58d280462e
Co-authored-by: Barf-Vader <Barf-Vader@users.noreply.github.com> Co-authored-by: Gleb Koval
106 lines
3.5 KiB
Scala
106 lines
3.5 KiB
Scala
package wacc
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import parsley.Parsley
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import parsley.character
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import parsley.token.{Basic, Lexer}
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import parsley.token.descriptions.*
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import parsley.token.errors._
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/** ErrorConfig for producing more informative error messages
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*/
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val errConfig = new ErrorConfig {
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override def labelSymbol = Map(
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"!=" -> Label("binary operator"),
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"%" -> Label("binary operator"),
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"&&" -> Label("binary operator"),
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"*" -> Label("binary operator"),
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"/" -> Label("binary operator"),
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"<" -> Label("binary operator"),
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"<=" -> Label("binary operator"),
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"==" -> Label("binary operator"),
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">" -> Label("binary operator"),
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">=" -> Label("binary operator"),
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"||" -> Label("binary operator"),
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"!" -> Label("unary operator"),
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"len" -> Label("unary operator"),
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"ord" -> Label("unary operator"),
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"chr" -> Label("unary operator"),
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"bool" -> Label("valid type"),
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"char" -> Label("valid type"),
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"int" -> Label("valid type"),
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"pair" -> Label("valid type"),
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"string" -> Label("valid type"),
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"fst" -> Label("pair extraction"),
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"snd" -> Label("pair extraction"),
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"false" -> Label("boolean literal"),
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"true" -> Label("boolean literal"),
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"=" -> Label("assignment"),
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"[" -> Label("array index")
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)
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}
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object lexer {
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/** Language description for the WACC lexer
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*/
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private val desc = LexicalDesc.plain.copy(
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nameDesc = NameDesc.plain.copy(
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identifierStart = Basic(c => c.isLetter || c == '_'),
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identifierLetter = Basic(c => c.isLetterOrDigit || c == '_')
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),
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symbolDesc = SymbolDesc.plain.copy(
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hardKeywords = Set(
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"begin", "end", "is", "skip", "if", "then", "else", "fi", "while", "do", "done", "read",
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"free", "return", "exit", "print", "println", "true", "false", "int", "bool", "char",
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"string", "pair", "newpair", "fst", "snd", "call", "chr", "ord", "len", "null"
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),
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hardOperators = Set(
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"+", "-", "*", "/", "%", ">", "<", ">=", "<=", "==", "!=", "&&", "||", "!"
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)
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),
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spaceDesc = SpaceDesc.plain.copy(
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lineCommentStart = "#"
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),
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textDesc = TextDesc.plain.copy(
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graphicCharacter = Basic(c => c >= ' ' && c != '\\' && c != '\'' && c != '"'),
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escapeSequences = EscapeDesc.plain.copy(
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literals = Set('\\', '"', '\''),
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mapping = Map(
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"0" -> '\u0000',
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"b" -> '\b',
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"t" -> '\t',
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"n" -> '\n',
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"f" -> '\f',
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"r" -> '\r'
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)
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)
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),
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numericDesc = NumericDesc.plain.copy(
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decimalExponentDesc = ExponentDesc.NoExponents
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)
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)
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/** Token definitions for the WACC lexer
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*/
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private val lexer = Lexer(desc, errConfig)
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val ident = lexer.lexeme.names.identifier
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val integer = lexer.lexeme.integer.decimal32[Int]
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val negateCheck = lexer.nonlexeme.symbol("-") ~> character.digit
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val charLit = lexer.lexeme.character.ascii
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val stringLit = lexer.lexeme.string.ascii
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val implicits = lexer.lexeme.symbol.implicits
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/** Tokens for producing lexer-backed error messages
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*/
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val errTokens = Seq(
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lexer.nonlexeme.names.identifier.map(v => s"identifier $v"),
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lexer.nonlexeme.integer.decimal32[Int].map(n => s"integer $n"),
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lexer.nonlexeme.character.ascii.map(c => s"character literal \'$c\'"),
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lexer.nonlexeme.string.ascii.map(s => s"string literal \"$s\""),
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lexer.nonlexeme.symbol("[").as("array literal"),
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character.whitespace.map(_ => "")
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) ++ desc.symbolDesc.hardKeywords.map { k =>
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lexer.nonlexeme.symbol(k).as(s"keyword $k")
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}
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def fully[A](p: Parsley[A]): Parsley[A] = lexer.fully(p)
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}
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