4 Pretty-Printing

Formats an expression expr that occurs as an immediate subexpression of parent as a doc for pretty-printing. The parenthesization is determined based on the precedence of the two expressions.

procedure
( format-statement stmt)→doc?
stmt:Statement/X?

Formats a statement as a doc for pretty-printing. Post-conditions: The statement output includes its own semicolon if appropriate, and statement output is not newline-terminated.

procedure
( format-nested-substatement stmt)→doc?
stmt:SubStatement/X?

Formats a statement that occurs as an indented substatement as a doc for pretty-printing. Post-condition: The indentation level is returned to its previous level after the substatement.

procedure
( format-substatement stmt)→doc?
stmt:SubStatement/X?

Formats a statement that occurs as a substatement as a doc for pretty-printing.

procedure
( format-case-clause clause)→doc?
clause:CaseClause?

Formats a case clause as a doc for pretty-printing.

procedure
( format-property property)→doc?
property:Property?

Formats an object property as a doc for pretty-printing.

procedure
( format-identifier id)→doc?
id:Identifier?

Formats an identifier as a doc for pretty-printing.

4.2Configuration Parameters🔗 i

value
current-indentation-width :(parameter/c natural-number/c )

The number of spaces to indent.

value
collapse-lines? :(parameter/c boolean? )

(Currently ignored.)

value
collapse-simple-substatements? :(parameter/c boolean? )

Non-block substatements stay on same line?

4.3Extending the Pretty-Printer🔗 i

As described in Extending the Language, it is possible to extend the language with custom forms. The pretty-printer can be extended with extra matchers that recognize just their form types and produce pretty-printed docs. Matchers should simple fail to match (raising the same error as (match) would for anything other than the forms they recognize.

value
formatters/Expression :(parameter/c (listof (any -> doc?)))

value
formatters/Statement :(parameter/c (listof (any -> doc?)))

value
formatters/ExpressionList :(parameter/c (listof (any -> doc?)))

value
formatters/StatementList :(parameter/c (listof (any -> doc?)))

procedure
( format-map feltsparam)→c
f:(a-> c)
elts:(or (listof a)b)
param:(parameter/c (b-> c))

Applies a formatter to an extensible list of terms (such as an ExpressionList/X or StatementList/X). If the formatter fails to match, the current value of the param parameter is used to format the elements instead.

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