Class: TPPlus::Scanner
- Inherits:
-
Object
- Object
- TPPlus::Scanner
- Defined in:
- lib/tp_plus/scanner.rb
Instance Attribute Summary collapse
-
#col ⇒ Object
readonly
Returns the value of attribute col.
-
#lineno ⇒ Object
readonly
Returns the value of attribute lineno.
-
#tok_col ⇒ Object
readonly
Returns the value of attribute tok_col.
-
#tok_line ⇒ Object
readonly
Returns the value of attribute tok_line.
Instance Method Summary collapse
-
#initialize ⇒ Scanner
constructor
A new instance of Scanner.
- #isDigit?(ch) ⇒ Boolean
- #isLetter?(ch) ⇒ Boolean
- #next ⇒ Object
-
#next_token ⇒ Object
return token.
- #scan_setup(src) ⇒ Object
- #scanComment ⇒ Object
- #scanIdentifier ⇒ Object
- #scanLabel ⇒ Object
- #scanNumber ⇒ Object
- #scanReal ⇒ Object
- #scanString(type) ⇒ Object
- #skipWhitespace ⇒ Object
Constructor Details
#initialize ⇒ Scanner
Returns a new instance of Scanner.
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# File 'lib/tp_plus/scanner.rb', line 3 def initialize end |
Instance Attribute Details
#col ⇒ Object (readonly)
Returns the value of attribute col.
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# File 'lib/tp_plus/scanner.rb', line 6 def col @col end |
#lineno ⇒ Object (readonly)
Returns the value of attribute lineno.
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# File 'lib/tp_plus/scanner.rb', line 6 def lineno @lineno end |
#tok_col ⇒ Object (readonly)
Returns the value of attribute tok_col.
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# File 'lib/tp_plus/scanner.rb', line 7 def tok_col @tok_col end |
#tok_line ⇒ Object (readonly)
Returns the value of attribute tok_line.
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# File 'lib/tp_plus/scanner.rb', line 7 def tok_line @tok_line end |
Instance Method Details
#isDigit?(ch) ⇒ Boolean
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# File 'lib/tp_plus/scanner.rb', line 39 def isDigit?(ch) return false if ch == -1 case ch when '0','1','2','3','4','5','6','7','8','9' return true else return false end end |
#isLetter?(ch) ⇒ Boolean
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# File 'lib/tp_plus/scanner.rb', line 50 def isLetter?(ch) return false if ch == -1 case ch when 'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z', 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z', '_' return true else return false end end |
#next ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 23 def next if @rdOffset < @src.length @offset = @rdOffset @ch = @src[@rdOffset] if @ch == "\n" @lineno += 1 @col = 0 end @rdOffset += 1 @col += 1 else @offset = @src.length @ch = -1 end end |
#next_token ⇒ Object
return token
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# File 'lib/tp_plus/scanner.rb', line 140 def next_token self.skipWhitespace @tok_line = @lineno @tok_col = @col tok = nil lit = "" ch = @ch if isLetter?(ch) lit = self.scanIdentifier if @ch == '[' tok = TPPlus::Token.lookup_data(lit) elsif lit == "DIV" tok = :DIV else # keywords are longer than 1 char, avoid lookup otherwise if lit.length > 1 if @prevDot case lit when "gp1","gp2","gp3","gp4","gp5" tok = :GROUP else tok = TPPlus::Token.lookup(lit) end else tok = TPPlus::Token.lookup(lit) end else tok = :WORD end end elsif isDigit?(ch) tok, lit = self.scanNumber else self.next # always make progress case ch when -1 return nil when '=' if @ch == '=' tok = :EEQUAL self.next else tok = :EQUAL end when ':' if @ch == "=" tok = :ASSIGN self.next else tok = :COLON end when "<" if @ch == "=" tok = :LTE self.next elsif @ch == ">" tok = :NOTEQUAL self.next else tok = :LT end when ">" if @ch == "=" tok = :GTE self.next else tok = :GT end when "+" tok = :PLUS when "-" tok = :MINUS when "*" tok = :STAR when "/" tok = :SLASH when "&" if @ch == "&" tok = :AND self.next elsif isLetter?(@ch) tok = :ADDRESS lit = self.scanIdentifier else tok = :ILLEGAL end when "|" if @ch == "|" tok = :OR self.next else tok = :ILLEGAL end when "%" tok = :MOD when ";" tok = :SEMICOLON when "." if self.isDigit?(@ch) tok, lit = self.scanReal else tok = :DOT end when "!" if @ch == "=" tok = :NOTEQUAL self.next else tok = :BANG end when "\"", "'" tok = :STRING lit = self.scanString(ch) when "#" tok = :COMMENT lit = self.scanComment when "@" tok = :LABEL lit = self.scanLabel when '(' tok = :LPAREN when ')' tok = :RPAREN when ',' tok = :COMMA when '[' tok = :LBRACK when ']' tok = :RBRACK when '{' tok = :LBRACE when '}' tok = :RBRACE when "\n" tok = :NEWLINE else tok = :ILLEGAL lit = ch end end if tok == :DOT @prevDot = true else @prevDot = false end return [tok, lit] end |
#scan_setup(src) ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 8 def scan_setup(src) @src = src @lineno = 1 @ch = " " @offset = 0 @col = 0 @rdOffset = 0 @prevDot = false # for groups @tok_line = 0 @tok_col = 0 self.next end |
#scanComment ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 109 def scanComment offs = @offset-1 # opening # already consumed while @ch != "\n" && @ch != -1 self.next end return @src[offs,(@offset-offs)] end |
#scanIdentifier ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 69 def scanIdentifier offs = @offset while isLetter?(@ch) || isDigit?(@ch) self.next end # allow one ? or ! at end if @ch == '?' || @ch == '!' self.next end return @src[offs,(@offset-offs)] end |
#scanLabel ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 130 def scanLabel offs = @offset while self.isLetter?(@ch) self.next end return @src[offs, (@offset-offs)] end |
#scanNumber ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 92 def scanNumber offs = @offset while self.isDigit?(@ch) self.next end if @ch == '.' self.next while self.isDigit?(@ch) self.next end return [:REAL, @src[offs,(@offset-offs)].to_f] else return [:DIGIT, @src[offs,(@offset-offs)].to_i] end end |
#scanReal ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 83 def scanReal offs = @offset-1 while self.isDigit?(@ch) self.next end return [:REAL, @src[offs,(@offset-offs)].to_f] end |
#scanString(type) ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 118 def scanString(type) offs = @offset while @ch != type && @ch != -1 self.next end # consume close self.next return @src[offs, (@offset-offs-1)] # -1 to remove trailing " or ' end |
#skipWhitespace ⇒ Object
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# File 'lib/tp_plus/scanner.rb', line 63 def skipWhitespace while @ch == ' ' || @ch == "\t" || @ch == "\r" self.next end end |