Initial commit

5 files changed, 108 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..84c048a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/build/
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..76b7081
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,4 @@
+build: grammar.y lex.l
+	bison -o build/grammar.tab.c -d grammar.y
+	flex -o build/lex.yy.c lex.l
+	gcc -o build/henshin build/grammar.tab.c build/lex.yy.c -lfl -ly
diff --git a/Readme.txt b/Readme.txt
new file mode 100644
index 0000000..6d26eb6
--- /dev/null
+++ b/Readme.txt
@@ -0,0 +1,3 @@
+- https://www.oreilly.com/library/view/flex-bison/9780596805418/ch01.html
+- https://raw.githubusercontent.com/richarddzh/gnu-flex-manual/master/flex.pdf
+- https://ftp.gnu.org/old-gnu/Manuals/flex-2.5.4/html_node/flex_toc.html
diff --git a/grammar.y b/grammar.y
new file mode 100644
index 0000000..fd9da47
--- /dev/null
+++ b/grammar.y
@@ -0,0 +1,53 @@
+%{
+#include <stdio.h>
+%}
+
+%define parse.error verbose
+
+%token OPERATOR_PLUS
+%token OPERATOR_MINUS
+%token ASSIGN
+
+%token FUNCTION
+%token IF
+%token ELSE
+%token RETURN
+%token CONST
+%token VAR
+
+%token PARENTHESIS_LEFT
+%token PARENTHESIS_RIGHT
+%token BRACE_LEFT
+%token BRACE_RIGHT
+%token BRACKET_LEFT
+%token BRACKET_RIGHT
+
+%token COMMA;
+
+%token NUMBER;
+%token IDENTIFIER
+%token COMMENT;
+
+%token END_OF_LINE;
+
+%%
+program:      
+            | program statement END_OF_LINE
+            ;
+
+statement:    expression
+            | RETURN expression
+            | CONST IDENTIFIER ASSIGN expression
+            | VAR IDENTIFIER ASSIGN expression
+            ;
+
+expression:   NUMBER
+            | IDENTIFIER
+            ;
+%%
+
+main (int argc, char **argv)
+{
+  //henshin_lex();
+  yyparse();
+}
diff --git a/lex.l b/lex.l
new file mode 100644
index 0000000..2f79474
--- /dev/null
+++ b/lex.l
@@ -0,0 +1,47 @@
+%{
+#include "grammar.tab.h"
+%}
+
+%%
+"+"                     { return OPERATOR_PLUS; }
+"-"                     { return OPERATOR_MINUS; }
+"="                     { return ASSIGN; }
+
+"function"              { return FUNCTION; }
+"if"                    { return IF; }
+"else"                  { return ELSE; }
+"return"                { return RETURN; }
+"const"                 { return CONST; }
+"var"                   { return VAR; }
+
+"("                     { return PARENTHESIS_LEFT; }
+")"                     { return PARENTHESIS_RIGHT; }
+"{"                     { return BRACE_LEFT; }
+"}"                     { return BRACE_RIGHT; }
+"["                     { return BRACKET_LEFT; }
+"]"                     { return BRACKET_RIGHT; }
+
+","                     { return COMMA; }
+
+[0-9]+                  { yylval = atoi(yytext); return NUMBER; }
+[a-zA-Z]+[a-zA-Z0-9]*   { return IDENTIFIER; }
+"//".*                  { return COMMENT; }
+
+\n                      { return END_OF_LINE; }
+[ \t]                   {}
+
+.                       { printf("undefined: %c\n", *yytext); }
+%%
+
+void henshin_lex(int argc, char **argv)
+{
+  int tok;
+
+  while (tok = yylex()) {
+    printf("%d", tok);
+    if (tok == NUMBER) {
+      printf(" = %d", yylval);
+    }
+    printf("\n");
+  }
+}