some comment typos

Hi,

found some comment typos:

~s/lenght/length
~s/yiels/yields

Greetings,
Jens

diff --git a/ChangeLog b/ChangeLog
index f49d36420..b8feb8081 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4329,7 +4329,7 @@
 
 2019-03-31  Shiro Kawai  <[email protected]>
 
-	* src/number.c (scm_div): Fix bug that yiels infinity in (/. +nan.0 0).
+	* src/number.c (scm_div): Fix bug that yields infinity in (/. +nan.0 0).
 
 2019-03-30  Shiro Kawai  <[email protected]>
 
diff --git a/doc/gauche-dev.texi b/doc/gauche-dev.texi
index 89c5cb006..3d6eac6e2 100644
--- a/doc/gauche-dev.texi
+++ b/doc/gauche-dev.texi
@@ -1728,7 +1728,7 @@ smaller than or equal to @code{*nelts}, the result is stored in @code{*store},
 and @code{store} is returned.  The value of @code{*nelts} is adjusted
 to contain the actual number of elements.
 
-If the lenght of @var{list} is greater than @var{*nelts},
+If the length of @var{list} is greater than @var{*nelts},
 the behavior depends on the @code{alloc} flag.  If it is @code{FALSE},
 an error is thrown.  Otherwise, a new storage is allocated, filled, and
 returned.  The value of @code{*nelts} is ajusted to contain the actual
diff --git a/ext/scheme/flonum.scm b/ext/scheme/flonum.scm
index ebb8ea10c..d725b4379 100644
--- a/ext/scheme/flonum.scm
+++ b/ext/scheme/flonum.scm
@@ -84,13 +84,13 @@
 (define-constant fl-e-2 7.38905609893065) ; e*e yields 1ulp error
 (define-constant fl-e-pi/4 (real-exp (/ const:pi 4)))
 (define-constant fl-log2-e (/ (real-ln 2)))
-(define-constant fl-log10-e 0.4342944819032518); (/ (real-ln 10)) yiels 1ulp error
+(define-constant fl-log10-e 0.4342944819032518); (/ (real-ln 10)) yields 1ulp error
 (define-constant fl-log-2 (real-ln 2))
 (define-constant fl-1/log-2 (/ (real-ln 2)))
 (define-constant fl-log-3 (real-ln 3))
 (define-constant fl-log-pi (real-ln const:pi))
 (define-constant fl-log-10 (real-ln 10))
-(define-constant fl-1/log-10 0.4342944819032518); (/ (%log 10)) yiels 1ulp error
+(define-constant fl-1/log-10 0.4342944819032518); (/ (%log 10)) yields 1ulp error
 (define-constant fl-pi const:pi)
 (define-constant fl-1/pi (/ const:pi))
 (define-constant fl-2pi (* const:pi 2))
diff --git a/src/compile-1.scm b/src/compile-1.scm
index f2170f587..52edcf30d 100644
--- a/src/compile-1.scm
+++ b/src/compile-1.scm
@@ -1413,7 +1413,7 @@
 ;;   <args> is the list of requried args, plus a restarg if any.
 ;;   <formals> is a copy of input sans type annotation.
 ;;   <types> is a list of types for required args.  If there's a restarg,
-;;      the lenght of <types> is one shorter than the length of <args>.
+;;      the length of <types> is one shorter than the length of <args>.
 ;;      Can be #f if there's no type annotation.
 ;;   <nreqs> is the number of required arguments.
 ;;   <nopts> is 0 if no optional arg, 1 if not.
diff --git a/src/gauche/priv/stringP.h b/src/gauche/priv/stringP.h
index 3f9425353..9ec024b8b 100644
--- a/src/gauche/priv/stringP.h
+++ b/src/gauche/priv/stringP.h
@@ -103,7 +103,7 @@ typedef union ScmStringIndexRec {
        index type, regardless of endianness.
 
        The index array has the signature in the first element, and the total
-       lenght of the index array in the second.  The actual index array
+       length of the index array in the second.  The actual index array
        begins from the third element.  Given the character index N,
        indexX[(N>>shift)+2] contains the byte position of the character.
      */
diff --git a/src/gauche/string.h b/src/gauche/string.h
index 5f2e04309..adaf71057 100644
--- a/src/gauche/string.h
+++ b/src/gauche/string.h
@@ -62,7 +62,7 @@
  * ScmString is alive, even if its content is mutated and the initial
  * content isn't used.   Another reason to avoid string mutations.
  */
-/* NB: We used to have lengh and size as 'u_int'.  It effectively limited
+/* NB: We used to have length and size as 'u_int'.  It effectively limited
    the length and size of strings up to max(INT_MAX, SCM_SMALL_INT_MAX),
    for we accept fixnum range in Scheme level.  For 32bit architecture
    it was OK, but for 64bit architecture it became an issue.
diff --git a/src/number.c b/src/number.c
index 0a0cdb892..d3711c80a 100644
--- a/src/number.c
+++ b/src/number.c
@@ -1411,7 +1411,7 @@ double Scm_GetDouble(ScmObj obj)
     fullpath:;
         /* Need more precise but expensive calculation.
            We find K such that 2^K * numer >= 2^54 * denom, so that
-           the integer division yiels more than 53bit integral part.
+           the integer division yields more than 53bit integral part.
          */
         int shift = 0;
         if (n_hi - d_hi < 54) {