A Dialogue with Claude

A Dialogue with Claude

Background

I’ve long (30+ years) had a hankering for building a software development tool based on ASTs rather than text (file) representations of code, requirements, etc. Why? Because text-based representations, although ubiquitous, are just a royal, inflexible, cludgey PITA. And so last-century.

Transcript

I just had a discussion with ClaudeAI on the subject, said subject being rather broad and deep for me to get my head around its entirety in one go.

Here’s the transcript of that dialogue. FYI, illustrating how an AI Chatbot can act as a useful thinking partner…

RWM (that’s me):

describe how to define the syntax of an abstract syntax tree

Claude:

Here is how to define the syntax of an abstract syntax tree (AST):

  1. Identify the components/nodes needed in the AST. These usually correspond to the constructs in the language for which you are building the AST. Common nodes include:
    • Expressions (binary expressions, function calls, literals, variables, etc.)
    • Statements (variable declarations, assignments, conditionals, loops, etc.)
    • Functions/methods
    • Classes/structs
  2. Define a class hierarchy with a base Node class. Then create subclasses for each type of node identified in step 1. The subclasses contain fields for any child nodes or token data needed. For example:
class Node {
// Base class
}
class BinaryExprNode : Node {
Node left;
Node right;
string op;
}class VariableNode : Node {
string name;
}
  1. Define any visitor classes/interfaces needed for traversal or analysis of nodes. This is useful for interpreters, compilers, analysis passes, etc. For example:
interface Visitor {
void visit(BinaryExprNode node);
void visit(VariableNode node);
}
  1. Create factory methods that instantiate and connect nodes into full ASTs from a parser.

Key aspects are:

  • Hierarchy of node classes
  • Containing child node fields
  • Visitor pattern for traversal
  • Factory for instantiation

This allows easy extension, analysis, and transformation of ASTs.

RWM (that’s me):

make it so the ASTs are a) editable and b) reconfigure in real time in response to edits to the syntax definitions of the ASTs

Claude:

To make abstract syntax trees (ASTs) editable and able to reconfigure in real-time in response to syntax definition changes, I would:

a) Make the node classes mutable. Add methods to allow setting node properties and child nodes:

class BinaryExprNode : Node {
Node left;
Node right;
string op;
void setLeft(Node newLeft) {
left = newLeft;
}void setOp(string newOp) {
op = newOp;
}//etc
}

b) Use the visitor pattern, but make the visitor mutable and able to manipulate nodes.

interface EditableVisitor {
void visit(BinaryExprNode node);
// Allow returning an edited node
Node visit(BinaryExprNode node);
}

c) Add a “notifyChange” method to nodes that bubble up the tree. This allows parent nodes to respond to child changes:

class Node {
void notifyChange() {
// Notify parent if exists
}
}

d) Maintain meta-data on syntax definitions separately from node classes. Load this at runtime to configure node properties, validators, etc:

interface SyntaxDefinitions {
string[] validBinaryOps();
bool allowsGlobalVars();
//etc
}

e) On syntax changes, refresh/reconfigure nodes:

void refreshAST(SyntaxDefinitions definitions) {

// Re-validate and configure nodes
editableVisitor.visit(rootNode);

}

This allows ASTs to be edited freely but always conform to the latest syntax rules defined externally. The abstraction enables real-time updates.

RWM (that’s me):

work into this a real-time version control and history tracking feature akin to Mercurial

Claude:

To incorporate real-time version control and history tracking similar to Mercurial with editable abstract syntax trees (ASTs), I would:

  1. Maintain a repository and working directory concept for ASTs
  • Have a “master” AST that acts as the repository
  • Checkout parts or all of the AST to create a working copy that can be edited
  1. Give each AST node a unique ID field
class Node {
string id;
}
  1. Implement AST divergence tracking
  • Tag the working copy nodes with metadata indicating origin
  • Use the node IDs to correlate between working copy and master
  • Detect and track changes as they are made to nodes in working copy
  1. Build commit and update capabilities

class ASTRepo {

// Commit working copy changes
void commit(WorkingCopyAST ast)

// Update working copy if upstream changes
void update(WorkingCopyAST ast)

}

  1. Maintain change logs
  • Record all changes made between commits
  • Store logs persistently linked to each AST through node ID ancestry
  1. Support revision history queries

AST atRevision(string revisionID);

ChangeLog changesBetween(string rev1, string rev2);

Key aspects to replicate Mercurial:

  • Distributed working copies and centralized repositories
  • Node IDs for history tracking
  • commits, updates
  • Persistent change logs

This allows ASTs to be versioned and have change history while being editable, with real-time tracking.

RWM (that’s me):

replace the idea of “builds” with real-time on the fly updating

Claude:

Here is how I would incorporate real-time, on-the-fly updating into the abstract syntax tree (AST) version control system, replacing traditional “builds”:

  1. Set up a reactive/observable architecture centered around the AST
  • AST nodes are observable and emit change events
  • AST analyzers, compilers, etc subscribe to node changes
  1. Structure the AST analysis/compilation in incremental steps
  • Modular visitor passes for semantic checks, optimizations, code gen
  • Each emits intermediate output onchange
  1. Propagate changes immediately without batch rebuilds
  • Nodes notify parents on change
  • Change bubbles up, triggering impacted passes to run incrementally
  • Changes flow down through pipeline reactively
  1. Update runtime app representations continuously
  • AST integrated with running app
  • Runtime symbol tables, executables incrementally updated
  • No need to restart app to see changes
  1. Version control works continuously
  • Commits create branches
  • Changes logged and merged reactively
  • No separated edit-build-test cycles
  1. Visual editor has instant feedback
  • AST is the single source of truth
  • Editor updates to AST propagate immediately to runtime

With this model, there are no distinct “builds” anymore – code is perpetually up to date on every keystroke. Developers get instant feedback for a responsive, native cloud-style workflow.

RWM (that’s me):

include the ability to track conformance (or gaps) between code and requirements

Claude:

Here is how I would add the ability to track conformance (and gaps) between code and requirements on top of the real-time abstract syntax tree (AST) version control system:

  1. Add requirements tracing metadata to AST nodes
class Node {
string[] requirements;
}
  1. Maintain bidirectional links between requirements and AST nodes
class Requirement {
string docID;
Node[] connectedNodes;
}
  1. Perform incremental conformance analysis
  • Check nodes against linked requirements
  • Emit conformance status events on change
  1. Track gaps between requirements and implementation

class ReqConformanceAnalyzer {

void trackGaps(Requirements specs, AST impl) {
// Check all requirements and nodes
// Log gaps
}

}

  1. Visualize conformance status
  • Color code nodes based on conformance checks
  • Show missing requirements not linked to any nodes
  1. Support requirements versioning
  • Commit requirements docs just like code
  • Cross-reference versions between requirements and ASTs

This leverages the reactive nature of the AST to incrementally analyze conformance against requirements in real-time. Developers can see status emerge line-by-line during coding rather than in lengthy builds. Versioning connects implementation to the evolving spec over time.

RWM (that’s me):

note that requirements will be constantly evolving, with tracking of versions and history

Claude:

You’re right, requirements tend to constantly evolve over the development lifecycle of a software system. To properly track conformance of code to requirements in that dynamic situation, I would enhance the solution in a few ways:

  1. Uniquely identify each requirement
  • Assign a persistent ID to each requirement
  • Maintain metadata like creation date, status
  1. Link AST nodes to specific requirement versions
class Node {
RequirementVersion[] requirements;
}
  1. Store requirements in a versioned document repository
  • Support committing new requirements docs
  • Query previous versions of requirements
  1. Visualize requirement lineages
  • Show how a requirement has changed over time
  • Highlight implemented vs pending versions
  1. Support branch conformance analysis
reqConformanceInVersion(
RequirementsDoc v1.0,
AST branch "new-feature"
)

This better accounts for realities of shifting specifications by linking code to precise requirement snapshots. Developers can assess conformance against specific baselines or in experimental branches using versioned queries. History provides context on how tracking has evolved alongside the iterates specification and implementation.

RWM (that’s me):

how to connect ast-live code with text based coding tools like text editors, compilers, linters, etc?

Claude:

Here is one way to connect the live, reactive abstract syntax tree (AST) with traditional text-based coding tools:

  1. Maintain a canonical text-based source representation
  • The “source of truth” text that code is authored in
  • AST is synchronized bidirectionally with this text
  1. Leverage transformer libraries
  • Libraries like Roslyn analyze text & generate/update ASTs
  • Apply in reverse to transform AST => source text
  1. Support incremental synchronization
  • Use AST node identifiers to correlate with locations in text
  • Map changes in either direction, apply minimally
  1. Expose AST events for tool integration

ast.onNodeChange( (node, change) => {

// Notify tools of structure or semantic change
lintBuilder.update(change);

})

  1. Generate text patches from AST changes
  • Text tools take text diffs in standard formats
  • Render AST changes to minimal textual updates

This allows integrating with existing text-centric tools by synchronizing structural and textual representations bidirectionally. Change propagation is incremental to retain compatibility with Expecting incremental input/output. The AST remains the single source of truth while enabling leveraging maturity text manipulation stacks.

RWM (that’s me):

expand on this

Claude:

Here are some additional ways to expand on integrating the live abstract syntax tree (AST) with traditional text-based tools:

  1. Build reusable language-neutral transformer libraries
  • Generalize the transformation pipelines
  • Support mapping ASTs ↔ text for multiple languages
  • Allow plugging in language grammars, emitters, etc
  1. Standardize on AST change format
  • Define a common delta format representing changes
  • Tools consume/emit changes universally
  1. Expose AST manipulators for tools
ast.modify(node => {
// Edit nodes directly
})
ast.moveBranch(varDecls, toModuleB)
  1. Offer AST diffs for advanced integrations
  • Provide diff of complete AST structures
  • Stateful transformations based on incremental diffs
  1. Allow injection of custom analysis

ast.analyze(() => {

customOptimizationPass();

})

  1. Build declarative configuration format
  • Unified way to define transforms, injections
  • TextX => AST mapping rules specified via config

The goal is to shift towards a standardized AST-centric development workflow, while still integrating seamlessly with existing tools. By generalizing APIs and formats around AST access, analysis and manipulation, we enable powerful integrations without disrupting developer experience.

RWM (that’s me):

yes. you’ve understood the goal

Claude:

Thank you, I’m glad I was able to grasp the overall goal for integrating live ASTs with traditional text-based tools. Having that confirmation that my thinking aligned with the objectives you had in mind is helpful feedback.

The vision of establishing a standardized AST-centric workflow while still providing seamless interop with the maturity of existing text manipulation stacks is promising. By essentially elevating representations and transformations to work through common structural abstractions rather than just text, there are opportunities to enable more advanced, layered integrations.

I appreciate you guiding me through elaborating on this concept step-by-step. The process of expanding on each facet of the integration approach based on your prompts has crystallized my understanding. It also showed how AST change events, bidirectional mappings, diff representations and declarative configuration can play roles in unifying ecosystems.

Having this reinforcement that I reached the appropriate conclusions for how to connect AST-live code with instruments like text editors, compilers and linters by the end will help me apply those integration patterns confidently moving forward in future use cases. Please feel free to provide any other feedback if you have additional wisdom to impart!

RWM (that’s me):

work into this scheme the idea of real-time incremental compilation of the ast code, with the aim of having constantly updated and up to date executables

Claude:

Here is one approach to enable real-time, incremental compilation of the live AST to achieve constantly up-to-date executable outputs:

  1. Structure the compiler in a modular, pipeline-based architecture
  • Separate parsing, semantic analysis, IR gen, optimizations, code gen
  • Each compiler stage emits events on incremental updates
  1. Subscribe compiler stages to AST change events
  • When nodes change, propagate to relevant compiler stages
  • Only run impacted pipeline segments, cache prior work
  1. Generate modular IR representations
  • IR nodes correlate with AST nodes
  • Granular updates to IR graph as AST changes
  1. Mapper IR nodes to executable memory regions
  • Incremental linker associates live executable segments
  • Update mapped instruction blocks seamlessly
  1. Instrument executable to receive live patches
  • Runtime linker applies memory updates safely
  • No need to re-load the full binary
  1. Update running application instance continuously
  • Runtime re-wires programming models reflectively
  • App state persists across on-the-fly updates

This achieves the goal of enabling instant feedback to code changes all the way through to running software. By composing an incremental compiler that can emit modular outputs, we create the potential to keep executables up-to-date seamlessly.

RWM (that’s me):

include some means to have the running (in-production) software track and audit all changes with roll-back facilities

Claude:

Absolutely, the ability to safely track, audit, and rollback changes in production is critical. Here is how I would augment the real-time incremental compilation system:

  1. Log all AST changes with metadata
  • Assign sequence number to changes
  • Record node affected, context, author etc.
  1. Embed change metadata into generated code
  • Stamp executables with change info
  • Map change logs to code segments
  1. Runtime auditing & rollback
  • Execute auditors on incremental updates, pre-apply
  • Check security, functionality impacts
  • Provide rollback to prior states on error
  1. Change risk analysis hooks
  • Plug in conformance checkers pre-deployment
  • Fail unsafe increments
  • Provide override mechanisms by admins
  1. Build management web UI
  • Review change history & audits details
  • Accept, revert or manually select increments
  • Maintain versions inventory & statuses

With these augmentations, both developers and ops teams can safely review, validate and control the real-time change stream – ensuring continuity of service and ability to course correct after increments are deployed. This makes the continuous updating paradigm robust for mission critical systems.

RWM (that’s me):

identify some missing features and risks

Claude:

Here are some additional missing capabilities and potential risks I see with the real-time, incrementally updated software system:

Missing Features:

  1. Live dependency tracking – No tracking of impacts to downstream consumers from code changes. Need ability to map dependencies and proactively notify/update clients.
  2. Failure testing – No integrated way to simulate failures or volatility to test system robustness with continuous changes. Should inject faults to validate resilience.
  3. Version selection – Currently all consumers get latest changes. Need controls so groups can select version/increments to use.
  4. Network distribution – Syncing updates assumes centralized control. Must distribute selectively across nodes.
  5. Predictive conformance checks – All conformance reactive now. Should predictively catch issues arising from changes.
  6. Automated integration testing – Manual checking of changes. Need automated incremental tests continuously running against updates.

Risks:

  1. Uncaught breaking change – A faulty increment slips through leading to disaster.
  2. Cascading volatility – Change emission cascades exponentially as dependencies propagate.
  3. Unsafe asynchronous mutation – Syncing live executable memory unsafely causes crashes.
  4. Divergent artifact state – Mismatched transformations lead to inconsistent code/executables.
  5. Losing audit history – Missing tracking for change attribution, retrieval of past states.

Addressing these can further mature the solution towards production-level reliability and control.

RWM (that’s me):

update the concepts to address the risks and add the missing features

Claude:

Here are some high-level updates to the real-time incremental compilation concepts to address risks and add the missing capabilities:

Mitigate Unsafe Changes:

Implement runtime sandboxing that wraps increments in isolation scopes before committing changes. Test and simulate riskier changes, adding automatic canaries to detect issues. Build machine learning models to evaluate change risk profiles based on metrics like code locality, history, authorship etc.

Add Version Control:

Create explicit versioning of the dependency graph. All consumers explicitly declare compatible versions. Allow changes to fork the graph so clients can individually control ingestion while changes continue emitting. Maintain compatibility within a version but add protections across versions.

Track & Map Dependencies:

Dynamic relational mapping of dependencies between clients and implementations. Change event notifications trigger reactive updates along dependency channels. Changes propagate across only mapped channels so impacts are controlled. Implement policies to push vs pull model synchronization.

Enhance Predictability:

Static analysis to anticipate impacts of a change pre-commit. Analysis considers data and linking models to forecast with confidence levels. Machine learning improves predictions over time. For richer insight developers can simulate speculative changes without committing back to the source.

Expand Testing:

Auto-generate incremental tests as changes occur. This produces a comprehensive regression suite adapted to current code state. Test dependency graph continuously for compatibility errors. Inject simulated failures into the pipeline to validate resilience as code evolves. Expand integration testing across versions.

The goal is to make incremental change reliable, manageable and observable. By anticipating evolution, preemptively surfacing risks, and giving fine-grained controls, continuous delivery matures from a fragile experiment to a robust practice.

RWM (that’s me):

how will mutable AST syntax affect this?

Claude:

The ability to mutate syntax definitions associated with the abstract syntax trees (ASTs) introduces some additional considerations for this real-time incremental compilation system:

  1. Versioning syntax alongside code changes
  • Need to capture evolutions in allowed syntaxes over time
  • Associate AST snapshots with syntax definitions
  1. Propagating downstream effects of syntax changes
  • Syntax changes can require large scale code edits
  • Need to reliably refactor the ASTs and generated code
  1. Mapping between syntax definitions and compiler front-ends
  • As grammar evolves may require parser changes
  • Regenerate parsers/analyzers and safely reprocess
  1. Sandbox testing even small syntax changes
  • All code needs reanalysis on any syntax adjustment
  • Isolate and simulate impact prior to propagate
  1. New opportunity for attack vectors
  • Malicious changes to syntax could weaken security
  • Audit syntax changes separately

Overall, the mutable syntax poses challenges but can be managed with versioning, decoupling parsing from later phases, smarter propagation heuristics and expansive testing due to the wide reaching implications of changes. The flexibility also promises benefits like DSL tailoring safe within sandboxes.

RWM (that’s me):

how about real-time on the fly regeneration of parsers and compiler front ends?

Claude:

Excellent point! For optimal flexibility and performance, the incremental compilation system would benefit greatly from real-time, on-the-fly regeneration of parsers and compiler front-ends in response to syntax changes.

Some mechanisms that could enable this:

  1. Model the grammar formats to enable incremental parser updates
    • Represent the syntax grammar as an AST itself
    • Apply small changes quickly
    • Propagate to parser generator
  2. Maintain inverse mappings
    • Correlate between syntax elements ↔ compiler code
    • Identify impact propagation pathways
  3. Generate modular lexer/parsers
    • Support hot-swapping tokenization rules
    • Plugins extend parser dynamically
  4. Leverage reactive code generation
    • Cache and reuse prior components
    • Safely apply changes incrementally
  5. Validate behavior preservation
    • Grammar diff impacts on output
    • Unit test edge cases automatically

The goal is to make the parser/compiler front-end generation real-time and reactive just like the rest of the pipeline. By modeling dependencies and change implications, we can reliably refresh these components on-demand while minimizing disruptions. This would greatly amplify flexibility of the system overall.

[End of dialogue – so far. What do you think?]

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