RegCraft

1) What is RegCraft?

RegCraft lets you build regular expressions using connectable blocks. If two blocks don’t make sense together (e.g., a quantifier without something to quantify), the app prevents it or shows a helpful message.

2) Getting started

• Drag blocks from the Blocks panel into the Builder area. You can also click a block to add it to the end.
• Reorder by dragging chips inside the Builder.
• Remove a block with the × button on the chip.
• Use ^ (Start) and $ (End) to anchor your pattern, if needed.

3) Entering values

• Literal prompts for text and safely treats it as exact characters.
• Class [..] lets you type a set or range (e.g., abc0-9).
• Numbered quantifiers prompt for counts like {n} or {m,n}.

4) Quantifiers (repeaters)

Blocks like +, *, ?, or {m,n} must be placed after a block to apply to it. Try placing a word block, then a + to mean “one or more word characters”.

5) Groups and alternation

• Use ( and ) to group parts of your pattern.
• Use | for “or”, e.g., (cat|dog).

6) Test and highlight

• Type or paste text into Test Input. Matches appear highlighted.
• Different colored chips correspond to differently colored highlights for easier reading.

7) Flags

• /i – case-insensitive
• /m – multi-line (anchors ^ and $ work per line)
• /g – find all matches (recommended for highlighting)

8) Quick examples

• Starts with “Hello”: ^ → Literal “Hello” → $
• Word followed by digits: Word \w with + → Digit \d with +
• Email-like piece (simplified): Word+ → Literal “@” → Word+ → Literal “.” → Word+