diff options
| -rw-r--r-- | doc/manual.txt | 6 | ||||
| -rw-r--r-- | lib/system.nim | 16 |
2 files changed, 14 insertions, 8 deletions
diff --git a/doc/manual.txt b/doc/manual.txt index 32b0541e9..54c1477e8 100644 --- a/doc/manual.txt +++ b/doc/manual.txt @@ -4970,9 +4970,9 @@ or ``ref T`` or ``ptr T`` this means no locations are modified. It is a static error to mark a proc/iterator to have no side effect if the compiler cannot verify this. -As a special semantic rule, the built-in ``debugEcho`` pretends to be free of -side effects, so that it can be used for debugging routines marked as -``noSideEffect``. +As a special semantic rule, the built-in `debugEcho <system.html#debugEcho>`_ +pretends to be free of side effects, so that it can be used for debugging +routines marked as ``noSideEffect``. **Future directions**: ``func`` may become a keyword and syntactic sugar for a proc with no side effects: diff --git a/lib/system.nim b/lib/system.nim index 440c6474a..83428344b 100644 --- a/lib/system.nim +++ b/lib/system.nim @@ -2026,19 +2026,25 @@ elif hostOS != "standalone": {.pop.} proc echo*[T](x: varargs[T, `$`]) {.magic: "Echo", tags: [FWriteIO], gcsafe.} - ## special built-in that takes a variable number of arguments. Each argument + ## Writes and flushes the parameters to the standard output. + ## + ## Special built-in that takes a variable number of arguments. Each argument ## is converted to a string via ``$``, so it works for user-defined ## types that have an overloaded ``$`` operator. ## It is roughly equivalent to ``writeln(stdout, x); flush(stdout)``, but ## available for the JavaScript target too. + ## ## Unlike other IO operations this is guaranteed to be thread-safe as - ## ``echo`` is very often used for debugging convenience. + ## ``echo`` is very often used for debugging convenience. If you want to use + ## ``echo`` inside a `proc without side effects + ## <manual.html#nosideeffect-pragma>`_ you can use `debugEcho <#debugEcho>`_ + ## instead. proc debugEcho*[T](x: varargs[T, `$`]) {.magic: "Echo", noSideEffect, tags: [], raises: [].} - ## Same as ``echo``, but as a special semantic rule, ``debugEcho`` pretends - ## to be free of side effects, so that it can be used for debugging routines - ## marked as ``noSideEffect``. + ## Same as `echo <#echo>`_, but as a special semantic rule, ``debugEcho`` + ## pretends to be free of side effects, so that it can be used for debugging + ## routines marked as `noSideEffect <manual.html#nosideeffect-pragma>`_. template newException*(exceptn: typedesc, message: string): expr = ## creates an exception object of type ``exceptn`` and sets its ``msg`` field |