StringScanner

Scan characters in a string that allows tokenizers to look ahead through a stream to perform lexical analysis.

Implements: IScanner

Description

The StringScanner class is used to scan characters in a string that allows tokenizers to look ahead through a stream to perform lexical analysis.

Constructors

Creates an instance of this class.

public constructor(content: string)

  • content: string - text content to be read.

Fields

Eof

EOF

public static Eof: number = -1

Instance methods

column

Gets the column in the current line.

public column(): number

  • returns: number - column in the current line in the stream.

line

Gets the current line number.

public line(): number

  • returns: number - current line number in the stream.

peek

Returns the character from the top of the stream without moving the stream pointer.

public peek(): number

  • returns: number - character from the top of the stream or -1 if the stream is empty.

peekColumn

Gets the next character column number.

public peekColumn(): number

  • returns: number - next character column number in the stream.

peekLine

Gets the next character line number.

public peekLine(): number

  • returns: number - next character line number in the stream.

read

Reads a character from the top of the stream.

public read(): number

  • returns: number - read character or -1 if the stream is processed to the end.

reset

Resets the scanner to the initial position.

public reset(): void

unread

Puts one character back into the stream.

public unread(): void

unreadMany

Pushes the specified number of characters to the top of the stream.

public unreadMany(count: number): void

  • count: number - number of characcted to be pushed back.