1.9 Debugging and Inspection Tools

package: base

The following special forms are for debugging syntax classes.

syntax
(syntax-class-attributes syntax-class-id)

Returns a list of the syntax class’s attributes. Each attribute entry consists of the attribute’s name and ellipsis depth.

syntax
(syntax-class-arity syntax-class-id)
syntax
(syntax-class-keywords syntax-class-id)

Returns the syntax class’s arity and keywords, respectively. Compare with procedure-arity and procedure-keywords.

syntax
(syntax-class-parse syntax-class-id stx-expr arg ...)

stx-expr : syntax?

Runs the parser for the syntax class (parameterized by the arg-exprs) on the syntax object produced by stx-expr. On success, the result is a list of vectors representing the attribute bindings of the syntax class. Each vector contains the attribute name, depth, and associated value. On failure, the result is some internal representation of the failure.

syntax
(debug-parse stx-expr S-pattern ...+)

stx-expr : syntax?

Tries to match stx-expr against the S-patterns. If matching succeeds, the symbol 'success is returned. Otherwise, an S-expression describing the failure is returned.

The failure S-expression shows both the raw set of failures (unsorted) and the failures with maximal progress. The maximal failures are divided into equivalence classes based on their progress (progress is a partial order); that is, failures within an equivalence class have the same progress and, in principle, pinpoint the same term as the problematic term. Multiple equivalence classes only arise from ~parse patterns (or equivalently, #:with clauses) that match computed terms or ~fail (#:fail-when, etc) clauses that allow a computed term to be pinpointed.

procedure
(debug-syntax-parse!) → void?

Installs a syntax-parse reporting handler that prints debugging information to the current error port when a syntax-parse error occurs.

Added in version 6.5.0.3 of package base.

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1	Parsing and Specifying Syntax
2	Syntax Object Helpers
3	Datum Pattern Matching
4	Module-Processing Helpers
5	Macro Transformer Helpers
6	Reader Helpers
7	Parsing for Bodies
8	Unsafe for Clause Transforms
9	Source Locations
10	Preserving Source Locations
11	Non-Module Compilation And Expansion
12	Trusting Standard Recertifying Transformers
13	Attaching Documentation to Exports
14	Contracts for Macro Subexpressions
15	Macro Testing
16	Internal-Definition Context Helpers
	Index

1.1	Introduction
1.2	Examples
1.3	Parsing Syntax
1.4	Specifying Syntax with Syntax Classes
1.5	Syntax Patterns
1.6	Defining Simple Macros
1.7	Literal Sets and Conventions
1.8	Library Syntax Classes and Literal Sets
1.9	Debugging and Inspection Tools
1.10	Experimental