diff options
Diffstat (limited to 'src/interp/lexing.boot')
| -rw-r--r-- | src/interp/lexing.boot | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/src/interp/lexing.boot b/src/interp/lexing.boot index 712b1927..8be1464f 100644 --- a/src/interp/lexing.boot +++ b/src/interp/lexing.boot @@ -39,7 +39,9 @@ import sys_-macros namespace BOOT -module lexing +module lexing where + matchString: %String -> %Maybe %Short + matchAdvanceString: %String -> %Maybe %Short --% --% Line abstract datatype @@ -326,10 +328,12 @@ getIdentifier(tok,esc?) == 'IDENTIFIER tokenInstall(s,tt,tok,$nonblank) +escapeKeywords: (%String,%Symbol) -> %String escapeKeywords(nm,id) == symbolMember?(id,Keywords) => strconc('"__",nm) nm +underscore: %String -> %String underscore s == n := #s - 1 and/[alphabetic? stringChar(s,i) for i in 0..n] => s @@ -341,6 +345,7 @@ underscore s == buf := [c,:buf] listToString reverse! buf +quoteIfString: %Thing -> %Maybe %String quoteIfString tok == tok = nil => nil tt := tokenType tok @@ -349,7 +354,7 @@ quoteIfString tok == tt is 'SPECIAL_-CHAR => charString tokenSymbol tok tt is 'IDENTIFIER => escapeKeywords(symbolName tokenSymbol tok,tokenSymbol tok) - tokenSymbol tok + symbolName tokenSymbol tok ungetTokens() == $validTokens = 0 => true @@ -385,6 +390,18 @@ matchString x == and/[stringChar(x,i) = stringChar(buf,idx + i) for i in 0..nx-1] and nx nil +++ Same as matchString except if successful, advance inputstream past `x'. +matchAdvanceString x == + n := #x >= #quoteIfString currentToken() and matchString x => + lineCurrentIndex($spadLine) := lineCurrentIndex $spadLine + n + c := + linePastEnd? $spadLine => charByName '"Space" + lineBuffer($spadLine).(lineCurrentIndex $spadLine) + lineCurrentChar($spadLine) := c + $priorToken := makeToken(makeSymbol x,'IDENTIFIER,$nonblank) + n + nil + --% --% Stack abstract datatype. --% Operational semantics: |