Clarify some explanations in the README

[rrq/jonasforth.git] / bootstrap.asm

diff --git a/bootstrap.asm b/bootstrap.asm
index 1fc941a86e7eac80bb2615bccd64b33c16e0d960..1b8b65862947102c2c9117ae73eaf2890219d322 100644 (file)
--- a/bootstrap.asm
+++ b/bootstrap.asm
@@ -47,11 +47,10 @@ forth OUTOF_IMMEDIATE, ']'
   dq LIT, 1, STATE, PUT_BYTE
   dq EXIT
 
-;; The INTERPRET word reads and interprets user input. It's behavior depends on
-;; the current STATE. It provides special handling for integers.
-forth INTERPRET, 'INTERPRET'
-  ;; Read word
-  dq READ_WORD
+;; INTERPRET-WORD expects a word as a (buffer, length) pair on the stack. It
+;; interprets and executes the word. It's behavior depends on the current STATE.
+;; It provides special handling for integers.
+forth INTERPRET_WORD, 'INTERPRET-WORD'
   dq PAIRDUP
   ;; Stack is (word length word length).
   dq FIND                       ; Try to find word
@@ -95,3 +94,30 @@ forth INTERPRET, 'INTERPRET'
 
   ;; (Number, immediate mode)
   dq EXIT
+
+;; The INTERPRET word reads and interprets a single word from the user.
+forth INTERPRET, 'INTERPRET'
+  dq READ_WORD
+  dq INTERPRET_WORD
+  dq EXIT
+
+;; INTERPRET_STRING is a variant of INTERPRET that reads from a string instead
+;; of from the user. It takes a string as a (buffer, length) pair on the stack
+;; and interprets the entire string, even if the string has more than one word.
+forth INTERPRET_STRING, 'INTERPRET-STRING'
+  dq INPUT_LENGTH, PUT
+  dq INPUT_BUFFER, PUT
+
+  ;; Check if the buffer is-non-empty
+  ;; [TODO] This probably won't work for strings with whitespace at the end.
+  dq INPUT_LENGTH, GET
+  dq ZBRANCH, 8 * 5 ; to EXIT
+
+  dq READ_WORD
+
+  dq INTERPRET_WORD
+  dq BRANCH, -8 * 7 ; to INPUT-LENGTH @
+
+  dq LIT, 0, INPUT_BUFFER, PUT
+
+  dq EXIT