Spectrum ROM: Routine at 2951

This subroutine is called by LOOK_VARS when DEFADD-hi is non-zero, to make a search of the arguments area of a DEF FN statement, before searching in the variables area. If the variable is found in the DEF FN statement, then the parameters of a string variable are stacked and a signal is given that there is no need to call STK_VAR. But it is left to S_LETTER to stack the value of a numerical variable at 26DA in the usual way.

This subroutine is called by LOOK_VARS when DEFADD-hi is non-zero, to make a search of the arguments area of a DEF FN statement, before searching in the variables area. If the variable is found in the DEF FN statement, then the parameters of a string variable are stacked and a signal is given that there is no need to call STK_VAR. But it is left to S_LETTER to stack the value of a numerical variable at 26DA in the usual way.
STK_F_ARG	2951	LD HL,($5C0B)	Point to the first character in the arguments area (DEFADD) and put it into A.
	2954	LD A,(HL)
	2955	CP ")"	Is it a ')'?
	2957	JP Z,V_RUN_SYN	Jump to search the variables area.
SFA_LOOP	295A	LD A,(HL)	Get the next argument in the loop.
	295B	OR $60	Set bits 5 and 6, assuming a simple numeric variable; copy it to B.
	295D	LD B,A
	295E	INC HL	Point to the next code.
	295F	LD A,(HL)	Put it into the A register.
	2960	CP $0E	Is it the 'number marker' code, +0E?
	2962	JR Z,SFA_CP_VR	Jump if so: numeric variable.
	2964	DEC HL	Ensure that HL points to the character, not to a space or control code.
	2965	CALL FN_SKPOVR
	2968	INC HL	HL now points to the 'number marker'.
	2969	RES 5,B	Reset bit 5 of B: string variable.
SFA_CP_VR	296B	LD A,B	Get the variable name into A.
	296C	CP C	Is it the one we are looking for?
	296D	JR Z,SFA_MATCH	Jump if it matches.
	296F	INC HL	Now pass over the 5 bytes of the floating-point number or string parameters to get to the next argument.
	2970	INC HL
	2971	INC HL
	2972	INC HL
	2973	INC HL
	2974	CALL FN_SKPOVR	Pass on to the next character.
	2977	CP ")"	Is it a ')'?
	2979	JP Z,V_RUN_SYN	If so, jump to search the variables area.
	297C	CALL FN_SKPOVR	Point to the next argument.
	297F	JR SFA_LOOP	Jump back to consider it.
A match has been found. The parameters of a string variable are stacked, avoiding the need to call STK_VAR.
SFA_MATCH	2981	BIT 5,C	Test for a numeric variable.
	2983	JR NZ,SFA_END	Jump if the variable is numeric; SCANNING will stack it.
	2985	INC HL	Point to the first of the 5 bytes to be stacked.
	2986	LD DE,($5C65)	Point DE to STKEND.
	298A	CALL duplicate	Stack the 5 bytes.
	298D	EX DE,HL	Point HL to the new position of STKEND, and reset the system variable.
	298E	LD ($5C65),HL
SFA_END	2991	POP DE	Discard the LOOK_VARS pointers (second and first character pointers).
	2992	POP DE
	2993	XOR A	Return from the search with both the carry and zero flags reset - signalling that a call STK_VAR is not required.
	2994	INC A
	2995	RET	Finished.