add yacc programs

19 files changed, 426 insertions, 28 deletions

diff --git a/.direnv/flake-profile b/.direnv/flake-profile
index e2fe106..444fae1 120000
--- a/.direnv/flake-profile
+++ b/.direnv/flake-profile
@@ -1 +1 @@
-/nix/store/n8fwn588p25fgik3z6jr49x7l7ypsvkc-nix-shell-env
\ No newline at end of file
+/nix/store/q89kklg6h19vm15s7wh5lwjrj1jdz7k4-nix-shell-env
\ No newline at end of file
diff --git a/.direnv/flake-profile.rc b/.direnv/flake-profile.rc
index 34911e2..611c1da 100644
--- a/.direnv/flake-profile.rc
+++ b/.direnv/flake-profile.rc
@@ -32,7 +32,7 @@ NIX_CC=/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0
 export NIX_CC
 NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu=1
 export NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu
-NIX_CFLAGS_COMPILE=' -frandom-seed=n8fwn588p2 -isystem /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/include -isystem /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/include'
+NIX_CFLAGS_COMPILE=' -frandom-seed=q89kklg6h1 -isystem /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/include -isystem /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/include -isystem /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/include -isystem /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/include'
 export NIX_CFLAGS_COMPILE
 NIX_ENFORCE_NO_NATIVE=1
 export NIX_ENFORCE_NO_NATIVE
@@ -55,7 +55,7 @@ export OBJDUMP
 OPTERR=1
 OPTIND=1
 OSTYPE=linux-gnu
-PATH=/nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/bin:/nix/store/caxc3dmxqwy1ks03han5mlkr7sy6wh8y-gnum4-1.4.18/bin:/nix/store/ybl3zad6ihv60d4w0nprcj5a9g94z1z3-bison-3.7.6/bin:/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0/bin:/nix/store/sjfbbay5xhifzpipm4k007svlrpjbx2p-gcc-10.2.0/bin:/nix/store/l6blpd7anij8pzzgr30srmf919rg169v-glibc-2.32-39-bin/bin:/nix/store/485sqh570qixsv9wk0d59vrvs35pqja0-coreutils-8.32/bin:/nix/store/6zb7whdhsn7pq9vw086z5j3kw0qpgr3m-binutils-wrapper-2.35.1/bin:/nix/store/fx4kvd2440kgrq73irdkmwqf6vvzwf2m-binutils-2.35.1/bin:/nix/store/q5yia079krwdhp1ld00fv44sy072q5f5-patchelf-0.12/bin:/nix/store/485sqh570qixsv9wk0d59vrvs35pqja0-coreutils-8.32/bin:/nix/store/a7kzz70vzpsq3s2pgfw49q8ll356l13f-findutils-4.7.0/bin:/nix/store/b2rmyng3dryanc5g1jnsqqrbaclw52b3-diffutils-3.7/bin:/nix/store/xyd1a8i3sn1iah73sr3p15fx3y9v0rkc-gnused-4.8/bin:/nix/store/x604v97a5yi0yc07zfid76n7xqbcykmj-gnugrep-3.6/bin:/nix/store/3w93n4d1f0gj7xc2x7si46njlz9vkad9-gawk-5.1.0/bin:/nix/store/ym4ygxjyyym82j6mc3bjzx6527r1j9rj-gnutar-1.34/bin:/nix/store/fj1cn54yvinnd8ypi202jq3kd761d5sh-gzip-1.10/bin:/nix/store/ip4mcnr199dw3f750ka6543zgjpr3pgd-bzip2-1.0.6.0.2-bin/bin:/nix/store/chy0dyh9imv0qj4x3xd1a2w4rw9v77pj-gnumake-4.3/bin:/nix/store/p886sbvvzpqpxnb8a60djpp8dir9zfp9-bash-4.4-p23/bin:/nix/store/ay3j8pm23pilyj8gqqj7rkbzk7mdcfr0-patch-2.7.6/bin:/nix/store/k25g03svkjzl74c1bqkzx9anpg0438v1-xz-5.2.5-bin/bin
+PATH=/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0/bin:/nix/store/sjfbbay5xhifzpipm4k007svlrpjbx2p-gcc-10.2.0/bin:/nix/store/l6blpd7anij8pzzgr30srmf919rg169v-glibc-2.32-39-bin/bin:/nix/store/485sqh570qixsv9wk0d59vrvs35pqja0-coreutils-8.32/bin:/nix/store/6zb7whdhsn7pq9vw086z5j3kw0qpgr3m-binutils-wrapper-2.35.1/bin:/nix/store/fx4kvd2440kgrq73irdkmwqf6vvzwf2m-binutils-2.35.1/bin:/nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4/bin:/nix/store/caxc3dmxqwy1ks03han5mlkr7sy6wh8y-gnum4-1.4.18/bin:/nix/store/ybl3zad6ihv60d4w0nprcj5a9g94z1z3-bison-3.7.6/bin:/nix/store/q5yia079krwdhp1ld00fv44sy072q5f5-patchelf-0.12/bin:/nix/store/485sqh570qixsv9wk0d59vrvs35pqja0-coreutils-8.32/bin:/nix/store/a7kzz70vzpsq3s2pgfw49q8ll356l13f-findutils-4.7.0/bin:/nix/store/b2rmyng3dryanc5g1jnsqqrbaclw52b3-diffutils-3.7/bin:/nix/store/xyd1a8i3sn1iah73sr3p15fx3y9v0rkc-gnused-4.8/bin:/nix/store/x604v97a5yi0yc07zfid76n7xqbcykmj-gnugrep-3.6/bin:/nix/store/3w93n4d1f0gj7xc2x7si46njlz9vkad9-gawk-5.1.0/bin:/nix/store/ym4ygxjyyym82j6mc3bjzx6527r1j9rj-gnutar-1.34/bin:/nix/store/fj1cn54yvinnd8ypi202jq3kd761d5sh-gzip-1.10/bin:/nix/store/ip4mcnr199dw3f750ka6543zgjpr3pgd-bzip2-1.0.6.0.2-bin/bin:/nix/store/chy0dyh9imv0qj4x3xd1a2w4rw9v77pj-gnumake-4.3/bin:/nix/store/p886sbvvzpqpxnb8a60djpp8dir9zfp9-bash-4.4-p23/bin:/nix/store/ay3j8pm23pilyj8gqqj7rkbzk7mdcfr0-patch-2.7.6/bin:/nix/store/k25g03svkjzl74c1bqkzx9anpg0438v1-xz-5.2.5-bin/bin
 export PATH
 PIPESTATUS=([0]="0")
 PS4='+ '
@@ -107,13 +107,13 @@ doInstallCheck=
 export doInstallCheck
 dontAddDisableDepTrack=1
 export dontAddDisableDepTrack
-envHostHostHooks=([0]="ccWrapper_addCVars" [1]="bintoolsWrapper_addLDVars")
-envHostTargetHooks=([0]="ccWrapper_addCVars" [1]="bintoolsWrapper_addLDVars")
+envHostHostHooks=([0]="ccWrapper_addCVars" [1]="bintoolsWrapper_addLDVars" [2]="ccWrapper_addCVars")
+envHostTargetHooks=([0]="ccWrapper_addCVars" [1]="bintoolsWrapper_addLDVars" [2]="ccWrapper_addCVars")
 fixupOutputHooks=([0]="if [ -z \"\${dontPatchELF-}\" ]; then patchELF \"\$prefix\"; fi" [1]="_makeSymlinksRelative" [2]="if [ -z \"\${dontGzipMan-}\" ]; then compressManPages \"\$prefix\"; fi" [3]="_doStrip" [4]="patchShebangsAuto" [5]="_pruneLibtoolFiles" [6]="if [[ -z \"\${noAuditTmpdir-}\" && -e \"\$prefix\" ]]; then auditTmpdir \"\$prefix\"; fi" [7]="_moveSystemdUserUnits" [8]="_moveSbin" [9]="_moveLib64")
 initialPath='/nix/store/485sqh570qixsv9wk0d59vrvs35pqja0-coreutils-8.32 /nix/store/a7kzz70vzpsq3s2pgfw49q8ll356l13f-findutils-4.7.0 /nix/store/b2rmyng3dryanc5g1jnsqqrbaclw52b3-diffutils-3.7 /nix/store/xyd1a8i3sn1iah73sr3p15fx3y9v0rkc-gnused-4.8 /nix/store/x604v97a5yi0yc07zfid76n7xqbcykmj-gnugrep-3.6 /nix/store/3w93n4d1f0gj7xc2x7si46njlz9vkad9-gawk-5.1.0 /nix/store/ym4ygxjyyym82j6mc3bjzx6527r1j9rj-gnutar-1.34 /nix/store/fj1cn54yvinnd8ypi202jq3kd761d5sh-gzip-1.10 /nix/store/ip4mcnr199dw3f750ka6543zgjpr3pgd-bzip2-1.0.6.0.2-bin /nix/store/chy0dyh9imv0qj4x3xd1a2w4rw9v77pj-gnumake-4.3 /nix/store/p886sbvvzpqpxnb8a60djpp8dir9zfp9-bash-4.4-p23 /nix/store/ay3j8pm23pilyj8gqqj7rkbzk7mdcfr0-patch-2.7.6 /nix/store/k25g03svkjzl74c1bqkzx9anpg0438v1-xz-5.2.5-bin'
 name=nix-shell
 export name
-nativeBuildInputs='/nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4 /nix/store/ybl3zad6ihv60d4w0nprcj5a9g94z1z3-bison-3.7.6 /nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0'
+nativeBuildInputs='/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0 /nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4 /nix/store/ybl3zad6ihv60d4w0nprcj5a9g94z1z3-bison-3.7.6 /nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0'
 export nativeBuildInputs
 nobuildPhase=$'echo\necho "This derivation is not meant to be built, aborting";\necho\nexit 1\n'
 export nobuildPhase
@@ -135,7 +135,7 @@ export patches
 phases=nobuildPhase
 export phases
 pkg=/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0
-pkgsBuildHost=([0]="/nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4" [1]="/nix/store/caxc3dmxqwy1ks03han5mlkr7sy6wh8y-gnum4-1.4.18" [2]="/nix/store/ybl3zad6ihv60d4w0nprcj5a9g94z1z3-bison-3.7.6" [3]="/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0" [4]="/nix/store/6zb7whdhsn7pq9vw086z5j3kw0qpgr3m-binutils-wrapper-2.35.1" [5]="/nix/store/q5yia079krwdhp1ld00fv44sy072q5f5-patchelf-0.12" [6]="/nix/store/mjjy30kxz775bhhi6j9phw81qh6dsbrf-move-docs.sh" [7]="/nix/store/kxw6q8v6isaqjm702d71n2421cxamq68-make-symlinks-relative.sh" [8]="/nix/store/cl3qd985p1yxyfkj96v0hqxiy3w69xq5-compress-man-pages.sh" [9]="/nix/store/h54dzwd7rdh2jlcv91424csl6d0ccgjy-strip.sh" [10]="/nix/store/bnj8d7mvbkg3vdb07yz74yhl3g107qq5-patch-shebangs.sh" [11]="/nix/store/cickvswrvann041nqxb0rxilc46svw1n-prune-libtool-files.sh" [12]="/nix/store/8zxndz5ag0p6s526c2xyllhk1nrn4c3i-audit-tmpdir.sh" [13]="/nix/store/c8n9kcdddp9np665xz6ri61b383nxvz8-move-systemd-user-units.sh" [14]="/nix/store/1i5y55x4b4m9qkx5dqbmr1r6bvrqbanw-multiple-outputs.sh" [15]="/nix/store/kd4xwxjpjxi71jkm6ka0np72if9rm3y0-move-sbin.sh" [16]="/nix/store/fyaryjvghbkpfnsyw97hb3lyb37s1pd6-move-lib64.sh" [17]="/nix/store/ngg1cv31c8c7bcm2n8ww4g06nq7s4zhm-set-source-date-epoch-to-latest.sh" [18]="/nix/store/pr6nzbscdpg94yvr151lrif2kg0csx7b-reproducible-builds.sh")
+pkgsBuildHost=([0]="/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0" [1]="/nix/store/6zb7whdhsn7pq9vw086z5j3kw0qpgr3m-binutils-wrapper-2.35.1" [2]="/nix/store/qrq8px6m7v85j9jcp7zzk1pkawmrll43-flex-2.6.4" [3]="/nix/store/caxc3dmxqwy1ks03han5mlkr7sy6wh8y-gnum4-1.4.18" [4]="/nix/store/ybl3zad6ihv60d4w0nprcj5a9g94z1z3-bison-3.7.6" [5]="/nix/store/gdg97kdw8k7nqg704g4gm3cn8280bmgr-gcc-wrapper-10.2.0" [6]="/nix/store/q5yia079krwdhp1ld00fv44sy072q5f5-patchelf-0.12" [7]="/nix/store/mjjy30kxz775bhhi6j9phw81qh6dsbrf-move-docs.sh" [8]="/nix/store/kxw6q8v6isaqjm702d71n2421cxamq68-make-symlinks-relative.sh" [9]="/nix/store/cl3qd985p1yxyfkj96v0hqxiy3w69xq5-compress-man-pages.sh" [10]="/nix/store/h54dzwd7rdh2jlcv91424csl6d0ccgjy-strip.sh" [11]="/nix/store/bnj8d7mvbkg3vdb07yz74yhl3g107qq5-patch-shebangs.sh" [12]="/nix/store/cickvswrvann041nqxb0rxilc46svw1n-prune-libtool-files.sh" [13]="/nix/store/8zxndz5ag0p6s526c2xyllhk1nrn4c3i-audit-tmpdir.sh" [14]="/nix/store/c8n9kcdddp9np665xz6ri61b383nxvz8-move-systemd-user-units.sh" [15]="/nix/store/1i5y55x4b4m9qkx5dqbmr1r6bvrqbanw-multiple-outputs.sh" [16]="/nix/store/kd4xwxjpjxi71jkm6ka0np72if9rm3y0-move-sbin.sh" [17]="/nix/store/fyaryjvghbkpfnsyw97hb3lyb37s1pd6-move-lib64.sh" [18]="/nix/store/ngg1cv31c8c7bcm2n8ww4g06nq7s4zhm-set-source-date-epoch-to-latest.sh" [19]="/nix/store/pr6nzbscdpg94yvr151lrif2kg0csx7b-reproducible-builds.sh")
 postFixupHooks=([0]="_multioutPropagateDev")
 postUnpackHooks=([0]="_updateSourceDateEpochFromSourceRoot")
 preConfigureHooks=([0]="_multioutConfig")
@@ -955,7 +955,7 @@ getRole ()
             role_post='_FOR_TARGET'
         ;;
         *)
-            echo "binutils-wrapper-2.35.1: used as improper sort of dependency" > 2;
+            echo "gcc-wrapper-10.2.0: used as improper sort of dependency" > 2;
             return 1
         ;;
     esac
@@ -972,16 +972,16 @@ getTargetRoleWrapper ()
 { 
     case $targetOffset in 
         -1)
-            export NIX_BINTOOLS_WRAPPER_TARGET_BUILD_x86_64_unknown_linux_gnu=1
+            export NIX_CC_WRAPPER_TARGET_BUILD_x86_64_unknown_linux_gnu=1
         ;;
         0)
-            export NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu=1
+            export NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu=1
         ;;
         1)
-            export NIX_BINTOOLS_WRAPPER_TARGET_TARGET_x86_64_unknown_linux_gnu=1
+            export NIX_CC_WRAPPER_TARGET_TARGET_x86_64_unknown_linux_gnu=1
         ;;
         *)
-            echo "binutils-wrapper-2.35.1: used as improper sort of dependency" > 2;
+            echo "gcc-wrapper-10.2.0: used as improper sort of dependency" > 2;
             return 1
         ;;
     esac
diff --git a/10/input b/10/input
new file mode 100644
index 0000000..fdfb61b
--- /dev/null
+++ b/10/input
@@ -0,0 +1 @@
+1+2-3*6/2
diff --git a/10/main.l b/10/main.l
new file mode 100644
index 0000000..9962054
--- /dev/null
+++ b/10/main.l
@@ -0,0 +1,22 @@
+%{
+extern int yylval;
+%}
+
+d [0-9]+
+
+%%
+"+" return ADD;
+"-" return SUB;
+"*" return MUL;
+"/" return DIV;
+[0-9]+ {
+    yylval = atoi(yytext);
+    return NUM;
+};
+. return yytext[0];
+\n return 0;
+%%
+
+int yywrap() {
+    return 1;
+}
diff --git a/10/main.y b/10/main.y
new file mode 100644
index 0000000..f45e23f
--- /dev/null
+++ b/10/main.y
@@ -0,0 +1,33 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+int yylex();
+int yyerror(char *);
+%}
+
+%token ADD SUB MUL DIV NUM
+%left ADD SUB MUL DIV
+
+%%
+R: E {
+    printf("result: %d", $$);
+    return 0;
+ }
+E: E ADD T { $$ = $1 + $3; }
+ | E SUB T { $$ = $1 - $3; }
+ | T
+ ;
+T: T MUL NUM { $$ = $1 * $3; }
+ | T DIV NUM { $$ = $1 / $3; }
+ | NUM { $$ = $1; }
+ ;
+%%
+
+int main() {
+    yyparse();
+}
+
+int yyerror(char *s) {
+    printf("error: %s", s);
+    exit(0);
+}
diff --git a/11/input b/11/input
new file mode 100644
index 0000000..7e9718c
--- /dev/null
+++ b/11/input
@@ -0,0 +1 @@
+for(i=0;i!=20;i--){for(;;){for(;;)i=1;}}
diff --git a/11/main.l b/11/main.l
new file mode 100644
index 0000000..5cc2a4e
--- /dev/null
+++ b/11/main.l
@@ -0,0 +1,33 @@
+%{
+#include "y.tab.h"
+extern int yylval;
+%}
+
+%%
+"++" return INC;
+"--" return DEC;
+"+" return ADD;
+"-" return SUB;
+"*" return MUL;
+"/" return DIV;
+"=" return ASSIGN;
+"==" return EQ;
+"!=" return NEQ;
+"<" return LT;
+">" return GT;
+"<=" return LTE;
+">=" return GTE;
+";" return ENDL;
+"for" return FOR;
+[0-9]+ {
+    yylval = atoi(yytext);
+    return NUM;
+};
+[a-zA-Z_][a-zA-Z_0-9]* return ID;
+. return yytext[0];
+\n return 0;
+%%
+
+int yywrap() {
+    return 1;
+}
diff --git a/11/main.y b/11/main.y
new file mode 100644
index 0000000..9ed51a0
--- /dev/null
+++ b/11/main.y
@@ -0,0 +1,76 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+#include "lex.yy.cc"
+int yylex();
+int yyerror(char *);
+int loop_count = 0;
+%}
+
+%token ADD SUB MUL DIV INC DEC
+%token LT GT LTE GTE EQ NEQ ASSIGN
+%token FOR
+%token ENDL
+%token NUM ID
+
+%start statement
+
+%%
+primary_expr: NUM
+            | ID
+            ;
+
+postfix_expr: postfix_expr INC
+            | postfix_expr DEC
+            | primary_expr
+            ;
+
+unary_expr: INC unary_expr
+          | DEC unary_expr
+          | postfix_expr
+          ;
+
+boolean_expr: unary_expr LT unary_expr
+            | unary_expr GT unary_expr
+            | unary_expr LTE unary_expr
+            | unary_expr GTE unary_expr
+            | unary_expr EQ unary_expr
+            | unary_expr NEQ unary_expr
+            ;
+
+assignment_expr: unary_expr ASSIGN unary_expr
+               | unary_expr ASSIGN boolean_expr
+               ;
+
+expression: unary_expr
+          | boolean_expr
+          | assignment_expr
+          ;
+
+block: '{' statement block_cont
+     ;
+block_cont: statement block_cont
+          | '}'
+          ;
+
+statement: expression ENDL
+         | block
+         | for_expr {loop_count++;}
+         | ENDL
+         ;
+
+for_expr: FOR '(' statement statement expression ')' statement
+        | FOR '(' statement statement ')' statement
+        ;
+
+%%
+
+int main() {
+    yyparse();
+    printf("valid expression, nested %d", loop_count);
+}
+
+int yyerror(char *s) {
+    printf("error: %s", s);
+    exit(0);
+}
diff --git a/6/main.l b/6/main.l
new file mode 100644
index 0000000..55dac30
--- /dev/null
+++ b/6/main.l
@@ -0,0 +1,16 @@
+%{
+#include "y.tab.h"
+#include <stdlib.h>
+%}
+
+%%
+
+a return A;
+b return B;
+. return yytext[0];
+\n return 0;
+%%
+
+int yywrap() {
+    return 1;
+}
diff --git a/6/main.y b/6/main.y
new file mode 100644
index 0000000..25005df
--- /dev/null
+++ b/6/main.y
@@ -0,0 +1,28 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+int yylex();
+int yyerror(char *);
+%}
+
+%token A B ERR
+
+%%
+
+S:
+ A S B
+ |
+ ;
+
+%%
+
+int yyerror(char *s) {
+    printf("error: %s", s);
+    exit(0);
+}
+
+int main() {
+    yyparse();
+    printf("valid string\n");
+    return 0;
+}
diff --git a/7/main.l b/7/main.l
new file mode 100644
index 0000000..7e1332f
--- /dev/null
+++ b/7/main.l
@@ -0,0 +1,22 @@
+%{
+#include "y.tab.h"
+extern int yylval;
+%}
+
+%%
+[0-9]+ {
+    yylval = atoi(yytext);
+    return NUM;
+}
+"+" return ADD;;
+"-" return SUB;
+"*" return MUL;
+"/" return DIV;
+"(" return LPAR;
+")" return RPAR;
+\n return 0;
+%%
+
+int yywrap() {
+    return 1;
+}
diff --git a/7/main.y b/7/main.y
new file mode 100644
index 0000000..26a2007
--- /dev/null
+++ b/7/main.y
@@ -0,0 +1,34 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+int yylex();
+int yyerror(char *);
+%}
+
+%token NUM ADD SUB MUL DIV LPAR RPAR
+%left ADD SUB MUL DIV
+%right NEG
+
+%%
+
+S:
+ E { printf("\n"); };
+E:
+ E ADD E   { printf("+ "); }
+ | E MUL E { printf("* "); }
+ | E SUB E { printf("- "); }
+ | E DIV E { printf("/ "); }
+ | LPAR E RPAR
+ | SUB E %prec NEG { printf("- "); }
+ | NUM { printf("%d ", yylval); }
+ ;
+%%
+
+int main() {
+    yyparse();
+}
+
+int yyerror(char *s) {
+    printf("error: %s", s);
+    exit(0);
+}
diff --git a/8/input b/8/input
new file mode 100644
index 0000000..5c11124
--- /dev/null
+++ b/8/input
@@ -0,0 +1 @@
+aaaab
diff --git a/8/main.l b/8/main.l
new file mode 100644
index 0000000..3db9d6d
--- /dev/null
+++ b/8/main.l
@@ -0,0 +1,15 @@
+%{
+#include "y.tab.h"
+extern int yylval;
+%}
+
+%%
+a return A;
+b return B;
+. return yytext[0];
+\n return 0;
+%%
+
+int yywrap() {
+    return 1;
+}
diff --git a/8/main.y b/8/main.y
new file mode 100644
index 0000000..04e98a7
--- /dev/null
+++ b/8/main.y
@@ -0,0 +1,28 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+int yyerror(char *);
+%}
+
+%token A B
+%start S
+
+%%
+
+S: C B
+ |
+ ;
+C: A C
+ | A A A A
+ ;
+%%
+
+int main() {
+    yyparse();
+    printf("valid string");
+}
+
+int yyerror(char *s) {
+    printf("error: %s", s);
+    exit(0);
+}
diff --git a/9/input b/9/input
new file mode 100644
index 0000000..01efb5e
--- /dev/null
+++ b/9/input
@@ -0,0 +1 @@
+aaabbbbc
diff --git a/9/main.l b/9/main.l
new file mode 100644
index 0000000..04c6bf0
--- /dev/null
+++ b/9/main.l
@@ -0,0 +1,16 @@
+%{
+#include "y.tab.h"
+extern int yylval;
+%}
+
+%%
+a return A;
+b return B;
+c return C;
+. return yytext[0];
+\n return 0;
+%%
+
+int yywrap() {
+    return 1;
+}
diff --git a/9/main.y b/9/main.y
new file mode 100644
index 0000000..0db29c1
--- /dev/null
+++ b/9/main.y
@@ -0,0 +1,30 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+int yylex();
+int yyerror(char *);
+%}
+
+%token A B C
+
+%%
+S: X Y
+ |
+ ;
+X: A X B
+ |
+ ;
+Y: B Y C
+ |
+ ;
+%%
+
+int main() {
+    yyparse();
+    printf("valid string");
+}
+
+int yyerror(char *s) {
+    printf("error: %s", s);
+    exit(0);
+}
diff --git a/flake.nix b/flake.nix
index c85db6e..2e717b8 100644
--- a/flake.nix
+++ b/flake.nix
@@ -8,23 +8,67 @@
       let
         pkgs = nixpkgs.legacyPackages."${system}";
         nativeBuildInputs = with pkgs; [
+          gcc
           flex
           bison
         ];
+        defs = [
+          { name = "1"; yacc = false; }
+          { name = "2"; yacc = false; }
+          { name = "3"; yacc = false; }
+          { name = "4"; yacc = false; }
+          { name = "5"; yacc = false; }
+          { name = "6"; yacc = true; }
+          { name = "7"; yacc = true; }
+          { name = "8"; yacc = true; }
+        ];
+        apps = builtins.listToAttrs (builtins.map
+          (def:
+            let
+              builder = pkgs.stdenv.mkDerivation {
+                name = "${def.name}-v0.1.0";
+                src = ./.;
+                buildInputs = nativeBuildInputs;
+                unpackCmd = ''
+                  cp -r $src/${def.name} .
+                '';
+                buildPhase = ''
+                  flex -o ${def.name}.yy.cc main.l
+                  if [[ ${pkgs.lib.trivial.boolToString def.yacc} = true ]]; then
+                    yacc -d main.y
+                    gcc -o exec y* ${def.name}.yy.cc
+                  else
+                    gcc -o exec ${def.name}.yy.cc
+                  fi
+                '';
+                installPhase = ''
+                  mkdir -p $out/bin
+                  install -m 755 -D exec -t $out/bin/
+                '';
+              };
+            in
+            {
+              name = def.name;
+              value = {
+                type = "app";
+                program = "${builder}/bin/exec";
+              };
+            })
+          defs);
+        # buildYacc = pkgs.writeScriptBin "build-yacc"
+        #   ''
+        #     set -e
+        #     prog_name="$1"
+        #     outdir="outputs/$prog_name"
+        #     mkdir -p "$outdir"
 
-        buildScript = pkgs.writeScriptBin "build-script"
-          ''
-            set -e
-            prog_name="$1"
-            outdir="outputs/$prog_name"
-            mkdir -p "$outdir"
-
-            ${pkgs.flex}/bin/flex -o "$outdir"/lex.yy.cc "$prog_name"/main.l
-            ${pkgs.gcc}/bin/gcc "$outdir"/lex.yy.cc -o "$outdir"/exec
+        #     ${pkgs.flex}/bin/flex -o "$outdir"/lex.yy.cc "$prog_name"/main.l
+        #     ${pkgs.bison}/bin/yacc -b "$outdir"/y -d "$prog_name"/main.y
+        #     ${pkgs.gcc}/bin/gcc -o "$outdir"/exec "$outdir"/y.*
 
-            ./"$outdir"/exec < "$prog_name"/input
-            rm -r outputs
-          '';
+        #     ./"$outdir"/exec < "$prog_name"/input
+        #     rm -r outputs
+        #   '';
 
       in
       rec {
@@ -33,9 +77,6 @@
             gcc
           ]);
         };
-        defaultApp = {
-          type = "app";
-          program = "${buildScript}/bin/build-script";
-        };
+        inherit apps;
       });
 }