PEGO
PEGO Parser and Runtime Specification
This specification defines what happens when a compiled grammar meets input: the start rule, positions, results, syntax errors, the node and value model, incremental documents and streaming, and the tools around a running parser: tracing, compiled grammars, generated parsers, output schemas and the linter. The grammars themselves are defined by the Grammar Language Specification; the portable instruction set that a grammar compiles to is defined by the Bytecode Specification.
Behavior described as supported in this specification is implemented. Features proposed but not yet implemented are marked "(not implemented)".
Contents
The chapters are in two groups, in reading order: each builds on the ones before it.
Parsing and Results
Running a grammar on input and the results it produces, for whole texts, edited documents and streams.
| Chapter | Defines | |
|---|---|---|
| 1 | Parsing | A parse as a whole: the start rule, input and positions, results, syntax errors, memoization, prefix parsing, time and memory, limits and modes |
| 2 | Nodes and Values | The value and node model, source information, the Go Node type, traversal, and the text and JSON renderings |
| 3 | Incremental Documents | Editing and reparsing text: versions, snapshots, interruption and change notifications |
| 4 | Streaming | Parsing a reader and delivering the elements of a #stream repetition as they match |
Tools and Formats
Observing a parse, saving and generating parsers, describing their output and checking grammars.
| Chapter | Defines | |
|---|---|---|
| 5 | Tracing and Profiling | Rule tracing and profiling of the engine and of generated parsers |
| 6 | Compiled Grammars | Saving and loading .pegoc files, their modes and the operations each serves, versions and loading checks |
| 7 | Generated Parsers | pego gen: the Go and TypeScript parsers, their APIs and what each supports |
| 8 | Output Schemas and Structural Queries | Describing the output of a grammar and searching result nodes (experimental) |
| 9 | Grammar Lint | The checks of the linter, severities and suppression directives |
The Glossary lists the terms of the specifications, with the place where each is defined.
Conventions
The conventions of the specifications apply.