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reader: factor out read_negative

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This commit is contained in:
Aryadev Chavali
2026-02-11 08:30:45 +00:00
committed by oreodave
parent 04be0ecad0
commit 4936460b39
1 changed files with 23 additions and 18 deletions
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41
src/reader.c
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@@ -95,6 +95,28 @@ read_err_t read_int(sys_t *sys, stream_t *stream, lisp_t **ret)
return READ_ERR_OK; return READ_ERR_OK;
} }
read_err_t read_negative(sys_t *sys, stream_t *stream, lisp_t **ret)
{
char c = stream_next(stream);
if (isdigit(c))
{
read_err_t err = read_int(sys, stream, ret);
if (err)
return err;
i64 n = as_int(*ret);
n *= -1;
*ret = make_int(n);
return READ_ERR_OK;
}
else if (is_sym(c) || isspace(c))
{
stream_seek_backward(stream, 1);
return read_sym(sys, stream, ret);
}
else
return READ_ERR_UNKNOWN_CHAR;
}
read_err_t read_list(sys_t *sys, stream_t *stream, lisp_t **ret) read_err_t read_list(sys_t *sys, stream_t *stream, lisp_t **ret)
{ {
// skip past the open parentheses '(' // skip past the open parentheses '('
@@ -172,24 +194,7 @@ read_err_t read(sys_t *sys, stream_t *stream, lisp_t **ret)
if (isdigit(c)) if (isdigit(c))
return read_int(sys, stream, ret); return read_int(sys, stream, ret);
else if (c == '-') else if (c == '-')
{ return read_negative(sys, stream, ret);
char c1 = stream_next(stream);
if (isdigit(c1))
{
read_err_t err = read_int(sys, stream, ret);
if (err)
return err;
i64 n = as_int(*ret);
n *= -1;
*ret = make_int(n);
return READ_ERR_OK;
}
else if (is_sym(c1))
{
stream_seek_backward(stream, 1);
return read_sym(sys, stream, ret);
}
}
else if (is_sym(c)) else if (is_sym(c))
return read_sym(sys, stream, ret); return read_sym(sys, stream, ret);
else if (c == '\'') else if (c == '\'')