fix examples

examples/01_Hello_Name.mers

@@ -1,3 +1,3 @@
 "What's you name?".println
-name := ().read_line.trim
+name := ().read_line.try((name) -> name.trim, () -> "<no name given>")
 ("Hello, ", name, "!").concat.println

examples/02_Calc_Sum.mers

@@ -1,9 +1,12 @@
 total := 0.0
 loop {
   ("Total: ", total, ". Type a number to change.").concat.println
-  ().read_line.trim.parse_float.try(
+  ().read_line.try(
+    (line) -> line.trim.parse_float.try(
       (n) -> &total = (total, n).sum
-    // not a number, so return a 1-tuple to break from the loop
+      () -> "Not a number".eprintln
+    )
+    // CTRL+D, so return a 1-tuple to break from the loop
     () -> (())
   )
 }

examples/03_Basic_Calculator.mers

@@ -1,13 +1,15 @@
 "- Calculator -".println
 "Type =<num> to set the value to that number.".println
 "Type +<num>, -<num>, *<num> or /<num> to change the value.".println
-"Type exit to exit.".println
+"Type exit or press CTRL+D to exit.".println
 
 current := 0.0
 
 loop {
   ("[ ", current, " ]").concat.println
-  input := ().read_line.trim
+  ().read_line.try(
+    (line) -> {
+      input := line.trim
       num := (input, 1).substring.trim.parse_float.try(
         (val) -> val
         () -> 0.0
@@ -23,7 +25,13 @@ loop {
         &current = (current, num).div
       } else if mode.eq("=") {
         &current = num
-  } else if (input.eq("exit"), input.eq("")).any {
+      } else if input.eq("exit") {
         (())
+      } else {
+        "Expected one of +-*/= followed by a number".eprintln
       }
+    }
+    // CTRL+D
+    () -> (())
+  )
 }

examples/04_Greatest_Common_Divisor.mers

@@ -12,7 +12,7 @@ gcd := vals -> {
 
 get_num := () -> {
   loop {
-    line := ().read_line.trim
+    line := ().read_line.try((line) -> line.trim, () -> "")
     line.parse_float.try(
       (n) -> (n)
       () -> ("Error: '", line, "' not a number!").concat.println

examples/05_Matrix_Multiplicator.mers

@@ -2,8 +2,8 @@ parse_matrix_line := input -> {
   vals := input.str_split(" ")
   vals_len := vals.len
   // reverse vals
-  vals_rev := {() -> &vals.pop}.as_list
-  nums := vals_rev.filter_map(v -> v.parse_float).as_list
+  // vals_rev := {() -> &vals.pop}.as_list
+  nums := vals.filter_map(v -> v.parse_float).as_list
   if nums.len.eq(vals_len)
     if nums.len.signum.eq(1)
       (nums)
@@ -12,7 +12,7 @@ parse_matrix_line := input -> {
 }
 
 read_matrix_line := width -> {
-  ().read_line.trim.parse_matrix_line.try(
+  ().read_line.try((line) -> line.trim, () -> "").parse_matrix_line.try(
     (line) -> {
       line := [List<Float>] line
       w := width.deref
@@ -81,9 +81,7 @@ matrix_print := matrix -> {
 
 fget := v -> v.get.try(
   () -> {
-    "called fget but get returned ():".println
-    v.println
-    5.panic
+    ("called fget but get returned (): ", v).concat.panic
   }
   (v) -> v
 )

examples/06_TicTacToe.mers

@@ -60,7 +60,9 @@ loop {
   ().print_board
   loop {
     (if player c_blue else c_green, "> ", c_gray).concat.print
-    input := ().read_line.trim
+    ().read_line.try(
+      (line) -> {
+        input := line.trim
         input.parse_int.try(
           (field) -> {
             if (field.gt(0), field.ltoe(9)).all {
@@ -78,6 +80,9 @@ loop {
           () -> "not a number!".println
         )
       }
+      () -> (())
+    )
+  }
   &player = player.eq(false)
   ().check_board.try(
     () -> (),