Interactive REPL Guide
Master Hype's Interactive Development Environment
The REPL (Read-Eval-Print Loop) is your playground for rapid Lua development, API exploration, and interactive debugging. Available in both TUI and simple modes.
🚀 Quick Start
Hype REPL v1.9.0
Type :help for commands
hype>
2 + 2
4
hype>
user = {name = "Alice", role = "Developer"}
{
["name"] = "Alice",
["role"] = "Developer"
}
hype>
crypto.sha256("hello")
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
hype>
_
# Launch TUI REPL (default)
./hype repl
# Launch simple REPL
./hype repl --simple
# With plugins
./hype repl --plugins fs@1.0.0,json
⌨️ Keyboard Shortcuts
| Key | Action | Description |
|---|---|---|
| ↑ / ↓ | Navigate history | Browse through previous commands |
| Ctrl + A | Start of line | Move cursor to beginning |
| Ctrl + E | End of line | Move cursor to end |
| Ctrl + U | Clear line | Delete current input |
| Ctrl + L | Clear screen | Clear output panel |
| Tab | Auto-complete | Complete function/variable names |
| PageUp / PageDown | Scroll output | Navigate through output history |
| Ctrl + D | Exit REPL | Quit the session |
🎯 Special Commands
-- Show help
hype> :help
Available commands:
:help, :h - Show this help
:clear, :c - Clear output
:exit, :q - Exit REPL
:history - Show command history
:h=N - Recall command N
-- Clear the output panel
hype> :clear
-- Exit the REPL
hype> :exit-- View command history
hype> :history
Command History:
1: 2 + 2
2: user = {name = "Alice"}
3: crypto.sha256("test")
4: http.get("https://api.example.com")
-- Recall command 2
hype> :h=2
Recalled: user = {name = "Alice"}
-- Modify and execute
hype> user = {name = "Alice", updated = os.time()}-- Load and execute a file
hype> :load utils.lua
Loaded: utils.lua
-- Alternative method
hype> dofile("config.lua")
-- Load with error handling
hype> ok, err = pcall(dofile, "script.lua")
hype> if not ok then print("Error:", err) end🔧 Working with Modules
TUI Module
-- Create app
app = tui.newApp()
-- Build interface
text = tui.newTextView("Hello")
text:SetBorder(true)
-- Run in background
go(function()
app:SetRoot(text, true)
app:Run()
end)HTTP Module
-- Make request
resp = http.get("https://api.github.com")
print(resp.status_code)
-- Start server
server = http.newServer()
server:handle("/", function(req, res)
res:json({msg = "Hello"})
end)
go(function() server:listen(8080) end)Database Module
-- Open database
db = kv.open(":memory:")
db:open_db("test")
-- Store and retrieve
db:put("test", "key", "value")
result = db:get("test", "key")
print(result)Crypto Module
-- Generate hash
hash = crypto.sha256("secret")
-- Generate keys
key = crypto.generate_jwk("ES256")
pub = crypto.jwk_to_public(key)
-- Sign and verify
sig = crypto.sign(key, "data")
valid = crypto.verify(pub, "data", sig)💡 Advanced Techniques
Multi-line Input
-- Define complex functions
hype> function process_data(items)
local results = {}
for i, item in ipairs(items) do
if item.active then
table.insert(results, {
id = item.id,
processed = true,
timestamp = os.time()
})
end
end
return results
end
-- Test the function
hype> data = {{id=1, active=true}, {id=2, active=false}}
hype> process_data(data)Performance Testing
-- Benchmark function
function benchmark(fn, iterations)
iterations = iterations or 1000
local start = os.clock()
for i = 1, iterations do
fn()
end
local elapsed = os.clock() - start
return string.format("%d ops in %.3fs (%.0f ops/sec)",
iterations, elapsed, iterations/elapsed)
end
-- Test performance
hype> benchmark(function() crypto.sha256("test") end, 10000)
"10000 ops in 0.125s (80000 ops/sec)"Interactive Debugging
-- Create debug helper
function inspect(obj, depth)
depth = depth or 0
if depth > 3 then return "..." end
if type(obj) ~= "table" then
return tostring(obj)
end
local parts = {}
for k, v in pairs(obj) do
local key = tostring(k)
local value = inspect(v, depth + 1)
table.insert(parts, key .. " = " .. value)
end
return "{" .. table.concat(parts, ", ") .. "}"
end
-- Use it
hype> complex = {a = {b = {c = "deep"}}, x = 42}
hype> print(inspect(complex))🚀 Common Workflows
API Exploration
- Load module:
server = http.newServer() - Explore methods:
for k,v in pairs(getmetatable(server).__index) do print(k) end - Test functionality:
server:handle("/", handler) - Run in background:
go(function() server:listen(8080) end) - Verify:
http.get("http://localhost:8080")
Testing Code
- Define test data
- Write test function
- Run multiple iterations
- Check edge cases
- Save working code
Plugin Development
- Create plugin table:
plugin = {} - Add functions:
function plugin.method() ... end - Test thoroughly in REPL
- Save to file:
save_plugin("myplugin.lua", plugin) - Load and verify:
dofile("myplugin.lua")
Debugging Scripts
- Load problematic script
- Add print statements
- Inspect variables
- Test functions individually
- Fix and re-test
🔧 Troubleshooting
REPL Won't Start
# Check version (needs v1.9.0+)
./hype version
# Try simple mode
./hype repl --simple
# Check for errors
./hype repl 2>&1 | lessMemory Issues
-- Clear large variables
hype> bigdata = nil
hype> collectgarbage()
-- Check memory usage
hype> collectgarbage("count")
1234.56 -- KB used
-- Force full collection
hype> collectgarbage("collect")Hanging Operations
-- Use Ctrl+C to interrupt
-- Or use timeout wrapper
function timeout(fn, seconds)
local co = coroutine.create(fn)
local start = os.time()
while coroutine.status(co) ~= "dead" do
if os.time() - start > seconds then
error("Timeout after " .. seconds .. "s")
end
coroutine.resume(co)
end
endOutput Not Visible
-- Clear output panel
hype> :clear
-- Check if output is being captured
hype> print("Test output")
hype> io.flush()
-- Try direct write
hype> io.write("Direct output\n")