Brandon Lucas
b0f6756411
Adds two essential effects that enable Lux to interact with the system:
File effect:
- read(path) - Read file contents as string
- write(path, content) - Write string to file
- append(path, content) - Append to file
- exists(path) - Check if file/directory exists
- delete(path) - Delete a file
- readDir(path) - List directory contents
- isDir(path) - Check if path is directory
- mkdir(path) - Create directory (including parents)
Process effect:
- exec(cmd) - Run shell command, return stdout
- execStatus(cmd) - Run command, return exit code
- env(name) - Get environment variable (returns Option)
- args() - Get command line arguments
- exit(code) - Exit program with code
- cwd() - Get current working directory
- setCwd(path) - Change working directory
Also fixes formatter bug with empty handler blocks in `run ... with {}`.
These effects make Lux capable of writing real CLI tools and scripts.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
51 lines
1.4 KiB
Plaintext
51 lines
1.4 KiB
Plaintext
// File I/O example - demonstrates the File effect
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//
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// This script reads a file, counts lines/words, and writes a report
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fn countLines(content: String): Int = {
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let lines = String.split(content, "\n")
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List.length(lines)
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}
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fn countWords(content: String): Int = {
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let words = String.split(content, " ")
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List.length(List.filter(words, fn(w: String): Bool => String.length(w) > 0))
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}
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fn analyzeFile(path: String): Unit with {File, Console} = {
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Console.print("Analyzing file: " + path)
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if File.exists(path) then {
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let content = File.read(path)
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let lines = countLines(content)
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let words = countWords(content)
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let chars = String.length(content)
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Console.print(" Lines: " + toString(lines))
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Console.print(" Words: " + toString(words))
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Console.print(" Chars: " + toString(chars))
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} else {
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Console.print(" Error: File not found!")
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}
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}
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fn main(): Unit with {File, Console} = {
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Console.print("=== Lux File Analyzer ===")
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Console.print("")
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// Analyze this file itself
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analyzeFile("examples/file_io.lux")
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Console.print("")
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// Analyze hello.lux
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analyzeFile("examples/hello.lux")
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Console.print("")
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// Write a report
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let report = "File analysis complete.\nAnalyzed 2 files."
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File.write("/tmp/lux_report.txt", report)
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Console.print("Report written to /tmp/lux_report.txt")
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}
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let result = run main() with {}
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