Files
lambda/internal/config/parse_from_args.go
M.V. Hutz f3b9137d75 feat: add De Bruijn index reduction engine
Closes #26

- Added -i flag to select interpreter (lambda or debruijn)
- Created debruijn package with Expression interface
  - Variable contains index and optional label
  - Abstraction contains only body (no parameter)
  - Application structure remains similar
- Implemented De Bruijn reduction without variable renaming
  - Shift operation handles index adjustments
  - Substitute replaces by index instead of name
- Abstracted Engine into interface with two implementations
  - LambdaEngine: original named variable engine
  - DeBruijnEngine: new index-based engine
- Added conversion functions between representations
  - LambdaToDeBruijn: converts named to indexed
  - DeBruijnToLambda: converts indexed back to named
  - SaccharineToDeBruijn: direct saccharine to De Bruijn
- Updated main to switch engines based on -i flag
- All test samples pass with both engines

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2026-01-12 21:27:40 -05:00

64 lines
2.1 KiB
Go

package config
import (
"flag"
"fmt"
)
// Extract the program configuration from the command-line arguments.
func FromArgs() (*Config, error) {
// Relevant flags.
verbose := flag.Bool("v", false, "Verbosity. If set, the program will print logs.")
explanation := flag.Bool("x", false, "Explanation. Whether or not to show all reduction steps.")
statistics := flag.Bool("s", false, "Statistics. If set, the process will print various statistics about the run.")
profile := flag.String("p", "", "CPU profiling. If an output file is defined, the program will profile its execution and dump its results into it.")
file := flag.String("f", "", "File. If set, read source from the specified file.")
output := flag.String("o", "", "Output. If set, write result to the specified file. Use '-' for stdout (default).")
interpreter := flag.String("i", "lambda", "Interpreter. Choose 'lambda' or 'debruijn' reduction engine (default: lambda).")
flag.Parse()
// Parse source type.
var source Source
if *file != "" {
// File flag takes precedence.
if flag.NArg() > 0 {
return nil, fmt.Errorf("cannot specify both -f flag and positional argument")
}
source = FileSource{Path: *file}
} else if flag.NArg() == 0 {
return nil, fmt.Errorf("no input given")
} else if flag.NArg() > 1 {
return nil, fmt.Errorf("more than 1 command-line argument")
} else {
// Positional argument.
if flag.Arg(0) == "-" {
source = StdinSource{}
} else {
source = StringSource{Data: flag.Arg(0)}
}
}
// Parse destination type.
var destination Destination
if *output == "" || *output == "-" {
destination = StdoutDestination{}
} else {
destination = FileDestination{Path: *output}
}
// Validate interpreter flag.
if *interpreter != "lambda" && *interpreter != "debruijn" {
return nil, fmt.Errorf("invalid interpreter: %s (must be 'lambda' or 'debruijn')", *interpreter)
}
return &Config{
Source: source,
Destination: destination,
Verbose: *verbose,
Explanation: *explanation,
Profile: *profile,
Statistics: *statistics,
Interpreter: *interpreter,
}, nil
}