Forward-Only Processing

Kind: constraint

Layer: Execution Core

Aliases: No Backtracking Requirement

Record: architecture:forward-only-processing

Severity: contextual

Scope: stream, parser, iterator

Canonical: Ontology

A rule or precondition that a stream is read once in order, keeping only rolling state, so no decision ever needs to revisit earlier input.

Listed in Architecture principles, after Sequential Access and before Dataflow Architecture.

Reinforces

• Single-Pass Processing

Enables

• Streaming Parsers

In tension with

• Complex Grammar/Global State
• Backtracking Algorithm

Tensions

• Forward-Only Processing / Complex Grammar/Global State
• Forward-Only Processing / Backtracking Algorithm

Violated by

• Look-Back Buffering

Refactored by

• Windowing
• Tolerant Reader

Severity

• contextual

Category

• Streaming / Pipeline / Dataflow Processing

Linked from

• Streaming / Pipeline / Dataflow Processing
• Contracts / Interfaces / Compatibility
• Streaming / Pipeline / Dataflow Processing
• Severity levels
• The resolutions