Add awk examples

examples/awk.msh

@@ -0,0 +1,98 @@
+#!/usr/bin/env mshell-go
+
+# 1. Print the total nubmer of input lines:
+# END { print NR }
+stdin lines len wl
+
+# 2. Print the 10th input line:
+# NR == 10
+stdin lines :10: wl
+
+# 3. Print the last field of every input line:
+# { print $NF }
+stdin lines (" " split :-1: wl) each
+
+# 4. Print the last field of the last input line:
+#     { field = $NF }
+# END { print field }
+stdin lines :-1: " " split :-1: wl
+
+# 5. Print every input line with more than four fields
+# NF > 4
+stdin lines (" " split) map (len 4 >) filter unlines wl
+
+# 6. Print every input line in which the last field is more than 4
+# $NF > 4
+stdin lines (" " split) map (:-1: toFloat 4 >) filter unlines wl
+
+# 7. Print the total number of fields in all input lines
+#     { nf = nf + $NF }
+# END { print nf }
+stdin lines (" " split len) map sum wl
+
+# 8. Print the total number of lines that contain 'Beth'
+# /Beth/ { nlines = nlines + 1 }
+# END { print nlines }
+stdin lines ("Beth" in) filter len wl
+
+# 9. Print the largest first field and the line that contains it (assumes some $1 is positive):
+# $1 > max { max = $1; line = $0 }
+# END      { print max, line }
+
+0 @max 
+stdin lines 
+# line first 
+(dup " " split :1: toFloat [(dup max! >) (@max @line)] if)
+each max! w " " w line! w
+
+# 10. Print every line that has at least one field
+# NF > 0
+stdin lines (len 0 >) filter (wl) each
+
+# 11. Print every line longer than 80 characters
+# length($0) > 80
+stdin lines (len 80 >) filter (wl) each
+
+# 12. Print the number of fields in every line followed by the line itself
+# { print NF, $0 }
+stdin lines (dup " " split len w " " w wl) each
+
+# 13. Print the first two fields in opposite order, of every line
+# { print $2, $1 }
+stdin lines (" " split :1: :2: w w) each
+
+# 14. Exchange the first two fields of every line and then print the line
+# { temp = $1; $1 = $2; $2 = temp; print }
+# Need a way to write value into an index.
+# stdin lines (dup " " split :1: :2: swap w w) each
+
+# 15. Print every line with the first field replaced by the line number
+# { $1 = NR; print }
+# Need a way to write value into an index.
+# stdin lines (dup w 1 w w) each
+
+# 16. Print every line after erasing the second field
+# { $2 = ""; print }
+# Need a way to delete at an index.
+
+# 17. Print in reverse order the fields of every line
+# { for (i = NF; i > 0; i = i - 1) printf "%s ", $i
+# printf "\n" 
+# }
+stdin lines (" " split reverse " " join wl) each
+
+# 18. Print the sums of the fields of every line
+# { sum = 0
+#   for (i = 1; i <= NF; i = i + 1) sum = sum + $i
+#   print sum
+# }
+=> (" " split (toFloat) map sum wl) each
+
+# 19. Add up all fields in all lines and print the sum
+# { for (i = 1; i <= NF; i = i + 1) sum = sum + $i }
+# END { print sum }
+stdin lines (" " split (toFloat) map sum) map sum wl
+
+# 20. Print every line after replacing each field by its absolute value
+# { for (i = 1; i <= NF; i = i + 1) $i = ($i < 0) ? -$i : $i; print }
+stdin lines (" " split (toFloat abs) map " " join wl) each

examples/awk/1.awk

@@ -0,0 +1 @@
+END { print NR }

examples/awk/1.msh

@@ -0,0 +1 @@
+.. len wl

examples/awk/2.awk

@@ -0,0 +1 @@
+NR == 10

examples/awk/2.msh

@@ -0,0 +1 @@
+.. :10: wl

examples/awk/emp.data

@@ -0,0 +1,6 @@
+Beth 4.00 0
+Dan 3.75 0
+Kathy 4.00 10
+Mark 5.00 20
+Mary 5.50 22
+Susie 4.25 18

lib/std.msh

@@ -34,8 +34,9 @@ def map
     drop drop map-accum!
 end
 
-# .. (-- str)
-def .. stdin end
+
+# .. (-- list[str]), equals kinda looks like lines.
+def .. stdin lines end
 
 # tt = Tab separated Table (-- list[list[str]])
 def tt stdin lines ("	" split) map end