
char buf[256];
char c, buf[256];
READ_INTO_(in, buf, 255, c, length,
std::isalnum(c) || c == '_' || c == '.' || c == '-');
switch (buf[0]) {
case 'f':
if (std::strcmp(buf, "false") == 0) {
kind = VALUE;
value = false;
}
break;
case 't':
if (std::strcmp(buf, "true") == 0) {
kind = VALUE;
value = true;
}
break;
}
if (kind == IDENT)
value.set_string(buf);
value.set_string(buf);
}
void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
@ -82,7 +113,8 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
kind = TOK_EOF;
return;
}
assert(in.good());
if (! in.good())
throw_(parse_error, "Input stream no longer valid");
char c = peek_next_nonws(in);
@ -90,7 +122,8 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
kind = TOK_EOF;
return;
}
assert(in.good());
if (! in.good())
throw_(parse_error, "Input stream no longer valid");
symbol[0] = c;
symbol[1] = '\0';
@ -100,10 +133,22 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
switch (c) {
case '&':
in.get(c);
if (c == '&') {
in.get(c);
kind = KW_AND;
length = 2;
break;
}
kind = KW_AND;
break;
case '|':
in.get(c);
if (c == '|') {
in.get(c);
kind = KW_OR;
length = 2;
break;
}
kind = KW_OR;
break;
@ -201,7 +246,6 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
in.get(c);
kind = QUERY;
break;
case ':':
in.get(c);
kind = COLON;
@ -234,6 +278,14 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
length = 2;
break;
}
else if (c == '=') {
in.get(c);
symbol[1] = c;
symbol[2] = '\0';
kind = EQUAL;
length = 2;
break;
}
kind = EQUAL;
break;
@ -269,29 +321,46 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
break;
default: {
amount_t temp;
istream_pos_type pos = 0;
istream_pos_type pos = in.tellg();
// When in relaxed parsing mode, we want to migrate commodity
// flags so that any precision specified by the user updates the
// current maximum displayed precision.
pos = in.tellg();
// First, check to see if it's a reserved word, such as: and or not
int result = parse_reserved_word(in);
if (std::isalpha(c) && result == 1)
break;
// If not, rewind back to the beginning of the word to scan it
// again. If the result was -1, it means no identifier was scanned
// so we don't have to rewind.
if (result == 0) {
in.clear();
in.seekg(pos, std::ios::beg);
if (in.fail())
throw_(parse_error, "Failed to reset input stream");
}
// When in relaxed parsing mode, we want to migrate commodity flags
// so that any precision specified by the user updates the current
// maximum displayed precision.
amount_t::flags_t parse_flags = 0;
if (pflags & EXPR_PARSE_NO_MIGRATE)
parse_flags |= AMOUNT_PARSE_NO_MIGRATE;
if (pflags & EXPR_PARSE_NO_REDUCE)
parse_flags |= AMOUNT_PARSE_NO_REDUCE;
amount_t temp;
if (! temp.parse(in, parse_flags | AMOUNT_PARSE_SOFT_FAIL)) {
// If the amount had no commodity, it must be an unambiguous
// variable reference
in.clear();
in.seekg(pos, std::ios::beg);
if (in.fail())
throw_(parse_error, "Failed to reset input stream");
c = in.peek();
assert(! (std::isdigit(c) || c == '.'));
if (std::isdigit(c) || c == '.')
expected('\0', c);
parse_ident(in);
} else {
kind = VALUE;
@ -304,8 +373,9 @@ void expr_t::token_t::next(std::istream& in, const uint_least8_t pflags)
void expr_t::token_t::rewind(std::istream& in)
{
for (unsigned int i = 0; i < length; i++)
in.unget();
in.seekg(- length, std::ios::cur);
if (in.fail())
throw_(parse_error, "Failed to rewind input stream");
}

9
src/token.h
View file

@ -61,9 +61,9 @@ struct expr_t::token_t : public noncopyable
STAR, // *
KW_DIV, // /
EXCLAM, // !
KW_AND, // &
KW_OR, // |
EXCLAM, // !, not
KW_AND, // &, &&, and
KW_OR, // |, ||, or
KW_MOD, // %
QUERY, // ?
@ -90,7 +90,7 @@ struct expr_t::token_t : public noncopyable
token_t& operator=(const token_t& other) {
if (&other == this)
return *this;
assert(false);
assert(false); // only one token object is used at a time
return *this;
}
@ -104,6 +104,7 @@ struct expr_t::token_t : public noncopyable
symbol[2] = '\0';
}
int parse_reserved_word(std::istream& in);
void parse_ident(std::istream& in);
void next(std::istream& in, const uint_least8_t flags);
void rewind(std::istream& in);