Support hexadecimal literals

boot/driver.cc

@@ -117,7 +117,7 @@ namespace elna::boot
             }
             ++current_position;
         }
-        result.pop_back();
+        result.pop_back(); // Remove the terminating quote character.
 
         return result;
     }

boot/lexer.ll

@@ -32,6 +32,11 @@ along with GCC; see the file COPYING3.  If not see
 
 %x IN_COMMENT
 
+ID1 [A-Za-z_]
+ID2 [A-Za-z0-9_]
+HIGIT [0-9a-fA-F]
+BIGIT [01]
+
 %%
 %{
     this->location.step();
@@ -146,43 +151,79 @@ case                    {
 of {
     return yy::parser::make_OF(this->location);
 }
-[A-Za-z_][A-Za-z0-9_]*  {
+{ID1}{ID2}* {
     return yy::parser::make_IDENTIFIER(yytext, this->location);
 }
-#[A-Za-z_][A-Za-z0-9_]* {
+#{ID1}{ID2}* {
     return yy::parser::make_TRAIT(yytext + 1, this->location);
 }
-[0-9]+u                 {
-                            return yy::parser::make_WORD(strtoul(yytext, NULL, 10), this->location);
-                        }
-[0-9]+                  {
-                            return yy::parser::make_INTEGER(strtol(yytext, NULL, 10), this->location);
-                        }
-[0-9]+\.[0-9]           {
-                            return yy::parser::make_FLOAT(strtof(yytext, NULL), this->location);
-                        }
-'[[:print:]]'           {
-                            if (yytext[1] == '\\' || yytext[1] == '\'')
+[[:digit:]]+u {
+    unsigned long result = strtoul(yytext, NULL, 10);
+
+    if (errno == ERANGE)
     {
         REJECT;
     }
     else
     {
-                                return yy::parser::make_CHARACTER(std::string(yytext, 1, 1), this->location);
+        return yy::parser::make_WORD(result, this->location);
     }
 }
-'\\x[0-9a-fA-F]{1,2}'   {
-                            char character = static_cast<char>(std::stoi(yytext + 3, nullptr, 16));
+[[:digit:]]+ {
+    long result = strtol(yytext, NULL, 10);
 
-                            return yy::parser::make_CHARACTER(std::string(&character, 1), this->location);
-                        }
-'\\[0nabtfrv\\'"?]'     {
-                            char escape = escape_char(yytext[2]);
-                            if (escape == escape_invalid_char)
+    if (errno == ERANGE)
     {
         REJECT;
     }
-                            return yy::parser::make_CHARACTER(std::string(&escape, 1), this->location);
+    else
+    {
+        return yy::parser::make_INTEGER(result, this->location);
+    }
+}
+0x{HIGIT}+ {
+    unsigned long result = strtoul(yytext, NULL, 16);
+
+    if (errno == ERANGE)
+    {
+        REJECT;
+    }
+    else
+    {
+        return yy::parser::make_WORD(result, this->location);
+    }
+}
+0b{BIGIT}+ {
+    unsigned long result = strtoul(yytext, NULL, 2);
+
+    if (errno == ERANGE)
+    {
+        REJECT;
+    }
+    else
+    {
+        return yy::parser::make_WORD(result, this->location);
+    }
+}
+[[:digit:]]+\.[[:digit:]]+ {
+    float result = strtof(yytext, NULL);
+
+    if (errno == ERANGE)
+    {
+        REJECT;
+    }
+    else
+    {
+        return yy::parser::make_FLOAT(result, this->location);
+    }
+}
+'[[:print:]]+' {
+    std::optional<std::string> result = escape_string(yytext);
+    if (!result.has_value() || result.value().size() != 1)
+    {
+        REJECT;
+    }
+    return yy::parser::make_CHARACTER(result.value(), this->location);
 }
 \"[[:print:]]*\" {
     std::optional<std::string> result = escape_string(yytext);

source/main.elna

@@ -1074,6 +1074,12 @@ begin
   return return_code
 end;
 
+proc f();
+var x: Char;
+begin
+  x := '\x4'
+end;
+
 begin
   exit(process(count, parameters))
 end.