CText is a tool for processing text.
Use the following command to install CText. It requires Python >=3.11 to work.
curl -fsSLO "https://raw.githubusercontent.com/arielherself/ctext/main/ctext" && chmod +x ctext && sudo mv ctext /usr/local/binTo start using CText, you need to create a configuration file CTextLists.toml which is composed of some functions. Here is an example configuration:
[debug]
nargs = 0
comma = false
permissive = true
value = 'std::cerr $debug_expand(#...#) << std::endl;'
[debug_expand]
nargs = 0
comma = false
permissive = true
value = '$arrow_out(#0#) $debug_expand(#1...#)'
[arrow_out]
nargs = 1
comma = false
permissive = false
value = '<< "#0# = " << (#0#) << ", "'If we use it in a C++ file like this:
$debug(x,y,z)then the following code will be generated by CText:
std::cerr << "x = " << (x) << ", " << "y = " << (y) << ", " << "z = " << (z) << ", " << std::endl;A CText function declaration in CTextLists.toml has a name, several properties, and a value expression.
When calling a function, you pass a parameter list to it, and the function generates some text using the input parameters. The formal definition is like this:
$function_name(parameter_1,parameter_2,parameter_3)
As you can see, there are some characters like $ and () which have special meaning in CText. If you prefer not to let CText treat them as special tokens, you can add a backslash before them like this:
\$hello
A value expression is a piece of text, with pound sign (#) as a special character.
When you want to use the i'th parameter in your value with i starts from 0, you can type #i# as a placeholder.
For example, say you want to add two variables a and b, you can define a function:
[add]
nargs = 2
comma = false
permissive = true
value = '((#0#) + (#1#))'When calling it using $add(a,b), the function will expand to ((a) + (b)).
You could also refer to a range of the parameter list using range selector #i...#. It concatenates parameters ranging from i to the last with commas.
This feature is especially useful when designing recursive functions.
Number of arguments that this function receives. It's only for verification in strict mode.
The comma-bypass feature allows you to forward the argument including a comma (,) received from caller to another function. For example:
[define]
nargs = 2
comma = true
permissive = false
value = '$__replace_with(#0#,#1#)'If we define this function called define like this, then we must ensure that the comma in the argument won't be interpreted as a separator in the argument list during the function expansion.
Suppose we have comma = false and this function call:
$define(pair_gen,x\,y)
int x, y; std::cin >> x >> y;
std::pair<int, int> my_pair = {pair_gen};We expect pair_gen to expand to x,y. But instead it's x because the define function expands to $__replace_with(pair_gen,x,y) and the built-in function __replace_with replaces all occurrences of the first argument with the second argument.
On the other hand, if we have comma = true set then define will expand to $__replace_with(pair_gen,x\,y) as the comma-bypass feature treats the comma in an argument as an escape character and keeps the backslash all the time.
A permissive function gracefully expands to nothing when there is an index overflow in the argument list, like when it tries to get the 3rd argument #2# although there are only no more than 2 arguments passed to it.
This feature makes it easier to write recursive functions. Take the first configuration above as an example.
In function debug_expand We use an argument range #1...# to call itself recursively, and when there is no #0# during a call, the function automatically finish the recursion.
If a function is not permissive, it will ignore any occurrence of overflowed parameters, placing nothing on its position in the expanded expression.
CText offers some settings to satisfy special needs.