3.19 Continuation Marks: with-continuation-mark

► |  | The Racket Reference

1 | Language Model
2 | Notation for Documentation
3 | Syntactic Forms
4 | Datatypes
5 | Structures
6 | Classes and Objects
7 | Units
8 | Contracts
9 | Pattern Matching
10 | Control Flow
11 | Concurrency and Parallelism
12 | Macros
13 | Input and Output
14 | Reflection and Security
15 | Operating System
16 | Memory Management
17 | Unsafe Operations
18 | Running Racket
| Bibliography
| Index

▼ | 3 | Syntactic Forms

3.1 | Modules: module, module*, ...
3.2 | Importing and Exporting: require and provide
3.3 | Literals: quote and #%datum
3.4 | Expression Wrapper: #%expression
3.5 | Variable References and #%top
3.6 | Locations: #%variable-reference
3.7 | Procedure Applications and #%app
3.8 | Procedure Expressions: lambda and case-lambda
3.9 | Local Binding: let, let*, letrec, ...
3.10 | Local Definitions: local
3.11 | Constructing Graphs: shared
3.12 | Conditionals: if, cond, and, and or
3.13 | Dispatch: case
3.14 | Definitions: define, define-syntax, ...
3.15 | Sequencing: begin, begin0, and begin-for-syntax
3.16 | Guarded Evaluation: when and unless
3.17 | Assignment: set! and set!-values
3.18 | Iterations and Comprehensions: for, for/ list, ...
3.19 | Continuation Marks: with-continuation-mark
3.20 | Quasiquoting: quasiquote, unquote, and unquote-splicing
3.21 | Syntax Quoting: quote-syntax
3.22 | Interaction Wrapper: #%top-interaction
3.23 | Blocks: block
3.24 | Internal-Definition Limiting: #%stratified-body
3.25 | Performance Hints: begin-encourage-inline
3.26 | Importing Modules Lazily: lazy-require

On this page:

with-continuation-mark

top contents ← prev up next →

#### 3.19`` Continuation Marks: with-continuation-mark🔗ℹ

> syntax (with-continuation-mark key-expr val-expr result-expr)

The key-expr, val-expr, and result-expr expressions are evaluated in order. After key-expr is evaluated to obtain a key and val-expr is evaluated to obtain a value, the key is mapped to the value as a continuation mark in the current continuation’s initial continuation frame. If the frame already has a mark for the key, the mark is replaced. Finally, the result-expr is evaluated; the continuation for evaluating result-expr is the continuation of the with-continuation-mark expression (so the result of the result-expr is the result of the with-continuation-mark expression, and result-expr is in tail position for the with-continuation-mark expression).

> > > Continuation Marks provides more information on continuation marks.

top contents ← prev up next →