diff options
Diffstat (limited to 'lib/system.nim')
| -rw-r--r-- | lib/system.nim | 73 |
1 files changed, 65 insertions, 8 deletions
diff --git a/lib/system.nim b/lib/system.nim index ca17f70f6..83e87683a 100644 --- a/lib/system.nim +++ b/lib/system.nim @@ -1325,6 +1325,7 @@ proc add*(x: var string, y: string) {.magic: "AppendStrStr", noSideEffect.} ## tmp.add("cd") ## assert(tmp == "abcd") + type Endianness* = enum ## is a type describing the endianness of a processor. littleEndian, bigEndian @@ -2503,9 +2504,9 @@ proc `$`*[T: tuple|object](x: T): string = when compiles($value): when compiles(value.isNil): if value.isNil: result.add "nil" - else: result.add($value) + else: result.addQuoted(value) else: - result.add($value) + result.addQuoted(value) firstElement = false else: result.add("...") @@ -2525,12 +2526,9 @@ proc collectionToString[T](x: T, prefix, separator, suffix: string): string = if value.isNil: result.add "nil" else: - result.add($value) - # prevent temporary string allocation - elif compiles(result.add(value)): - result.add(value) + result.addQuoted(value) else: - result.add($value) + result.addQuoted(value) result.add(suffix) @@ -3893,6 +3891,65 @@ proc compiles*(x: untyped): bool {.magic: "Compiles", noSideEffect, compileTime. when declared(initDebugger): initDebugger() +proc addEscapedChar*(s: var string, c: char) {.noSideEffect, inline.} = + ## Adds a char to string `s` and applies the following escaping: + ## + ## * replaces any ``\`` by ``\\`` + ## * replaces any ``'`` by ``\'`` + ## * replaces any ``"`` by ``\"`` + ## * replaces any other character in the set ``{'\0'..'\31', '\127'..'\255'}`` + ## by ``\xHH`` where ``HH`` is its hexadecimal value. + ## + ## The procedure has been designed so that its output is usable for many + ## different common syntaxes. + ## **Note**: This is not correct for producing Ansi C code! + case c + of '\0'..'\31', '\127'..'\255': + add(s, "\\x") + const HexChars = "0123456789ABCDEF" + let n = ord(c) + s.add(HexChars[int((n and 0xF0) shr 4)]) + s.add(HexChars[int(n and 0xF)]) + of '\\': add(s, "\\\\") + of '\'': add(s, "\\'") + of '\"': add(s, "\\\"") + else: add(s, c) + +proc addQuoted*[T](s: var string, x: T) = + ## Appends `x` to string `s` in place, applying quoting and escaping + ## if `x` is a string or char. See + ## `addEscapedChar <system.html#addEscapedChar>`_ + ## for the escaping scheme. + ## + ## The Nim standard library uses this function on the elements of + ## collections when producing a string representation of a collection. + ## It is recommended to use this function as well for user-side collections. + ## Users may overload `addQuoted` for custom (string-like) types if + ## they want to implement a customized element representation. + ## + ## .. code-block:: Nim + ## var tmp = "" + ## tmp.addQuoted(1) + ## tmp.add(", ") + ## tmp.addQuoted("string") + ## tmp.add(", ") + ## tmp.addQuoted('c') + ## assert(tmp == """1, "string", 'c'""") + when T is string: + s.add("\"") + for c in x: + s.addEscapedChar(c) + s.add("\"") + elif T is char: + s.add("'") + s.addEscapedChar(x) + s.add("'") + # prevent temporary string allocation + elif compiles(s.add(x)): + s.add(x) + else: + s.add($x) + when hasAlloc: # XXX: make these the default (or implement the NilObject optimization) proc safeAdd*[T](x: var seq[T], y: T) {.noSideEffect.} = @@ -4034,4 +4091,4 @@ template doAssertRaises*(exception, code: untyped): typed = except Exception as exc: raiseAssert(astToStr(exception) & " wasn't raised, another error was raised instead by:\n"& - astToStr(code)) \ No newline at end of file + astToStr(code)) |