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kernel: clang-format GetNumber
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The code formatting in this function is way off and that makes it hard
to read (granted, it used to be even worse before recent refactoring).
Let's clang-format it -- tools like `tig blame` easily dig through this.
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@fingolfin
fingolfin committed May 22, 2020
1 parent 9ec66cf commit 0d6f7ad
Showing 1 changed file with 105 additions and 99 deletions.
204 changes: 105 additions & 99 deletions src/scanner.c
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Original file line number Diff line number Diff line change
Expand Up @@ -385,138 +385,144 @@ static UInt AddCharToValue(ScannerState * s, UInt pos, Char c)

static UInt GetNumber(ScannerState * s, Int readDecimalPoint, Char c)
{
UInt symbol = S_ILLEGAL;
UInt i = 0;
BOOL seenADigit = FALSE;
UInt symbol = S_ILLEGAL;
UInt i = 0;
BOOL seenADigit = FALSE;

s->ValueObj = 0;
s->ValueObj = 0;

if (readDecimalPoint) {
s->Value[i++] = '.';
}
else {
// read initial sequence of digits into 'Value'
while (IsDigit(c)) {
i = AddCharToValue(s, i, c);
seenADigit = TRUE;
c = GET_NEXT_CHAR();
if (readDecimalPoint) {
s->Value[i++] = '.';
}
else {
// read initial sequence of digits into 'Value'
while (IsDigit(c)) {
i = AddCharToValue(s, i, c);
seenADigit = TRUE;
c = GET_NEXT_CHAR();
}

// maybe we saw an identifier character and realised that this is an
// identifier we are reading
if (IsIdent(c) || c == '\\') {
// if necessary, copy back from s->ValueObj to s->Value
if (s->ValueObj) {
i = GET_LEN_STRING(s->ValueObj);
GAP_ASSERT(i >= MAX_VALUE_LEN - 1);
memcpy(s->Value, CONST_CSTR_STRING(s->ValueObj), MAX_VALUE_LEN);
s->ValueObj = 0;
}
// this looks like an identifier, scan the rest of it
return GetIdent(s, i, c);
}

// Or maybe we saw a '.' which could indicate one of three things:
// - a float literal: 12.345
// - S_DOT, i.e., '.' used to access a record entry: r.12.345
// - S_DDOT, i.e., '..' in a range expression: [12..345]
if (c == '.') {
GAP_ASSERT(i < MAX_VALUE_LEN - 1);

// If the symbol before this integer was S_DOT then we must be in
// a nested record element expression, so don't look for a float.
// This is a bit fragile
if (s->Symbol == S_DOT || s->Symbol == S_BDOT) {
symbol = S_INT;
goto finish;
}
// maybe we saw an identifier character and realised that this is an
// identifier we are reading
if (IsIdent(c) || c == '\\') {
// if necessary, copy back from s->ValueObj to s->Value
if (s->ValueObj) {
i = GET_LEN_STRING(s->ValueObj);
GAP_ASSERT(i >= MAX_VALUE_LEN - 1);
memcpy(s->Value, CONST_CSTR_STRING(s->ValueObj),
MAX_VALUE_LEN);
s->ValueObj = 0;
}
// this looks like an identifier, scan the rest of it
return GetIdent(s, i, c);
}

// peek ahead to decide if we are looking at a range expression
if (PEEK_NEXT_CHAR() == '.') {
// we are looking at '..' and are probably inside a range expression
symbol = S_INT;
goto finish;
}
// Or maybe we saw a '.' which could indicate one of three things:
// - a float literal: 12.345
// - S_DOT, i.e., '.' used to access a record entry: r.12.345
// - S_DDOT, i.e., '..' in a range expression: [12..345]
if (c == '.') {
GAP_ASSERT(i < MAX_VALUE_LEN - 1);

// If the symbol before this integer was S_DOT then we must be in
// a nested record element expression, so don't look for a float.
// This is a bit fragile
if (s->Symbol == S_DOT || s->Symbol == S_BDOT) {
symbol = S_INT;
goto finish;
}

// Now the '.' must be part of our number; store it and move on
i = AddCharToValue(s, i, '.');
c = GET_NEXT_CHAR();
}
else {
// Anything else we see tells us that the token is done
symbol = S_INT;
goto finish;
// peek ahead to decide if we are looking at a range expression
if (PEEK_NEXT_CHAR() == '.') {
// we are looking at '..' and are probably inside a range
// expression
symbol = S_INT;
goto finish;
}

// Now the '.' must be part of our number; store it and move on
i = AddCharToValue(s, i, '.');
c = GET_NEXT_CHAR();
}
else {
// Anything else we see tells us that the token is done
symbol = S_INT;
goto finish;
}
}
}

// When we get here we have read possibly some digits, a . and possibly
// some more digits, but not an e,E,d,D,q or Q
// In any case, from now on, we know we are dealing with a float literal
symbol = S_FLOAT;
// When we get here we have read possibly some digits, a . and possibly
// some more digits, but not an e,E,d,D,q or Q
// In any case, from now on, we know we are dealing with a float literal
symbol = S_FLOAT;

// read digits
while (IsDigit(c)) {
i = AddCharToValue(s, i, c);
seenADigit = TRUE;
c = GET_NEXT_CHAR();
i = AddCharToValue(s, i, c);
seenADigit = TRUE;
c = GET_NEXT_CHAR();
}
if (!seenADigit)
SyntaxError(s, "Badly formed number: need a digit before or after the "
"decimal point");
SyntaxError(s,
"Badly formed number: need a digit before or after the "
"decimal point");
if (c == '\\')
SyntaxError(s, "Badly formed number");
SyntaxError(s, "Badly formed number");

// If the next thing is the start of the exponential notation, read it now.
if (c == 'e' || c == 'E' || c == 'd' || c == 'D' || c == 'q' || c == 'Q') {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
if (c == '+' || c == '-') {
// If the next thing is the start of the exponential notation, read it
// now.
if (c == 'e' || c == 'E' || c == 'd' || c == 'D' || c == 'q' ||
c == 'Q') {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
}
if (c == '+' || c == '-') {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
}

// Here we are into the unsigned exponent of a number in scientific
// notation, so we just read digits
if (!IsDigit(c))
SyntaxError(s,
"Badly formed number: need at least one digit in the exponent");
while (IsDigit(c)) {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
}
// Here we are into the unsigned exponent of a number in scientific
// notation, so we just read digits
if (!IsDigit(c))
SyntaxError(s, "Badly formed number: need at least one digit in "
"the exponent");
while (IsDigit(c)) {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
}
}

// Allow one letter at the end of the number, which is a conversion
// marker; e.g. an `i` as in C99, to indicate an imaginary value.
if (IsAlpha(c)) {
// Allow one letter at the end of the number, which is a conversion
// marker; e.g. an `i` as in C99, to indicate an imaginary value.
if (IsAlpha(c)) {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
}
}

// independently of that, we allow an _ signalling immediate or "eager" conversion
if (c == '_') {
// independently of that, we allow an _ signalling immediate or "eager"
// conversion
if (c == '_') {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
// After which there may be one character signifying the
// conversion styles
if (IsAlpha(c)) {
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
i = AddCharToValue(s, i, c);
c = GET_NEXT_CHAR();
}
}
}

// Now if the next character is an identifier symbol then we have an error
if (IsIdent(c)) {
// Now if the next character is an identifier symbol then we have an error
if (IsIdent(c)) {
SyntaxError(s, "Badly formed number");
}
}

finish:
i = AddCharToValue(s, i, '\0');
if (s->ValueObj) {
// flush buffer
AppendBufToString(s->ValueObj, s->Value, i - 1);
}
return symbol;
i = AddCharToValue(s, i, '\0');
if (s->ValueObj) {
// flush buffer
AppendBufToString(s->ValueObj, s->Value, i - 1);
}
return symbol;
}


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