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Adding infix and parsing example.

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This commit is contained in:
Brad Nelson
2025-01-25 09:31:27 -08:00
parent 0fc77179af
commit 53dfc659c3
4 changed files with 154 additions and 0 deletions
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87
examples/infix/infix_parsing.fs Executable file
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#! /usr/bin/env ueforth
needs parsing.fs
also internals
: space? ( ch -- f )
dup bl = over nl = or over 10 = or swap 9 = or ;
kind <SPACE>
{{ }}
{{ @token space? 0= throw +token <SPACE> }}
: st' postpone <SPACE> postpone t' postpone <SPACE> ; immediate
: st" postpone <SPACE> postpone t" postpone <SPACE> ; immediate
kind <DIGIT>
{{ [char] 0 [char] 9 []token [char] 0 - }}
: letnum? ( ch -- f )
dup [char] 0 [char] 9 within
over [char] A [char] Z within or
over [char] a [char] z within or
swap [char] _ = or ;
kind <IDENTIFIER>
{{ >in @ tib + 0 begin @token letnum? while 1+ +token repeat dup 0= throw }}
kind <NUMBER'>
{{ <DIGIT> 1 }}
{{ <DIGIT> <NUMBER'> rot over 0 do 10 * loop -rot 1+ >r + r> }}
kind <NUMBER>
{{ <NUMBER'> drop aliteral }}
kind <FORTH>
{{ [char] ] parse evaluate }}
kind <EXPRESSION'>
kind <IDENTIFIERS>
{{ }}
{{ <SPACE> <IDENTIFIER> <SPACE> evaluate <IDENTIFIERS> }}
kind <FACTOR>
{{ <SPACE> <IDENTIFIER> <SPACE> evaluate <IDENTIFIERS> }}
{{ <SPACE> <NUMBER> <SPACE> }}
{{ st' ( <EXPRESSION'> st' ) }}
{{ st' [ <FORTH> }}
kind <TERM>
{{ <FACTOR> }}
{{ <FACTOR> st' * <TERM> postpone * }}
{{ <FACTOR> st' / <TERM> postpone / }}
{{ <FACTOR> st" mod" <TERM> postpone mod }}
{{ <FACTOR> st" and" <TERM> postpone and }}
kind <SIMPLE-EXPRESSION>
{{ <TERM> }}
{{ <TERM> st' + <SIMPLE-EXPRESSION> postpone + }}
{{ <TERM> st' - <SIMPLE-EXPRESSION> postpone - }}
{{ <TERM> st" or" <SIMPLE-EXPRESSION> postpone or }}
{{ st' + <SIMPLE-EXPRESSION> }}
{{ st' - <SIMPLE-EXPRESSION> postpone negate }}
kind <EXPRESSION>
{{ <SIMPLE-EXPRESSION> }}
{{ <SIMPLE-EXPRESSION> st' = <EXPRESSION> postpone = }}
{{ <SIMPLE-EXPRESSION> st" <>" <EXPRESSION> postpone <> }}
{{ <SIMPLE-EXPRESSION> st' < <EXPRESSION> postpone < }}
{{ <SIMPLE-EXPRESSION> st" <=" <EXPRESSION> postpone <= }}
{{ <SIMPLE-EXPRESSION> st" >=" <EXPRESSION> postpone >= }}
{{ <SIMPLE-EXPRESSION> st' > <EXPRESSION> postpone > }}
' <EXPRESSION'> :{{ <EXPRESSION> }}
kind <STATEMENTS>
{{ <EXPRESSION> <STATEMENTS> }}
{{ st' } }}
kind def
{{ : st' { postpone { st' { <STATEMENTS> postpone ; }}
kind on
{{ ' :{{ st' { <STATEMENTS> postpone }} }}
kind expr
{{ :noname <EXPRESSION> postpone ; execute }}