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JSON File Edit Example

Reads a JSON file, decodes it with JSON.parse, modifies the data, then writes it back with JSON.stringify and writeFile.

Features Used

  • fs – file system access (readFile, writeFile)

What It Does

  1. Read – readFile(data.json) loads the raw string
  2. Decode – JSON.parse(raw) turns the string into an object
  3. Modify – Increments version, updates updated, appends an item, adds lastRun
  4. Write back – JSON.stringify(data) then writeFile(data.json, output)
  5. Verify – Reads the file again to confirm changes

Local Development

Run from this directory (tish repo is ../..). File I/O requires the fs feature and the interpreter backend:

# Run with interpreter (fs feature required for readFile/writeFile)
cargo run -p tishlang--manifest-path ../../Cargo.toml --release --features fs -- run src/main.tish --backend interp
 
# Or with tish installed
tish run src/main.tish --backend interp

(Ensure tish was built with --features fs or --features full.)

To compile to a native binary (includes fs when built with full):

cargo run -p tishlang--manifest-path ../../Cargo.toml --release --features full -- build src/main.tish -o json-file-edit
./json-file-edit

Files

  • src/main.tish – entry point
  • data.json – JSON file (created with defaults if missing)

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