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-rw-r--r--py/lexer.c128
-rw-r--r--py/lexer.h11
-rw-r--r--py/mpconfig.h5
-rw-r--r--py/parse.c8
4 files changed, 149 insertions, 3 deletions
diff --git a/py/lexer.c b/py/lexer.c
index 07ea2b96a..ba118c9d2 100644
--- a/py/lexer.c
+++ b/py/lexer.c
@@ -62,6 +62,12 @@ STATIC bool is_char_or3(mp_lexer_t *lex, byte c1, byte c2, byte c3) {
return lex->chr0 == c1 || lex->chr0 == c2 || lex->chr0 == c3;
}
+#if MICROPY_PY_FSTRINGS
+STATIC bool is_char_or4(mp_lexer_t *lex, byte c1, byte c2, byte c3, byte c4) {
+ return lex->chr0 == c1 || lex->chr0 == c2 || lex->chr0 == c3 || lex->chr0 == c4;
+}
+#endif
+
STATIC bool is_char_following(mp_lexer_t *lex, byte c) {
return lex->chr1 == c;
}
@@ -105,7 +111,13 @@ STATIC bool is_following_odigit(mp_lexer_t *lex) {
STATIC bool is_string_or_bytes(mp_lexer_t *lex) {
return is_char_or(lex, '\'', '\"')
+ #if MICROPY_PY_FSTRINGS
+ || (is_char_or4(lex, 'r', 'u', 'b', 'f') && is_char_following_or(lex, '\'', '\"'))
+ || (((is_char_and(lex, 'r', 'f') || is_char_and(lex, 'f', 'r'))
+ && is_char_following_following_or(lex, '\'', '\"')))
+ #else
|| (is_char_or3(lex, 'r', 'u', 'b') && is_char_following_or(lex, '\'', '\"'))
+ #endif
|| ((is_char_and(lex, 'r', 'b') || is_char_and(lex, 'b', 'r'))
&& is_char_following_following_or(lex, '\'', '\"'));
}
@@ -132,9 +144,35 @@ STATIC void next_char(mp_lexer_t *lex) {
++lex->column;
}
+ // shift the input queue forward
lex->chr0 = lex->chr1;
lex->chr1 = lex->chr2;
- lex->chr2 = lex->reader.readbyte(lex->reader.data);
+
+ // and add the next byte from either the fstring args or the reader
+ #if MICROPY_PY_FSTRINGS
+ if (lex->fstring_args_idx) {
+ // if there are saved chars, then we're currently injecting fstring args
+ if (lex->fstring_args_idx < lex->fstring_args.len) {
+ lex->chr2 = lex->fstring_args.buf[lex->fstring_args_idx++];
+ } else {
+ // no more fstring arg bytes
+ lex->chr2 = '\0';
+ }
+
+ if (lex->chr0 == '\0') {
+ // consumed all fstring data, restore saved input queue
+ lex->chr0 = lex->chr0_saved;
+ lex->chr1 = lex->chr1_saved;
+ lex->chr2 = lex->chr2_saved;
+ // stop consuming fstring arg data
+ vstr_reset(&lex->fstring_args);
+ lex->fstring_args_idx = 0;
+ }
+ } else
+ #endif
+ {
+ lex->chr2 = lex->reader.readbyte(lex->reader.data);
+ }
if (lex->chr1 == '\r') {
// CR is a new line, converted to LF
@@ -272,7 +310,7 @@ STATIC bool get_hex(mp_lexer_t *lex, size_t num_digits, mp_uint_t *result) {
return true;
}
-STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw) {
+STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw, bool is_fstring) {
// get first quoting character
char quote_char = '\'';
if (is_char(lex, '\"')) {
@@ -293,12 +331,57 @@ STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw) {
}
size_t n_closing = 0;
+ #if MICROPY_PY_FSTRINGS
+ if (is_fstring) {
+ // assume there's going to be interpolation, so prep the injection data
+ // fstring_args_idx==0 && len(fstring_args)>0 means we're extracting the args.
+ // only when fstring_args_idx>0 will we consume the arg data
+ // note: lex->fstring_args will be empty already (it's reset when finished)
+ vstr_add_str(&lex->fstring_args, ".format(");
+ }
+ #endif
+
while (!is_end(lex) && (num_quotes > 1 || !is_char(lex, '\n')) && n_closing < num_quotes) {
if (is_char(lex, quote_char)) {
n_closing += 1;
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
} else {
n_closing = 0;
+
+ #if MICROPY_PY_FSTRINGS
+ while (is_fstring && is_char(lex, '{')) {
+ next_char(lex);
+ if (is_char(lex, '{')) {
+ // "{{" is passed through unchanged to be handled by str.format
+ vstr_add_byte(&lex->vstr, '{');
+ next_char(lex);
+ } else {
+ // remember the start of this argument (if we need it for f'{a=}').
+ size_t i = lex->fstring_args.len;
+ // extract characters inside the { until we reach the
+ // format specifier or closing }.
+ // (MicroPython limitation) note: this is completely unaware of
+ // Python syntax and will not handle any expression containing '}' or ':'.
+ // e.g. f'{"}"}' or f'{foo({})}'.
+ while (!is_end(lex) && !is_char_or(lex, ':', '}')) {
+ // like the default case at the end of this function, stay 8-bit clean
+ vstr_add_byte(&lex->fstring_args, CUR_CHAR(lex));
+ next_char(lex);
+ }
+ if (lex->fstring_args.buf[lex->fstring_args.len - 1] == '=') {
+ // if the last character of the arg was '=', then inject "arg=" before the '{'.
+ // f'{a=}' --> 'a={}'.format(a)
+ vstr_add_strn(&lex->vstr, lex->fstring_args.buf + i, lex->fstring_args.len - i);
+ // remove the trailing '='
+ lex->fstring_args.len--;
+ }
+ // comma-separate args
+ vstr_add_byte(&lex->fstring_args, ',');
+ }
+ vstr_add_byte(&lex->vstr, '{');
+ }
+ #endif
+
if (is_char(lex, '\\')) {
next_char(lex);
unichar c = CUR_CHAR(lex);
@@ -451,6 +534,23 @@ STATIC bool skip_whitespace(mp_lexer_t *lex, bool stop_at_newline) {
}
void mp_lexer_to_next(mp_lexer_t *lex) {
+ #if MICROPY_PY_FSTRINGS
+ if (lex->fstring_args.len && lex->fstring_args_idx == 0) {
+ // moving onto the next token means the literal string is complete.
+ // switch into injecting the format args.
+ vstr_add_byte(&lex->fstring_args, ')');
+ lex->chr0_saved = lex->chr0;
+ lex->chr1_saved = lex->chr1;
+ lex->chr2_saved = lex->chr2;
+ lex->chr0 = lex->fstring_args.buf[0];
+ lex->chr1 = lex->fstring_args.buf[1];
+ lex->chr2 = lex->fstring_args.buf[2];
+ // we've already extracted 3 chars, but setting this non-zero also
+ // means we'll start consuming the fstring data
+ lex->fstring_args_idx = 3;
+ }
+ #endif
+
// start new token text
vstr_reset(&lex->vstr);
@@ -506,6 +606,7 @@ void mp_lexer_to_next(mp_lexer_t *lex) {
do {
// parse type codes
bool is_raw = false;
+ bool is_fstring = false;
mp_token_kind_t kind = MP_TOKEN_STRING;
int n_char = 0;
if (is_char(lex, 'u')) {
@@ -524,7 +625,25 @@ void mp_lexer_to_next(mp_lexer_t *lex) {
kind = MP_TOKEN_BYTES;
n_char = 2;
}
+ #if MICROPY_PY_FSTRINGS
+ if (is_char_following(lex, 'f')) {
+ // raw-f-strings unsupported, immediately return (invalid) token.
+ lex->tok_kind = MP_TOKEN_FSTRING_RAW;
+ break;
+ }
+ #endif
+ }
+ #if MICROPY_PY_FSTRINGS
+ else if (is_char(lex, 'f')) {
+ if (is_char_following(lex, 'r')) {
+ // raw-f-strings unsupported, immediately return (invalid) token.
+ lex->tok_kind = MP_TOKEN_FSTRING_RAW;
+ break;
+ }
+ n_char = 1;
+ is_fstring = true;
}
+ #endif
// Set or check token kind
if (lex->tok_kind == MP_TOKEN_END) {
@@ -543,7 +662,7 @@ void mp_lexer_to_next(mp_lexer_t *lex) {
}
// Parse the literal
- parse_string_literal(lex, is_raw);
+ parse_string_literal(lex, is_raw, is_fstring);
// Skip whitespace so we can check if there's another string following
skip_whitespace(lex, true);
@@ -703,6 +822,9 @@ mp_lexer_t *mp_lexer_new(qstr src_name, mp_reader_t reader) {
lex->num_indent_level = 1;
lex->indent_level = m_new(uint16_t, lex->alloc_indent_level);
vstr_init(&lex->vstr, 32);
+ #if MICROPY_PY_FSTRINGS
+ vstr_init(&lex->fstring_args, 0);
+ #endif
// store sentinel for first indentation level
lex->indent_level[0] = 0;
diff --git a/py/lexer.h b/py/lexer.h
index 91767a44b..e16b9a8ce 100644
--- a/py/lexer.h
+++ b/py/lexer.h
@@ -44,6 +44,10 @@ typedef enum _mp_token_kind_t {
MP_TOKEN_INVALID,
MP_TOKEN_DEDENT_MISMATCH,
MP_TOKEN_LONELY_STRING_OPEN,
+ #if MICROPY_PY_FSTRINGS
+ MP_TOKEN_MALFORMED_FSTRING,
+ MP_TOKEN_FSTRING_RAW,
+ #endif
MP_TOKEN_NEWLINE,
MP_TOKEN_INDENT,
@@ -158,6 +162,9 @@ typedef struct _mp_lexer_t {
mp_reader_t reader; // stream source
unichar chr0, chr1, chr2; // current cached characters from source
+ #if MICROPY_PY_FSTRINGS
+ unichar chr0_saved, chr1_saved, chr2_saved; // current cached characters from alt source
+ #endif
size_t line; // current source line
size_t column; // current source column
@@ -173,6 +180,10 @@ typedef struct _mp_lexer_t {
size_t tok_column; // token source column
mp_token_kind_t tok_kind; // token kind
vstr_t vstr; // token data
+ #if MICROPY_PY_FSTRINGS
+ vstr_t fstring_args; // extracted arguments to pass to .format()
+ size_t fstring_args_idx; // how many bytes of fstring_args have been read
+ #endif
} mp_lexer_t;
mp_lexer_t *mp_lexer_new(qstr src_name, mp_reader_t reader);
diff --git a/py/mpconfig.h b/py/mpconfig.h
index a91c39b01..a5d639efe 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -875,6 +875,11 @@ typedef double mp_float_t;
#define MICROPY_PY_ASYNC_AWAIT (1)
#endif
+// Support for literal string interpolation, f-strings (see PEP 498, Python 3.6+)
+#ifndef MICROPY_PY_FSTRINGS
+#define MICROPY_PY_FSTRINGS (0)
+#endif
+
// Support for assignment expressions with := (see PEP 572, Python 3.8+)
#ifndef MICROPY_PY_ASSIGN_EXPR
#define MICROPY_PY_ASSIGN_EXPR (1)
diff --git a/py/parse.c b/py/parse.c
index da2f5e796..ae3fa8ea6 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -1152,6 +1152,14 @@ mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) {
} else if (lex->tok_kind == MP_TOKEN_DEDENT_MISMATCH) {
exc = mp_obj_new_exception_msg(&mp_type_IndentationError,
MP_ERROR_TEXT("unindent doesn't match any outer indent level"));
+ #if MICROPY_PY_FSTRINGS
+ } else if (lex->tok_kind == MP_TOKEN_MALFORMED_FSTRING) {
+ exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
+ MP_ERROR_TEXT("malformed f-string"));
+ } else if (lex->tok_kind == MP_TOKEN_FSTRING_RAW) {
+ exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
+ MP_ERROR_TEXT("raw f-strings are not supported"));
+ #endif
} else {
exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
MP_ERROR_TEXT("invalid syntax"));
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-25 06:22:16 +0000