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lexer.grace
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#pragma DefaultVisibility=public
import "io" as io
import "sys" as sys
import "util" as util
import "unicode" as unicode
import "mgcollections" as collections
import "errormessages" as errormessages
// Return the numeric value of the single hexadecimal character c.
method hexdecchar(c) {
var chars := ["0", "1", "2", "3", "4", "5", "6", "7", "8",
"9", "a", "b", "c", "d", "e", "f"]
var ret := 0
var i := 0
for (chars) do {cr->
if (cr == c) then {
ret := i
}
i := i + 1
}
ret
}
method padl(s, l, w) {
if (s.size >= l) then {
return s
}
var s' := s
while {s'.size < l} do {
s' := w ++ s'
}
return s'
}
def LexerClass = object {
method new {
var lineNumber := 1
var linePosition := 0
var startPosition := 1
var indentLevel := 0
class Token.new() {
def line = lineNumber
def indent = indentLevel
def linePos = startPosition
var next := false
var prev := false
method ==(other) {
if(other == false) then {
false
} else {
(other.line == line) && (other.linePos == linePos)
}
}
}
class IdentifierToken.new(s) {
inherits Token.new
def kind = "identifier"
def value = s
def size = s.size
}
class StringToken.new(s) {
inherits Token.new
def kind = "string"
def value = s
def size = s.size + 2
}
class CommentToken.new(s) {
inherits Token.new
def kind = "comment"
def value = s
def size = s.size + 2
}
class OctetsToken.new(s) {
inherits Token.new
def kind = "octets"
def value = s
def size = s.size + 3
}
class LBraceToken.new {
inherits Token.new
def kind = "lbrace"
def value = "\{"
def size = 1
}
class RBraceToken.new {
inherits Token.new
def kind = "rbrace"
def value = "}"
def size = 1
}
class LParenToken.new {
inherits Token.new
def kind = "lparen"
def value = "("
def size = 1
}
class RParenToken.new {
inherits Token.new
def kind = "rparen"
def value = ")"
def size = 1
}
class LSquareToken.new {
inherits Token.new
def kind = "lsquare"
def value = "["
def size = 1
}
class RSquareToken.new {
inherits Token.new
def kind = "rsquare"
def value = "]"
def size = 1
}
class CommaToken.new {
inherits Token.new
def kind = "comma"
def value = ","
def size = 1
}
class ColonToken.new {
inherits Token.new
def kind = "colon"
def value = ":"
def size = 1
}
class DotToken.new {
inherits Token.new
def kind = "dot"
def value = "."
def size = 1
}
class NumToken.new(v, b) {
inherits Token.new
def kind = "num"
def value = v
def base = b
def size = linePosition - startPosition
}
class KeywordToken.new(v) {
inherits Token.new
def kind = "keyword"
def value = v
def size = v.size
}
class OpToken.new(v) {
inherits Token.new
def kind = "op"
def value = v
def size = v.size
}
class ArrowToken.new {
inherits Token.new
def kind = "arrow"
def value = "->"
def size = 2
}
class BindToken.new {
inherits Token.new
def kind = "bind"
def value = ":="
def size = 2
}
class SemicolonToken.new {
inherits Token.new
def kind = "semicolon"
def value = ";"
def size = 1
}
class LGenericToken.new {
inherits Token.new
def kind = "lgeneric"
def value = "<"
def size = 1
}
class RGenericToken.new {
inherits Token.new
def kind = "rgeneric"
def value = ">"
def size = 1
}
object {
// When a new lexical class has begun, add to the tokens list
// the token corresponding to the previous accumulated data.
// mode is the previous lexical mode (a string), and accum the
// accumulated characters since that mode began. Modes are:
// n Whitespace i Identifier
// " Quoted string x Octets literal
// m Number o Any operator
// p Pragma d Indentation
// c Comment
// ,.{}()[]<>; The corresponding literal character
//
// There are three special cases for mode o. If accum is "->",
// ":=", or "=", the corresponding special token is created.
// For mode i, a keyword token is created for an identifier
// whose name is a reserved keyword.
method modechange(tokens, mode, accum) {
var done := false
var tok := 0
if ((mode != "n") || (accum.size > 0)) then {
if (mode == "i") then {
tok := IdentifierToken.new(accum)
if ((accum == "object") || (accum == "method")
|| (accum == "var") || (accum == "type")
|| (accum == "import") || (accum == "class")
|| (accum == "return") || (accum == "def")
|| (accum == "inherits") || (accum == "is")
|| (accum == "dialect")) then {
tok := KeywordToken.new(accum)
}
tokens.push(tok)
done := true
}
if (mode == "I") then {
tok := IdentifierToken.new(accum)
tokens.push(tok)
done := true
} elseif (mode == "\"") then {
tok := StringToken.new(accum)
tokens.push(tok)
done := true
} elseif (mode == "x") then {
tok := OctetsToken.new(accum)
tokens.push(tok)
done := true
} elseif (mode == ",") then {
tok := CommaToken.new
tokens.push(tok)
done := true
} elseif (mode == ".") then {
tok := DotToken.new
tokens.push(tok)
done := true
} elseif (mode == "\{") then {
tok := LBraceToken.new
tokens.push(tok)
done := true
} elseif (mode == "}") then {
tok := RBraceToken.new
tokens.push(tok)
done := true
} elseif (mode == "(") then {
tok := LParenToken.new
tokens.push(tok)
done := true
} elseif (mode == ")") then {
tok := RParenToken.new
tokens.push(tok)
done := true
} elseif (mode == "[") then {
tok := LSquareToken.new
tokens.push(tok)
done := true
}
if (mode == "]") then {
tok := RSquareToken.new
tokens.push(tok)
done := true
} elseif (mode == "<") then {
tok := LGenericToken.new
tokens.push(tok)
done := true
} elseif (mode == ">") then {
tok := RGenericToken.new
tokens.push(tok)
done := true
} elseif (mode == ";") then {
tok := SemicolonToken.new
tokens.push(tok)
done := true
} elseif (mode == "m") then {
if ((tokens.size > 1).andAlso {tokens.last.kind == "dot"}) then {
def dot = tokens.pop
if (tokens.last.kind == "num") then {
if (tokens.last.base == 10) then {
tok := tokens.pop
var decimal := makeNumToken(accum)
if(decimal.base == 10) then {
tok := NumToken.new(tok.value ++ "." ++ accum, 10)
} else {
def suggestions = []
var suggestion := errormessages.suggestion.new
suggestion.replaceRange(dot.linePos + 1, linePosition - 1)with(decimal.value)onLine(lineNumber)
suggestions.push(suggestion)
suggestion := errormessages.suggestion.new
suggestion.deleteRange(dot.linePos, linePosition - 1)onLine(lineNumber)
suggestions.push(suggestion)
errormessages.syntaxError("The fractional part of a number must be in base 10.")atRange(
lineNumber, dot.linePos + 1, linePosition - 1)withSuggestions(suggestions)
}
} else {
def suggestions = []
var suggestion := errormessages.suggestion.new
suggestion.replaceRange(tokens.last.linePos, dot.linePos - 1)with(tokens.last.value)onLine(lineNumber)
suggestions.push(suggestion)
suggestion := errormessages.suggestion.new
suggestion.deleteChar(dot.linePos)onLine(lineNumber)
suggestions.push(suggestion)
errormessages.syntaxError("A number in base {tokens.last.base} cannot have a fractional part.")atRange(
lineNumber, dot.linePos, linePosition - 1)withSuggestions(suggestions)
}
} else {
if(tokens.last.kind == "string") then {
def suggestion = errormessages.suggestion.new
suggestion.replaceChar(dot.linePos)with("++")onLine(dot.line)
errormessages.syntaxError("A number may only follow a '.' if there is a number before the '.'. "
++ "To join a number to a string, use '++'.")atRange(
dot.line, dot.linePos, dot.linePos)withSuggestion(suggestion)
} elseif((tokens.last.kind == "op") || (tokens.last.kind == "bind")) then {
def suggestion = errormessages.suggestion.new
suggestion.insert("0")atPosition(dot.linePos)onLine(dot.line)
errormessages.syntaxError("A number must have a digit before the decimal point.")atPosition(
dot.line, dot.linePos)withSuggestion(suggestion)
} elseif(tokens.last.kind == "identifier") then {
def suggestions = []
if(tokens.last.value == "o") then {
def suggestion = errormessages.suggestion.new
suggestion.replaceChar(tokens.last.linePos)with("0")onLine(tokens.last.line)
suggestions.push(suggestion)
}
def suggestion = errormessages.suggestion.new
suggestion.replaceRange(dot.linePos, linePosition - 1)with("({accum})")onLine(tokens.last.line)
suggestions.push(suggestion)
errormessages.syntaxError("A number may only follow a '.' if there is a number before the '.'.")atRange(
dot.line, dot.linePos, dot.linePos)withSuggestions(suggestions)
} else {
errormessages.syntaxError("A number may only follow a '.' if there is a number before the '.'.")atRange(
dot.line, dot.linePos, dot.linePos)
}
}
} else {
tok := makeNumToken(accum)
}
tokens.push(tok)
done := true
} elseif (mode == "o") then {
tok := OpToken.new(accum)
if (accum == "->") then {
tok := ArrowToken.new
} elseif (accum == ":=") then {
tok := BindToken.new
} elseif (accum == ":") then {
tok := ColonToken.new
}
tokens.push(tok)
done := true
} elseif (mode == "d") then {
indentLevel := linePosition - 1//accum.size
done := true
} elseif (mode == "n") then {
done := true
} elseif (mode == "c") then {
def cmt = accum.substringFrom(3)to(accum.size)
tokens.push(CommentToken.new(cmt))
done := true
} elseif (mode == "p") then {
if (accum.substringFrom(1)to(8) == "#pragma ") then {
util.processExtension(
accum.substringFrom(9)to(accum.size))
}
} elseif (done) then {
//print(mode, accum, tokens)
} else {
errormessages.syntaxError("Lexing error: no handler for mode {mode} with accum {accum}.")atPosition(lineNumber, linePosition)
}
}
startPosition := linePosition
}
method fromBase(str, base) {
var val := 0
var i := 0
for (str) do {c->
def n = c.ord
val := val * base
var inc := 0
if ((n >= 48) && (n <= 57)) then {
inc := n - 48 // 0
} elseif((n >= 65) && (n <= 90)) then {
inc := n - 55 // 'A' - 10
} else {
inc := n - 87 // 'a' - 10
}
if (inc >= base) then {
if((str[1] == "0") && (inc < 16)) then {
def suggestion = errormessages.suggestion.new
suggestion.insert("x")atPosition(linePosition - str.size + 1)onLine(lineNumber)
errormessages.syntaxError("A number in base 16 must start with '0x'.")atPosition(
lineNumber, linePosition - str.size + 1)withSuggestion(suggestion)
} else {
def suggestion = errormessages.suggestion.new
if(str.size == 1) then {
suggestion.deleteRange(linePosition - str.size - 1, linePosition - 1)onLine(lineNumber)
} else {
suggestion.deleteChar(linePosition - str.size + i)onLine(lineNumber)
}
def validDigits = if(base <= 10) then {
"'0' to '{base - 1}'"
} else {
"'0' to '9', 'a' to '{unicode.create(87 + base)}'"
}
errormessages.syntaxError("'{c}' is not a valid digit in base {base}. Valid digits are {validDigits}.")atRange(
lineNumber, linePosition - str.size + i, linePosition - str.size + i)withSuggestion(suggestion)
}
}
val := val + inc
i := i + 1
}
val
}
method makeNumToken(accum) {
var base := 10
var baseSet := false
var sofar := ""
var i := 0
for (accum) do {c->
if ((c == "x") && (!baseSet)) then {
base := sofar.asNumber
baseSet := true
if (base == 0) then {
base := 16
}
if((base < 2) || (base > 36)) then {
def suggestions = []
var suggestion := errormessages.suggestion.new
suggestion.replaceChar(linePosition - accum.size + i)with("*")onLine(lineNumber)
suggestions.push(suggestion)
suggestion := errormessages.suggestion.new
suggestion.deleteRange(linePosition - accum.size, linePosition - accum.size + i)onLine(lineNumber)
suggestions.push(suggestion)
errormessages.syntaxError("Base {base} is not a valid numerical base.")atRange(
lineNumber, linePosition - accum.size, linePosition - accum.size + i - 1)withSuggestions(suggestions)
}
sofar := ""
} else {
sofar := sofar ++ c
}
i := i + 1
}
if(sofar == "") then {
def suggestions = []
var suggestion := errormessages.suggestion.new
suggestion.deleteRange(linePosition - accum.size + i - 1, linePosition - 1)onLine(lineNumber)
suggestions.push(suggestion)
suggestion := errormessages.suggestion.new
suggestion.insert("0")atPosition(linePosition)onLine(lineNumber)
suggestions.push(suggestion)
errormessages.syntaxError("At least one digit must follow the 'x' in a number.")atPosition(
lineNumber, linePosition - accum.size + i)withSuggestions(suggestions)
}
NumToken.new(fromBase(sofar, base).asString, base)
}
// True if ov is a valid identifier character. Identifier
// characters are Unicode letters, Unicode numbers, apostrophe,
// and (currently) underscore.
method isidentifierchar(ov) {
if (unicode.isLetter(ov)) then {
return true
}
if (unicode.isNumber(ov)) then {
return true
}
if ((ov == 95) || (ov == 39)) then {
// 95 is _, 39 is '
true
} else {
false
}
}
// True if c (with codepoint ordval) is a valid operator character.
method isoperatorchar(c, ordval) {
if ((c == "-") || (c == "&") || (c == "|") || (c == ":")
|| (c == "%") || (c == "^") || (c == "@") || (c == "?")
|| (c == "*") || (c == "/") || (c == "+") || (c == "!")
) then {
return true
}
if (unicode.isSymbolMathematical(ordval)) then {
return true
} elseif (unicode.iscategory(c, "So")) then {
return true
}
return false
}
// Read the program text from util.infile and return a list of
// tokens.
method lexfile(file) {
util.log_verbose("reading source.")
def lines = []
def cLines = []
var line := ""
var cLine := ""
var source := ""
for(file.read) do { c ->
if((c == "\n") || (c == "\l")) then {
lines.push(line)
cLines.push(cLine)
line := ""
cLine := ""
} elseif(c == "\r") then {
} elseif(c == "\\") then {
line := line ++ "\\"
cLine := cLine ++ "\\\\"
} elseif(c == "\"") then {
line := line ++ "\""
cLine := cLine ++ "\\\""
} else {
line := line ++ c
cLine := cLine ++ c
}
source := source ++ c
}
if(line != "") then {
lines.push(line)
cLines.push(cLine)
}
util.lines := lines
util.cLines := cLines
lexinput(source)
}
method lexinput(input) {
// tokens is a doubly-linked list of tokens.
var tokens := object {
var first := false
var last := false
var size' := 0
method push(t) {
if(first == false) then {
first := t
last := t
} else {
last.next := t
t.prev := last
last := t
}
size' := size' + 1
}
method pop {
if(last != false) then {
def popped = last
last := last.prev
if(last == false) then {
first := false
}
size' := size' - 1
popped
}
}
method poll {
if(first != false) then {
def polled = first
first := first.next
if(first == false) then {
last := false
}
size' := size' - 1
polled
}
}
method size {
size' + 0
}
method iter {
object {
var n := first
method havemore {
n != false
}
method next {
def ret = n
n := n.next
ret
}
}
}
method iterator {
iter
}
}
var mode := "d"
var newmode := mode
var instr := false
var inBackticks := false
var backtickIdent := false
var accum := ""
var escaped := false
var prev := ""
var unichars := 0
var codepoint := 0
var interpdepth := 0
var interpString := false
var atStart := true
linePosition := 0
util.log_verbose("lexing.")
def badSeparator = unicode.pattern("Z", 9)not(32, 8232)
def badControl = unicode.pattern("C")not(10, 13)
def selfModes = unicode.pattern("(".ord, ")".ord, ",".ord,
".".ord, "\{".ord, "}".ord, "[".ord, "]".ord, ";".ord)
def brackets = unicode.pattern("(".ord, ")".ord,
"\{".ord, "}".ord, "[".ord, "]".ord)
def identifierChar = unicode.pattern("L", "N", 95, 39)
def digit = unicode.pattern("0".ord, "1".ord, "2".ord, "3".ord,
"4".ord, "5".ord, "6".ord, "7".ord, "8".ord, "9".ord)
def digitB = unicode.pattern("0".ord, "1".ord, "2".ord, "3".ord,
"4".ord, "5".ord, "6".ord, "7".ord, "8".ord, "9".ord)
def operatorChar = unicode.pattern("Sm", "So",
"-".ord, "&".ord, "|".ord, ":".ord,
"%".ord, "^".ord, "@".ord, "?".ord,
"*".ord, "/".ord, "+".ord, "!".ord
)
def iGTLT = unicode.pattern("i".ord, "<".ord, ">".ord)
def notcp = unicode.pattern()not("c".ord, "p".ord)
def mainBlock = { c->
var ct := ""
var ordval := c.ord // String.ord gives the codepoint
if (badSeparator.match(ordval)) then {
// Character is whitespace, but not an ASCII space or
// Unicode LINE SEPARATOR, or is a tab
def suggestion = errormessages.suggestion.new
suggestion.replaceChar(linePosition)with(" ")onLine(lineNumber)
if(ordval == 9) then {
if (instr) then {
suggestion.replaceRange(linePosition, linePosition)
with("\\u{padl(ordval.inBase 16, 4, "0")}")
onLine(lineNumber)
errormessages.syntaxError("tabs cannot be "
++ "written in the source code; "
++ "use the Unicode escape \\u"
++ padl(ordval.inBase 16, 4, "0")
++ " instead")
atRange(lineNumber, linePosition, linePosition)
withSuggestion(suggestion)
}
errormessages.syntaxError("Tabs are not allowed; use spaces instead.")atRange(lineNumber,
linePosition, linePosition)withSuggestion(suggestion)
} else {
if (instr) then {
suggestion.replaceRange(linePosition, linePosition)
with("\\u{padl(ordval.inBase 16, 4, "0")}")
onLine(lineNumber)
errormessages.syntaxError("{unicode.name(c)} (U+{padl(ordval.inBase 16, 4, "0")}) "
++ "is not a valid whitespace character"
++ " and cannot be "
++ "written in the source code; "
++ "use the Unicode escape \\u"
++ padl(ordval.inBase 16, 4, "0")
++ " instead")
atRange(lineNumber, linePosition, linePosition)
withSuggestion(suggestion)
}
errormessages.syntaxError("{unicode.name(c)} (U+{padl(ordval.inBase 16, 4, "0")}) "
++ "is not a valid whitespace character; use spaces instead.")atRange(lineNumber,
linePosition, linePosition)withSuggestion(suggestion)
}
}
if (badControl.match(ordval)) then {
// Character is a control character other than
// carriage return or line feed.
def suggestion = errormessages.suggestion.new
if (instr) then {
suggestion.replaceRange(linePosition, linePosition)
with("\\u{padl(ordval.inBase 16, 4, "0")}")
onLine(lineNumber)
errormessages.syntaxError("{unicode.name(c)} (U+{padl(ordval.inBase 16, 4, "0")}) "
++ "is a control character and cannot be "
++ "written in the source code; "
++ "use the Unicode escape \\u"
++ padl(ordval.inBase 16, 4, "0")
++ " instead")
atRange(lineNumber, linePosition, linePosition)
withSuggestion(suggestion)
}
suggestion.deleteChar(linePosition)onLine(lineNumber)
errormessages.syntaxError("{unicode.name(c)} (U+{padl(ordval.inBase 16, 4, "0")}) "
++ "is a control character and cannot be written in the source code; consider using spaces instead.")atRange(lineNumber,
linePosition, linePosition)withSuggestion(suggestion)
}
if (atStart) then {
if (linePosition == 1) then {
if (c == "#") then {
mode := "p"
newmode := mode
} else {
atStart := false
}
}
}
if (instr) then {
} elseif ((mode != "c") && (mode != "p")) then {
// Not in a comment, so look for a mode.
if ((c == " ") && (mode != "d")) then {
newmode := "n"
}
if (c == "\"") then {
// Beginning of a string
newmode := "\""
instr := true
}
if (identifierChar.match(ordval)) then {
newmode := "i"
}
ct := ((ordval >= 48) && (ordval <=57))
if (digit.match(ordval)) then {
if (mode != "i") then {
newmode := "m"
}
}
if (mode == "m") then {
if ((ordval >= 97) && (ordval <=122)) then {
newmode := "m"
} else {
if ((ordval >= 65) && (ordval <= 90)) then {
newmode := "m"
}
}
}
if ((mode == "i") && (c == "<")) then {
newmode := "<"
} elseif (iGTLT.match(mode)
&& (c == ">")) then {
if (mode == ">") then {
modechange(tokens, mode, accum)
}
newmode := ">"
} elseif (operatorChar.match(ordval)) then {
newmode := "o"
}
if (selfModes.match(ordval)) then {
newmode := c
}
if (c == "#") then {
if (mode != "p") then {
if(util.lines.at(lineNumber).substringFrom(1)to(7) == "#pragma") then {
if(tokens.size == 0) then {
def suggestion = errormessages.suggestion.new
suggestion.addLine(1, util.lines.at(lineNumber))
suggestion.addLine(lineNumber, "")
errormessages.syntaxError("Pragma directives must be at the start of the file.")atLine(
lineNumber)withSuggestion(suggestion)
} else {
errormessages.syntaxError("Pragma directives must be at the start of the file.")atLine(
lineNumber)
}
} else {
def suggestion = errormessages.suggestion.new
suggestion.replaceChar(linePosition)with("//")onLine(lineNumber)
errormessages.syntaxError("'#' is not allowed here. For a comment use '//'.")atRange(
lineNumber, linePosition, linePosition)withSuggestion(suggestion)
}
}
}
if (c == ".") then {
if (accum == ".") then {
// Special handler for .. operator
mode := "o"
newmode := mode
}
if (accum == "..") then {
// Special handler for ... identifier
mode := "n"
newmode := mode
modechange(tokens, "i", "...")
accum := ""
}
}
if (c == "/") then {
if (accum == "/") then {
// Start of comment
mode := "c"
newmode := mode
}
}
if (mode == "n") then {
if (mode == newmode) then {
if (unicode.isSeparator(ordval).not) then {
if (unicode.isControl(ordval).not) then {
if (ordval != 10) then {
if (ordval != 13) then {
if (ordval != 32) then {
if (c != ".") then{
errormessages.syntaxError("{unicode.name(c)} (U+{padl(ordval.inBase 16, 4, "0")}) "
++ "is not a valid character; use spaces instead.")atRange(
lineNumber, linePosition, linePosition)
}
}
}
}
}
}
}
}
}
if (mode == "\"") then {
if (c == "\"") then {
if (escaped.not) then {
// End of string literal
newmode := "n"
instr := false
if (interpString) then {
modechange(tokens, mode, accum)
modechange(tokens, ")", ")")
mode := newmode
interpString := false
}
}
}
}
if (newmode != mode) then {
// This character is the beginning of a different
// lexical mode - process the old one now.
modechange(tokens, mode, accum)
if (interpdepth > 0) then {
if (newmode == "}") then {
// Find the position of the opening brace to check in the interpolation is empty.
if (util.lines.at(tokens.last.line)[tokens.last.linePos] == "\{") then {
def suggestion = errormessages.suggestion.new
suggestion.deleteRange(linePosition - 1, linePosition)onLine(lineNumber)
errormessages.syntaxError("A string interpolation cannot be empty.")atRange(
lineNumber, tokens.last.linePos, linePosition)withSuggestion(suggestion)
}
modechange(tokens, ")", ")")
modechange(tokens, "o", "++")
newmode := "\""
instr := true
interpdepth := interpdepth - 1
}
}
mode := newmode
if (instr) then {
// String accum should skip the opening quote, but
// other modes' should include their first
// character.
accum := ""
} else {
accum := c
}
if (brackets.match(mode)) then {
modechange(tokens, mode, accum)
mode := "n"
newmode := "n"
accum := ""
}
} elseif (instr) then {
if (c == "\n") then {
if (interpdepth > 0) then {
// Find closest {.
var line := lineNumber
var i := util.lines.at(line).size
while { util.lines.at(line)[i] != "\{" } do {
i := i - 1
if(i == 0) then {
lineNumber := line - 1
i := util.lines.at(line).size
}
}
def suggestions = []
var suggestion := errormessages.suggestion.new
suggestion.insert("\\")atPosition(i)onLine(line)
suggestions.push(suggestion)
if((line == lineNumber) && (i == (linePosition - 2))) then {
errormessages.syntaxError("For a '\{' character in a string use '\\\{'.")atPosition(
line, i)withSuggestions(suggestions)
} else {
suggestion := errormessages.suggestion.new
suggestion.insert("}")atPosition(linePosition - accum.size - 1)onLine(lineNumber)
suggestions.push(suggestion)
errormessages.syntaxError("A string interpolation must end with a '}'. For a '\{' character in a string use '\\\{'.")atPosition(
lineNumber, linePosition - accum.size - 1)withSuggestions(suggestions)
}
} else {
def errorLine = util.lines.at(lineNumber)
def nextLine = if(util.lines.size >= (lineNumber + 1)) then {
util.lines.at(lineNumber + 1)
} else {
""
}
// Count the number of literal quotes in the next line.
var i := 1
var count := 0
while { i <= nextLine.size } do {
if(nextLine[i] == "\"") then { count := count + 1 }
elseif(nextLine[i] == "\\") then { i := i + 1 }
i := i + 1
}
if ((count % 2) == 1) then {
def suggestions = []
var suggestion := errormessages.suggestion.new
suggestion.addLine(lineNumber, errorLine ++ nextLine)
suggestion.addLine(lineNumber + 1, "")
suggestions.push(suggestion)
suggestion := errormessages.suggestion.new
suggestion.addLine(lineNumber, errorLine ++ "\"")
suggestion.addLine(lineNumber + 1, " ++ \"" ++ nextLine)
suggestions.push(suggestion)
suggestion := errormessages.suggestion.new
suggestion.addLine(lineNumber, errorLine ++ "\\n" ++ nextLine)
suggestion.addLine(lineNumber + 1, "")
suggestions.push(suggestion)
errormessages.syntaxError("A string must end with a '\"'. To insert a newline in a string use '\\n'. "
++ "To split a string over multiple lines use '++' to join strings together.")atRange(
lineNumber, linePosition, linePosition)withSuggestions(suggestions)
} else {
def suggestion = errormessages.suggestion.new
suggestion.addLine(lineNumber, errorLine ++ "\"")
errormessages.syntaxError("A string must end with a '\"'.")atPosition(
lineNumber, linePosition)withSuggestion(suggestion)
}
}
}
if (escaped) then {
if (c == "n") then {
// Newline escape
accum := accum ++ "\u000a"
} elseif (c == "u") then {
// Beginning of a four-digit Unicode escape
// (for a BMP codepoint).
unichars := 4
codepoint := 0
} elseif (c == "U") then {
// Beginning of a six-digit Unicode escape
// (for a general codepoint).
unichars := 6
codepoint := 0
} elseif (c == "t") then {
// Tab escape
accum := accum ++ "\u0009"
} elseif (c == "r") then {
// Carriage return escape
accum := accum ++ "\u000d"
} elseif (c == "b") then {
// Backspace escape
accum := accum ++ "\u0008"
} elseif (c == "l") then {
// LINE SEPARATOR escape
accum := accum ++ "\u2028"
} elseif (c == "f") then {
// Form feed/"page down" escape
accum := accum ++ "\u000c"
} elseif (c == "e") then {
// Escape escape
accum := accum ++ "\u001b"
} else {
// For any other character preceded by \,
// insert it literally.
accum := accum ++ c
}
escaped := false
} elseif (c == "\\") then {
// Begin an escape sequence
escaped := true
} elseif (unichars > 0) then {
// There are still hex digits to read for a
// Unicode escape. Use the current character
// as a hex digit and update the codepoint
// being calculated with its value.
unichars := unichars - 1
codepoint := codepoint * 16
codepoint := codepoint + hexdecchar(c)
if (unichars == 0) then {
// At the end of the sequence construct
// the character in the unicode library.
accum := accum ++ unicode.create(codepoint)
}
} elseif (c == "\{") then {
if (interpString.not) then {
modechange(tokens, "(", "(")
interpString := true
}
modechange(tokens, mode, accum)
modechange(tokens, "o", "++")
modechange(tokens, "(", "(")
mode := "n"
newmode := "n"
accum := ""
instr := false
interpdepth := interpdepth + 1
} else {
accum := accum ++ c
}
} elseif ((c == "\n") || (c == "\r")) then {
// Linebreaks terminate any open tokens
modechange(tokens, mode, accum)
mode := "d"