circumflex | 🌿 It's Hacker News in your terminal | Command Line Interface library

To put in simpler way, Is it possible to combine two or more lex files and given as an input ( from where Bison (.y) file reads the tokens) ?

The lex (or flex) utility generates C source code for (among other things) a scanner function, based on one input file. If you run two separate inputs through it then you will get two separate functions. With some versions of lex and some extra work you could get those functions to have different names, but you cannot successfully make them scan the same input stream because they maintain their own input buffers and scanning state information, so they will interfere with each other.

You also cannot concatenate lex input files to combine them into one, at least because each consists of two or three sections, whose relative order is significant. Concatenating two lex input files does not yield a valid lex input file.

You may be able to merge two lex input files into one on a section-by-section basis, but this exercise is at best difficult if the files involved are of any complexity. Merely combining the contents of each pair of corresponding sections may produce a valid lex input file, but it is unlikely to be one that does the job you want.

If you have a third-party lex input that describes scanning rules similar to what you want, and you would like somehow to reuse that code, then your best bet is probably to take that and modify it to suit you. This may be tricky, because you will first need to achieve a good understanding of the existing input before you can modify it for your needs. But you would anyway need that and more to merge two lex inputs.

Alternatively, you might simply take the existing file as inspiration for writing your own. Study it, gather ideas from it for how you can achieve similar goals, etc.. This is the option that I would recommend myself. You will probably learn more this way, and you will likely understand the resulting code better.

Thanks to Mr. T & tmdavison, either $^{A}$ or $\hat{A}$ work for some reason:

I just want to say, this question became a fun learning adventure. But....

As it turns out KeyboardEvent.keyCode has been deprecated for a while. Because it uses the decimal version of ASCII. The correct code to use is actually event.Code. But that's not what you're after.

To get the ascii number, you can just use event.key.charCodeAt() This does have some flaws as it will report S when you hit shift. But you can use event.location to figure out if the key is a special control key. Zero is standard keys and 1-3 are special locations (I think).

The for /F command, when used to capture and parse command output, actually uses cmd /C to execute that command, which handles quotation marks in a particular way. From its help (cmd /?):

In .NET (as well as XMLSchema, Python 3 (not Python 2), ICU (Android, R stringr / stringi functions), \w is Unicode-aware by default.

It is not Unicode-aware by default in PCRE and Java, but you may turn it on using the right flag, /u in PCRE and (?U) / Pattern.UNICODE_CHARACTER_CLASS in Java.

See the Shorthand Character Classes reference:

\w stands for “word character”. It always matches the ASCII characters [A-Za-z0-9_]. Notice the inclusion of the underscore and digits. In most flavors that support Unicode, \w includes many characters from other scripts. There is a lot of inconsistency about which characters are actually included. Letters and digits from alphabetic scripts and ideographs are generally included. Connector punctuation other than the underscore and numeric symbols that aren’t digits may or may not be included. XML Schema and XPath even include all symbols in \w. Again, Java, JavaScript, and PCRE match only ASCII characters with \w.

The Unicode-aware \w meanings:

• c# - [\p{L}\p{Nd}\p{Mn}\p{Pc}] (source)
• python - [\p{L}\p{Mn}\p{Nd}_] (source) (Note: this is an approximate pattern that can only be used with PyPi regex since re does not support Unicode property classes, so it's really great \w is Unicode aware in Python 3)
• android - [\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}] (source)
• icu - [\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\u200c\u200d] (source)
• xsd - [#x0000=#x10FFFF]-[\p{P}\p{Z}\p{C}] (source)

When \w is made Unicode-aware:

• pcre - (With /u in PHP or (*UCP) / (*UTF)(*UCP)) - [^\p{L}\p{N}_] ("\w any character that matches \p{L} or \p{N}, plus underscore")
• java - (With (?U) or Pattern.UNICODE_CHARACTER_CLASS) - [\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}] (same as Andoid, source)
• perl - (make the file treat as Unicode, see Does \w match all alphanumeric characters defined in the Unicode standard?) - [\p{GC=Alphabetic}\p{GC=Mark}\p{GC=Connector_Punctuation}\p{GC=Decimal_Number}]

In JavaScript, there is no way to make \w Unicode-aware, so use [\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\p{Join_Control}].

1st off the caret (^) is the escape character for cmd, when used as the last character on a line it removed the end of the line and appends the next line and escapes the 1st character

2ndly contrary to popular belief, you can write multi-line commands into the cmd prompt, normally this is done by wrapping the commands in parenthesis. eg:

I would keep the span empty and add a box-shadow to create the line:

Always use AscW when using non-ASCII characters.

A copyright sign is not part of standard ASCII, so may or may not be represented in the codepage Windows uses, depending on locale settings.

AscW uses unicode instead of the Windows codepage, which means it will reliably produce the same result.

Also, never store non-ASCII characters in VBA. If you need a specific character, you can look up the codepoint and use ChrW to generate the string. For multiple characters, I recommend you look at this answer, or store them outside of VBA.

Then, as for the immediate window, that also does not support unicode characters, so you can't trust what gets displayed there. Nor does MsgBox. This makes debugging a pain. Look at this answer for having a messagebox with unicode support.

An operator name (or any other identifier) cannot start with the U+0302 character. Like all combining marks, it is an allowed “operator-character” but not an allowed “operator-head”. From Lexical Structure > Operators in “The Swift Programming Language”:

GRAMMAR OF OPERATORS
operator → operator-head operator-characters_opt
...
operator-character → U+0300–U+036F