# HG changeset patch
# User Christian Urban <urbanc@in.tum.de>
# Date 1546079427 0
# Node ID f7de0915fff202798f0a607c7412a010356b7ad8
# Parent  24bbe4e4b37b7bb72baae1474cbc8f7712e4c0d9
updated

diff -r 24bbe4e4b37b -r f7de0915fff2 hws/hw02.pdf
Binary file hws/hw02.pdf has changed
diff -r 24bbe4e4b37b -r f7de0915fff2 hws/hw02.tex
--- a/hws/hw02.tex	Tue Dec 04 00:33:26 2018 +0000
+++ b/hws/hw02.tex	Sat Dec 29 10:30:27 2018 +0000
@@ -35,9 +35,10 @@
       expressions $r_1^*$, $r_2^*$ and $r_3^*$ each match?
 
 \item Give regular expressions for (a) decimal numbers and for
-      (b) binary numbers. (Hint: Observe that the empty string
+      (b) binary numbers. Hint: Observe that the empty string
       is not a number. Also observe that leading 0s are
-      normally not written.)
+      normally not written---for example the JSON format for numbers
+      explicitly forbids this.
 
 \item Decide whether the following two regular expressions are
       equivalent $(\ONE + a)^* \equiv^? a^*$ and $(a \cdot
diff -r 24bbe4e4b37b -r f7de0915fff2 progs/fib.j
--- a/progs/fib.j	Tue Dec 04 00:33:26 2018 +0000
+++ b/progs/fib.j	Sat Dec 29 10:30:27 2018 +0000
@@ -13,11 +13,55 @@
     .limit stack 2 
     getstatic java/lang/System/out Ljava/io/PrintStream; 
     iload 0
-    i2c
-    invokevirtual java/io/PrintStream/print(C)V 
+    invokevirtual java/io/PrintStream/println(I)V 
     return 
 .end method
 
+.method public static writes(Ljava/lang/String;)V
+    .limit stack 2
+    .limit locals 1
+    getstatic java/lang/System/out Ljava/io/PrintStream;
+    aload 0
+    invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V
+    return
+.end method
+
+.method public static read()I 
+    .limit locals 10 
+    .limit stack 10
+
+    ldc 0 
+    istore 1  ; this will hold our final integer 
+
+Label1: 
+    getstatic java/lang/System/in Ljava/io/InputStream; 
+    invokevirtual java/io/InputStream/read()I 
+    istore 2 
+    iload 2 
+    ldc 10  ; the newline delimiter 
+    isub 
+    ifeq Label2 
+    iload 2 
+    ldc 32   ; the space delimiter 
+    isub 
+    ifeq Label2
+
+    iload 2 
+    ldc 48   ; we have our digit in ASCII, have to subtract it from 48 
+    isub 
+    ldc 10 
+    iload 1 
+    imul 
+    iadd 
+    istore 1 
+    goto Label2
+    goto Label1 
+
+Label2: 
+    iload 1 ; when we come here we have our integer computed in local variable 1 
+    ireturn 
+.end method
+
 .method public static main([Ljava/lang/String;)V
    .limit locals 200
    .limit stack 200
diff -r 24bbe4e4b37b -r f7de0915fff2 progs/token.scala
--- a/progs/token.scala	Tue Dec 04 00:33:26 2018 +0000
+++ b/progs/token.scala	Sat Dec 29 10:30:27 2018 +0000
@@ -291,3 +291,19 @@
 }
 
 
+val fib = """
+write "Fib";
+read n;
+minus1 := 0;
+minus2 := 1;
+while n > 0 do {
+temp := minus2;
+minus2 := minus1 + minus2;
+minus1 := temp;
+n := n - 1
+};
+write "Result";
+write minus2
+"""
+
+println(env(lexing_simp(WHILE_REGS, prog2)).filterNot{_._1 == "w"})
diff -r 24bbe4e4b37b -r f7de0915fff2 slides/slides10.pdf
Binary file slides/slides10.pdf has changed
diff -r 24bbe4e4b37b -r f7de0915fff2 slides/slides10.tex
--- a/slides/slides10.tex	Tue Dec 04 00:33:26 2018 +0000
+++ b/slides/slides10.tex	Sat Dec 29 10:30:27 2018 +0000
@@ -63,8 +63,8 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[c]
 
-  \Large\bf Are there more strings in \bf{$L(a^*)$} or
-  \bf{$L((a + b)^*)$}?
+  \Large\bf Are there more strings in \bl{$L(a^*)$} or
+  \bl{$L((a + b)^*)$}?
 
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%