TwirlParser

TwirlParser is a recursive descent parser for a modified grammar of the Play2 template language as loosely defined here and more rigorously defined by the original template parser, play.templates.ScalaTemplateCompiler.TemplateParser. TwirlParser is meant to be a near drop in replacement for play.templates.ScalaTemplateCompiler.TemplateParser.

The original grammar, as reversed-engineered from play.templates.ScalaTemplateCompiler.TemplateParser, is defined as follows:

parser : comment? whitespace? ('@' parentheses+)? templateContent
templateContent : (importExpression | localDef | template | mixed)*
templateDeclaration : '@' identifier squareBrackets? parentheses*
localDef : templateDeclaration (' ' | '\t')* '=' (' ' | '\t') scalaBlock
template : templateDeclaration (' ' | '\t')* '=' (' ' | '\t') '{' templateContent '}'
mixed : (comment | scalaBlockDisplayed | caseExpression | matchExpression | forExpression | safeExpression | plain | expression) | ('{' mixed* '}')
scalaBlockDisplayed : scalaBlock
scalaBlockChained : scalaBlock
scalaBlock : '@' brackets
importExpression : '@' 'import ' .* '\r'? '\n'
caseExpression : whitespace? 'case' .+ '=>' block whitespace?
forExpression : '@' "for" parentheses block
matchExpression : '@' (simpleExpr | complexExpr) whitespaceNoBreak 'match' block
simpleExpr : methodCall expressionPart*
complexExpr : parentheses
safeExpression : '@' parentheses
elseCall : whitespaceNoBreak "else" whitespaceNoBreak?
chainedMethods : ('.' methodCall)+
expressionPart : chainedMethods | block | (whitespaceNoBreak scalaBlockChained) | elseCall | parentheses
expression : '@' methodCall expressionPart*
methodCall : identifier squareBrackets? parentheses?
blockArgs : [^'=>' '\n']* '=>'
block : whitespaceNoBreak '{' blockArgs? mixed* '}'
brackets : '{' (brackets | [^'}'])* '}'
comment : '@*' [^'*@']* '*@'
parentheses : '(' (parentheses | [^')'])* ')'
squareBrackets : '[' (squareBrackets | [^']'])* ']'
plain : ('@@' | ([^'@'] [^'{' '}']))+
whitespaceNoBreak : [' ' '\t']+
identifier : javaIdentStart javaIdentPart* // see java docs for what these two rules mean

TwirlParser implements a slightly modified version of the above grammar that removes some back-tracking within the 'mixed' non-terminal. It is defined as follows:

parser : comment? whitespace? ('@' parentheses+)? templateContent
templateContent : (importExpression | localDef | template | mixed)*
templateDeclaration : '@' identifier squareBrackets? parentheses*
localDef : templateDeclaration (' ' | '\t')* '=' (' ' | '\t') scalaBlock
template : templateDeclaration (' ' | '\t')* '=' (' ' | '\t') '{' templateContent '}'
mixed : (comment | scalaBlockDisplayed | forExpression | matchExpOrSafeExpOrExpr | caseExpression | plain) | ('{' mixed* '}')
matchExpOrSafeExpOrExpr : (expression | safeExpression) (whitespaceNoBreak 'match' block)?
scalaBlockDisplayed : scalaBlock
scalaBlockChained : scalaBlock
scalaBlock : '@' brackets
importExpression : '@' 'import ' .* '\r'? '\n'
caseExpression : (whitespace? 'case' .+ '=>' block whitespace?) | whitespace
forExpression : '@' "for" parentheses block
simpleExpr : methodCall expressionPart*
complexExpr : parentheses
safeExpression : '@' parentheses
elseCall : whitespaceNoBreak? "else" whitespaceNoBreak?
elseIfCall : whitespaceNoBreak? "else if" parentheses  whitespaceNoBreak?
chainedMethods : ('.' methodCall)+
expressionPart : chainedMethods | block | (whitespaceNoBreak scalaBlockChained) | elseIfCall | elseCall | parentheses
expression : '@' methodCall expressionPart*
methodCall : identifier squareBrackets? parentheses?
blockArgs : [^'=>' '\n']* '=>'
block : whitespaceNoBreak? '{' blockArgs? mixed* '}'
brackets : '{' (brackets | [^'}'])* '}'
comment : '@*' [^'*@']* '*@'
parentheses : '(' (parentheses | [^')'])* ')'
squareBrackets : '[' (squareBrackets | [^']'])* ']'
plain : ('@@' | '@}' | ([^'@'] [^'{' '}']))+
whitespaceNoBreak : [' ' '\t']+
identifier : javaIdentStart javaIdentPart* // see java docs for what these two rules mean

TwirlParser can detect several type of parse errors and provides line information. In all cases, the parser will continue parsing the best it can after encountering an error. The following errors are what can be detected:

EOF found when more input was expected.
Unmatched curly braces
Missing blocks after case and match statements
Invalid ("alone") '@' symbols.

Linear Supertypes

AnyRef, Any

Instance Constructors

new TwirlParser(shouldParseInclusiveDot: Boolean)

Type Members

case class Error(template: Template, input: Input, errors: List[PosString]) extends ParseResult with Product with Serializable
case class Input() extends Product with Serializable
sealed abstract class ParseResult extends AnyRef
case class Success(template: Template, input: Input) extends ParseResult with Product with Serializable

Value Members

final def !=(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def !=(arg0: Any): Boolean

Definition Classes
Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def ==(arg0: Any): Boolean

Definition Classes
Any
def accept(str: String): Unit

Try to match str and advance str.length characters.
Try to match str and advance str.length characters.
Reports an error if the input does not match str or if str.length goes past the EOF.
def any(length: Int = 1): String

Consume/Advance length characters, and return the consumed characters.
Consume/Advance length characters, and return the consumed characters. Returns "" if at EOF.
def anyUntil(f: (Char) ⇒ Boolean, inclusive: Boolean): String

Consume characters until f returns false on the peek of input.
Consume characters until f returns false on the peek of input.
inclusive
- should the stopped character be included in the consumed characters?
returns
the consumed characters
def anyUntil(stop: String, inclusive: Boolean): String

Consume characters until input matches stop
Consume characters until input matches stop
inclusive
- should stop be included in the consumed characters?
returns
the consumed characters
final def asInstanceOf[T0]: T0

Definition Classes
Any
def block(blockArgsAllowed: Boolean): Block
def blockArgs(): PosString
def brackets(): String
def caseExpression(): TemplateTree
def chainedMethods(): Simple
def check(str: String): Boolean

Does the current input match str? If so, advance str.length.
Does the current input match str? If so, advance str.length.
Will not advance if str.length surpasses EOF
returns
true if advancing, false otherwise.
def check(f: (Char) ⇒ Boolean): Boolean

Does f applied to the current peek return true or false? If true, advance one character.
Does f applied to the current peek return true or false? If true, advance one character.
Will not advance if at EOF.
returns
true if advancing, false otherwise.
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
def comment(): Comment

Parse a comment.
def elseCall(): Simple
def elseIfCall(): Simple
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def error(message: String, offset: Int = input.offset()): Unit
def expression(): Display
def expressionPart(blockArgsAllowed: Boolean): ScalaExpPart
def extraImports(): Seq[Simple]
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
def forExpression(): Display
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

Definition Classes
AnyRef → Any
def identifier(): String
def importExpression(): Simple
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
def lastComment(): Comment

Parses comments and/or whitespace, ignoring both until the last comment is reached, and returning that (if found)
def localDef(): Def
def matchExpOrSafeExpOrExpr(): Display
def methodCall(): String
def mixed(): ListBuffer[TemplateTree]
def mkRegressionStatisticsString(): Unit
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
def parentheses(): String
def parse(source: String): ParseResult
def plain(): Plain
def position[T <: Positional](positional: T, offset: Int): T

Set the source position of a Positional
def recursiveTag(prefix: String, suffix: String, allowStringLiterals: Boolean = false): String

Recursively match pairs of prefixes and suffixes and return the consumed characters
Recursively match pairs of prefixes and suffixes and return the consumed characters
Terminates at EOF.
def safeExpression(): Display
def scalaBlock(): Simple
def scalaBlockChained(): Block
def scalaBlockDisplayed(): Display
def setSource(source: String): Unit
def several[T, BufferType <: Buffer[T]](parser: () ⇒ T, provided: BufferType = null)(implicit manifest: Manifest[BufferType]): BufferType

Match zero or more parser
val shouldParseInclusiveDot: Boolean
def squareBrackets(): String
def stringLiteral(quote: String, escape: String): String

Match a string literal, allowing for escaped quotes.
Match a string literal, allowing for escaped quotes. Terminates at EOF.
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def template(): Template
def templateContent(): (Seq[Simple], Seq[Def], Seq[Template], Seq[TemplateTree])
def templateDeclaration(): (PosString, PosString)
def toString(): String

Definition Classes
AnyRef → Any
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
def whitespace(): String
def whitespaceNoBreak(): String

class TwirlParser extends AnyRef

Instance Constructors

new TwirlParser(shouldParseInclusiveDot: Boolean)

Type Members

case class Error(template: Template, input: Input, errors: List[PosString]) extends ParseResult with Product with Serializable

case class Input() extends Product with Serializable

sealed abstract class ParseResult extends AnyRef

case class Success(template: Template, input: Input) extends ParseResult with Product with Serializable

Value Members

final def !=(arg0: AnyRef): Boolean

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: AnyRef): Boolean

final def ==(arg0: Any): Boolean

def accept(str: String): Unit

def any(length: Int = 1): String

def anyUntil(f: (Char) ⇒ Boolean, inclusive: Boolean): String

def anyUntil(stop: String, inclusive: Boolean): String

final def asInstanceOf[T0]: T0

def block(blockArgsAllowed: Boolean): Block

def blockArgs(): PosString

def brackets(): String

def caseExpression(): TemplateTree

def chainedMethods(): Simple

def check(str: String): Boolean

def check(f: (Char) ⇒ Boolean): Boolean

def clone(): AnyRef

def comment(): Comment

def elseCall(): Simple

def elseIfCall(): Simple

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def error(message: String, offset: Int = input.offset()): Unit

def expression(): Display

def expressionPart(blockArgsAllowed: Boolean): ScalaExpPart

def extraImports(): Seq[Simple]

def finalize(): Unit

def forExpression(): Display

final def getClass(): Class[_]

def hashCode(): Int

def identifier(): String

def importExpression(): Simple

final def isInstanceOf[T0]: Boolean

def lastComment(): Comment

def localDef(): Def

def matchExpOrSafeExpOrExpr(): Display

def methodCall(): String

def mixed(): ListBuffer[TemplateTree]

def mkRegressionStatisticsString(): Unit

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

def parentheses(): String

def parse(source: String): ParseResult

def plain(): Plain

def position[T <: Positional](positional: T, offset: Int): T

def recursiveTag(prefix: String, suffix: String, allowStringLiterals: Boolean = false): String

def safeExpression(): Display

def scalaBlock(): Simple

def scalaBlockChained(): Block

def scalaBlockDisplayed(): Display

def setSource(source: String): Unit

def several[T, BufferType <: Buffer[T]](parser: () ⇒ T, provided: BufferType = null)(implicit manifest: Manifest[BufferType]): BufferType

val shouldParseInclusiveDot: Boolean

def squareBrackets(): String

def stringLiteral(quote: String, escape: String): String

final def synchronized[T0](arg0: ⇒ T0): T0

def template(): Template

def templateContent(): (Seq[Simple], Seq[Def], Seq[Template], Seq[TemplateTree])

def templateDeclaration(): (PosString, PosString)

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

def whitespace(): String

def whitespaceNoBreak(): String

Inherited from AnyRef

Inherited from Any

Ungrouped