TinyForth.js

このプロジェクトは、組み込みを目的として設計したForth言語を、Javascript言語でプロトタイプ版を開発して、内部処理の仕組みを検証することを目的とする。言語仕様は、ターゲットMPU上で省メモリ動作させること、かつ、アセンブラでの実装も考慮することで、既存の仕様のサブセットとする。

Instruction Set

• D0 (push number) '{number}' (→ n)
• D1 (pop number) '.' (n →)
• D2 (emit string) '."{string}"' (→)
• D3 (emit number) 'EMIT' (n →)
• D4 (collect key) 'KEY' (→ n)
• D5 (duplicate data stack) 'DUP' (n → n n)
• D6 (roll data stack) 'ROLL' (indx →)
• D7 (depth data stack) 'DEPTH' (→ dpth)
• D8 (drop data stack) 'DROP' (n →)
• D9 (drop address stack) 'DROPA' (→) [adrs →]
• DA (fetch memory) '@' (adrs → n)
• DB (store memory) '!' (n adrs →)
• DC (fetch data stack) '@#' (indx → n)
• DD (store data stack) '!#' (n indx →)
• DE (fetch address stack) '@_' (indx → adrs) [→]
• DF (store address stack) '!_' (adrs indx →) [→]
• E0 (add) '+' (n1 n2 → (n1+n2))
• E1 (subtract) '-' (n1 n2 → (n1-n2))
• E2 (multiple) '' (n1 n2 → (n1n2))
• E3 (divide) '/' (n1 n2 → (n1/n2))
• E4 (modulus) '%' (n1 n2 → (n1%n2))
• E5 (logical and) '&' (n1 n2 → (n1&n2))
• E6 (logical inclusive or) '|' (n1 n2 → (n1|n2))
• E7 (logical exclusive or) '* ' (n1 n2 → (n1* n2))
• E8 (logical not) '~' (n → (~n))
• E9 (logical shift left) '<<' (n bit → (n<<bit))
• EA (aithmetic shift right) '>>' (n bit → (n>>bit))
• EB (equals) '=' (n1 n2 → (n1=n2,flg:0|1))
• EC (less than) '<' (n1 n2 → (n1<n2,flg:0|1))
• ED (greater than) '>' (n1 n2 → (n1>n2,flg:0|1))
• EE (equal zero) '=0' (n → (n=0,flg:0|1))
• EF (positive) '>0' (n → (n>0,flg:0|1))
• F0 (begin condition) 'IF' (flg →)
• F1 (else condition) 'ELSE' (→)
• F2 (end condition) 'THEN' (→)
• F3 (begin loop) 'DO' (→) [→ adrs+1]
• F4 (next loop) 'NEXT' (→) [adrs → adrs]
• F5 (end loop) 'LOOP' (→) [adrs → adrs]
• F6 (leave loop) 'LEAVE' (→) [adrs →]
• F7 (check condition loop) 'WHILE' (flg →) (leave loop:) [adrs →]
• F8 (check count-up loop) 'COUNT' (n1 n2 → (n1+1) n2 n1) (leave loop:) [adrs →]
• F9 (exit word) 'EXIT' (→) [adrs →]
• FA (stop execution) 'STOP' (→)
• FB (allocate variable) 'VAR {name}' (→)
• FC (begin word) ': {name}' (→)
• FD (end word) ';' (→)
• FE (call variable|word) '{name}' ((variable:) adrs →) (word:) [→ adrs+1]
• FF (comment) '({comment})' (→)