app.py

import gradio as gr
import re

def show_latex(latex_input):
    # Use regex to find all occurrences of \begin{...} and \end{...} and wrap them with $$
    latex_input = wrap_begin_end_with_dollars(latex_input)
    # Convert inline LaTeX ($...$) to block LaTeX ($$...$$)
    latex_input = re.sub(r'(?<!\$)\$(?!\$)(.*?)\$', r'$$\1$$', latex_input)  # replace single $...$ with $$...$$ while keeping existing $$...$$ unchanged

    # Ensure **bold** text formatting
    latex_input = re.sub(r"\*\*(.*?)\*\*", r"**\1**", latex_input)
    return f"{latex_input}"

def clear():
    return "", ""

def wrap_begin_end_with_dollars(text):
    # Use regex to find all occurrences of \begin{...} and \end{...} and wrap them with $$
    text = re.sub(r'(\\begin{[^}]+})', r'$$\1', text)  # Wrap \begin{}
    text = re.sub(r'(\\end{[^}]+})', r'\1$$', text)    # Wrap \end{}
    return text

with gr.Blocks() as iface:
    with gr.Row():
        with gr.Column():
            latex_input = gr.Textbox(label="Enter LaTeX", lines=5, placeholder="Type your LaTeX here...")
            show_button = gr.Button("Show")
            clear_button = gr.Button("Clear")
        with gr.Column():
            latex_output = gr.Markdown(label="Rendered LaTeX")
    
    show_button.click(show_latex, inputs=latex_input, outputs=latex_output)
    clear_button.click(clear, inputs=[], outputs=[latex_input, latex_output])

iface.launch(share=True)