From 43e9448d6e1d742c1d8d7e8aee8a3e6a7ebda1fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Estev=C3=A3o=20Soares=20dos=20Santos?=
 <estevao.santos@gmail.com>
Date: Sat, 11 Jul 2015 15:59:06 +0100
Subject: [PATCH] feat(strikethrough):  add support for GFM strikethrough

Github Flavored Markdown supports strikethrough (`<del>`) syntax using double tilde `~~` delimiters.
This commit adds this feature to showdown through an option called "strikethrough".

Related to #164
---
 dist/showdown.js                        | Bin 56166 -> 56484 bytes
 dist/showdown.js.map                    | Bin 178543 -> 179233 bytes
 dist/showdown.min.js                    | Bin 18448 -> 18646 bytes
 dist/showdown.min.js.map                | Bin 20522 -> 20704 bytes
 src/showdown.js                         |   3 ++-
 src/subParsers/spanGamut.js             |   1 +
 src/subParsers/strikethrough.js         |   9 +++++++++
 test/features/#164.3.strikethrough.html |   5 +++++
 test/features/#164.3.strikethrough.md   |   5 +++++
 test/node/showdown.js                   |   3 ++-
 test/node/testsuite.features.js         |   2 ++
 11 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 src/subParsers/strikethrough.js
 create mode 100644 test/features/#164.3.strikethrough.html
 create mode 100644 test/features/#164.3.strikethrough.md

diff --git a/dist/showdown.js b/dist/showdown.js
index 561e2b1c94bd2fd6db25aef578829c5690084986..f61f1a0e0c09c2e6731740a01e66fb8e69802241 100644
GIT binary patch
delta 174
zcmaF1jd{sV<_+f<m2|iiz@WIKC^I{?B%>(5G(E!#A_gHhpJ4oOc5;8HEH8?h$qwN%
zlXsktnw&6I1Wo3_DyhkLmMf!)9t@Px)z`4MsteJqHmcQ#j;o8+)`au*({&WoZBkNm
W>{JYG^g*=x<o`j+n<X#!asvRvYd;+T

delta 27
lcmV+$0ObFqxdZ051F+5kv-Sb%&67@436n3-QL|9dR13sj4Kx4%

diff --git a/dist/showdown.js.map b/dist/showdown.js.map
index c14a07544df10b8828f299d05be0a44c809e4080..ba91e84d067717035002b38d9df69d732e51e890 100644
GIT binary patch
delta 1048
zcmZuvZ%kWN6wf)l2kWaq8yH*57-ePh$3n|kGg%q-tplnVjx7X3tSD#&=JHy)PM0aO
zW^tMrBkm+Si7^=@qbY4yAWPO|BkBiCW}M097r!iu$-cSBG=5k#Cf@g6B$@Gkc=!D7
zdH44_zjM#V@5=lmW%;`j%Nx<;WFmHIV)E)r$xle}qZS${-BK~8s$-szs)jszboHas
z)%Ftqu|Ar<QBT3Y6sl`e=*V@;x%2+wc|X__R8wBhbMJvdOAF03n69`mX(R7BnQa-c
zlm-M*yqE6YYNVa%fB}ymqWLl>rR*}T-`>NvmthzA?#p~P05$Zmyn=jtt@PP^HQl*f
z&0ih_g*UE16S)!+9A{SnynJsFIt7-Yj~fcm&f%<qrLwMGT~FoNENHxzhZ>&Ciu=I|
zkZI!=nS5(9eLiAgn-3h63R`J?*g~&-D4{=OGTFi)b2<keL#~Tf{;W01cn}jb!)|bs
zFC*!>GVdW%>S!J`njMv(g9r0aOY5H~q6rE=%EJ*3o)&aBQ(!0SLxoRVfuOA4(l&Yj
z$KJRh-Dx_#S%3}$Ck-s=Pr`$4X!*AeO!U%dgOhAu$ec<+mF@=OH2rlee^n>MCzjwj
zN{vgnFGK?iZo5&mr(ae30|7O(?_ik5;#&<``ZWDC#dk|&dsU{Du6la6PBd(<m3u}+
zv-;oJ#!GXsh2BcKDRQk^8d22|p0|OM;@2wa(mk`e=?^L?Rg?^uZ_<H<Zafw?CTDrI
zithAVIkzkZW!9^(?;=$3`jDXZ9hQpkFT=AAw<n^xjCC@ZnA#lA{pOkZE#CSDdVl1~
z4EFI08SIoaSF4w&gIL4P7%DtIgirF;AH>W5k-;GUoWpt^K8(Bh%p%t6u#rCwqMdIG
zC}!lrBKEK+i|zbd26ytAEbcO+)hxP2{(cq@usbK1qB-=Nsc&}(owb}vH(;JUpT|}s
zDu1kWUYS5=Ng$%}OdhxK_YU07g*-a8Yr4}!G<hnaxsuV-N%2cWn`sH~+%P)+!!b65
zPX2WVIvrE5yP9M1<Wx*M+5Wgrr3>rYyv@(-KReX&_MVyM7e~*&^i<0x_D*<QP2I0W
aPxLf)bbIx^i6afz#_<Bm#lQ2Ic;X)lt8MB4

delta 695
zcmZuuO-NKx80GtPW}JsV6Ab2zim#qOpy8x84oaC;TB{TcBKkpS5ej99Py~_GvZ#>{
zInknY)98C|#z8R&0+kd*DYG_GBqj(^R)dRZ5!Ca&+_kv(e)oLm9PYW_&@bi3mXdsx
zHoleilBJ?Ib9}>XR8q~I{_tdfm|A<_nWdogdHs^ql<kGWVQNIQi(JxIlFmKN*fmSV
znC>7&d^0Y&*AkHE3%^7gGEjMfDkSyXB}<PZ(h<oPHI|JpF4_lmjx@QN@QZIw!AhLU
zu+~UknI9?GM)7-uYHWn-TCkj;N?g=;kWe$0H7b^5RywA1YD02@yc|A;A)SH<8PqI;
z^Inb|b%etPRoPY)lBPHLwtbfQ50k}M0hUgag1$~``xCQ5tX)xL`n-Zc)q2q2IX51e
zRES&Gt-z_{xi(wWr+$1jsa4v(DH8qUK}(!YVLI1RJo#xy_<t}7eej?@VSRudw`kqr
z1`~(yR-*u-XUT=OQOetnfYo`*kjR)O3!4hg9Hbm1N2yl!*LksWgR-#cv7pod`9*!V
zo5M#yv!q(H%9GTFTkgMCWUAU4N~iK{jJgAp4;Sh1DqhFfjdqR8z&hvSuEy=??qvnN
zI+r4+m?Q9&aypiD-h)&Lt0+2YH4YdS*}h&jxEeQ0ITJC1Bh-VB28WzhxygH-s>@`}
zAq|*ZYmpXAZn6#~&b1EXLYzyS>T?78F%jSK{~qUZM|vs2KHRS3ARZ(*fc1K=n$$=6
GTIOFK;{-zh

diff --git a/dist/showdown.min.js b/dist/showdown.min.js
index b9e9494d4b491e246c86c48030ec511b97554b45..60cbcfd160b5903992e4e124bdd42eb1b2b7e994 100644
GIT binary patch
delta 153
zcmbO*f$`cz#tk#r_;iX(iZZiPOEQY`OVcwpPi1Shoh&8K%ZnmBna{<Z8?H!6XYwC*
z>B%2>*gcZ;P}HfZX(ZYv>J_CH<Rm7iYUpd&Th)bVRvXo7M90;|YHPyz`sq4KHYuq&
Ub}EK8`apW}0!y*Yo-W6k0o=bevH$=8

delta 27
jcmcaMk#WKV#tk#rHm_uBvYj00Vm!G<lxMTN>vm=Uo;eCt

diff --git a/dist/showdown.min.js.map b/dist/showdown.min.js.map
index 900b5d6d5a13d4f8678d30bf8b2761e42aff69b3..a1834e3e6a753513889ee9df9a930a75e1fb91fe 100644
GIT binary patch
delta 7865
zcmbVRYiwKBeTR%LVcbQsW7&FGvL#uM*rLRj__FN8=N?{CSJc%tP0<qFV2L9uB=sWo
zpd=ejl>r0xWm_?v6$RP_ORxc3yCN9YZ`-g2!wM8==VB-d?918|*f4AZ=3x5}AlSP7
z{{M3?Ny$pm?u+Gn&j0-1Z+`Qgwh!KI`?KCt&+qJRSJqZ`%iGm@sr>D(Q~&Tx+tjx|
z^gZ`0ZL8|z=fC7Lg^U=|zoK^9ueRM&Z?})NZK&_IU-#`wzbQn%uAc3<>Z|FGeU<3w
z^92mPd8l6L2!7$7KPz%kxvS5D(!XX1Q8oOFgx6mbQurMqoSNac#Qg;qEG+#6A&UOI
z5QTDzu-TQAKO^L()K4rStf=~zj%x#aZqE9pkaK_#)&Wz>Jv96)LaeN-(3#5}8z~}U
z`!_&)%h*(}p1F7$4=u4~>>5$^8)woJ9!OOR`vGod#3mDVvMh{bE)x=bi^ZDy=uGg+
zzDt1_iyM$r*d7*-(CpdQC1eI)6=RR_<?j=|>=OPpAq^f`TYRyyp7Prwv#Jr5G{+_Z
zudJ#kXNO{7xB~t+Sa+co-9<@v&ce1<@mk7X0@#|t+S^l^7lsbOmU{-ZKhjT=21Kf4
z((bcr%Cih9JxM&vZPK<WfL&M+9a2<{NUIcJU&0Td+pNBaK8bOwYyf&@uAcJegvd>@
zoY^!9vu145p@f+%k)PLo6N7_6PO@#ph^q_dhEJ7J>c+Y8_5)2$tAAhB&*hhKM0O@*
z8A1PAAVYtcw8)WNWzyK!FZC64Pj47J18_?$hKx`vZb_ULNM{veOO1Dqw8d4fv%76y
zt#)2+hbBNF?|OmyYUj|Ya!UPW=Syt~^>OEoZuklb>R%=)7?CB+npsuz=ljoThI7mT
zlX2?mOXvIB*46Ky9|3{CIe*7jV@o5N`YwF*5(I%J?z)z7W!Ds7RxpwS1RSvl88ae}
z2m#5wAOa<0PvyFV&-K(t>T6vC<KvR#%4sY3_u(Bu!woBc6^zE^zDbYkMpFHAmu%l>
zk~T?GG7eO%yK>rfk2OGiqx)`qT|1`67*fyo^mQcosAQzbr?VlI=;`Z29CO@NQlfwe
zCoW6uM|GgB^#q>-9(Y&{On;-N_?+wX(Cp`XzmPmigRxsPV3S<O7BbCrAefvvPWlge
z``W_luX_LU5HZDeq1eQuY{)=(K!FZ>Le{&saYDftIr*CSCX(@!ub+BNLc<)UP!oOa
zzOpuLSjoQ8=Eqjwpk3pLaJ>q)BvyCWz$G2MkH{>toC<2DJxrV(3mnoVL%U`+sD9el
z|H^8b?ARI`<4nDnG&vnGo(v_+2;0HBL-0<W87T$`R_+-wjut1%PM<@*0F1q*mik8q
zK1*Zj?f(8-t|&;5P<2I%5@AtRe=$)$?*G%C^$f`#H8z;HlChaa)H>_Nl=|ySH`@->
ze_x6nYDQbdjkAOW4&(yT9vC2T%|{ZiMHVPisZ|!wzDJh@Mj@AK4BComiWRp4z9}Kn
zwcL~LVbmn&bNZRZ1LL6v#VHh(nM#xWov3<z`NFF)HVD@covgBN5ZRIuZ^0Xqo(HcG
z-du<t$&e9dyd`6W@LF6EoG7a!1GvJj+)#2L>VwgNG9OlN4czF^K2>DXS=F@q`+*+y
zlYwV`4G80@P=+COMkylnL=g-ki6;#m5KxkN8{~oSz9ct!oz!LpS&GGZoXaJLanS!o
zCZ0x;koT%;X7Kt;uoyDNa#n|&8#Lx-YMk-egvlm7nzy4*^HEpt4_+G8(k<czsnCC)
z(y1jZ6iN!R03k}>j;YTLjdY%f<K|GbJ>H5uq23yLb*!9eNdpD)suBa`l1E|x{boQ#
zuS|4!UcLbttLBc{x^iAL&Y(%LLkg)FHA6Q($I?jx8Ft(NOjg+2shXw{R!*cxeQ>2K
zwaN!D5ip@wBHLETlhCcqux^ny(f$-TQ|}un^-z0Kn;-1~0AcIt;Wu7!S=wQIEB?Ac
z4U+ccqa5usM9H8I$tqLHhG4mX^l#zG-70?`eX*tfXZWJeB~VubBj=l`>%Gj_SyLdN
zgA>QgNoszsSABWptk(*L)t`)n8u@oi3b7-R+sLm|Q=Ax%67>IaAZ7!L$AGId1Z#ea
z@!N}jwKV!dlkcC8_Nw0+{nh5dJEJWL`SIwB&6}T(UiP`!Ijnvd8B=p(7f`P+kN2uK
z$4(zY<B&bOOQ~hYSb(#x8^S%*J;o!~<ERltw~N|RlMmSn*`oklJP>tz#);R6fMrAg
z0@S_UgNuBQJ>c|<6N4TZxXU73+>Cf&9uf6}_{G=cI%g)U&TQLz#I|)8T&IP5#NZav
z16ND0-bIWcvuq!|cI%y0GahJnRX=)hvZ*e(hYDVe-f*2K%qa4lMZqo{uaTU{8_*3x
zl@?5fKSc(R_k!x(tHZvK8x893uJ$xP{-gDy<Jx6`M9}0KszR35WSHy1v1>HlNcrUc
z2$UeX|CXv=yXK2}#NNF&)$7H&+cqSOXhYN|*8=Pam)ff8rSb4#z@_dPDr$@~b=_;4
z-Zgb=WXF(q9X}fClsMNo?I#Uz4F0mDu|+M4g~VD27{}g_nbec<k(WJok<af#7nxQ0
z$z2Yvk9RpL?;o3wv2QGM@{|t}T7$#~>JHfq#-OeS|Id^qA91mCrdW<yt-ckS70@Py
z)%X0v36CxI7qtAx>AJm{>rVN2L&w7t!JFP=ofe>rOel4tR7hcnK_twQ5tW`p{_aF@
z(!)Tpq0e>QTV}HdB<3jy=4B!EWMT|WW7lMm1~GOhwmuO)x$Wa?i1q2$&DU<C(o7`O
zw<dd=`R4JYc>}IO!zE`HR1TUBsq=t4Ax!RY0i=I&?ADnU=uBxwIf3j8s2;6+i$Ya>
zEAYQP-Z3EqK)&42(%%M$2Xy@9{Na?y-Ghne1;$ZI>`W%Ru6&_>-#+!-!ah(Fp-bn3
z?g!hyF%rENy4ZQ3kG%55xle7`-Rh4+qX?SEp-UI5?Bi~mI!jm=%T(3n(nIxZcx0#%
zl<a`iGi2^?`#=r|bD{DbPXOU#5&l^T0Qo_^9~P|<e^CubUg$YucU#!apm!qEjoTIK
z-n5(Zl43{wVPv>z$sa}{hkBUP1s+Qd2x(~z77u2SdW)Ej9kC$XGo7X)uJI_SVP*&s
zW`T=GuQ^ztl<kwR`Smln$8+_YQ$gP&*CgsYQ!h_>0=faY|49+Kg&-DQD7}NKITt<G
z={*k5AG`eRmdl;gvCGGwcG(eYL3{k=?O4+yELKir1C12%)<BoKG4^@&c5LcW+*KVr
zIJK*D{`+DX-HjveSz+}g_QlS4tFzh^SNR=v7!UMga9<W-)J*`dn*x(>tM7k5K0Fj-
zcP}Q7`Zm)2eQwOq9ILa5aQh=2733I^)VRte&Yi}bfn^u+!@k-~Bz$FdcR28Si3!Wo
zW(?UYp(ms*rchkBz=GV>75o29{EQ|}y$6D;oFW!N9eXCkM9<dbq+k70@~n={z9X@T
zodId0HtR-R@cJ8ltvH3XKsTA!fe}T#qW=7PBIF@<dofay?jUj@9%b@*K%<(b8okxU
z>8Nj43tm@C)4%T9q#?pw+EPE8UOI%*Pnamyf3b-|Ph~c0gCz=>lF93NzF4@er!sp_
z_lbaj#!nbZP8EadFK!H-G-|}uhc|L#h^}VF#avOA?yU3F3^J;I=Vt7em_t6i<$6eh
zl~Xb1!6Tx6my@BFoOPj!G05^9ibl33cRh=JXX>Jgy?o&?Dg9wXWbSU9(B}Kc;eS}k
zJcOUtPOh)6hhp_;uAdBn$5<%w_>p|N^LT)gMRNufX&|vePlGT7PY8_U6AHb{2o{-G
zSfLfLguUQ3|0-~6sT1DE*5GCs9rv~@&8n~8njCa5Dy$jqs|o?_bF31ps{ZZPWnWou
zdc*3h81QYHz%QI}l@u*EuZgiH*q6n`;JQoFP0N%}nTXRs_K)Jta~@+Zl({N*)Q0ik
z)xa!FCY%^;uT8!9r45C!*7Y9_FwXy0g_+9%EoC|GTzHMMr`I@jeqi%Zo?GRQ%)ScB
zZeQc$ww$I9B3M;QMh^EFCF{Z6qgMIE**s2UU2ZW-hjhXtJQ9N@q7ecsCKSTWr`A62
z3mBWb_0Y>a?-g}6hoXQ@36fJy9>3&96MD!3fUI!hJ+ZQ;wc;>k7T%+P2uF6x;(6vE
zt+$(w?)O~AW4#1nZW_2G8mt%>Lj5Gwb*hwAAElNC-7qXMrA5|$l1=PQF{)<Di72UY
zF=-(D!8h;zu&Z)M1BgS*Ut|ZOWL4A$=KY1w#LEI$WL^t9ck&7>pYX@Q=7<vSUb@BG
z3y2A$uD+69b^SBDrk>4E(>0mtLR*{8OkVd&PIDwZI5`yAO>L2DHstSRV%|7MMDvj2
zla`@;oe{SFL4@34HnpV&W+u~tERw%@n{~`y=RDN214<_Zg3_R!EJ6Y68J2gAf6%d6
z5q5bFK$&}M>i1@B-!^?vFZi!B6X)Q^9QHhcp%|5AU0t;z(|CceyPrxA_GiOaG{RM;
zn3+;vwE}mse5GO;BpI+SjdP@()Q({W*p@r&AbE`;dlVmy=5PUu+_37Ky*#+*^6%Ek
z6>cf%y0OfCWww6^J6lL;StQ2%j`mIcn+2Z<XGeW~cHnSZgJt!EfJ~w{GggdaF}u#R
zEK<I_gEI_?%h4=aSGj6TG1EF`aRx3OePjWdxoe<Z1qVl~4fH`=xoC6#9!yAxeR3Kk
z<t%=PY9wVRGS<C=&7y;4(Np`PFV3|rU*6BQEMGos{TOHkn{WL%g5aBTEeNp6IrNxt
zRZPE};fEb>F$4+Fi=d*0Qqa~@GP0@gla$?<m0UFRE1J8|Zs3A<Ahe1CTM|diV(v$f
z=8|w10L!~;Cskdyl%YG!xTP%L)Y_nZ4RJeXcO!0B>|mOI1c3V_W>KkWM2j0Vqaj#w
zP`7!93&c?yX|u5uY^~x{TD>;it^Ug%80H2`mfhuY&LqoGlLW45S3;TztN8rv6>n+E
z>1$D#NpEq2pN^_r&tvM3=Ius~Iqd}T|7mBa{~>!+)xgr7I_)w=yIj?SZ(Tid?Dix%
qWv0MCIWCQ>A3K530QWBoQ|zwU=o~#=q?};BQL!mVvys`MH~$aep@%8}

delta 7545
zcmbVRS!`U_c?N~V9jh|6kQ8@u5f_QP<m{UzMLze=o#CCU%h6~wB1bmh&=Nf)hvbkP
z?y$?`sX&voNe=SV8nA&pB}TI}K+~WI{L&VMABsE_ZBZL(3KVGIv`za`plI5D|9|eC
zg{BgxFGJ2b=U>kMfB$yoAKq#E#@lV*?mPEKQ|JErxwg=EpMU<-Z7cG8`)|pwwU4ze
z${(~(wpHXmw!i4xF*H+%LQRfcys2%fFMEczAjA?rj4fR&2}5W(A#x8j3m-|H2@d4Z
z#lXvpnl18CV^^&m8CpdbqN)>RxQTL82kFv7_gKKtib9mMf)GVNOLWR9Eh7wwXJM8Q
zR#<-O($p}on_0~e#yy-6);>$hAL!b$5X)<F{?gFJN{ZBTv<=AK*4O15m-^3x&=M7W
zR}af~E~RI@BUM8<Pq8y6)>CwioXwXp_<k|I_QIy@yd1c`=SpD3;yUgr9FL19sC@Y~
z19ygAtNJeUD=ZN|dl8=|ZUZ8#${WjTDa{d?HN|L}1v(}jUS5$Gu8g*orT<FLAdE&f
z-cj~kO=)G^siL!~cIDG6qbJb8U4xB}m5rfZPON6qF4;!Pa|2m8P6`@ub4i#2+=YdE
zLglI+Y*rb%8oR8Pt@bPW4%yXO(Q$h2UM;2Ng~-qHrR+3mUeUK`(KsZf3-by)5raKL
zjtuKj8SWT6H*LsL$8`I?5~pmvC%@WJ$YP0{O3X5XJ}ro$KP+10$%#f%-&2%o3x*~d
zKAypGODqKSW9jegX{*Y)&hfUW+{FKT^0zyO+P9Qau7BnCI!Dj>4f(g7pJ|K9?ylQC
zKmpxKdjdbue?_n}x6BP$=^E@%+T~fCLA$w{{Qa)Mwl(=DUE>h&<E{t3P4*$eCwcWh
z+jeBIyJHI45>I#yH_78Bh@}!1GorA<TLnQZ%lfX|>=r&3b%*kgyN9O}2Dv(~jI15N
z`2pPx5v>Z<;>Mmy#Cv*Np6fB%5vdG)=wH_NWua&FyzBi6PW*Y#qxPBtnc{dXr+No6
zF<vU`DZ;0H%-^gzuq8Y>!c0R4(`3XWRGI&3N)(X_aIZp{(X$6>U+N8<2YcXZOW!r+
z+m}b>PkUp}yWobMZ}h!<TK-r11}>hGFaNY}pe-Q(uJ1oi5F}(e77b18ppFoL6?5!u
z+uL@qLeUgHdz-Yxwh=#j`(xB}Mfk)NGCR=j^DD3g<kG}|d}H8zW8rrPMx0GXe!&H?
zQn$vQE~_X#B>xyIsUxMh$Bk27kwdqvD^%J?^1lZLUs*|$Lz`nD!5%5aO%8kJlc5Y4
zX3JX-=zOlmij<Oc*4Wo092GenA<)5(IOA01-r)G~ud<r_!QkLaE@+WgLBFc566C9_
zeX^@`U;Ae7T88c()hn!9Szk{hoO0`WNdEn`J8k>2cPKWj6m7n4ly6up@@*@!I&}2}
zaYFh(CS{6DVJvR)v1Y;$+i4kUQl6u2W8ZKW!;Ie?D|DzIsFPR(+e|1;9?ykY%M8de
zD{jDH*NUXISMZk$gGx&F>!e3nk2VPk8Xk(539b2K@}d#c11zbmFOwvT3sYT?EsDEF
zMSgZT>Vwn4vJjAO4d1?~FjZpLSsQ8jufx43*tIxu$5Y3oqHrNsLb!<%bVRyN>MATK
zXWfSaIJIODP+r4|u#Om53-eev7IVyl{uh~O8u`w6yuo}O-k<0FJQZ5=F?h?*jSL~r
zy*<)BkzmFSv2@7B=Kb);6{^V(N3KmMi!OkI?5izNQniGILP#-}Bu44`5jiqC-gzdE
z$D`5qXfyMed~5X8Nq@R2D-;P})2vfI-g?&e8NYmReJ11qegl`Sn%iWCRpT(NqV7~G
z*?`x?w*1cZu4^7y0$F!j2bnFLoz$k15s+JUul&XJ?$in|z+0g7bDUXaf*HDzIW{tK
zCfb`KXYT_Yp$PjY6%tVXaS(1_9DDs0SKc=BTh{h;YJgBtp>?a0dwim-QwL<NP?g4!
zeA3XiLGoyWzqV3TW#4%JxGSK><cMjMll+Q-f<!Hbmzd=HnaRthKyrs>x%z75UY~q-
z{IU<egD`0PXXC+&XQ6FFh?=oYBt|e5;hfQ`fcEPhG3#9F3M@@bG&1k+HGlb0w68NG
zoWm4!CR^1>KAO1EOw#uP9C(~^Gj>4!EIcV!C$9q5pPL*zf!T3kdxtV>O@9c)uIs{G
zRK3MvM!}A{J+!o_H(SO5+tO}5zy$>{xUZkNjWBoulOtT+?OovHQ*6}98#5!G7+_`r
z0?n{@%o8Gi8t<21zTsPhBcZahODbEBpmAEbOMKKqqTuT3)xWTQ#OgY&+iv}{w)Cg2
zZ-0Jc)>k(Z@F1O=(c7-G1I(hpDHf{2;PpgB?gyHnlf_sNB|cz0K9WDYId=27H5||d
zElhJo31XfgKHdTOn^V2M`WJ0#NFX~jZUWOGtt-(?SUk0jP8&4>9P_9V0g8#L{NmJ<
zFYGEHe>fHC^RP>OJbanZqxI`wnD#R$`aTUF)`om}I&_kBHSnAl)f23N>N`zun_4^a
zZP43}wq6>2*%MSl7%HhlYw)+pk_+lO7V>b>ub-kJ_sI*|_+3wBWc(%ABeP~ayBosx
z>264FX_NC2#>^AWs>aipvLfk$+JsN?0d+t4A4QOtxWeW_e2=U$;WEt)Xr}`5pR}=r
zrxxP~?f+@HZV%_etPro;S<D3Pc*H6{z!sTc>dadqw;?W(Nl|wV52$}Q6M(0FJTuge
z`3~xPNk?9ookR;6nGLkIki`D%CXitO<$w8hgW63p?jVuUR-xXi&dJf?l8kB*(xa(H
z0{UpyY)i_Z|LQo90{}eWB1j*3MsWrhqL`rg$xLVDy5GKn3c|Q&?Wn2Qkbmj_-(GK-
zR&b!OQa8v?0%Imh23X{^P)g(<!<+M>s+vI-<2B9f&m4!bP3j=AQ{e7V-!GhfnGIg+
zI&!}-1l)!rCf^M9`}WmRK)xN!!UG=#uk~**tk<~7u(HHu!OzX;;(;6sjgQu2kugX8
zL*@aO?Pte*=u}|;s<=m5kROIbbD;N6+ro-_rJ=<F@DPW-(}?^nds519XRn9KWoq*j
z*7=EITfP?_Yq<1h;qZwX_*D7FwBE2`X@3rRxrA{!CmsrA*OJOtLD#KbV%|3b?2c30
z95FD{&e_{c{T%i|F25cL_zpd%d=R-C@vh)T<-xPUavPB>ym<OibU;?3mpeV;(EO>*
zcbhhAsg})|I@PI-0XZ9MV%bVHAgi%Ulx<_(2-vrVyXCiHcQLa6Ta0GF3-LEPqs{1Z
z2(X21`3G_TAZGO^B82(~1FxF`qc4nK&j9}%9~+G@eoJxJE^Z%&6u!h=7+PW}lA-oP
z1#|LqIF*o}Pj;Ngz=4-5WP?5Vg+#*Vw}>~op7#?omS>z8LO!7;qbf@%t<f=Km!}Hr
z|1JEI5>7n^I>nU~sSv!lZ&G5;HEA+<rKX=oHbvq<OC)0YCbMj2DL>){&Wo=PGz$>c
zL)yu_2KK1lW%*YxHr@B)t&v72khm4Sw4-iXQzi`?@+<Q_@@u!2eCru_!(6P&|GBkz
zE^f(pMmiVQQ=e#9P}7)$>~4u79;OJgJUTqQkHH4oJL;8>PQbqR!}9aDd*lbV2hW-s
zBJzbh`ALLABXMFxSTS5pJ~mEF$Zy_>{Td_1&wZ}{V_&`7Kj{7+VRJmWhm>M(89Sb>
zKZx|p!riM0Jh_E*k$F@(qczv20VBMj906`yr%IoE=Wgf8nbi=d@e;%{Lh|e`z^#|4
zOIGk1C%9{89?z(`gzz3f91o0mX@Vk_a2kU`o7N#;eaY+uB-z&7u%av8F{Ul~{g-A(
z+>J7ugZrFfQo)DqfX?bS#E{SLS!-4d`_@g!5V?eW)V%Yim~0$-SIms8WtB)bLsD*I
zF1b3h{}OL@c#65F%r#?M{*M0i)nt}Ze=fq)t$Kl_5-6-S^@rnuGqqLbu|E&CRBO4%
z;HQ^;RV`~wz#}t8DgKh#laA5jtAE)rZqXMKxFNr7gkRZZmTU+2jdO!na_h=O4I%4B
zm09M<COm5+j+GF_5M0qm5^r9$_T=4E&#HUGV3qN<fh4j;&xF(;)%Uo`!<}s$Ad8>5
zPhwY<1#&Ef-wQk@5&2%K*XMGK$e*No`&zZb)8U$m=IN~LG#5wQXqjeTEwFxZ{@)uR
z<d;liCQP<jNa~1KD98_SB8R6W1{w6G2Ur9&scn_zFU+M+!1p9Q+_CFE8!%3bK(t<y
z-%YQ%$g)@ESZ1PL`Q6?i-{=jVWM*IVQh#FvJUlzL7;=utH=5n|GqL*18&_`bpj(4m
zj?DGr(fZEZY&vNpADj0X42+fBf$G3ftSFK5%e{>T1Fs*9-BtcQ#Nm$0@srask5}b)
z<{aPFJ*EiA=d76yppWgya||;6icynkD|`zS`1a_R$}{n^4dJ+~7_P9yOh|su@;|~e
zCzYoo0wNwJ`9}tERzHItd&k&jP!$vhyOkdez3?%`TR<kWLnFJc{%-kR=AMkU>(8b~
z*}+k~j>0aMMc0_$=6mFh)pcl1<hJGav%@D_>X@yXZ@g})hYl;k5oE8iEQ^it0Babv
zo`h}me#V*}Vx?82VGUa5)RF~e=B}<h<24{^>VZ8-E0=9v>%|0uh$VQy^>*{S3wqBU
zByH%rsekPG<y&^s>&J(7)4RqC_nN-kxz}{8()^``!Cy4fd^B<GW+r@ghfG$+&o`yU
zfbloZRDE=23^^i#_v@!F#NNww$-sPn7r%PLi-|018x0|GT~y^~=exZCYZ*UaqEbkH
zc|JMDU4*gXKAYxEvXm<Of~I^NL<{pT^V#d(8zAR{1z{$=ksrT~R8h8SdPF|XIi5Je
zEsgn2@%&znX2*ZejSe2LPpkSdr_6$%bTg2-2sJesxbL*b2^N_m|BSYnkYBj(pGb1C
be;8uG*x`Ew*aeD8^YyaB$ugWBee?eSYnLll

diff --git a/src/showdown.js b/src/showdown.js
index a0ee56f..14a472b 100644
--- a/src/showdown.js
+++ b/src/showdown.js
@@ -13,7 +13,8 @@ var showdown = {},
       headerLevelStart:          1,
       parseImgDimensions:        false,
       simplifiedAutoLink:        false,
-      literalMidWordUnderscores: false
+      literalMidWordUnderscores: false,
+      strikethrough:             false
     },
     globalOptions = JSON.parse(JSON.stringify(defaultOptions)); //clone default options out of laziness =P
 
diff --git a/src/subParsers/spanGamut.js b/src/subParsers/spanGamut.js
index 0193c3d..e2568da 100644
--- a/src/subParsers/spanGamut.js
+++ b/src/subParsers/spanGamut.js
@@ -20,6 +20,7 @@ showdown.subParser('spanGamut', function (text, options, globals) {
   text = showdown.subParser('autoLinks')(text, options, globals);
   text = showdown.subParser('encodeAmpsAndAngles')(text, options, globals);
   text = showdown.subParser('italicsAndBold')(text, options, globals);
+  text = showdown.subParser('strikethrough')(text, options, globals);
 
   // Do hard breaks:
   text = text.replace(/  +\n/g, ' <br />\n');
diff --git a/src/subParsers/strikethrough.js b/src/subParsers/strikethrough.js
new file mode 100644
index 0000000..b84ab39
--- /dev/null
+++ b/src/subParsers/strikethrough.js
@@ -0,0 +1,9 @@
+showdown.subParser('strikethrough', function (text, options) {
+  'use strict';
+
+  if (options.strikethrough) {
+    text = text.replace(/(?:~T){2}([^~]+)(?:~T){2}/g, '<del>$1</del>');
+  }
+
+  return text;
+});
diff --git a/test/features/#164.3.strikethrough.html b/test/features/#164.3.strikethrough.html
new file mode 100644
index 0000000..68139e4
--- /dev/null
+++ b/test/features/#164.3.strikethrough.html
@@ -0,0 +1,5 @@
+<p>a <del>strikethrough</del> word</p>
+
+<p>this should~~not be parsed</p>
+
+<p><del>strike-through text</del></p>
diff --git a/test/features/#164.3.strikethrough.md b/test/features/#164.3.strikethrough.md
new file mode 100644
index 0000000..3498b1a
--- /dev/null
+++ b/test/features/#164.3.strikethrough.md
@@ -0,0 +1,5 @@
+a ~~strikethrough~~ word
+
+this should~~not be parsed
+
+~~strike-through text~~
diff --git a/test/node/showdown.js b/test/node/showdown.js
index 80834ff..5dd74a7 100644
--- a/test/node/showdown.js
+++ b/test/node/showdown.js
@@ -24,7 +24,8 @@ describe('showdown.options', function () {
         headerLevelStart:          1,
         parseImgDimensions:        false,
         simplifiedAutoLink:        false,
-        literalMidWordUnderscores: false
+        literalMidWordUnderscores: false,
+        strikethrough:             false
       };
       expect(showdown.getDefaultOptions()).to.be.eql(opts);
     });
diff --git a/test/node/testsuite.features.js b/test/node/testsuite.features.js
index 77e0e24..4278638 100644
--- a/test/node/testsuite.features.js
+++ b/test/node/testsuite.features.js
@@ -18,6 +18,8 @@ describe('makeHtml() features testsuite', function () {
       converter = new showdown.Converter({simplifiedAutoLink: true});
     } else if (testsuite[i].name === '#164.2.disallow_underscore_emphasis_mid_word') {
       converter = new showdown.Converter({literalMidWordUnderscores: true});
+    } else if (testsuite[i].name === '#164.3.strikethrough') {
+      converter = new showdown.Converter({strikethrough: true});
     } else {
       converter = new showdown.Converter();
     }