save work

static/filemanager/src/util/StringStream.js

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+import { countColumn } from "./misc.js"
+
+// STRING STREAM
+
+// Fed to the mode parsers, provides helper functions to make
+// parsers more succinct.
+
+class StringStream {
+  constructor(string, tabSize, lineOracle) {
+    this.pos = this.start = 0
+    this.string = string
+    this.tabSize = tabSize || 8
+    this.lastColumnPos = this.lastColumnValue = 0
+    this.lineStart = 0
+    this.lineOracle = lineOracle
+  }
+
+  eol() {return this.pos >= this.string.length}
+  sol() {return this.pos == this.lineStart}
+  peek() {return this.string.charAt(this.pos) || undefined}
+  next() {
+    if (this.pos < this.string.length)
+      return this.string.charAt(this.pos++)
+  }
+  eat(match) {
+    let ch = this.string.charAt(this.pos)
+    let ok
+    if (typeof match == "string") ok = ch == match
+    else ok = ch && (match.test ? match.test(ch) : match(ch))
+    if (ok) {++this.pos; return ch}
+  }
+  eatWhile(match) {
+    let start = this.pos
+    while (this.eat(match)){}
+    return this.pos > start
+  }
+  eatSpace() {
+    let start = this.pos
+    while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos
+    return this.pos > start
+  }
+  skipToEnd() {this.pos = this.string.length}
+  skipTo(ch) {
+    let found = this.string.indexOf(ch, this.pos)
+    if (found > -1) {this.pos = found; return true}
+  }
+  backUp(n) {this.pos -= n}
+  column() {
+    if (this.lastColumnPos < this.start) {
+      this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue)
+      this.lastColumnPos = this.start
+    }
+    return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
+  }
+  indentation() {
+    return countColumn(this.string, null, this.tabSize) -
+      (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
+  }
+  match(pattern, consume, caseInsensitive) {
+    if (typeof pattern == "string") {
+      let cased = str => caseInsensitive ? str.toLowerCase() : str
+      let substr = this.string.substr(this.pos, pattern.length)
+      if (cased(substr) == cased(pattern)) {
+        if (consume !== false) this.pos += pattern.length
+        return true
+      }
+    } else {
+      let match = this.string.slice(this.pos).match(pattern)
+      if (match && match.index > 0) return null
+      if (match && consume !== false) this.pos += match[0].length
+      return match
+    }
+  }
+  current(){return this.string.slice(this.start, this.pos)}
+  hideFirstChars(n, inner) {
+    this.lineStart += n
+    try { return inner() }
+    finally { this.lineStart -= n }
+  }
+  lookAhead(n) {
+    let oracle = this.lineOracle
+    return oracle && oracle.lookAhead(n)
+  }
+  baseToken() {
+    let oracle = this.lineOracle
+    return oracle && oracle.baseToken(this.pos)
+  }
+}
+
+export default StringStream