/
StringReader.go
258 lines (205 loc) · 6.57 KB
/
StringReader.go
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package main
type StringReader struct {
TokenizerData
}
type StringEscReader struct {
TokenizerData
}
type StringFinReader struct {
TokenizerData
emptyAfterSub bool
}
type MaybeStringSubReader struct {
TokenizerData
}
type StringSubReader struct {
TokenizerData
stack []Rune // can be '$', '{' or '"' or '\'
// stack parts are added to end!
}
type StringSubPostReader struct {
TokenizerData
}
func NewStringReader(rs []Rune) *StringReader {
return &StringReader{TokenizerData{rs}}
}
func NewStringEscReader(rs []Rune) *StringEscReader {
return &StringEscReader{TokenizerData{rs}}
}
func NewStringFinReader(rs []Rune, eas bool) *StringFinReader {
return &StringFinReader{TokenizerData{rs}, eas}
}
func NewMaybeStringSubReader(rs []Rune) *MaybeStringSubReader {
return &MaybeStringSubReader{TokenizerData{rs}}
}
func NewStringSubReader(rs []Rune, stack []Rune) *StringSubReader {
return &StringSubReader{
TokenizerData{rs},
stack,
}
}
func NewStringSubPostReader(rs []Rune) *StringSubPostReader {
return &StringSubPostReader{TokenizerData{rs}}
}
func dispatchStringReader(rPrev []Rune, r Rune, ew ErrorWriter) Tokenizer {
switch {
case r.Is('\\'):
return NewStringEscReader(append(rPrev, r))
case r.Is('"'):
return NewStringFinReader(append(rPrev, r), false)
case r.Is('$'):
return NewMaybeStringSubReader(append(rPrev, r))
default:
return NewStringReader(append(rPrev, r))
}
}
func (rr *StringReader) Ingest(r Rune, ew ErrorWriter) (Tokenizer, []Token) {
return dispatchStringReader(rr.buf, r, ew), nil
}
func (rr *StringReader) Finalize(ew ErrorWriter) []Token {
ctx := rr.buf[0].Context()
ew.Add(ctx.Error("EOF while scanning string literal"))
return nil
}
func (rr *StringEscReader) Ingest(r Rune, ew ErrorWriter) (Tokenizer, []Token) {
n := len(rr.buf)
last := rr.last()
buf := rr.buf[0 : n-1]
newCtx := MergeContexts(last.Context(), r.Context())
switch {
case r.Is('"') || r.Is('$') || r.Is('\\'):
return NewStringReader(append(buf, NewRune(r.r, newCtx))), nil
case r.Is('n'):
return NewStringReader(append(buf, NewRune('\n', newCtx))), nil
case r.Is('t'):
return NewStringReader(append(buf, NewRune('\t', newCtx))), nil
default:
ew.Add(newCtx.Error("unrecognized escape sequence"))
return NewStringReader(buf), nil
}
}
func (rr *StringEscReader) Finalize(ew ErrorWriter) []Token {
ctx := rr.buf[0].Context()
ew.Add(ctx.Error("EOF while scanning string literal"))
return nil
}
func (rr *StringFinReader) toString() Token {
if rr.emptyAfterSub {
return nil
} else {
rs := rr.Runes()
t := NewString(string(rs[1:len(rs)-1]), rr.Context())
return t
}
}
func (rr *StringFinReader) Ingest(r Rune, ew ErrorWriter) (Tokenizer, []Token) {
newTr := dispatchTokenizer(r, ew)
t := rr.toString()
return newTr, []Token{t}
}
func (rr *StringFinReader) Finalize(ew ErrorWriter) []Token {
return []Token{rr.toString()}
}
func (rr *MaybeStringSubReader) Ingest(r Rune, ew ErrorWriter) (Tokenizer, []Token) {
switch {
case r.Is('{'):
rs := rr.Runes()
ts := []Token{}
if len(rs) > 2 {
tStr := NewString(string(rs[1:len(rs)-1]), MergeContexts(rr.buf[0].Context(), rr.buf[len(rs)-2].Context()))
plus := NewSymbol("+", rr.buf[len(rs)-1].Context())
ts = append(ts, tStr, plus)
}
openPar := NewSymbol("(", rr.buf[len(rs)-1].Context())
ts = append(ts, openPar)
return NewStringSubReader([]Rune{r}, []Rune{}), ts
default:
return dispatchStringReader(rr.buf, r, ew), nil
}
}
func (rr *MaybeStringSubReader) Finalize(ew ErrorWriter) []Token {
ctx := rr.buf[0].Context()
ew.Add(ctx.Error("EOF while scanning string literal"))
return nil
}
func (rr *StringSubReader) stackHead() Rune {
return rr.stack[len(rr.stack)-1]
}
func (rr *StringSubReader) stackHead2() Rune {
return rr.stack[len(rr.stack)-2]
}
func (rr *StringSubReader) popStackHead() []Rune {
n := len(rr.stack)
return rr.stack[0 : n-1]
}
func (rr *StringSubReader) popStackHead2() []Rune {
n := len(rr.stack)
return rr.stack[0 : n-2]
}
func (rr *StringSubReader) pushStackHead(r Rune) []Rune {
return append(rr.stack, r)
}
func (rr *StringSubReader) popPushStackHead(r Rune) []Rune {
n := len(rr.stack)
return append(rr.stack[0:n-1], r)
}
// this is a bit tricky because we want to allow nested string substitutions
func (rr *StringSubReader) Ingest(r Rune, ew ErrorWriter) (Tokenizer, []Token) {
switch {
case len(rr.stack) == 0 && r.Is('}'):
closePar := NewSymbol(")", r.Context())
innerTokens := TokenizeRunes(rr.buf[1:], ew)
if len(innerTokens) > 0 && IsNL(innerTokens[0]) {
innerTokens = innerTokens[1:]
}
show := NewWord("show", r.Context())
innerOpenPar := NewSymbol("(", r.Context())
innerClosePar := NewSymbol(")", r.Context())
ts := []Token{show, innerOpenPar}
ts = append(ts, innerTokens...)
ts = append(ts, innerClosePar, closePar)
return NewStringSubPostReader([]Rune{NewRune('"', r.Context())}), ts
case len(rr.stack) == 0:
newStack := []Rune{}
if r.Is('{') || r.Is('"') {
newStack = []Rune{r}
}
return NewStringSubReader(append(rr.buf, r), newStack), nil
case rr.stackHead().Is('{') && r.Is('}'):
return NewStringSubReader(append(rr.buf, r), rr.popStackHead()), nil
case rr.stackHead().Is('\\'):
return NewStringSubReader(append(rr.buf, r), rr.popStackHead()), nil
case rr.stackHead().Is('"') && r.Is('"'):
return NewStringSubReader(append(rr.buf, r), rr.popStackHead()), nil
case rr.stackHead().Is('"') && r.Is('\\'):
return NewStringSubReader(append(rr.buf, r), rr.pushStackHead(r)), nil
case rr.stackHead().Is('"') && r.Is('$'):
return NewStringSubReader(append(rr.buf, r), rr.pushStackHead(r)), nil
case rr.stackHead().Is('$') && r.Is('{'):
return NewStringSubReader(append(rr.buf, r), rr.popPushStackHead(r)), nil
case rr.stackHead().Is('$') && rr.stackHead2().Is('"') && r.Is('"'):
return NewStringSubReader(append(rr.buf, r), rr.popStackHead2()), nil
case rr.stackHead().Is('$'):
return NewStringSubReader(append(rr.buf, r), rr.popStackHead()), nil
default:
return NewStringSubReader(append(rr.buf, r), rr.stack), nil
}
}
func (rr *StringSubReader) Finalize(ew ErrorWriter) []Token {
ctx := rr.buf[0].Context()
ew.Add(ctx.Error("EOF while scanning string literal"))
return nil
}
func (rr *StringSubPostReader) Ingest(r Rune, ew ErrorWriter) (Tokenizer, []Token) {
if r.Is('"') {
return NewStringFinReader([]Rune{rr.buf[0], r}, true), nil
} else {
plus := NewSymbol("+", rr.buf[0].Context())
return dispatchStringReader(rr.buf, r, ew), []Token{plus}
}
}
func (rr *StringSubPostReader) Finalize(ew ErrorWriter) []Token {
ctx := rr.buf[0].Context()
ew.Add(ctx.Error("EOF while scanning string literal"))
return nil
}