justinhuprime / stacklang

Stack-based interpreted programming language inspired by Racket

StackLang Programming Language

A stack-oriented programming language with an interpreter implemented in C++. This language is heavily inspired by the HtDP xSL teaching languages and HP's RPL.

• For a complete language reference, see the documentation pages.
• For instructions on compiling the interpreter, see the file INSTALLING.

StackLang is a toy language intended mainly to explore the interesting (lack of) grammar in RPN languages. While prefix (Polish notation) and infix languages require many parenthesis to make order of operations unambiguous, postfix languages do not. The downside, however, is that postfix languages cannot have variadic functions. Additionally, the decision was made to avoid the use of grouping operators as much as possible. This leads to quoted commands and the need for an eval-like primitive. Grouping of commands together for control flow is mainly accomplished through the use of quoted, locally defined, commands acting as thunks.

StackLang is written by Justin Hu. See the contact info in the documentation pages.

Additional contributions by Bronwyn Damm, Jacques Marais, Ramon Rakow, and Jude Sidloski

stacklang's Issues

Inconsistent treatment of decimal places

Description
Decimal places are not displayed consistent with significant figures.

To Reproduce
Enter commands 5 2 divide, produces 2.

Expected behavior
Expected 2.5

g++ bug when compiling stackElements.cc for release

Describe the bug
g++ warns of overflow assumptions when simplifying parseLevel conditionals in stackElements.cc, in the method SubstackElement::parse

To Reproduce
Steps to reproduce the behavior:

1. make clean
2. make release
3. See the compiler warning.

Expected behavior
Expected no warning to be sent regarding overflow assumptions

Screenshots

Additional context
This is a known g++ bug that has not yet been resolved.

Recursive functions error

Description
Recursive functions are either segfaulting or redefining internal definitions

To Reproduce

1. Run stacklang with no flags
2. Enter

10
sequence

3. See error

Expected behavior
Expected to produce << 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 >>

Environment

• OS (and version): Ubuntu 18.04
• StackLang Version: 2.0 alpha
• Compiler (and version) used to build: g++-8

include can't handle comments in substacks

Description
include can't handle comments in substacks

To Reproduce
Steps to reproduce the behavior:

1. Run stacklang and include a file that has the following text:

<<
1
;comment
2
>>

2. See error

Expected behavior
Expected << 1, 2 >>

Environment

• OS (and version): Ubuntu 18.04
• StackLang Version: 2.0 alpha
• Compiler (and version) used to build: g++-8