Examples Cookbook

Examples Cookbook

What you'll learn

This guide walks through the example and regression files in tests/regression/, explains what each one demonstrates, and shows the fastest command to run it.

Prerequisites

• Read First Programs first.

Cookbook Index

File	Main topic
01_web_fetcher_thread.lp	HTTP + threads + SQLite
02_oop_game_engine.lp	classes, inheritance, methods
03_memory_arena.lp	manual arena allocation
04_parallel_for.lp	parallel for syntax
05_system_sqlite.lp	platform + SQLite
test_global_multiline_lambda.lp	top-level multiline lambda
test_inheritance_access.lp	protected inheritance rules
test_json.lp	JSON round-trip
test_memory_control.lp	arena and pool helpers
test_multiline_lambda.lp	local multiline lambda
test_string_operations.lp	string methods
test_thread_sqlite.lp	thread join + nested subscript + SQLite
test_type_inference.lp	local type inference

01_web_fetcher_thread.lp

What it teaches

• http.get(...)
• thread.spawn(...)
• thread.join(...)
• SQLite writes from worker threads

Run it

lp tests/regression/01_web_fetcher_thread.lp

What to notice

• each worker is a named function
• each worker returns int
• the main thread validates thread.join(...) results

02_oop_game_engine.lp

What it teaches

• class fields
• inherited movement logic
• subclass-specific behavior
• method calls on objects

Run it

lp tests/regression/02_oop_game_engine.lp

What to notice

• both Player and Enemy inherit from Entity
• methods mutate object fields directly through self

03_memory_arena.lp

What it teaches

• memory.arena_new(...)
• memory.arena_alloc(...)
• memory.cast(...)
• explicit arena cleanup

Run it

lp tests/regression/03_memory_arena.lp

What to notice

• memory is managed explicitly
• cleanup is part of the example, not optional decoration

04_parallel_for.lp

What it teaches

• the parallel for syntax
• numeric range iteration for heavy work
• current reduction caveats

Run it

lp tests/regression/04_parallel_for.lp

What to notice

• the example uses math.sin(...) and math.cos(...)
• the code comments already warn that reductions are not automatic

05_system_sqlite.lp

What it teaches

• platform.os()
• platform.arch()
• platform.cores()
• SQLite table creation and querying

Run it

lp tests/regression/05_system_sqlite.lp

What to notice

• platform helpers return runtime values that are easy to print with str(...)
• SQLite query results are accessed through nested subscript

test_global_multiline_lambda.lp

What it teaches

• top-level multiline lambda assignment

Run it

lp test examples

test_inheritance_access.lp

What it teaches

• protected field access from a subclass
• protected method access from a subclass
• override behavior

Run it

lp test examples

test_json.lp

What it teaches

• json.loads(...)
• json.dumps(...)
• indexed access into parsed JSON values

Run it

lp test examples

test_memory_control.lp

What it teaches

• arena allocation
• pool allocation
• memory.cast(...) on both allocation paths

Run it

lp test examples

test_multiline_lambda.lp

What it teaches

• multiline lambda inside local scope

Run it

lp test examples

test_string_operations.lp

What it teaches

• strip, lower, upper
• find, count
• split, join
• startswith, endswith, isdigit

Run it

lp test examples

test_thread_sqlite.lp

What it teaches

• thread return values through join
• SQLite use from multiple workers
• nested subscript access like rows[0]["n"]

Run it

lp test examples

test_type_inference.lp

What it teaches

• inferred int and str
• inferred value flow into another function call

Run it

lp test examples

Common errors and limitations

• Some examples require network access, especially 01_web_fetcher_thread.lp.
• SQLite examples create local .db files as part of normal execution.
• parallel for syntax is demonstrated in the examples, but actual parallel speedup still depends on toolchain configuration.

See also

• Runtime Modules
• Troubleshooting