Stepping through a Push solution

push-string-thing.txt

;; I've used «» to indicate the results of applying an instruction to arguments

;; initial state
EXEC: (exec_dup (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length)

;; program gets "unwrapped"
EXEC: exec_dup (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length

;; duplicate next item on exec
EXEC: (\space \newline in1 string_replacechar) (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length

;; code literal gets unwrapped
EXEC: \space \newline in1 string_replacechar (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length

;; char to :char stack
CHAR: \space 
EXEC: \newline in1 string_replacechar (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length

;; char to :char stack
CHAR: \newline \space 
EXEC: in1 string_replacechar (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length

;; input is a string
CHAR: \newline \space 
EXEC: string_replacechar (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length
STRING: in1 

;; string_replacechar produces a string
CHAR: 
EXEC:  (\space \newline in1 string_replacechar) print_string \newline string_removechar string_length
STRING: «string_replacechar in1 \newline \space»

;; code literal on :exec gets unwrapped
CHAR: 
EXEC:  \space \newline in1 string_replacechar print_string \newline string_removechar string_length
STRING: «string_replacechar in1 \newline \space»

;; char
CHAR:  \space
EXEC:  \newline in1 string_replacechar print_string \newline string_removechar string_length
STRING: «string_replacechar in1 \newline \space»

;; char
CHAR:  \newline \space
EXEC:   in1 string_replacechar print_string \newline string_removechar string_length
STRING: «string_replacechar in1 \newline \space»

;; input again
CHAR:  \newline \space
EXEC:   string_replacechar print_string \newline string_removechar string_length
STRING: in1 «string_replacechar in1 \newline \space»

;; another of those results
CHAR:  
EXEC:   print_string \newline string_removechar string_length
STRING: «string_replacechar in1 \newline \space» «string_replacechar in1 \newline \space»

;; print one
PRINT: «string_replacechar in1 \newline \space» 
CHAR:  
EXEC:    \newline string_removechar string_length
STRING: «string_replacechar in1 \newline \space»

;; char
PRINT: «string_replacechar in1 \newline \space» 
CHAR:  \newline 
EXEC:  string_removechar string_length
STRING: «string_replacechar in1 \newline \space»

;; delete newlines in this string
PRINT: «string_replacechar in1 \newline \space» 
CHAR: 
EXEC:   string_length
STRING: «string_removechar «string_replacechar in1 \newline \space» \newline»

;; how long is that now?
INT: «string_length «string_removechar «string_replacechar in1 \newline \space» \newline»»
PRINT: «string_replacechar in1 \newline \space» 
CHAR:  
EXEC:   
STRING: