[ruby/prism] Reject invalid rational literals like 1e1r on lexing

Fix https://github.com/ruby/prism/pull/1586

https://github.com/ruby/prism/commit/b3bde866f2

prism/prism.c

@@ -6315,7 +6315,7 @@ pm_strspn_hexadecimal_number_validate(pm_parser_t *parser, const uint8_t *string
 }
 
 static pm_token_type_t
-lex_optional_float_suffix(pm_parser_t *parser) {
+lex_optional_float_suffix(pm_parser_t *parser, bool* seen_e) {
     pm_token_type_t type = PM_TOKEN_INTEGER;
 
     // Here we're going to attempt to parse the optional decimal portion of a
@@ -6336,6 +6336,7 @@ lex_optional_float_suffix(pm_parser_t *parser) {
     // float. If it's not there, it's okay and we'll just continue on.
     if (match(parser, 'e') || match(parser, 'E')) {
         (void) (match(parser, '+') || match(parser, '-'));
+        *seen_e = true;
 
         if (pm_char_is_decimal_digit(*parser->current.end)) {
             parser->current.end++;
@@ -6351,8 +6352,9 @@ lex_optional_float_suffix(pm_parser_t *parser) {
 }
 
 static pm_token_type_t
-lex_numeric_prefix(pm_parser_t *parser) {
+lex_numeric_prefix(pm_parser_t *parser, bool* seen_e) {
     pm_token_type_t type = PM_TOKEN_INTEGER;
+    *seen_e = false;
 
     if (peek_offset(parser, -1) == '0') {
         switch (*parser->current.end) {
@@ -6423,14 +6425,14 @@ lex_numeric_prefix(pm_parser_t *parser) {
 
             // 0.xxx is a float
             case '.': {
-                type = lex_optional_float_suffix(parser);
+                type = lex_optional_float_suffix(parser, seen_e);
                 break;
             }
 
             // 0exxx is a float
             case 'e':
             case 'E': {
-                type = lex_optional_float_suffix(parser);
+                type = lex_optional_float_suffix(parser, seen_e);
                 break;
             }
         }
@@ -6440,7 +6442,7 @@ lex_numeric_prefix(pm_parser_t *parser) {
         parser->current.end += pm_strspn_decimal_number_validate(parser, parser->current.end);
 
         // Afterward, we'll lex as far as we can into an optional float suffix.
-        type = lex_optional_float_suffix(parser);
+        type = lex_optional_float_suffix(parser, seen_e);
     }
 
     return type;
@@ -6452,7 +6454,8 @@ lex_numeric(pm_parser_t *parser) {
     parser->integer_base = PM_INTEGER_BASE_FLAGS_DECIMAL;
 
     if (parser->current.end < parser->end) {
-        type = lex_numeric_prefix(parser);
+        bool seen_e = false;
+        type = lex_numeric_prefix(parser, &seen_e);
 
         const uint8_t *end = parser->current.end;
         pm_token_type_t suffix_type = type;
@@ -6468,7 +6471,7 @@ lex_numeric(pm_parser_t *parser) {
                 suffix_type = PM_TOKEN_INTEGER_IMAGINARY;
             }
         } else {
-            if (match(parser, 'r')) {
+            if (!seen_e && match(parser, 'r')) {
                 suffix_type = PM_TOKEN_FLOAT_RATIONAL;
 
                 if (match(parser, 'i')) {

test/prism/fixtures/numbers.txt

@@ -44,10 +44,14 @@
 
 1ri
 
+1.2r
+
 1.2ri
 
 -1ri
 
+-1.2r
+
 -1.2ri
 
 0o1r

test/prism/snapshots/numbers.txt

@@ -1,8 +1,8 @@
-@ ProgramNode (location: (1,0)-(63,5))
+@ ProgramNode (location: (1,0)-(67,5))
 ├── locals: []
 └── statements:
-    @ StatementsNode (location: (1,0)-(63,5))
+    @ StatementsNode (location: (1,0)-(67,5))
-    └── body: (length: 32)
+    └── body: (length: 34)
         ├── @ IntegerNode (location: (1,0)-(1,1))
         │   └── flags: decimal
         ├── @ IntegerNode (location: (3,0)-(3,1))
@@ -56,47 +56,53 @@
         │       └── numeric:
         │           @ IntegerNode (location: (45,0)-(45,1))
         │           └── flags: decimal
-        ├── @ ImaginaryNode (location: (47,0)-(47,5))
+        ├── @ RationalNode (location: (47,0)-(47,4))
         │   └── numeric:
-        │       @ RationalNode (location: (47,0)-(47,4))
+        │       @ FloatNode (location: (47,0)-(47,3))
-        │       └── numeric:
+        ├── @ ImaginaryNode (location: (49,0)-(49,5))
-        │           @ FloatNode (location: (47,0)-(47,3))
-        ├── @ ImaginaryNode (location: (49,0)-(49,4))
         │   └── numeric:
-        │       @ RationalNode (location: (49,0)-(49,3))
+        │       @ RationalNode (location: (49,0)-(49,4))
         │       └── numeric:
-        │           @ IntegerNode (location: (49,0)-(49,2))
+        │           @ FloatNode (location: (49,0)-(49,3))
+        ├── @ ImaginaryNode (location: (51,0)-(51,4))
+        │   └── numeric:
+        │       @ RationalNode (location: (51,0)-(51,3))
+        │       └── numeric:
+        │           @ IntegerNode (location: (51,0)-(51,2))
         │           └── flags: decimal
-        ├── @ ImaginaryNode (location: (51,0)-(51,6))
+        ├── @ RationalNode (location: (53,0)-(53,5))
         │   └── numeric:
-        │       @ RationalNode (location: (51,0)-(51,5))
+        │       @ FloatNode (location: (53,0)-(53,4))
+        ├── @ ImaginaryNode (location: (55,0)-(55,6))
+        │   └── numeric:
+        │       @ RationalNode (location: (55,0)-(55,5))
         │       └── numeric:
-        │           @ FloatNode (location: (51,0)-(51,4))
+        │           @ FloatNode (location: (55,0)-(55,4))
-        ├── @ RationalNode (location: (53,0)-(53,4))
+        ├── @ RationalNode (location: (57,0)-(57,4))
         │   └── numeric:
-        │       @ IntegerNode (location: (53,0)-(53,3))
+        │       @ IntegerNode (location: (57,0)-(57,3))
         │       └── flags: octal
-        ├── @ ImaginaryNode (location: (55,0)-(55,4))
+        ├── @ ImaginaryNode (location: (59,0)-(59,4))
-        │   └── numeric:
-        │       @ IntegerNode (location: (55,0)-(55,3))
-        │       └── flags: octal
-        ├── @ ImaginaryNode (location: (57,0)-(57,5))
-        │   └── numeric:
-        │       @ RationalNode (location: (57,0)-(57,4))
-        │       └── numeric:
-        │           @ IntegerNode (location: (57,0)-(57,3))
-        │           └── flags: octal
-        ├── @ RationalNode (location: (59,0)-(59,4))
         │   └── numeric:
         │       @ IntegerNode (location: (59,0)-(59,3))
-        │       └── flags: decimal
+        │       └── flags: octal
-        ├── @ ImaginaryNode (location: (61,0)-(61,4))
+        ├── @ ImaginaryNode (location: (61,0)-(61,5))
         │   └── numeric:
-        │       @ IntegerNode (location: (61,0)-(61,3))
+        │       @ RationalNode (location: (61,0)-(61,4))
+        │       └── numeric:
+        │           @ IntegerNode (location: (61,0)-(61,3))
+        │           └── flags: octal
+        ├── @ RationalNode (location: (63,0)-(63,4))
+        │   └── numeric:
+        │       @ IntegerNode (location: (63,0)-(63,3))
         │       └── flags: decimal
-        └── @ ImaginaryNode (location: (63,0)-(63,5))
+        ├── @ ImaginaryNode (location: (65,0)-(65,4))
+        │   └── numeric:
+        │       @ IntegerNode (location: (65,0)-(65,3))
+        │       └── flags: decimal
+        └── @ ImaginaryNode (location: (67,0)-(67,5))
             └── numeric:
-                @ RationalNode (location: (63,0)-(63,4))
+                @ RationalNode (location: (67,0)-(67,4))
                 └── numeric:
-                    @ IntegerNode (location: (63,0)-(63,3))
+                    @ IntegerNode (location: (67,0)-(67,3))
                     └── flags: binary