PTL (Pythonic Template Language)

Overview

At a glance

PTL is a python-like script language to generate a readable file from template, which support some [functions] defined in python. Here is an simple example:

// Template we used
int main() {
    {%
        for {<index>}, {<var>} in {<enumerate(vars)>}:
            if {<index>} >= {<2d>}:
                printf("%d", {<index>});
            elif {<index>} == {<1d>}:
                scanf("%d", &test{<var>});
            else:
                {<index>} = {<5d>}
                NULL; // {<index>}
    %}
}

// After running
int main() {
NULL; // 5
scanf("%d", &test2);
printf("%d", 2);
printf("%d", 3);
}

PTL, the simple way

In a template file, you can write a PTL script by enclosing it with "{%" and "%}", any other text out of these signs will be treated as plain text.

Varibales and function calls

In PTL, we enclose variables or function calls with "{<" and ">}". For example {} is a variable, and {<len(a)>} is a function call. All function calls MUST be enclosed by "{<" and ">}", or it may raise SyntaxError.

Instant values

To use an instant variable in PTL, you should following rules:

• Integer: An integer number followed by small letter d, for example, {<1d>}
• Float: An float point number followed by small letter f, for example, {<2.1f>}
• String: Enclosed by " and ", for example, {<"test">}

Statements

There are three types of statements in PTL: control flow statements, expression statements, string statements.

Control flow statements

Like python, PTL provides a same experience with control flow. You can feel free to use if, elif, else, while, for.

Expression statements

You can assign value to a new variable without declaration. Just use = to assign a result to a new variable.

String statements

String statements can contain variables and it will be replaced by variables' value. The results of the string statement will be combined and returned as plain text. If you want to have = in string statements, please use \= instead. Or it will be recognized as expression statements.

Initial values

When you are trying to generate text from a template, you must provide initial values for variables used without assignment. When you are writing your own script, do handle this properly, or it can raise KeyError.