java.lang.Object
- org.openjdk.asmtools.jasm.ParseBase
- - org.openjdk.asmtools.jasm.Scanner

```
public class Scanner
extends ParseBase
```
A Scanner for Jasm tokens. Errors are reported to the environment object.
The scanner keeps track of the current token, the value of the current token (if any), and the start position of the current token.
The scan() method advances the scanner to the next token in the input.
The match() method is used to quickly match opening brackets (ie: '(', '{', or '[') with their closing counter part. This is useful during error recovery.
The compiler treats either "\n", "\r" or "\r\n" as the end of a line.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

protected static class Scanner.SyntaxError
SyntaxError is the generic error thrown for parsing problems.

Field Summary

Fields
Modifier and Type	Field	Description
`protected int`	`ch`	The current character
`protected char`	`charValue`
`protected java.lang.String`	`docComment`
`protected double`	`doubleValue`
`protected float`	`floatValue`
`protected java.lang.String`	`idValue`
`protected Environment`	`in`	Input stream
`protected boolean`	`inBits`
`protected int`	`intValue`
`protected long`	`longValue`
`protected int`	`pos`	The position of the current token
`protected int`	`prevPos`	The position of the previous token
`protected int`	`radix`
`protected int`	`sign`
`protected java.lang.String`	`stringValue`
`protected JasmTokens.Token`	`token`	Current token

Fields inherited from class org.openjdk.asmtools.jasm.ParseBase
debugFlag, env, parser, scanner

Constructor Summary

Constructors
Modifier Constructor Description

protected Scanner(Environment env)
main constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`check(JasmTokens.Token t)`	Checks a token, throws an exception if not the same
`protected boolean`	`checkTokenIdent()`	Check the token may be identifier
`protected void`	`debugScan(java.lang.String dbstr)`
`protected void`	`expect(JasmTokens.Token t)`	Expects a token, scans the next token or throws an exception.
`static boolean`	`isUCDigit(int ch)`	Returns true if the character is a unicode digit.
`static boolean`	`isUCLetter(int ch)`	Returns true if the character is a Unicode letter.
`protected void`	`scan()`	scan Scan the next token.
`protected void`	`scanModuleStatement()`
`protected void`	`xscan()`

Methods inherited from class org.openjdk.asmtools.jasm.ParseBase
debugStr, enableDebug, init

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

in
```
protected Environment in
```
Input stream

ch
```
protected int ch
```
The current character

token
```
protected JasmTokens.Token token
```
Current token

pos
```
protected int pos
```
The position of the current token

charValue
```
protected char charValue
```

intValue
```
protected int intValue
```

longValue
```
protected long longValue
```

floatValue
```
protected float floatValue
```

doubleValue
```
protected double doubleValue
```

stringValue
```
protected java.lang.String stringValue
```

idValue
```
protected java.lang.String idValue
```

radix
```
protected int radix
```

docComment
```
protected java.lang.String docComment
```

prevPos
```
protected int prevPos
```
The position of the previous token

sign
```
protected int sign
```

inBits
```
protected boolean inBits
```

Constructor Detail
- Scanner
```
protected Scanner(Environment env)
           throws java.io.IOException
```
  main constructor. Create a scanner to scan an input stream.
  
  Throws:
  
  java.io.IOException

Method Detail

scanModuleStatement

protected void scanModuleStatement()
                            throws java.io.IOException

Throws:: java.io.IOException

scan

protected void scan()
             throws java.io.IOException

scan Scan the next token.

Throws:: java.io.IOException

checkTokenIdent
```
protected final boolean checkTokenIdent()
```
Check the token may be identifier

expect

protected final void expect(JasmTokens.Token t)
                     throws Scanner.SyntaxError,
                            java.io.IOException

Expects a token, scans the next token or throws an exception.

Throws:: Scanner.SyntaxError; java.io.IOException

check

protected final void check(JasmTokens.Token t)
                    throws Scanner.SyntaxError,
                           java.io.IOException

Checks a token, throws an exception if not the same

Throws:: Scanner.SyntaxError; java.io.IOException

isUCDigit
```
public static boolean isUCDigit(int ch)
```
Returns true if the character is a unicode digit.

Parameters:

ch - the character to be checked

isUCLetter
```
public static boolean isUCLetter(int ch)
```
Returns true if the character is a Unicode letter.

Parameters:

ch - the character to be checked

xscan

protected final void xscan()
                    throws java.io.IOException

Throws:: java.io.IOException

debugScan

protected void debugScan(java.lang.String dbstr)

Overrides:: debugScan in class ParseBase

Class Scanner

Nested Class Summary

Field Summary

Fields inherited from class org.openjdk.asmtools.jasm.ParseBase

Constructor Summary

Method Summary

Methods inherited from class org.openjdk.asmtools.jasm.ParseBase

Methods inherited from class java.lang.Object

Field Detail

in

ch

token

pos

charValue

intValue

longValue

floatValue

doubleValue

stringValue

idValue

radix

docComment

prevPos

sign

inBits

Constructor Detail

Scanner

Method Detail

scanModuleStatement

scan

checkTokenIdent

expect

check

isUCDigit

isUCLetter

xscan

debugScan