us.bpsm.edn.parser

Interface Scanner

public interface Scanner

A Scanner knows how to read syntactically correct edn tokens from any Parseable. Use Scanners.newScanner() to get an instance.

Method Summary

Methods

Modifier and Type	Method and Description
Object	nextToken(Parseable pbr) The next token read from the given Parseable may be any of the members of Token or instances of the Java classes used to represent atomic values recognized by Scanner.

Method Detail

nextToken

Object nextToken(Parseable pbr)

The next token read from the given Parseable may be any of the members of Token or instances of the Java classes used to represent atomic values recognized by Scanner.

The value Token.END_OF_INPUT marks the end of input, indicating that the underlying Parseable has been fully consumed.

In addition to the members of Token, nextToken(…) may return any of the following:

• A String with the contents of a string literal.
• A Character for a character literal.
• A Boolean for a 'true' or 'false'.
• A Long for an integer small enough to fit in its range and not marked by a trailing 'N'.
• A BigInteger for an integer too large to fit in a Long or marked by a trailing 'N'.
• A Double for a binary floating point literal
• A BigDecimal for an arbitrary precision decimal floating point literal, which is indicated by a trailing 'M' in edn.
• A Symbol for an edn symbol. ('nil', 'true' and 'false' are not symbols.)
• A Keyword for an edn keyword, which looks like :somename.
• A Tag indicating that the next value parsed from the TokenSeq should be transformed by a function associated with this Tag.

Parameters:

pbr - a Parseable to read the next token from; must not be null.

Returns:

the next token read from the Parseable (never null).

Throws:

EdnIOException - if the underlying Parseable throws an IOException.

EdnSyntaxException - if the contents of the underlying Parseable violates the syntax of edn.