Package org.apache.commons.jexl3.parser
Class JexlParser
java.lang.Object
org.apache.commons.jexl3.parser.StringParser
org.apache.commons.jexl3.parser.JexlParser
- Direct Known Subclasses:
Parser
The base class for parsing, manages the parameter/local variable frame.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic interface
A lexical unit is the container defining local symbols and their visibility boundaries. -
Field Summary
FieldsModifier and TypeFieldDescriptionThe set of assignment operators as classes.protected JexlParser.LexicalUnit
The current lexical block.protected final Deque<JexlParser.LexicalUnit>
Stack of lexical blocks.protected final Map<JexlParser.LexicalUnit,
Scope> The map of lexical to functional blocks.protected final FeatureController
The associated controller.protected JexlInfo
The basic source info.protected int
The number of nested loops.Stack of parsing loop counts.The known namespaces.static final String
The import pragma.static final String
The prefix of a namespace pragma.static final String
The prefix of a module pragma.static final String
The name of the options pragma.The list of pragma declarations.protected Scope
The map of named registers aka script parameters.When parsing inner functions/lambda, need to stack the scope (sic).protected String
The source being processed. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
allowRegisters
(boolean registers) Internal, for debug purpose only.protected boolean
allowVariable
(String image) Whether a given variable name is allowed.protected void
checkLambda
(Token token) Check fat vs thin arrow syntax feature.protected String
checkVariable
(ASTIdentifier identifier, String name) Checks whether an identifier is a local variable or argument, ie a symbol, stored in a register.protected void
cleanup
(JexlFeatures features) Cleanup.protected void
Disables pragma feature is pragma-anywhere feature is disabled.protected void
declareFunction
(ASTVar variable, Token token) Declares a local function.protected void
declareParameter
(Token token, boolean lexical, boolean constant) Declares a local parameter.protected void
declarePragma
(String key, Object value) Adds a pragma declaration.private boolean
declareSymbol
(int symbol) Declares a symbol.protected void
declareVariable
(ASTVar variable, Token token, boolean lexical, boolean constant) Declares a local variable.protected static Token
errorToken
(Token... tokens) Pick the most significant token for error reporting.protected JexlFeatures
protected Scope
getScope()
Gets the frame used by this parser.protected abstract Token
getToken
(int index) Overridden in actual parser to access tokens stack.protected JexlParser.LexicalUnit
getUnit()
Gets the lexical unit used by this parser.protected void
Identifier
(boolean top) Default implementation does nothing but is overridden by generated code.private boolean
isConstant
(int symbol) Checks whether a symbol has been declared as a const in the current stack of lexical units.protected boolean
isDeclaredNamespace
(Token token, Token colon) Checks whether a name identifies a declared namespace.private boolean
isSymbolDeclared
(JexlNode.Info info, int symbol) Checks if a symbol is defined in lexical scopes.protected boolean
isVariable
(String name) Checks whether an identifier is a local variable or argument.protected void
jjtreeCloseNodeScope
(JexlNode node) Called by parser at end of node construction.protected void
jjtreeOpenNodeScope
(JexlNode node) Called by parser at beginning of node construction.protected void
popScope()
Pops back to previous local variable scope.protected void
Restores the previous lexical unit.protected void
Create a new local variable scope and push it as current.protected void
Pushes a new lexical unit.protected static String
readSourceLine
(String src, int lineno) Read a given source line.protected void
setFeatures
(JexlFeatures features) Sets a new set of options.protected static String
Utility function to create '.' separated string from a list of string.protected void
Throws Ambiguous exception.protected void
throwFeatureException
(int feature, JexlInfo info) Throws a feature exception.protected void
throwFeatureException
(int feature, Token trigger) Throws a feature exception.protected void
throwParsingException
(Token parsed) Throws a parsing exception.Methods inherited from class org.apache.commons.jexl3.parser.StringParser
buildRegex, buildString, buildTemplate, escapeIdentifier, escapeString, readString, unescapeIdentifier
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Field Details
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featureController
The associated controller. -
info
The basic source info. -
source
The source being processed. -
scope
The map of named registers aka script parameters.Each parameter is associated to a register and is materialized as an offset in the registers array used during evaluation.
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scopes
When parsing inner functions/lambda, need to stack the scope (sic). -
pragmas
The list of pragma declarations. -
namespaces
The known namespaces. -
loopCount
protected int loopCountThe number of nested loops. -
loopCounts
Stack of parsing loop counts. -
block
The current lexical block. -
blocks
Stack of lexical blocks. -
blockScopes
The map of lexical to functional blocks. -
PRAGMA_OPTIONS
The name of the options pragma.- See Also:
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PRAGMA_JEXLNS
The prefix of a namespace pragma.- See Also:
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PRAGMA_MODULE
The prefix of a module pragma.- See Also:
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PRAGMA_IMPORT
The import pragma.- See Also:
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ASSIGN_NODES
The set of assignment operators as classes.
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Constructor Details
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JexlParser
public JexlParser()
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Method Details
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cleanup
Cleanup.- Parameters:
features
- the feature set to restore if any
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stringify
Utility function to create '.' separated string from a list of string.- Parameters:
lstr
- the list of strings- Returns:
- the dotted version
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readSourceLine
Read a given source line.- Parameters:
src
- the sourcelineno
- the line number- Returns:
- the line
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allowRegisters
public void allowRegisters(boolean registers) Internal, for debug purpose only.- Parameters:
registers
- whether register syntax is recognized by this parser
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setFeatures
Sets a new set of options.- Parameters:
features
- the parser features
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getFeatures
- Returns:
- the current set of features active during parsing
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controlPragmaAnywhere
protected void controlPragmaAnywhere()Disables pragma feature is pragma-anywhere feature is disabled. -
getScope
Gets the frame used by this parser.Since local variables create new symbols, it is important to regain access after parsing to known which / how-many registers are needed.
- Returns:
- the named register map
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pushScope
protected void pushScope()Create a new local variable scope and push it as current. -
popScope
protected void popScope()Pops back to previous local variable scope. -
getUnit
Gets the lexical unit used by this parser.- Returns:
- the named register map
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pushUnit
Pushes a new lexical unit.- Parameters:
unit
- the new lexical unit
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popUnit
Restores the previous lexical unit.- Parameters:
unit
- restores the previous lexical scope
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isSymbolDeclared
Checks if a symbol is defined in lexical scopes.This works with parsed scripts in template resolution only.
- Parameters:
info
- an info linked to a nodesymbol
- the symbol number- Returns:
- true if symbol accessible in lexical scope
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isVariable
Checks whether an identifier is a local variable or argument.- Parameters:
name
- the variable name- Returns:
- true if a variable with that name was declared
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checkVariable
Checks whether an identifier is a local variable or argument, ie a symbol, stored in a register.- Parameters:
identifier
- the identifiername
- the identifier name- Returns:
- the image
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allowVariable
Whether a given variable name is allowed.- Parameters:
image
- the name- Returns:
- true if allowed, false if reserved
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declareSymbol
private boolean declareSymbol(int symbol) Declares a symbol.- Parameters:
symbol
- the symbol index- Returns:
- true if symbol can be declared in lexical scope, false (error) if it is already declared
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declareFunction
Declares a local function.- Parameters:
variable
- the identifier used to declaretoken
- the variable name toekn
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declareVariable
Declares a local variable.This method creates an new entry in the symbol map.
- Parameters:
variable
- the identifier used to declarelexical
- whether the symbol is lexicalconstant
- whether the symbol is constanttoken
- the variable name toekn
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declareParameter
Declares a local parameter.This method creates an new entry in the symbol map.
- Parameters:
token
- the parameter name tokenlexical
- whether the parameter is lexical or notconstant
- whether the parameter is constant or not
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declarePragma
Adds a pragma declaration.- Parameters:
key
- the pragma keyvalue
- the pragma value
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isDeclaredNamespace
Checks whether a name identifies a declared namespace.- Parameters:
token
- the namespace token- Returns:
- true if the name qualifies a namespace
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Identifier
Default implementation does nothing but is overridden by generated code.- Parameters:
top
- whether the identifier is beginning an l/r value- Throws:
ParseException
- subclasses may throw this
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getToken
Overridden in actual parser to access tokens stack.- Parameters:
index
- 0 to get current token- Returns:
- the token on the stack
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jjtreeOpenNodeScope
Called by parser at beginning of node construction.- Parameters:
node
- the node
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jjtreeCloseNodeScope
Called by parser at end of node construction.Detects "Ambiguous statement" and 'non-left value assignment'.
- Parameters:
node
- the node- Throws:
JexlException.Parsing
- when parsing fails
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isConstant
private boolean isConstant(int symbol) Checks whether a symbol has been declared as a const in the current stack of lexical units.- Parameters:
symbol
- the symbol- Returns:
- true if constant, false otherwise
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checkLambda
Check fat vs thin arrow syntax feature.- Parameters:
token
- the arrow token
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throwAmbiguousException
Throws Ambiguous exception.Seeks the end of the ambiguous statement to recover.
- Parameters:
node
- the first token in ambiguous expression- Throws:
JexlException.Ambiguous
- in all cases
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throwFeatureException
Throws a feature exception.- Parameters:
feature
- the feature codeinfo
- the exception surroundings- Throws:
JexlException.Feature
- in all cases
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throwFeatureException
Throws a feature exception.- Parameters:
feature
- the feature codetrigger
- the token that triggered it- Throws:
JexlException.Parsing
- if actual error token can not be foundJexlException.Feature
- in all other cases
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throwParsingException
Throws a parsing exception.- Parameters:
parsed
- the token to report- Throws:
JexlException.Parsing
- in all cases
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errorToken
Pick the most significant token for error reporting.- Parameters:
tokens
- the tokens to choose from- Returns:
- the token
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