CHANGES_AND_BUILD.md

CHANGES_AND_BUILD

This document captures the implemented work for the RPAL interpreter, plus build, run, and test instructions.

0) Step-by-Step Implementation Plan

1. Confirm current scanner/parser/AST baseline from existing code and docs.
2. Implement AST standardization rules and expose a reusable standardizer API.
3. Implement evaluator runtime: environments, closures, application, tuples, operators, and builtins.
4. Add a unified CLI entrypoint supporting scanner/parser/ast/st/eval modes.
5. Wire build system to compile all modules.
6. Update README and capture complete change/build/run notes in this file.
7. Build and run provided RPAL test programs; fix gaps found.

Status:

• Steps 1-7: Completed.

1) Components

Standardizer

Files:

• src/standardizer.h
• src/standardizer.cpp

Implements AST to ST conversion rules:

• let
• where
• within
• and
• rec
• fcn_form
• @
• tuple-form lambda parameters are preserved for tuple pattern binding

Evaluator

Files:

• src/evaluator.h
• src/evaluator.cpp

Implements:

• Environment chain
• Closures (lambda)
• Function application (gamma)
• Tuple values and tuple indexing by application
• Tuple construction (tau) and aug
• Arithmetic (+, -, *, /, **, neg)
• Comparisons (gr, ge, ls, le, eq, ne)
• Boolean ops (or, &, not, conditional ->)
• Builtins:
  • Print
  • Order
  • Conc
  • Stem
  • Stern
  • ItoS
  • Isinteger
  • Istruthvalue
  • Isstring
  • Istuple
  • Isfunction
  • Isdummy
  • Null
• Recursive definitions through standardized Y*

Unified CLI

File:

• src/main.cpp

Modes:

• --scan
• --parse
• --ast
• --st
• --eval
• default mode: evaluate

2) Build System

Root Makefile is provided for the lab-required flow:

make
./rpal20 file_name

CMakeLists.txt is also available for local development.

3) Build Instructions

From repository root:

make

This produces:

./rpal20

Alternative CMake build:

mkdir build
cd build
cmake ..
cmake --build .

Output executable:

• Makefile: ./rpal20
• Linux/macOS CMake: build/rpal20
• Windows Visual Studio CMake: build/Release/rpal20.exe

4) Run Instructions

From repository root:

./rpal20 rpal_test_programs/rpal_01

Mode-specific examples:

./rpal20 --scan rpal_test_programs/rpal_01
./rpal20 --ast rpal_test_programs/rpal_01
./rpal20 --st rpal_test_programs/rpal_01
./rpal20 --eval rpal_test_programs/rpal_01

On Windows CMD/PowerShell with the CMake build:

.\build\Release\rpal20.exe rpal_test_programs\rpal_01

5) Tests

Core tests follow the lab naming style:

rpal_test_programs/rpal_01
rpal_test_programs/output01.test

Manual lab-style run:

./rpal20 rpal_test_programs/rpal_01 > output.01
diff output.01 rpal_test_programs/output01.test

Run all tests:

python3 scripts/run_tests.py

All tests now use the same lab-style layout:

• Programs: rpal_test_programs/rpal_01 through rpal_97
• Expected outputs: rpal_test_programs/output01.test through output97.test

If output mismatches expected RPAL behavior, inspect AST and ST:

./rpal20 --ast rpal_test_programs/rpal_01
./rpal20 --st rpal_test_programs/rpal_01

6) Notes for Commit

The implementation is structured so commits can be grouped by:

1. Runtime pipeline (standardizer, evaluator, main)
2. Build integration (Makefile, CMakeLists.txt)
3. Tests and docs (rpal_test_programs, scripts, README.md, CHANGES_AND_BUILD.md)

7) Verification

Verified in this branch:

• CMake/Visual Studio build completes and produces build/Release/rpal20.exe.
• GCC C++11 compile with -Wall -Wextra -pedantic completes.
• Tests rpal_01 through rpal_97 pass against output01.test through output97.test.
• Additional checks cover recursion, tuple-parameter functions, curried functions, string/type builtins, comments, and tuple equality.

The local Windows shell does not have GNU make installed, so the Makefile was syntax-reviewed and its exact GCC compile command was verified manually.