Emulating GOTO in Scheme with continuations

Summary

The article explains how to emulate the GOTO statement in Scheme using continuations. It details the functionality of call/cc and provides code examples. The author concludes that while the implementation is technically interesting, it's ultimately not very useful.

Key Takeaways

1. Scheme programmers can emulate GOTO-style control flow using the call/cc procedure.
2. The call/cc procedure takes a procedure as an argument and applies it with the current continuation.
3. The author admits the implementation is "useless" but hopes readers learned about call/cc and building abstractions.

Statement Breakdown

• Claimed Facts: 60% of statements the article presents as facts
• Opinions: 30% of statements classified as editorial or subjective
• Claims: 10% of statements surfaced for additional reader evaluation

Credibility & Bias Reasoning

Credibility assessment: The article provides clear explanations and examples of Scheme code, enhancing its credibility. The author demonstrates a strong understanding of the subject matter. The inclusion of references to established resources like Dybvig's "The Scheme Programming Language" further supports the article's reliability.

Bias assessment: Technical Explanation with Self-Deprecating Humor. The article focuses on explaining a specific programming concept (GOTO emulation in Scheme) with a lighthearted and self-aware tone. While the author expresses opinions on the usefulness of the technique, the primary goal is educational. The author's self-deprecating humor doesn't significantly skew the technical content.

Note: This article provides a technical explanation of a programming concept. While the author demonstrates expertise, readers should independently verify the information.

Credibility flag: Informative, Technical

Claimed Facts (7)

• This is a direct quote attributed to Dijkstra.
• This is a definition of the abbreviation.
• This describes the functionality of call/cc.
• This is an equivalence in Scheme.
• This describes a step in the implementation.
• This explains how the continuation is used.
• This explains the syntax of the code.

Opinions (6)

• This is Dijkstra's opinion on the GOTO statement.
• This is the author's opinion on using goto for cleanup logic.
• This is the author's assessment of their own example.
• This is the author's opinion on the %labels helper.
• This is the author's concluding opinion on the implementation.
• This is the author's opinion on the specific application of call/cc.

Claims (6)

• This statement is subjective and lacks specific evidence.
• This is a hyperbolic statement and lacks specific evidence.
• This is an assumption about the reader's knowledge.
• This is a contradictory and hyperbolic statement.
• This statement lacks specific evidence or citation.
• This is a subjective statement without supporting evidence in this context.

Key Sources

• Dijkstra — Computer Scientist
• Author — Programmer