Getting Started¶

Basic Syntax¶

With $\LaTeX$ syntax in mind, latest defines a command and an environment. But, first of all, let’s see how to leverage all the power of python in a template.

Python expressions¶

You can include a python expression within a template. By default, the syntax is:

{$ python expression $}

A python expression returns a python object, so if you want a string instead, you can use the latest command. For more complex tasks involving some logic like for loops or conditionals you can refer to latest environment.

Contexts¶

An expression needs a context (like a python dictionary) to be evaluated. A context is generally provided globally for a template. This context object is passed to every python expression, command or environment in the template. However, commands and environments can modify the context to work with in their content.

Commands¶

The latest command let you automatically convert to a string the output of a python expression. By default, the syntax is:

\latest[options]{$ python expression $}

For example, the expression:

If a = \latest{$ a $} and b = \latest{$ b $}, then a + b = \latest{$ a+b $}

with a data context {'a': 1, 'b': 2} evaluates to:

If a = 1 and b = 2, then a + b = 3

Environments¶

A latest environment allow us to change the globally defined context. This can be useful for many purposes depending on the context provided:

dict context: to ease the access to names in the context for the python expressions, commands, or enviroments nested inside the environment
boolean context: to provide a conditional functionality
list context: to provide a loop functionality

By default, the syntax is:

\begin{latest}{$ context $}[options]
     content...
\end{latest}

Creating a template¶

A template file can be of any type but latest searches in it for latest commands and enviroments.

Creating a data file¶

Data formats supported by latest are

json
yaml

The latest cli¶

Run latest script from the command line:: bash

$ latest template data

where

template is the path to a template file

data is the path to a json or yaml formatted data file.

Example¶

An example template file can be something like

\documentclass{article}

\title{\latest{$ meta $}}

\begin{document}
\begin{latest}{$ False $}It doesn't exist.\end{latest}
\begin{latest}{$ True $}This exists and x = \latest{$ data.scalar $}.\end{latest}
\begin{latest}{$ data $}
x = \latest{$ scalar $} so that $x^2$ = \latest{$ scalar ** 2 $}.
\end{latest}
\begin{itemize}
\begin{latest}{$ [{'i': i, 'v': v} for i, v in enumerate(data.vector)] $}[join={$ '\n' $}]
\item index = \latest{$ i $}, value = \latest{$ v $}
\end{latest}
\end{itemize}
\begin{latest}{$ data.tensor $}[join={$ '\n' $}]
true = \latest{$ true $} and false = \latest{$ false $}
\end{latest}
\begin{latest}{$ data $}
\begin{latest}{$ tensor $}
Testing nested structures:
true = \latest{$ true $} and false = \latest{$ false $}
\end{latest}
\end{latest}
\end{document}

while the data file can be something like (yaml)

meta: Testing latest...
data:
  scalar: 3
  vector:
    - 1
    - 2
    - 3
  tensor:
    'true': 1
    'false': 0

The expected output is

\documentclass{article}

\title{Testing latest...}

\begin{document}

This exists and x = 3.
x = 3 so that $x^2$ = 9.
\begin{itemize}
\item index = 0, value = 1
\item index = 1, value = 2
\item index = 2, value = 3
\end{itemize}
true = 1 and false = 0
Testing nested structures:
true = 1 and false = 0
\end{document}